Starting out on the learning curve - Flash

[rob marshall]

Certainly, for fill flash on my landscape work, I was envisaging holding the flash at the end of a cord with the camera of the tripod.

Yes, you can do that, but make sure the cable isn't showing. And you don't want too much foreground light or the shot looks unbalanced. It's also very good for flower shots outdoors, as well as indoors.

[revi]

From what I found on the web, that canon flash might already be equiped for off-camera use ('wireless control'). That might of course also depend on the camera. Not knowing Canon, I wouldn't know such details, but Sony A330 + Sony flash work together out of the box (no extensive testing, just a bit of playing around)

[bambleweeney]

I think wireless is the way to go. It's not that expensive (look on ebay for Yungnuo or Cactus and/or look at the Cactus review posted on the site) Easily expandable and you can use pretty much any flash. I bought an SB600 Nikon dedicated flash a few years back to go with a D80, infra red wireless and a revelation to me at the time. Really expensive though and limited range. A year or two ago I invested in a couple of Yungnuo wireless units (an on camera transmitter and two receivers) added a second hand non dedicated Nikon flash that had survived the 90s for about 50 euros and the whole setup works like a dream, totally plug and play. Flexibility is the main advantage, the camera can sit on a tripod on self timer while I wander off and light up a tree or something and at the same time my self propelled light stand (a Tracey) can hide in the bushes and throw light on some other part of the scenery; no cables to trip over or pull expensive cameras crashing to the ground either. Total cost for this (not including choccies for the light stand) just over 100 euros , plus of course the expensive all singing and dancing doesnt' get used that much because the second hand one is so much more powerful Nikon dedicated flash I started with. Only drawback; the Tracey has to be programmed to adjust the flash or it requires a short stroll into the undergrowth to find it and adjust manually.

[Colin Southern]

Just a few psudo-random thoughts from some of the posts above ...

Yes, sorry, that's right. I normally use manual mode, which is a different situation.

Assuming you're talking manual flash, and not manual camera exposure. That's one of the nice things about how Canon do it (with essentially 2 zones of light); one can control the ambient light using manual settings, but the flash will still be E-TTL.

After my first evening's activity I, beginning to get a sense of what I'm meant to be doing and, Colin, I was very proud myself when I managed to find the solutions to the questions:

But wait ... there's more

Seriously, if you get a chance, have a read through the photonotes link I posted above; a lot of it you can gloss over, but some sections will save much gnashing of teeth.

From what I found on the web, that canon flash might already be equiped for off-camera use ('wireless control').

The flash is, but the camera isn't. Contrary to popular misconception, the flash doesn't work on IR signals; it works on info encoded in the visible pre-flash.

I think wireless is the way to go. It's not that expensive (look on ebay for Yungnuo or Cactus and/or look at the Cactus review posted on the site) Easily expandable and you can use pretty much any flash

With a couple of caveats ...

1. A lot of cheap radio triggers have problems with Canon flashes because of the way it triggers. With many it'll flash once, and then you have to power-off the flash and back on again to get it to work a 2nd time. I'd like to think it's something that more modern 3rd party triggers have now solved, but something to be aware of anyway.

2. Keep in mind that the cheap triggers don't pass ETTL info, so it's manual flash only which can be anything from a "no consequence" all the way through to a royal PITA, depending on how much light is changing and how quickly you need to work. Ultimately, it's prtty hard to beat the TT1 / TT5 PocketWizards for sheer total fingertip control.

[Donald]

Seriously, if you get a chance, have a read through the photonotes link I posted above; a lot of it you can gloss over, but some sections will save much gnashing of teeth.

Don't worry, I am .... avidly.

At the moment I'm trying to get my head around focusing and the notion of giving enough light for the foreground subject to be illuminated correctly whilst leaving the background. Was reading about not focusing and then recomposing, but instead working with AF point selection more than I do now. Still not quite sunk-in.

[Colin Southern]

Don't worry, I am .... avidly.

At the moment I'm trying to get my head around focusing and the notion of giving enough light for the foreground subject to be illuminated correctly whilst leaving the background. Was reading about not focusing and then recomposing, but instead working with AF point selection more than I do now. Still not quite sunk-in.

Hi Donald,

I take it that you're aware that if your camera is in manual exposure mode then the exposure graph in the viewfinder essentially becomes an indicator of how the ambient (read "background" when using a flash) scene will expose at your current shutterspeed / aperture / ISO settings? Once you couple this with spot-metering and knowing how to apply the compensations to spot-metering, you then have TOTAL control over your ambient exposure. You CAN achieve something similar using EC (Exposure Compensation), but doing it manually will give you consistant & predictable results, which is important when you're playing with background levels.

The beauty of it is - while all this is going on - the flash will continue to create what Canon term a "normal exposure" for the flash zone, which inturn, you can bias with +/- FEC (Flash Exposure Compensation).

So how does all this work to produce a photo in practice? In reality (in terms of background), it comes down to a couple of things (a) what you want creatively, and (b) how light or dark the background already is (eg if you're shooting someone in the shade, and the background is in full sunlight, then you'll need to knock it back more than if both were in the shade - ditto where the background is a lighter colour (or backlit) -v- one where it's a darker colour). So first thing is to consider your scene without a foreground subject, and without a flash. If all else fails, chuck the camera into evaluative metering & AV mode, and meter the scene to see what the camera comes back with as a starting point. Even consider taking a few shots to see how it works out - then lock the camera into the ideal parameters in manual mode ("set and forget") - then you only have to worry about the flash (which is highly automated anyway).

So it really just comes down to gaining the knowledge to know how the camera will react to the scene you have - and that comes from experience - and that comes from getting out there and shooting ...

... so stop reading and get out there and start shooting!

PS: And if you think this is hard, wait until you start working with 5 or more zones of light at the same time

[bambleweeney]

JUltimately, it's prtty hard to beat the TT1 / TT5 PocketWizards for sheer total fingertip control.

You're probably right, looked up the spec and they're pretty impressive. .... On the minus side for the slightly more impoverished amongst us, one tx/rx combination would cost between 500 to 700 pounds depending upon the (Nikon) flash used. Extra flash units with receivers between 300 to 500 a shot again, depending upon the flash used. I'm thinking I could pay the clouds to go away/not move for less than that to keep the light constant. To put it another way, for the price of one mid range Nikon flash (200 pounds ish) I could find a couple of decent second hand Nikon manual flashes and set them up with cheaper wireless units and still have change. Nice as they are I can't see myself laying off the chauffeur and selling the Bentley to afford them.
Changing light has never been a real problem for me. Once the flashes are balanced a quick tweak to shutter speed to balance the ambient or a quick adjustment to aperture/shutter speed to adjust flash output works pretty well and the trusty histogram will point out the PITAs (just figured out what that was by the way).
In other words much as I crave for them (and trust me I do) neither my wallet, bank manager or (most importantly) wife is going to approve. (Chauffeur breathes sigh of relief and carries on polishing Bentley)

[Colin Southern]

Hi Paul,

The way I see it, photography is all about compromises & consequences - from the compromises & consequences of aperture / shutterspeed / ISO decisions, all the way through to those of equipment, software, and training. Personally, I like to use the automation as much as I can; when the light is changing rapidly (eg shooting during twilight), things change so fast it's difficult to keep things balanced - so the automation means I can probably get 3 or 4 times as many correctly exposed images during that 15 to 20 minute window. So I'm not saying any given approach is right or wrong, but I do believe it's an area where one "gets what one pays for".

In contrast, tomorrow I'm booked for a beach shot (weather permitting). I'll probably be shooting only during twilight, and I'll be using one of my Elinchrom 1200RX heads + softbox + light stand (complete with portable generator) ... and it's all going to be manual ... and I have a feeling it's going to be "interesting". Unfortunately, histograms really don't help much as they don't give seperate readings for flash and ambient (at least the lightmeter can give contrast ratios), and I can't even shoot tethered to my 40" screen

[bambleweeney]

Absolutely Colin, every piece of kit has limitations, you either work within them, work round them or ... miss the shot. If you're paid to turn up and shoot within a time frame then that is a limitation so your kit has to adapt, missing a requested shot is probably not an option. For me, my kit adapts according to what I want to shoot and how successful my last exhibition was, a successful expo sometimes means new kit for those missed shots that would have been awesome (possibly ). I can afford to revisit a location when the light is right or I can make it so with the kit I have, I'm pretty sure you can't so your kit has to cover all eventualities. The last time I was booked for a shoot was for an ancient abbey and I had three or four months to get the shots, not exactly stressful and the gear I had sufficed. I they'd have wanted me to do the whole thing in one day I would have been screwed.
Horses for courses as they say.
No, you're right the histogram isn't going to be much help. I meant to write LCD display but I'm having a bad English/French day, amazing how you forget your own language when you're learning another one.

[Donald]

I take it that you're aware that if your camera is in manual exposure mode then the exposure graph in the viewfinder essentially becomes an indicator of how the ambient (read "background" when using a flash) scene will expose at your current shutterspeed / aperture / ISO settings? Once you couple this with spot-metering and knowing how to apply the compensations to spot-metering, you then have TOTAL control over your ambient exposure.

Yes, I understood all that bit.

But it's the rest of Colin's post that just slots a lot of things into place. I had read all this in others forms and formats, but it wasn't clicking into place in my tiny and befuddled brain. I understand it totally now given the way Colin has explained it in post #26 above.

[Wirefox]

I take it that you're aware that if your camera is in manual exposure mode then the exposure graph in the viewfinder essentially becomes an indicator of how the ambient (read "background" when using a flash) scene will expose at your current shutterspeed / aperture / ISO settings? Once you couple this with spot-metering and knowing how to apply the compensations to spot-metering, you then have TOTAL control over your ambient exposure. You CAN achieve something similar using EC (Exposure Compensation), but doing it manually will give you consistant & predictable results, which is important when you're playing with background levels.

Once this has clicked Donald you are well on your way. I read up on a ton of stuff on various sites and had a mental block with the 2 exposures thing. It eventually clicked big time and you wonder how people can male such a dogs dinner of explaining it. Colin's explanations are always clear and concise and the one he has provided above will give you an enormous leg up.

There has been a lot of talk on these forums about radio triggers, cost and general uming and arring. I do not have an opinion at present because I cannot justify the cost of the kit Colin talks about so I cannot try it myself. Undoubtably the way to go will be the sort of kit Colin has in his arsenal but I am sort of glad I didn't have the option of having this gear initially because I think it would have confused a lot of my initial issues when trying to use flash. What I will say (as many have said) is this - if you are impressed now...get it off the camera regardless of how you do it you will be stunned at the amount of creativity this small move will open to you. If it means a cheapo 5m ETTL cable from ebay - so be it - just do it. I use one such 5m cable. It is OK but does suffer every so often with the issues Colin quite rightly says are due to the mounting and seating (it have never found it to be the cleanliness of contacts). I also have two short Canon cables (I use one with a flash bracket). They are not as flexible being 1m and 3m in length but the seating and locking to the hot shoe is far more positive and precise.

I am looking foward to seeing your initial results. And most of all have fun

[Donald]

Once this has clicked Donald you are well on your way.

Before starting the reply ......

Don't know if any of the rest of you are seeing a problem with Kay's avatar attaching itself to quotations included in replies. I've reported it to Sean.

Anyway .... the subject at hand.

Steve, many thanks for your comments.

The one thing I haven't ......... No, re-write............... One of the many things I haven't cracked yet is this thing about focusing.

Okay, I've got the camera on manual and flash on E-TTL. If I'm using centre point focusing (and I do that via back-button focusing not half-depress shutter), can I focus on the subject and then recompose (so the subject is, say, off to one side) and will the flash still know that that is the subject to compute power for? Because I think I read somewhere (I need to be better at bookmarking things) that I should use the focus point that is on the subject once I have composed. And I can't see why I need to do the latter and that the former is 'not good'.

Even if this question is making sense then I must be learning something!

[Donald]

Appropo my post immediately, above - What I was reading was in the photonotes link that both Colin and Rob referred me to. And it is the following that I'm trying to get my head around (I know I'm probably being very stupid and it's probably painfully obvious to everyone else what is being said, but ...........! I take time to get some thinks to sink in.)

Remember - I'm shooting with the camera in manual.

Sorry for the size

"Do not focus and recompose with flash.

The fact that the camera biases flash exposure to the nearest focus point, if the camera has multiple focus points, is important to keep in mind. If you’re in the habit of using the old “focus, lock AE and recompose image” technique, be sure not do this when taking flash photos.
Flash metering occurs after ambient light metering, so in this case you’re locking AE but not flash metering, and therefore recomposing messes up your flash metering. Instead, select the focus point that’s closest to your subject in order to bias flash exposure to that area.
There are two exceptions to this rule, however. First there are type A bodies which support FEL. You can use FEL in such situations to lock flash exposure to a given area of your photo before recomposing. Second, cameras with support for E-TTL II are potentially less vulnerable to this problem in part because they can include distance data in flash metering."

[Donald]

I think I might be starting to get this. Guy, in his/her 'photonotes' says, later on, "If you lock focus on a scene and recompose you will likely have poor flash metering, since E-TTL biases flash metering to the current focus point. Use FEL instead to avoid this problem."

And from this I'm taking it that irrespective of where I have focused, if I re-compose and the centre-focus point which I am using is now onto something in the far distance, for example, then the E-TTL computation is going to compute on that point, not where I focused a few seconds earlier. Am I getting there?

[Wirefox]

Donald,

No problems with Kays avatar at this end.

cameras with support for E-TTL II are potentially less vulnerable to this problem in part because they can include distance data in flash metering."

Does not sound as if you need to worry about it too much. I must admit though I remember reading about this when i was in my dazed phase of flash so rightly or wrongly I always select a focus point rather than focus/recompose when using flash. Not too much choice on the 40D but I usually find one to suit.

I will be interested to see what Colin and Rob have to say on this because I may have misunderstood the reasons for doing this

What does seem to be apparent is that you can still use focus/recompose if you use Flash Exposure Locking. Same result in principle as when AE locking. As I said though I do not bother. I think I need to look into FEL more it may be easier for my style of working (bone idle)

[Colin Southern]

Hi Donald,

Hate to do this to you mate ...

E-TTL and E-TTL II are different; For E-TTL II the biggest change was the incorporation of lens distance data into the algorithm, but at the same time they discontinued biasing the exposure towards the active AF point. You have E-TTL II, so basically it's OK to focus & recompose so long as the final thing you compose is in (very roughly) the same plane as the original. Honestly, don't worry about it; it'll make bugger all difference to the flash exposure - you're likely to have a far bigger issue with focusing errors (potentially anyway; hence always better to "work your AF points".

Personally, I've never found a need to assign AF on to a seperate button - what I DO do though is assign AF point select to the joystick on the back of the camera (works for the 1Ds3 and I THINK other later pro-sumer models).

Edit: Also, what NK Guy was referring to above was MULTIPLE AF points; not sure what you use, but I NEVER, EVER have my camera in multiple AF point mode ... I only ever use a single AF point (WHICH point it is is constantly changing though).

[Donald]

Hi Donald,

Hate to do this to you mate ...

E-TTL and E-TTL II are different; For E-TTL II the biggest change was the incorporation of lens distance data into the algorithm, but at the same time they discontinued biasing the exposure towards the active AF point. You have E-TTL II, so basically it's OK to focus & recompose so long as the final thing you compose is in (very roughly) the same plane as the original. Honestly, don't worry about it; it'll make bugger all difference to the flash exposure - you're likely to have a far bigger issue with focusing errors (potentially anyway; hence always better to "work your AF points".

Personally, I've never found a need to assign AF on to a seperate button - what I DO do though is assign AF point select to the joystick on the back of the camera (works for the 1Ds3 and I THINK other later pro-sumer models).

You've just made me very happy. That's what I was understanding, but yet seemed to be reading stuff that contradicted it. Another 'Now I know what that means' box ticked!

[Colin Southern]

You've just made me very happy. That's what I was understanding, but yet seemed to be reading stuff that contradicted it. Another 'Now I know what that means' box ticked!

Hi Donald,

You would not believe the amount of mis-information floating around regarding EOS flash, and that can be a BIG problem for folks trying to feel their way. Often people will get the wrong end of the stick -- think they understand why -- and then promulgate that mis-info ... which others then pick up on and repeat

Hence one of the reasons I suggested getting NK's book. "In NK we trust" (and you can trust me too )

[Colin Southern]

PS: I added a little edit to the bottom of post 36 that you probably didn't see.

[Donald]

PS: I added a little edit to the bottom of post 36 that you probably didn't see.

I only ever use single AF point as well, but in my case, up to now, it's tended to be the centre and that's why I've been going on about focus and recompose; i.e. I make my composition, then I move to focus on whatever I want to focus on (using back button) and then realign up to my original composition.

That's what I've been trying to figure out - Do I change my practice when I'm using flash and start using different single AF points; i.e. constantly changing, as you do.

EDIT - It seems to me that the answer is 'No' I can keep doing what I've been doing OR I can start using the joystick and moving the AF point