Cactus RQ250 portable monolight

[Class A]

What do you think about the Cactus RQ250?

At $699 (without any Kickstarter rebates) it is pricier than I thought it would be but it comes with some stand-out features like 1.1s recycling rate (250Ws), active cooling (for 400+ 1/1 shots without overheating), colour stability (in a special colour mode), and convertible bare-bulb with a removable reflector that doubles as a protector.

For Pentax and Sigma strobists it is the only viable monolight location shooting choice, but it may be of appeal to photographers from other brands as well, in particular, if they are already using a Cactus trigger like the V6 or V6II.

[Manfred M]

Except for the Sigma and Pentax users, the Cactus unit does not appear to be price competitive when compared to the Godox AD200 (which runs at 50W-s lower power) and in fact looks like it is in the same price range as the Godox AD360 (which has 160 W-s more power).

Given Cactus so-so reputation on quality, I would go with the Godox right now until there is some history on the unit.

[rpcrowe]

I cannot speak for the Cactus brand but, I am pretty familiar with the Godox units (under various brands).

The Godox quality, especially at their price point, is quite good! I have three Godox hotshoe flashes and two transceiver triggers that in total, cost a hundred dollars less than a single Canon 600EX RT.

I also have a Streaklight (Adorama's rebranded Godox) 360TTL which is a powerful unit and which combined with the inexpensive Godox bracket - opens the door to a plethora of low priced and well made accessories.

Each Godox flash can control and be controlled by any other Godox flash as well as by the two Godox transceivers. These units have HSS and second curtain sync while some have Canon TTL exposure capability. They integrate well with any number of modifiers that are available at very low prices. As an example Godox has a large 47-inch (120 cm) portable umbrella that sets up easily, is light weight, provides lovely soft light (in diffusers BIGGER IS BETTER) and which runs only about $27 USD or $44 USD with the Bowens Mount.

Godox also offers two unique modifiers: the AD-S7 Combo (about $30) softbox and beauty dish which is absolutely great for head and shoulder portraits outdoors, especially in a windy environment https://www.ebay.com/i/252590801131?chn=ps and the AD-S17 Wide Angle Soft Focus Shade Diffuser (less than $15) which is an easy to use, very inexpensive modifier that functions like a bare bulb on the 360TTL and really spreads the light around. https://www.ebay.com/itm/Godox-AD-S1...kAAOSw7Etak7F~

I am mentioning the above to give an idea of the versatility available within the Godox line at prices that won't break the bank...

[Class A]

Except for the Sigma and Pentax users, the Cactus unit does not appear to be price competitive when compared to the Godox AD200 (which runs at 50W-s lower power) and in fact looks like it is in the same price range as the Godox AD360 (which has 160 W-s more power).

I don't think the AD200 and the RQ250 are comparable.

The AD200 has no active cooling, so will overheat much earlier.
The AD200 doesn't offer colour-stability mode.
It takes almost twice as long to recycle even though it delivers less power.
You only get a comparable round-head diffusion disc option with the quick magnetic accessory mounts, if you add an $80 round-head option to the AD200.
With the AD200, you have to store parts you don't use and personally I wouldn't want to have to store the bare-bulb part as it may not be super fragile, but certainly can break if one isn't careful.
There is no umbrella swivel included with the AD200, it doesn't have an AF-assist function to the best of my knowledge and it doesn't offer a decent modelling light option when using the bare-bulb part.

The AD400 is much more comparable and outspecs the RQ250 in some aspects, but it is in a different price league as well and has a rather different form factor as well.

Given Cactus so-so reputation on quality, I would go with the Godox right now until there is some history on the unit.

Where did you get the impression from that Cactus' quality reputation is only "so-so"?

I haven't had any trouble with my Cactus gear and if you look at Amazon reviews people seem to be happy (no comparison to Yongnuo last time I checked).

On the contrary, I'd say Cactus deserves a special mention for their excellent customer service. Unlike Godox, they will accept a faulty unit to repair it. Once you are outside the warranty period with a Godox unit, you are sadly on your own.

As a Pentax shooter, Godox isn't really an option for me as they don't offer a Pentax-dedicated trigger (apart from the fact that most of their triggers are pretty poor, with the XPro being the notable exception), but even if Godox were a viable alternative for me, I'd think very hard before I fell for the allure of their wide range and attractive prices. Usability, reliability and sustainable product management count for something as well.

[rpcrowe]

I will readily admit that my Streaklight 360TTL doesn't have a modeling light. However, I use this unit outdoors and have not found a modeling light that functions well in the bright sunlight... I have A.C. powered lights for studio use.

I have not found the 360TTL to overheat, although I don't use the unit in repetitive flashes that would overheat a strobe. I certainly never envision 400 full power shots in a burst. It can, in TTL, however, (using the inexpensive Y-Yoke adapter) keep up with my Canon 6D2 slower burst rate. I have not tried it at the high speed burst rate or at full power setting.

I also have not missed a "colour-stability mode". None of my strobes ever had one.

At the price I paid for the Flashpoint 360TTL ($299), I think that this is a better buy than the AD200 model at roughly the same price. The "Y" connector which allows feed from both of the battery pack ports really speeds up the recycle time of the 360TTL...

BTW: I could purchase two 360TTL units for a hundred U.S. Dollars less than the Cactus you are considering and use that extra hundred for brackets and various modifiers.

Of course this is a moot question since Godox is not compatible with your camera selection. IMO, despite the excellence of Pentax gear, the compatibility with some third party systems seems to be lacking. Many third party manufacturers seem to aim their sights only at the BIG THREE: Canon, Nikon and now SONY...

[Manfred M]

I don't think the AD200 and the RQ250 are comparable.

The AD200 has no active cooling, so will overheat much earlier.
The AD200 doesn't offer colour-stability mode.
It takes almost twice as long to recycle even though it delivers less power.
You only get a comparable round-head diffusion disc option with the quick magnetic accessory mounts, if you add an $80 round-head option to the AD200.
With the AD200, you have to store parts you don't use and personally I wouldn't want to have to store the bare-bulb part as it may not be super fragile, but certainly can break if one isn't careful.
There is no umbrella swivel included with the AD200, it doesn't have an AF-assist function to the best of my knowledge and it doesn't offer a decent modelling light option when using the bare-bulb part.

The AD400 is much more comparable and outspecs the RQ250 in some aspects, but it is in a different price league as well and has a rather different form factor as well.



Where did you get the impression from that Cactus' quality reputation is only "so-so"?

I haven't had any trouble with my Cactus gear and if you look at Amazon reviews people seem to be happy (no comparison to Yongnuo last time I checked).

On the contrary, I'd say Cactus deserves a special mention for their excellent customer service. Unlike Godox, they will accept a faulty unit to repair it. Once you are outside the warranty period with a Godox unit, you are sadly on your own.

As a Pentax shooter, Godox isn't really an option for me as they don't offer a Pentax-dedicated trigger (apart from the fact that most of their triggers are pretty poor, with the XPro being the notable exception), but even if Godox were a viable alternative for me, I'd think very hard before I fell for the allure of their wide range and attractive prices. Usability, reliability and sustainable product management count for something as well.

Let me try to address some of your comments. Both flashes are battery powered, which suggests they are aimed at user who is shooting on location away from readily available power. Given the power rating, this is the type of flash one will marry up with an external light modifier, often with a light stand.

1. Active cooling on a battery operated light is a power drain. Not an issue when using a monolight connected to the mains, but something I would be cautious about on a battery powered light. With a portable light, I would be very interested in how this affects battery life.

2. I use modelling lights in the studio, but not on location. Studios are generally fairly dark a modelling light is useful when feathering or lining up a light. My studio lights use 250W halogen bulbs. Move them to a location shoot, they are generally useless and I shut them down. Location shooting tends to be in well lit areas, not in a studio.

Would an AF assist light be useful; I guess so. I've never actually shot in a situation where the light levels were so low that I couldn't focus. I often feather my lights, so I'm not sure if the built in LED light would be bright enough. I always carry a powerful LED flashlight in my travel kit (to help find stuff in the dark); the standard photographer's trick is to use that for AF if needed.

3. One of the reviews I read on the Cactus suggested just under 2 second cycle time is the design goal for the unit whereas the Godox AD200 is running at 2.1 seconds. Not much to choose here. The Cactus site does not mention the recycle time in the documentation that I have found. The standard comparison is for full power setting and that seems to be what Godox uses.

4. I've been shooting with a bare bulb flash in field locations for around four years. I have yet to break a bulb. I use a bulb protector when travelling with my bare bulb flash and my studio flash. Cactus describes their unit as a bare bulb flash, so I would suspect the bulb is likely exposed to some extent as well.

5. Colour stability mode - show me the specs because unless I understand what the colour temperature variation is across the range and what the maximum variability is between shots this doesn't tell me much. That being said, if one shoots raw, this is easy to compensate for in post. If you are a JPEG shooter, then this will be more important.

5. Umbrella swivels, unless they are top notch, will creep. I generally do not shoot umbrellas outdoors as they tend to be quite fragile and touchy to use if there is even the slightest wind. Soft boxes tend to be the direction I go here. The only time I generally use umbrellas is when I go ultra light weight and portable with Speed lights. There is just too much light spill with umbrellas for most shooting.

6. I don't pay too much attention to the reviews on Amazon (or other online store sites). Many of them do little more than show the ignorance of the reviewers than something useful about the product.

I find myself shooting with a large community of experienced photographers who share their experiences. I have not heard a bad word said about Godox, especially when it comes to build quality and reliability; after warranty service I don't know because none of the people that shoot Godox have needed to send their units back for service.

Cactus, according to my sources, seems to be in a category where they make some good stuff but also some rather mediocre gear (much like Yongnuo). That is why I suggested that one should wait until the units have shipped and there is some solid field experience before buying as a way of minimizing risk. Frankly, that is the same advice I would give for virtually any new product, regardless of who makes it. All new products will have some teething issues and it is better to have those discovered by someone else.

Your comment as a Pentax shooter, is valid to a point. When shooting anything other than Speedlights in a "Gun & Run" shooting situation, more powerful flash using grip equipment and light modifiers tends to be shot in manual mode. This maximizes consistency. The power output of both the Cactus and Godox units puts them in this type of category. Frankly, once I put even a Speedlight on a stand and pop an umbrella on it, I switch to manual. It's a lot easier and a lot more consistent from shot to shot.

[Class A]

1. Active cooling on a battery operated light is a power drain.

Agreed, but it seems that the active cooling will only kick in if necessary.
Being able to continue to shoot beats extending the battery life, no?

I'm more concerned about the modelling light as a potential threat to battery life. Hopefully there will be ways to use it strategically, i.e., only activate it manually when needed, rather than having it turn itself on every time one composes a shot.

Location shooting tends to be in well lit areas, not in a studio.

I agree, but there can be dark areas in some places and I think it is nice to be able to use the RQ250 at home for portraits or product shots with the modelling light coming in handy then.

I think it is sad that there seems to be no A/C-adapter option. It would have been optimal to have the option of directly connecting the RQ250 to a mains outlet.

I always carry a powerful LED flashlight in my travel kit (to help find stuff in the dark); the standard photographer's trick is to use that for AF if needed.

Sure, but can be tough to do when you are on your own.

I have no experience with LED-based AF-assist lights. 20W (100W Tungsten equivalent, apparently) don't appear to be too shabby.

3. One of the reviews I read on the Cactus suggested just under 2 second cycle time is the design goal for the unit whereas the Godox AD200 is running at 2.1 seconds. Not much to choose here.

Cactus state a 1.1s recycling rate for the RQ250 which is impressive at 250Ws.

4. I've been shooting with a bare bulb flash in field locations for around four years. I have yet to break a bulb.

Good to hear. I always hold my breath when I change modifiers on my studio strobes.

Cactus describes their unit as a bare bulb flash, so I would suspect the bulb is likely exposed to some extent as well.

Well, the reflector with the diffusion disc doubles as a protector during transport. There is also a cap for the diffusion disc, so the whole unit should be safe and compact during transport.

5. Colour stability mode - show me the specs because unless I understand what the colour temperature variation is across the range and what the maximum variability is between shots this doesn't tell me much.

They claim +/- 80K across the power range.

I'm shooting RAW and hence am not too fuzzed, but even as a RAW shooter it is nice if you don't have to adjust colour temperature individually for images taken at different power levels. It's a bit of a luxury feature, but quite common these days in better units (I think Paul C. Buff may have started it with his Einstein units).

There is just too much light spill with umbrellas for most shooting.

Yeah, I'm not a fan of umbrellas either. The Photek Softlighter is phenomenal, though (although not quite an umbrella, technically).

6. I don't pay too much attention to the reviews on Amazon (or other online store sites). Many of them do little more than show the ignorance of the reviewers than something useful about the product.

I'm not disagreeing, but if you see people complaining about a product breaking and not receiving customer service, then its paints a pretty clear picture.

I have not heard a bad word said about Godox, especially when it comes to build quality and reliability; after warranty service I don't know because none of the people that shoot Godox have needed to send their units back for service.

I'd rate Godox to be much better than Yongnuo, but I've read about Godox failures (e.g., one out of two AD200 units dying with the other developing a fuzzy power switch). I most certainly do not approve of Godox not responding to customers when their units fail outside the warranty period. Sometimes it may just be a matter of replacing a cheap part to get a unit going again, but Godox either cannot or does not want to care. I realise that the days of repair shops where skilled people could take a look at your TV set, for instance, and make it work again are gone. That doesn't mean though, that I don't hate the "throw away" mentality that comes with selling products at a price that has a "no repair service"-approach priced in.

Cactus, according to my sources, seems to be in a category where they make some good stuff but also some rather mediocre gear (much like Yongnuo).

The only mediocre Cactus gear I know of were their early V2s radio triggers which were cheap and not very useful. Everything after that (including the V4 which was my first contact with Cactus) has been rock solid. I once opened up one of their speedlights (RF60) out of curiosity and it had better built-quality inside than the Metz 58 AF-2 that I had to open up as well because its display had a fault. EDIT: Cactus also sold a version of the venerable Vivitar 285 as the KF36 which apparently was not very reliable. I tend to forget about that one as it wasn't their design and a pretty unattractive product to begin with.

When shooting anything other than Speedlights in a "Gun & Run" shooting situation, more powerful flash using grip equipment and light modifiers tends to be shot in manual mode.

Same here. I much prefer the manual approach (David Hobby style). I've never needed TTL so far and don't like any interfering automated systems which are a) typically not well-documented so you have to second-guess their decisions, and b) sometimes fooled by lighting conditions (reflective material in the frame, etc.).

[rpcrowe]

Three quick comments about my Flashpoint (Godox) 360TTL and then I wll quit posting on this string...

1. The unit is very powerful which enables me to use it at a lower power, most often 1/4 power or lower. Using the flash at that power with the Y power cord gives me exceptionally fast recycle time.

2. Although this unit is large and rather heavy, separating the battery pack from the flash head makes that head quite a bit lighter. In fact I can use it on my modified camera flip bracket



I have shown the unit mounted with the standard 7-inch reflector. However, I most often use the 360TTL with on my bracket with modifiers attached - especially with the AD S-7 Beauty Dish/Octabox or the AD S-17 Dome Diffuser. I am guessing that this is one of the most powerful flashes that can be carried on and used with a bracket. Certainly, the most powerful at that price point.

Whatever unit you decide upon, I wish you great images with it!!!

3. I would like to try the Sony line of cameras. A local guy has offered me a Sony A7Sii at a very tempting price. With the ability to use all my present Godox gear with that camera (TTL excepted) by just purchasing a Sony compatible XT Pro trigger is certainly a great idea. The fact (not pertinent to this posting) that I can use many of my present Canon lenses with the Sony makes that transition even less financially painful. I could even shoot OCF with two cameras: one the Canon and one the Sony; by just having the compatible triggers on these cameras.

[Manfred M]

Agreed, but it seems that the active cooling will only kick in if necessary.
Being able to continue to shoot beats extending the battery life, no?

That is typical behaviour of cooling systems for this type of use. The problem I have with the solution is that this is more likely driven by a marketing decision than a real need to build a device that uses passive cooling. On top of the power draw when the unit is running, you also have an active component (the fan motor) that will eventually fail. This is not a particularly elegant design approach. I suspect that the designers had a product size and shooting rate requirement from the Marketing group that led to this decision.

I own a Nikon SB-900 Speedlight. It was replaced by the SB-910, primarily due to its overheating issues. In the 8 years that I've owned it, I only managed to shut it down due to overheating on two occasions. The first time was when I purposefully pushed it to see how long it would take and the second time was during a real shoot. It has a setting where I can turn off the thermal protection and know a number of photographers that have done this. I prefer this approach to the active cooling solution that Cactus is using.

I'm more concerned about the modelling light as a potential threat to battery life. Hopefully there will be ways to use it strategically, i.e., only activate it manually when needed, rather than having it turn itself on every time one composes a shot.

Try putting a 20W LED light inside your Phottix Softlighter and see how much light output you get. There's a reason that pro studio lights use 250W halogen bulbs. One needs the power to get good definition of the shadows on the subject, especially when shooting with multiple lights and trying to set up the lighting ratios visually. That is why they have this feature in the first place.

I've shot with a friend's Alien Bees that use 100W tungsten modelling light and the only real use for the modelling light is to run it full out to make sure that the subject's irises are not open too wide.

I agree, but there can be dark areas in some places and I think it is nice to be able to use the RQ250 at home for portraits or product shots with the modelling light coming in handy then.

If that's the way you work. I prefer to use monolights at home or in the studio. More flexibility on the modifiers I own and use. As mentioned before, I find that a 100W equivalent modelling light is inadequate.

I think it is sad that there seems to be no A/C-adapter option. It would have been optimal to have the option of directly connecting the RQ250 to a mains outlet.

Again, that is the way these battery operated lights are designed. Adding a direct AC option would require additional circuitry and that would add cost.

Sure, but can be tough to do when you are on your own.

Actually it's quite easy, especially if you use back button focus. Hold the camera in one hand, the light in the other and focus. Put the light down and shoot normally.

I have no experience with LED-based AF-assist lights. 20W (100W Tungsten equivalent, apparently) don't appear to be too shabby.

See my comments above. 20W LED is inadequate for serious work.

Cactus state a 1.1s recycling rate for the RQ250 which is impressive at 250Ws.

As mentioned before, if this is for a full discharge recycle, then this is quite good. My mains connected (640 W-s) lights recycle in 1.7 s at full power. That being said, I usually shoot at 1/4 power or below, so recycle time is not an issue unless I'm shooting at ISO 64 and am really pushing the lights. That does happen from time to time.

Good to hear. I always hold my breath when I change modifiers on my studio strobes.

I've knocked off and broken the diffusion dome on my studio lights while shooting in the field twice in the past year. New ones are quite inexpensive, so the shipping cost is by far the biggest expense when I do that.

Well, the reflector with the diffusion disc doubles as a protector during transport. There is also a cap for the diffusion disc, so the whole unit should be safe and compact during transport.

As neither of us have actually seen and handled the light, I wouldn't know.

They claim +/- 80K across the power range.

If this is what the light can deliver, then this is very good.

I'm shooting RAW and hence am not too fuzzed, but even as a RAW shooter it is nice if you don't have to adjust colour temperature individually for images taken at different power levels. It's a bit of a luxury feature, but quite common these days in better units (I think Paul C. Buff may have started it with his Einstein units).

At a nominal 5600K, there is very little difference between between what a ±80K (Cactus) and ±200K (Godox) shot look like, unless you are getting into some very high end advertising work. The higher the colour temperature the lower the impact of the variability.

Yeah, I'm not a fan of umbrellas either. The Photek Softlighter is phenomenal, though (although not quite an umbrella, technically).

It's really an umbrella with a diffuser on it.

I'm not disagreeing, but if you see people complaining about a product breaking and not receiving customer service, then its paints a pretty clear picture.

I've never had to deal with either Cactus or Godox customer service, so have no personal experience here. That being said, I have dealt with Canon, Nikon and Panasonic and frankly their reputation is not stellar either.

I'd rate Godox to be much better than Yongnuo, but I've read about Godox failures (e.g., one out of two AD200 units dying with the other developing a fuzzy power switch). I most certainly do not approve of Godox not responding to customers when their units fail outside the warranty period. Sometimes it may just be a matter of replacing a cheap part to get a unit going again, but Godox either cannot or does not want to care. I realise that the days of repair shops where skilled people could take a look at your TV set, for instance, and make it work again are gone. That doesn't mean though, that I don't hate the "throw away" mentality that comes with selling products at a price that has a "no repair service"-approach priced in.

By reputation (again based on the the large group of photographers I regularly work with) Godox quality is generally up there with the OEM products and third party manufacturers like Metz and Nissin. I've heard a number of people who are happy with their Phottix. I know some Yongnuo shooters who are happy with their gear and others that do not. Cactus and Neweer do not have a good reputation with the people I shoot with. Then there are the ones that have Elinchrom and ProPhoto gear.

The only mediocre Cactus gear I know of were their early V2s radio triggers which were cheap and not very useful. Everything after that (including the V4 which was my first contact with Cactus) has been rock solid. I once opened up one of their speedlights (RF60) out of curiosity and it had better built-quality inside than the Metz 58 AF-2 that I had to open up as well because its display had a fault. EDIT: Cactus also sold a version of the venerable Vivitar 285 as the KF36 which apparently was not very reliable. I tend to forget about that one as it wasn't their design and a pretty unattractive product to begin with.

Again, I have no personal experience with Cactus, but the reputable folks that I trust are not impressed with that line.

Same here. I much prefer the manual approach (David Hobby style). I've never needed TTL so far and don't like any interfering automated systems which are a) typically not well-documented so you have to second-guess their decisions, and b) sometimes fooled by lighting conditions (reflective material in the frame, etc.).

Dave Hobby was a newpaper photographer and would have started with either totally manual or thiristor controlled flash, so he is comfortable shooting on manual, as this is something he would have done throughout his career. I know a couple of ex newspaper photographers who are in the same age range and think the same way.

That being said, automation does work, but as no one knows how the internal algorithms in our cameras work, automation can be quite unpredictable. I generally shoot on manual because a lot of my work is done in the studio using studio flash, so it is the only way to shoot there. Integrated small flash is useful in highly dynamic situations where the photographer does not have time to do test shots, the so called "Run & Gun" shooting.

Whatever works best for you...

[xpatUSA]

Manfred said: Try putting a 20W LED light inside your Phottix Softlighter and see how much light output you get. There's a reason that pro studio lights use 250W halogen bulbs. One needs the power to get good definition of the shadows on the subject

Really one needs to compare the light output (lumens) rather than the supply power - due to the much greater efficacy of LED lamps over halogen.

LED flood lamps' light output does seem to be improving!

Here's a 250W-halogen-equivalent 2400-lumen flood for 24 bucks:

https://www.amazon.com/SYLVANIA-Equi.../dp/B01B0M9T44

No need to remind me about blue spikes, etc. and, yes, it's a household lamp. I'm thinking that LED lamps designed for photography will have adequate CRI or Ra and be available with high light output.

I use a couple of 3500K 1100-lumen 60-degree LED floods for table-top work and they are quite adequate, no blue cast at all.

Please pardon the off-topic comment.

[Manfred M]

Really one needs to compare the light output (lumens) rather than the supply power - due to the much greater efficacy of LED lamps over halogen.

LED flood lamps' light output does seem to be improving!

Here's a 250W-halogen-equivalent 2400-lumen flood for 24 bucks:

https://www.amazon.com/SYLVANIA-Equi.../dp/B01B0M9T44

No need to remind me about blue spikes, etc. and, yes, it's a household lamp. I'm thinking that LED lamps designed for photography will have adequate CRI or Ra and be available with high light output.

I use a couple of 3500K 1100-lumen 60-degree LED floods for table-top work and they are quite adequate, no blue cast at all.

Please pardon the off-topic comment.

You are not as "off-topic" as you think, Ted. A lot of photographers do shoot images with the modelling lights on their studio flash; sometimes on their own and sometimes in conjunction with the flash.

With the traditional flash, using either tungsten or halogen bulbs, colour correction was easy as the light from these types of light sources is "good" from a spectral curve standpoint. Photographers using a combination of modelling light and flash would generally use two light sources; one tungsten / halogen and one flash and would either gel the tungsten or halogen source with CTB gel or put a CTO gel on the flash.

I strongly suspect that Cactus has not put any thought into putting a LED that has good CRI into this unit. Their purpose is to add a modelling light that is not totally brutal on battery life (although given the 20W power rating, one could argue this is not the case. For normal modelling light use, this is going to be adequate as all the photographer is looking at seeing is how the light pattern is working, although this is generally more of an issue when using multiple light sources.

[rpcrowe]

Lots of photographers worry about slight differences in color values of the various lights they use.

IMO... when I use the WhiBal Card to determine white balance with the eyedropper in Adobe Camera RAW, there really isn't much problem with slight differences in light temperatures. The major exception to this statement is if you are shooting for commercial purposes and if your color needs to "absolutely" match the "standard" colors of a manufacturer such as the red that Coca Cola has opted as their color...



This is an image with relatively decent color values... Measuring on the white dog's chest, the values are: R=217, G=217, and B=216. That is pretty neutral.

The dog was lit with a combination of lights:

1. LED Can light from the ceiling
2. Four daylight CFL bulbs in a softbox
3. My wife's Ott light for a rim light
4. Godox tt685C in TTL bounced off the ceiling and modified with a Joe Demb Flash Diffuser Pro

I didn't originally plan to light the images in this fashion, the technique just evolved over time but, it is successful and "Don't fix it if it ain't broke" is my motto! I can set up in my living room in about two minutes and the images are pretty well standardized; so photographing large numbers of dogs over different periods is relatively easy for me.

I doubt that any image is normally shot with a greater variety of light sources. So, worrying about a small amount of Kelvin difference really doesn't make a lot of sense...

Regarding Dave Hobby... All photographers of my generation used manual flash... In fact since I am 78 years old, I began flash photography using flashbulbs. There are some photographers who remained using manual flash while other photographers (like me) embraced automatic flash capabilities (originally thyrister and then TTL) in situations when these are most beneficial while using manual flash in situations when manual is to my advantage.

IMO: the destination is what is important not the road to the destination. In other words, however you get a good image is just fine...

[inkista]

Except for the Sigma and Pentax users, the Cactus unit does not appear to be price competitive when compared to the Godox AD200...

Um. I think in near-future it's going to be just the Sigma users.

http://www.godox.com/EN/Products_Rem...h_Trigger.html

https://www.adorama.com/fprrr2propn.html

Yup. Xpro-P on the horizon. Let's cross our fingers for the Pentax shooters that they get all the TTL speedlights, too. The 645Z shooters must be doing happy dances the way the Fuji GFX50S shooters were over the X1T-F.

[xpatUSA]

Lots of photographers worry about slight differences in color values of the various lights they use.

IMO... when I use the WhiBal Card to determine white balance with the eyedropper in Adobe Camera RAW, there really isn't much problem with slight differences in light temperatures. The major exception to this statement is if you are shooting for commercial purposes and if your color needs to "absolutely" match the "standard" colors of a manufacturer such as the red that Coca Cola has opted as their color...

<dog image>

The dog was lit with a combination of lights:

1. LED Can light from the ceiling
2. Four daylight CFL bulbs in a softbox
3. My wife's Ott light for a rim light
4. Godox tt685C in TTL bounced off the ceiling and modified with a Joe Demb Flash Diffuser Pro

I doubt that any image is normally shot with a greater variety of light sources. So, worrying about a small amount of Kelvin difference really doesn't make a lot of sense...

Since I don't use flash, my bench top lighting variety is similar but with greater spectral variations:

Up top, a Philips TL950 5000K fluorescent with a horrendous spectrum but a claimed 95 CRI (they must have selected the phospors VERY carefully!) 640 lux on the bench.



Two Satco 3500K LED floods . . 4750 lx with home-made tracing-paper diffusers . . . 10250 lx without.



Occasionally, a pre-LED variable-focus Mini-Maglite for accent lighting ... illuminance highly variable.

In spite of the large variation in spectra, a custom WB is usually good enough for Government Work (eBay) . . .

IMO: the destination is what is important not the road to the destination. In other words, however you get a good image is just fine...

Yep.

[Manfred M]

Regarding Dave Hobby... All photographers of my generation used manual flash... In fact since I am 78 years old, I began flash photography using flashbulbs. There are some photographers who remained using manual flash while other photographers (like me) embraced automatic flash capabilities (originally thyrister and then TTL) in situations when these are most beneficial while using manual flash in situations when manual is to my advantage.

IMO: the destination is what is important not the road to the destination. In other words, however you get a good image is just fine...

Agreed 100% Richard.

Thyristor is effectively "dead", with TTL being a superior successor. Manual is also a very important mode; certainly the norm when shooting studio lights but also a mode I use when shooting a fixed scene with Speedlights. Unfortunately, while TTL flash is good in "gun & run" situations, it can give inconsistent results in static shooting, so manual mode is superior in those situations. TTL can be used, but it is a lot more work in PP.

[xpatUSA]

Agreed 100% Richard.

Thyristor is effectively "dead", with TTL being a superior successor.

Please help! I am hampered both by my past career and by a lack of knowledge re: "flash", "strobe", speedlight", etc.

In my day, a thyristor was a single device needing stuff to be connected to it before it could do anything; often found in AC motor control circuits.

TTL was a particular form of logic circuitry; I can guess that here it means 'through-the-lens' ...

... but I am sorry to say that "thyristor" has me beat as it relates to flash operation - other than it being obvious that a thyristor can switch a high voltage on and off pretty quick.

Anyone?

[Manfred M]

Please help! I am hampered both by my past career and by a lack of knowledge re: "flash", "strobe", speedlight", etc.

In my day, a thyristor was a single device needing stuff to be connected to it before it could do anything; often found in AC motor control circuits.

TTL was a particular form of logic circuitry; I can guess that here it means 'through-the-lens' but I am sorry to say that "thyristor" has me beat, as to flash operation - other than it being obvious that a thyristor can switch a high voltage on and off.

Anyone?

There was a period for probably around 30 years where flash manufacturers manufactured small flash units that measured the light coming back to the unit and once it had determined that sufficient light had been received to create a correctly exposed image, the circuitry in the flash turned off the flash tube. These were generally referred to as thyristor flash. I can only assume that a thyristor was a key element in the circuitry that managed exposure.

The problem with these units is that there was no way set the sensor in a way that was representative of the focal length of the lens used, so exposure errors were not uncommon, especially with longer focal length lenses. I owned several of these small flash units. An experienced photographer would override the automated settings much like exposure compensation is used on current flash and cameras.

[xpatUSA]

There was a period for probably around 30 years where flash manufacturers manufactured small flash units that measured the light coming back to the unit and once it had determined that sufficient light had been received to create a correctly exposed image, the circuitry in the flash turned off the flash tube. These were generally referred to as thyristor flash. I can only assume that a thyristor was a key element in the circuitry that managed exposure.

That would make sense. Thyristors were/are able to take very high peak currents; they could have "turned off" the xenon tube just by shorting out the capacitor ... or by opening the path from the capacitor to the tube (but that would leave residual charge in the capacitor so maybe a combination of both). Not real important either way; I see the purpose now, thanks.

[Manfred M]

that would leave residual charge in the capacitor

Which is how these flashes worked. Residual charge in the capacitor would result in a faster recycle time and lower battery use.

[rpcrowe]

Ted,

I may have misunderstood you when you mentioned lack of knowledge re: "flash", "strobe", speedlight", etc."

You may very well know all this information but here it is from flash powder to TTL electronic flash...

Flash: is a generic term referring to virtually any light source that is not continuous beginning with:

1. Flash Powder - we have all seen the guy with the "T" shaped stick in old movies or photos holding up in the air it while the photographer had the shutter open to shoot the image. Quite often the "shutter" in this case was a lens cap that the photographer removed and replaced. The "flash powder" was distributed in a groove along the top of the stick and literally exploded causing a pyrotechnic "FLASH" of light enabling the exposure. This could be pretty darn dangerous and fatal in some environments.

2. The next process was the flash bulb invented in about 1925. The photographer would open the shutter and cause the flashbulb to ignite. That is why the mode that opens the shutter and keeps it open as long as the shutter button is pressed has been named "BULB". Some of the early flashbulbs were quite large. A number eleven bulb had a standard screw base and was about the size of a 15-20 watt incandescent bulb. The Number five bubs. with a bayonet type attachment. were the most standard towards the end of the flashbulb era.

Digressing, more than one Navy photographer was burned when he waked in front of an aircraft that was testing its radar. The microwaves from the radar would set off the bulbs which were pretty hot. Imagine a pocket full of hot barbecue coals

3. The next advance in photo lighting was synchronizing the shutter with the flashbulb. This is about the time I entered photography. I think that Canon produced the first 35mm film camera with flash synchronization. There were at least two different types of synchronization, each using its own type of flashbulb: M-sync was used with leaf shutters causing a delay before the shutter opened allowing the light from the flashbulb to reach maximum intensity; FP-sync was used for focal plane shutters and allowed the light to remain bright as the focal plane shutter traveled across the film plane. there were also other types but these were the main two. The Speed Graphic Press Camera had both leaf and focal plane shutters.

4. Then came the electronic flash - at first heavy and bulky but, you did not need to have a bag of flashbulbs or switch the bulbs between each shot. X-sync came out when electronic flash was used and did not delay the shutter because electronic flash was instantaneous. The first electronic flashes were studio models and then came the portable models. They were all designed for manual exposure control.

BTW: you determined your exposure using the guide number for that bulb and reflector and dividing the distance (guide numbers are in feet or meters) into the guide number. Which, if your distance estimate and if your math was up to par, would provide the correct f/stop (kind-of)... A slow and agonizing process which was simplified by the photographer memorizing the f/stop for each type of shot: head and shoulders, 3/4 view, full figure, 2-person shot and group shot, etc. The old advice among press photographers was: "f/8 and there".

5. Next came thyristor exposure control which has been explained above

6. Then came through the lens exposure control which is great but often not entirely accurate. However, I and many other photographers use a combination of TTL exposure control when that mode benefits me and manual exposure control at other times.

The term "Strobe, came, I believe from Stroboscopy which was a technique developed by H. Edgerson taking advantage of the exceptionally short duration of electronic flash to "stop" things like a bullet hitting and going through an apple. Strobe is a general term can be used for any electronic flash but is quite often used for studio electronic flash which can also be called "studio strobes"

Speedlight or Speedlite: is usually reserved for the smaller type electronic flashes quite often the hotshoe type. Originally "Speedlite" was a proprietary Canon term reserved for their hotshoe flashes. The term began to be genarally accepted to include hotshoe flashes of any make and the spelling was changed to "Speedlight" but, Canon still uses "Speedlite" to designate their electronic flashes such as the 600EX RT... Some folks will call a studio strobe a "speedlight" but, that is really incorrect...