Using warming gels with external flash - advice?

[Daniel Salazar]

Hi all, I just got on Friday my first external flash. As everybody recommended on another thread, I decided to give some extra money to buy a good one.

As many of you know, I'm a proud Sony user. I had two choices either get a Sony flash with no so many options and range or get an external one, so I decided to get a Metz 58 AF-1.

Since Friday I'm experimenting a little bit. Due to the fact that the flashes produce a white light, I wanted to give my light a little bit of warm, therefore I'm using some CTO gels in order to produce some more warmer light.

Do any of you have experience using gels? What do you recommend when shooting in interiors and exteriors?

Do you have some recommendations about the use of a external flash?

[Dave Humphries]

Hi Daniel,

The strobist is a good place to start for such advice, they claim to be "The world's most popular free resource for learning how to use off-camera flash".

There's a "First time here" panel top right of that page link with some more links to help get you started.

You can always try a word search here at CiC too.

You have to be a bit careful with the search terms , but there are some reasonable video tutorials on u-tube too. Once you've found one good 'un, it helps filter out the 'unwanted' stuff. These are perhaps more biassed towards studio softbox/brolly use though.

Cheers,

[Daniel Salazar]

Does someone could recommend me also a good book?

[nobby]

Must admit Daniel I have done all my learning here http://www.strobist.blogspot.com/:)

[Daniel Salazar]

@ Dave & Nobby thanks about the link to the Strobist. I must be honest, I already visited the site and I really didn't like it. It's not so well organized and it's not so easy to find the topics you're looking for, however I'll continue searching there.

[nobby]

There are a lot of books on photography lighting at http://www.amazon.co.uk/s/ref=nb_ss_...raphy+lighting which may be of use to you

[Daniel Salazar]

Thanks nobby.

[George Harrison]

Daniel

I do not know which camera you use, but if it is a Sony camera then perhaps there is some means of altering the White Balance (WB) inside the camera. This would obviate the need for gels or other filters both for indoor and outdoor use.

Do you use Photoshop?

George

[Colin Southern]

Daniel

I do not know which camera you use, but if it is a Sony camera then perhaps there is some means of altering the White Balance (WB) inside the camera. This would obviate the need for gels or other filters both for indoor and outdoor use.

Hi George,

Welcome to the CiC forums - great to have you with us! Do you know about the introduction thread where people can tell us a bit about themselves?

With regard to not needing gels if you have in-camera white balance adjustments, well ... not really true I'm afraid ...

Gels are typically used in mixed lighting situations to balance the colour temperature of the flash to the colour temperature of the existing light source so that one doesn't get uncorrectable mixed temperature situations. Flash is typically 5500 deg whereas for example tungsten can be very low (3200K).

As far as white balance adjustments go it's easy to do them in post-processing these days (even JPEGs).

[Daniel Salazar]

@ George, I do have a Sony, however if I adjust the WB the temperature will be set to the kind of illumination surrounding. Using gels will help me setting my external flash to produce a light equal to the environment, eg a CTO gel could help me when shouting indoors where the light is Tungsten.

@ Colin, do you mean then that instead of using gels to obtain instead of a flat white light, produced by my external flash, I could let it and then adjust it in PP?.....I don't get it. Using gels is not only about WB it's about equilibrating the lights, or not?

[Colin Southern]

@ Colin, do you mean then that instead of using gels to obtain instead of a flat white light, produced by my external flash, I could let it and then adjust it in PP?.....I don't get it. Using gels is not only about WB it's about equilibrating the lights, or not?

Hi Daniel,

It's all just about standardising the light sources so that they're all the same temperature - to a point it really doesn't matter what that temperature is as we can adjust it in PP but if you have 2 people standing side-by-side with one being lit from the left by a tungsten bulb and the other lit from the right from a flash, there's no way in hades that you'll be able to correctly whitebalance the skin tones. Put a gel on the flash so that it's colour temp matches the tungsten light source and you're away laughing.

In practice though - if the flash is responsible for most of the illumination or the temperatures are relatively close then it's usually not a big issue. If it helps, Sekonic have recently released a colour light meter just for balancing temperatures.

[Daniel Salazar]

@ Colin, thanks for the explanation!

[William W]

Also . . . following on from Colin’s comments – even if there is not mixed lighting n the subjects:

As one example, when shooting Portraits outside around sunset, and using Flash as the Fill Light, it is likely the Photographer might gel the Flash Fill to keep a particular warmth across the whole scene (the Colour Temperature of Sunlight around sunset is quite low).

But remembering that the Flash EV drops off quite rapidly, behind the subject, when shooting in a large area and remembering also around sunset, there will be a point in time (which happens rapidly) when the Flash has to become the Key light, the Photographer might keep the gel on, even after the sun has set – or even gel warmer when the Flash is key: . . .

Even though essentially there is no “mixed lighting” on the subject: . . .

If the Photographer Drags the Shutter (extends the Tv to expose the ambient sky), if the Flash is not (heavily) gelled it will put out 5500K and the sky will be a lovely 2800K: . . .

The gel can make the difference between a beautiful warm outdoor portrait and a snapshot look with an “on stage spotlight square in the face”: and this is true, even if the shutter is not held sufficiently to reap the maximum from the sky’s hues.


WW

[Colin Southern]

As one example, when shooting Portraits outside around sunset, and using Flash as the Fill Light, it is likely the Photographer might gel the Flash Fill to keep a particular warmth across the whole scene (the Colour Temperature of Sunlight around sunset is quite low).

As a "case in point" to illustrate what Bill is talking about, consider this portrait of my daughter. I'd encourage folks to think of the various colour temperatures involved in a shot like this ...

[Daniel Salazar]

thanks Bill & Colin

@ Colin, checking the picture of your daughter, some questions come across my mind

- did you meter the scene using the spot mode? if yes, did you take your reading from the sky?
- did you gelled your flash or did you just used a diffuser?....I believe you just used a diffuser.
- did you place your external flash on your left side / also your daughter's left side?

@ Bill, what do you mean with "heavily gelled"?, do you recommend using a full CTO or a lower number?

[Colin Southern]

[quote=Daniel Salazar;10069]thanks Bill & Colin

@ Colin, checking the picture of your daughter, some questions come across my mind

- did you meter the scene using the spot mode? if yes, did you take your reading from the sky?
- did you gelled your flash or did you just used a diffuser?....I believe you just used a diffuser.
- did you place your external flash on your left side / also your daughter's left side?
quote]
Hi Daniel,

I deliberately left out the details because I thought it might be a good thought-provoking exercise for you

To answer your questions ...

- I can't remember what metering mode the camera was in, although for this kind of shot it's actually quite easy to expose if you just think of it as being 2 unrelated exposure zones (which it is). These days I'd just use my lightmeter, but it's almost as easy (without model) to just stick the camera in AV mode - meter - see what it suggests - switch to manual - dial in same settings - take a few test shots - and fine-tune it from there. Next step is to introduce the model - take a few more test shots - and vary the FEC to suit. On a side note, with this type of scene you can spot-meter the sky looking for the brightest part and then shift the reading up two stops so that what you meter exposes as a highlight rather than a mid-tone.

- Flash wasn't gelled

- I used a single flash on a light stand - up high - with a Lightsphere (remotely triggered by an ST-E2 controller).

[William W]

thanks Bill & Colin

@ Bill, what do you mean with "heavily gelled"?, do you recommend using a full CTO or a lower number?

I think a full Colour To Orange (CTO) drops you to 2900K? . . . and I pulled 2800K out of my head for the sky’s CT, so let’s say that is the same, that is what I was thinking at the time I wrote my comment yesterday.

So, to answer your specific question I meant two things by “heavily” and that was combined with the fact I put “heavily” into brackets “(heavily)”:

1. Please read the comment without the word “heavily” included: meaning you will need about a full CTO to get the same warmth on the Subject as you have in the sky – what that will do is give a portrait with an even warmth OVERALL, and although the Subject will be highlighted (by the Flash Exposure) the Subject will blend into the warmth of the total scene.

2. Please read the word “heavily” in the sentence: this means that as the sun is setting and the night sky is a hotter than 2800K / 2900K, if you use a Full CTO, the subject will appear warmer than the night sky and this can be used effectively too.

My use of the word “heavily” was as term of comparison – between the CT of the Flash and the CT of the night sky - and the latter changes rapidly.

I do not suggest you begin changing gels. Choose one and stick with it.

As the sun is setting one has less than one or two minutes to pull a dozen shots. Attention to: exposure (remembering that one is changing the ambient drag factor all the time) composition; and lighting (Flash) direction, are enough to handle in those fleeting seconds.

When the sun has set and if you are lucky enough to have a strong afterglow and a subject who can remain still, then that is the time to play with different gels.


***

With Colin’s permission, please . . . on another theme:

I mentioned “The gel can make the difference between a beautiful warm outdoor portrait and a snapshot look with an ‘on stage spotlight square in the face’: and this is true, even if the shutter is not held sufficiently to reap the maximum from the sky’s hues.”

When I first looked at the image above, it was obvious to me that Colin’s image had none, or very little gel; one Flash head; Diffused; about 8ft to 10 ft elevation (which is reasonable high for a seated subject); camera left; 15 degrees off camera axis.

I am not writing this to make out I am a smarty pants, what I am getting at is I understood most of the “whys” all these details were chosen by Colin . . . my guess would be: to mainly better define the Middle-ground – the black shore line of negative space which in turn allows the subject to sit well in front of it and that in turn brings out the background, thus creates a greater sense of depth and perspective.

Although the Flash is not gelled the “spotlight in the eyes look”, I was mentioning is avoided as the picture has other elements happening to keep the viewer’s eye interested – and the Flash is relatively quite high.

***

On another note . . . one has to be very careful with the height of the flash relative to the subject, if Colin had gone two feet higher, or 2 feet closer, likely there would be the those dark circles under the subject’s eyes, even using a diffused Flash.

I reckon Colin also asked the Subject to “sit up straight” or keep a “straight neck” to ensure the face (and eyes) were correctly lit . . . and it looks to me he might have been kneeling, to get the correct camera elevation for the face and the perspective on the middle ground and background he wanted to create.

Thanks in advance for allowing my unsolicited (guesses) and comments on your Photograph, Colin,

How do you pay your models? I used to give mine Mars Bars - they seem to grow out of that too quickly . . . don't daughters keep one poor, I do so want that . . . . new lens.

Cheers

WW

[Colin Southern]

When I first looked at the image above, it was obvious to me that Colin’s image had none, or very little gel; one Flash head; Diffused; about 8ft to 10 ft elevation (which is reasonable high for a seated subject); camera left; 15 degrees off camera axis.

Spot on

I am not writing this to make out I am a smarty pants, what I am getting at is I understood most of the “whys” all these details were chosen by Colin . . . my guess would be: to mainly better define the Middle-ground – the black shore line of negative space which in turn allows the subject to sit well in front of it and that in turn brings out the background, thus creates a greater sense of depth and perspective.

To be honest Bill, it was more a case of "good luck" than "good management". We were out for a drive that evening with the kids on board - ended up at the beach - and I saw that a colourful sunset was likely. I quicky setup - luckily these kinds of sunset are my specialty to working out the exposure for the background is fairly instinctive - and as for the flash setup is was more a case of "one good guess". My preferred composition was with things less centered, but I wasn't happy with the expressions etc - this one was a wee bit of a crop, but had by far the best expression, so ran with it. Off memory I tweaked the skin tones so that they looked more like the warm light of the background (ie reflector more than flash type temperature).

I reckon Colin also asked the Subject to “sit up straight” or keep a “straight neck” to ensure the face (and eyes) were correctly lit . . . and it looks to me he might have been kneeling, to get the correct camera elevation for the face and the perspective on the middle ground and background he wanted to create.

Of my two kids, the younger one is a natural in front of the camera - unfortunately No 1 daughter pictured here is a bit stiff in front of a camera, so more formal posing was all that was going to work (and even that was a struggle) (somehow "smile or I'll make your life a living hell for the next week" never seems to get the result I'm after!) (the terms "the floggings will continue until morale improves" comes to mind!).

Off memory I was crouched low on rocks to take the shot - most uncomfortable in bare feet, but we photographers are famous for doing whatever it takes to get the shot (it's quite normal for me to setup shop in 2 feet of salt water before dawn!).

How do you pay your models? I used to give mine Mars Bars - they seem to grow out of that too quickly . . . don't daughters keep one poor, I do so want that . . . . new lens.

I usually have to improvise (food / DVDs / clothes etc). I usually just buy the lenses I want; Buy first, justify later has always worked well for me

[Daniel Salazar]

What can I say Bill & Colin?....Thank you, I'm really grateful for your help and time!

[Colin Southern]

What can I say Bill & Colin?....Thank you, I'm really grateful for your help and time!

No worries Daniel ... that's what they pay us the big bucks for! (yeah right!)