Photoshoot of children and flash use

[Stagecoach]

I raised a thread a short time ago with regard to using flash indoor under specific backlit situations in preparation for a project I had been asked to do. Following the excellent advice I received, the purchase of another flash, three days of practice at home and lots of reading I have undertaken the first session of the work.

My brief for the session was to provide pictures that show disabled/impaired young children undertaking classroom learning, play, physiotherapy etc in a positive manner, not child portraits and not staged scenes. Spaces varied from large, small to minute with lighting from poor to poor.

Here's an update as to how I tackled things, specific findings and those that I will address for the next session.

Equipment use and method

The D800 was set in manual (my regular mode) giving me full control of shutter speed, I wanted as near 1/250th (sync speed) to eliminate camera shake/subject movement where ambient light was predominant. I also wanted full control of aperture for low DoF. ISO was varied when necessary.

I varied exposure for the ambient light, e.g window with bright light in the frame, by offsetting the exposure bar and not by adjusting camera EV. By not adjusting camera EV, it appears the flash EV is not affected (I will confirm this once I get a new battery in my flash meter).

The flash was in iTTL mode throughout and I used the SB600 although having the new Rollei with me in case I found I needed more power. No diffuser was used on the flash based upon an article I had read. I did not adjust the flash EV once and the few exposure failures encountered were down to me.

Having read some excellent articles online I decided that I would not just bounce the flash straight ahead from a ceiling but from any wall/corner that could be used.

This setup enabled me to concentrate on the job and move around freely, and again I found myself spending a lot of time on the floor

Problems encountered to address

a) Colour balancing

Many walls were from bright blue to sickly orange and some results require colour balancing. Test edit work so far is suggesting simple white balance correction using a known white/black in the scene works and I have no knowledge/practice of other methods.

I hope to standardise a method to ensure the skin tones remain equal.

b) Ghosting

A couple of images taken where activity involved movement (e.g throwing a ball) have ghosting on the moving part which so far I'm putting down to the shutter speed being too low to freeze movement recorded by the ambient light but then frozen by the flash.

c) Catchlights

These vary from good to not so good. There are some instances where there are two that I suspect are coming from both the flash location and the bounced flash light location. I will experiment to learn more about this and also have the option to place the flash on an L bracket and trigger it from the popup.

But overall, the results achieved with lighting that was even, had no harsh shadow lines, good exposures giving easily workable images in post and most importantly the content of many of the captures exceeded my expectations.

Grahame

[george013]

I raised a thread a short time ago with regard to using flash indoor under specific backlit situations in preparation for a project I had been asked to do. Following the excellent advice I received, the purchase of another flash, three days of practice at home and lots of reading I have undertaken the first session of the work.

My brief for the session was to provide pictures that show disabled/impaired young children undertaking classroom learning, play, physiotherapy etc in a positive manner, not child portraits and not staged scenes. Spaces varied from large, small to minute with lighting from poor to poor.

Here's an update as to how I tackled things, specific findings and those that I will address for the next session.

Equipment use and method

The D800 was set in manual (my regular mode) giving me full control of shutter speed, I wanted as near 1/250th (sync speed) to eliminate camera shake/subject movement where ambient light was predominant. I also wanted full control of aperture for low DoF. ISO was varied when necessary.

I varied exposure for the ambient light, e.g window with bright light in the frame, by offsetting the exposure bar and not by adjusting camera EV. By not adjusting camera EV, it appears the flash EV is not affected (I will confirm this once I get a new battery in my flash meter).

The flash was in iTTL mode throughout and I used the SB600 although having the new Rollei with me in case I found I needed more power. No diffuser was used on the flash based upon an article I had read. I did not adjust the flash EV once and the few exposure failures encountered were down to me.

Having read some excellent articles online I decided that I would not just bounce the flash straight ahead from a ceiling but from any wall/corner that could be used.

This setup enabled me to concentrate on the job and move around freely, and again I found myself spending a lot of time on the floor

Problems encountered to address

a) Colour balancing

Many walls were from bright blue to sickly orange and some results require colour balancing. Test edit work so far is suggesting simple white balance correction using a known white/black in the scene works and I have no knowledge/practice of other methods.

I hope to standardise a method to ensure the skin tones remain equal.

b) Ghosting

A couple of images taken where activity involved movement (e.g throwing a ball) have ghosting on the moving part which so far I'm putting down to the shutter speed being too low to freeze movement recorded by the ambient light but then frozen by the flash.

c) Catchlights

These vary from good to not so good. There are some instances where there are two that I suspect are coming from both the flash location and the bounced flash light location. I will experiment to learn more about this and also have the option to place the flash on an L bracket and trigger it from the popup.

But overall, the results achieved with lighting that was even, had no harsh shadow lines, good exposures giving easily workable images in post and most importantly the content of many of the captures exceeded my expectations.

Grahame

No examples?

You didn't consider hss?

I wonder if you can have ever a good wb when bouncing from a colored wall.

George

[Stagecoach]

No examples?

I do not have clearance yet for allowing any public use of the photos due to the consent policy of the facility.

You didn't consider hss?

No, but I would be interested to know how you see it as an advantage under my specific shooting criteria.

I wonder if you can have ever a good wb when bouncing from a colored wall.

It's very unlikely but those with experience under these conditions may have some tips as to how they tackle correcting the results obtained.

[george013]

I do not have clearance yet for allowing any public use of the photos due to the consent policy of the facility.



No, but I would be interested to know how you see it as an advantage under my specific shooting criteria.



It's very unlikely but those with experience under these conditions may have some tips as to how they tackle correcting the results obtained.

If you want to freeze the movements and your sync time is to slow, than hss might help.

If everything is in 1 colour there might be a way but if the walls have different colours I doubt. Be aware that if the indoor light is done with fluorescent lamps, the colourtemp is changing all the time. This will be visible with short shutter speed.

George

[Mike Buckley]

The camera's auto white balance might work fine but it also might be fooled by the light being bounced off non-white walls. In theory, you could photograph a white balance card and use that as your neutral reference during post-processing. However, doing so might not have been practical in your situation. Considering that you were using a flash unit, next time try setting your camera's white balance to K5500 or, if you shoot raw files, set your post-processing software to using K5500. That also may not work if the ambient light is not that temperature and if the flash isn't overpowering it.

For others reading the thread and seeing that you bounced the light off walls rather than the ceiling, that method can be extremely bothersome to anyone in the line of sight of the flash in a room full of people.

I'll be interested in learning about whether your flash output was affected when adjusting the camera's exposure in manual mode and using iTTL. I've never given any thought to that and haven't looked it up in the manual.

Why did you decide to bounce off the walls rather than the ceiling? If the reason is that you were getting dark shadows in the eyes and under the nose and chin, you could have directed some of the flash directly forward while at the same time bouncing off the ceiling.

[Stagecoach]

The camera's auto white balance might work fine but it also might be fooled by the light being bounced off non-white walls. In theory, you could photograph a white balance card and use that as your neutral reference during post-processing. However, doing so might not have been practical in your situation. Considering that you were using a flash unit, next time try setting your camera's white balance to K5500 or, if you shoot raw files, set your post-processing software to using K5500. That also may not work if the ambient light is not that temperature and if the flash isn't overpowering it.

Mike, I used daylight WB throughout knowing that I could easily adjust the NEFs in post and even more easily now I know how to group a number of files in ACR.

Due to my constant moving around and change of camera angle trying to use a WB card would have been near impossible.

For others reading the thread and seeing that you bounced the light off walls rather than the ceiling, that method can be extremely bothersome to anyone in the line of sight of the flash in a room full of people.

At almost all times my subjects were in front of me with no one in line of the flash direction which was also pointed upwards slightly.

I'll be interested in learning about whether your flash output was affected when adjusting the camera's exposure in manual mode and using iTTL. I've never given any thought to that and haven't looked it up in the manual.

I'll confirm this today with the flash meter, but it makes sense as you are not actually 'feeding' in an EC figure, simply under/over exposing for your natural/ambient light.

I have read an article that states that the D800 upwards has an option in the menu to separate the camera EC adjustment from the flash EC adjustment but I can't find it on mine but it may be on the D810.

Why did you decide to bounce off the walls rather than the ceiling? If the reason is that you were getting dark shadows in the eyes and under the nose and chin, you could have directed some of the flash directly forward while at the same time bouncing off the ceiling.

This was based on the practice mentioned in some of these articles/tutorials https://neilvn.com/tangents/flash-ph...lash-examples/ which I have been studying.

I have had no experience of shooting flash for such subjects and locations as this but am now going to set up some simulations where I can see exactly the difference the methods give.

One specific situation I want to look at is that when a child sat at a table lets say drawing tends to have their head looking down close to their work, how I can best light that to reduce the shadow on the face, to save PP work. I obviously don't want to use direct flash so this may be an option for the bounce pointing in their direction with a bounce card fitted.

Perhaps it may appear I'm overthinking a lot of this but having now done a session, speed in working, being able to instantly change your subject to capture the result you want leaves little time for change.

[Mike Buckley]

Thanks for the explanations, Grahame. The only reason I wondered why you didn't use the ceiling to bounce the flash assumed that it was closer to a white color, which might have minimized your color-correction issues during post-processing.

[george013]

I have read an article that states that the D800 upwards has an option in the menu to separate the camera EC adjustment from the flash EC adjustment but I can't find it on mine but it may be on the D810.

.

Wen I understand you, they're separated. Always have been. Two independent routes for the final exposure.

George

[Mike Buckley]

George,

When Grahame explained that the flash's exposure compensation and the camera's exposure compensation are not separated, I think he means that in the context that the two compensation values are added together. That's well documented in the Nikon manuals.

[Stagecoach]

I'll be interested in learning about whether your flash output was affected when adjusting the camera's exposure in manual mode and using iTTL. I've never given any thought to that and haven't looked it up in the manual.

Mike, I have now completed controlled tests to confirm to me the difference when using the D800 in Manual mode with the SB-600 flash in iTTL mode between;

a) 'Adjusting EC dialed in on camera'

compared to

b) 'Adjusting EC (exposure setting) by use of the metering bar'

Test setup .....................

A white wall/ceiling with wooden sideboard running along it. A window consisting of glass blocks with bright light coming through and placed in front of this a dark box, head size as subject. Distance and FL similar to what I had experienced, generally 35 to 60 mm.

Test 1 : Adjusting Exposure by dialing in an EC value on the camera

a) Shot taken at camera suggested setting, matrix metering and left at that for this test.
Result - Blown out window and well exposed subject as would be expected.

b) Shot taken with -2EV dialed in
Result - Blown out window and darker subject as would be expected.

c) Shot taken with -4EV dialed in
Result - Blown out window and even darker subject as would be expected.

Note : as we would expect, EC dialed in for the camera has affected exposure of the subject lit by the flash.

Test 2 : Adjusting Exposure by altering either speed/aperture to offset meter bar

a) Shot taken at camera suggested setting, matrix metering.
Result - Blown out window and well exposed subject as would be expected.

b) Shot taken with exposure adjusted so that meter bar showed -2EV
Result - Window less blown out and almost the same well exposed subject.

c) Shot taken with exposure adjusted so that meter bar showed -4EV (wind it to -2 and six more clicks)
Result - Window not blown out and almost the same well exposed subject.

Note : There were very minor changes in subject exposure, I would say insignificant to me compared to those in Test 1.

I had tried to get readings from my flash meter but it does not appear too sensitive at the flash powers used. It does however register well through its scale using the flash on manual, but it is 40 years old

Conclusion,

In the situations where this has worked so well for me I suspect it may be due to the 'range' of the work.

But, being able to go from a subject in a poorly lit corner and swinging ninety degrees to another subject a similar distance away but with a bright window behind and just having to spin the exposure bar to where I want it is a bonus.

[Mike Buckley]

Thanks again for the information, Grahame. I wonder why you used matrix metering in this situation rather than center-weighted metering, assuming the subject is approximately in the center. If the subject isn't in the center, matrix metering seems ideal in this situation.

[Stagecoach]

Thanks again for the information, Grahame. I wonder why you used matrix metering in this situation rather than center-weighted metering, assuming the subject is approximately in the center. If the subject isn't in the center, matrix metering seems ideal in this situation.

Mike, I never seem to use anything other than matrix metering, perhaps a habit from macro and seascape work where what the camera 'suggests' is rarely what I end up using. My thinking has been that by sticking to one method I get to know what it will give.

I have read that certain metering methods work best with iTTL flash but looking through my results subject positions varied between centre and on the 1/3rd and it could possibly add just a different variable.

[george013]

Not sure I understand you. With EC on camera you mean that little button where you can correct the exposure?

And the other way is changing exposure settings manual. There's a difference between changing shutter speed and aperture. Changing shutter speed doesn't influence flash power, changing aperture does. Within limits of the flash off course.

My conclusion would be there are two different ways to influence exposure, working independent from each other. In case of EC there is a list of possibilities out of which the camera takes the first. Shutter speed, aperture, iso, flash. Depending on the camera settings. From what I've read from Niekerk, that last one is only with Nikon.https://neilvn.com/tangents/flash-ph...-compensation/

I don't know if you have seen this one. http://nikonclspracticalguide.blogsp...-metering.html

George

[Stagecoach]

Not sure I understand you.

With EC on camera you mean that little button where you can correct the exposure?

Yes.

And for Nikon (except some later models its rumoured, not mine) this is linked to the flash EC and will affect both the ambient and flash exposures.

And the other way is changing exposure settings manual.

Yes.

There's a difference between changing shutter speed and aperture.

Yes, and they will have differing affects when we change them in relation to flash use.

Changing shutter speed doesn't influence flash power,

But it changes the background exposure (window light in this case) relative to the flash exposure when the camera is in manual with flash in iTTL as shown in my Test 2 example for Mike.

changing aperture does. Within limits of the flash off course.

It's not that straight forward. In Test 2 I changed the aperture in manual to reduce the exposure of the bright window, from blown right out, by 4 stops, where the window then looked dark and my flash maintained the same exposure on the subject in manual mode, iTTL flash.

My conclusion would be there are two different ways to influence exposure, working independent from each other.

I don't understand what you mean by that.

In case of EC there is a list of possibilities out of which the camera takes the first. Shutter speed, aperture, iso, flash. Depending on the camera settings. From what I've read from Niekerk, that last one is only with Nikon.https://neilvn.com/tangents/flash-ph...-compensation/

I am only looking at the affects on flash use when using the camera in manual mode with respect to giving me absolute control of speed and aperture.

In the case of EC (overall) being applied on the D800 in manual with the SB-600 in iTTL mode the 'flash power' changes as shown in Test 1, aperture, speed and ISO remained the same for both a), b) and c), as would be expected.

What happens is that say a -2EV is dialed in this is applied to both the camera exposure and the flash exposure. For the camera exposure it simply biases the meter bar which has no affect on exposure but the flash power is varied by -2EV accordingly.

[george013]

There're two different measurements for ambient light and flash light.
The first one is just metering the ambient light and calculates a setting for the SS,A or ISO when not in M.
The second one the flash fires a pre-flash and measures the returning light. Based on that quantity and the A and ISO the amount of flash light is calculated.

If you use the EC button, you just tell the camera to change the measured exposure with a certain value. I think there's a kind of list of hierarchy : A,SS,ISO,Flash. It would be interesting to test it in SS, so the A is variable. Does the flash change or not. I'll try it later.

George

[Stagecoach]

There're two different measurements for ambient light and flash light.
The first one is just metering the ambient light and calculates a setting for the SS,A or ISO when not in M.
The second one the flash fires a pre-flash and measures the returning light. Based on that quantity and the A and ISO the amount of flash light is calculated.

Exactly, this is the basis of how the CLS system works (albeit there are differences in calculations between measured readings for iTTL and iTTL BL).

And we can use this to our advantage (Camera manual/iTTL flash as I have referred in this post) to provide certain results that can be advantageous under specific shooting conditions.

If you use the EC button, you just tell the camera to change the measured exposure with a certain value. I think there's a kind of list of hierarchy : A,SS,ISO,Flash.

Correct, and you need to be aware of what your specific camera does with respect to adjusting 'overall' EC.

It would be interesting to test it in SS, so the A is variable.

Does the flash change or not. I'll try it later.

Have fun.

[inkista]

Problems encountered to address

a) Colour balancing

Many walls were from bright blue to sickly orange and some results require colour balancing. Test edit work so far is suggesting simple white balance correction using a known white/black in the scene works and I have no knowledge/practice of other methods.

I hope to standardise a method to ensure the skin tones remain equal.

If the color of the ambient light differs from that of your flash, you may want to look into gelling your flash to match the ambient. Ambient light, tends to be warmer or greener than the light put out by a flash. White balancing for one will throw off the white balance for the other, so the easiest way to get post edits for white balancing to work is to gel the flash to match the ambient color. This just means putting a piece of colored plastic over the head of the flash so it gets warmer/greener, and a simple white balance setting will fix everything.

b) Ghosting

A couple of images taken where activity involved movement (e.g throwing a ball) have ghosting on the moving part which so far I'm putting down to the shutter speed being too low to freeze movement recorded by the ambient light but then frozen by the flash.

Also which end of the motion got frozen by flash is controlled by whether you were doing 1st or 2nd curtain. Remember that ambient is still part of the equation and ambient and flash are mixed everywhere. The motion blur typically only shows up in the ambient, but if there is ambient, it will appear. You either have to kill the ambient (i.e., set your exposure so ambient is so underexposed it doesn't register), or live with the blur, or use HSS to increase the shutter speed. But HSS may not be viable in low-light situations, since the faster the shutter speed, the less light you're getting from the flash as well as the ambient.

[Stagecoach]

Thank you Kathy for the input.

If the color of the ambient light differs from that of your flash, you may want to look into gelling your flash to match the ambient. Ambient light, tends to be warmer or greener than the light put out by a flash. White balancing for one will throw off the white balance for the other, so the easiest way to get post edits for white balancing to work is to gel the flash to match the ambient color. This just means putting a piece of colored plastic over the head of the flash so it gets warmer/greener, and a simple white balance setting will fix everything.

Gelling (I have a set) may be an option to assist as the predominant light sources were daylight and flash. Other sources such as fluorescent light, some incandescent light and reflected coloured light from the bounce surfaces may have had less impact.

With respect to post work at present my method is now to use WB balancing taking as a priority maintaining equal skin tones for a batch of the same subject. Whilst there still remain inconsistencies that I can see these are very unlikely to be noted or a concern of the end user.

Also which end of the motion got frozen by flash is controlled by whether you were doing 1st or 2nd curtain.

Yes, for info I used front curtain throughout.

Remember that ambient is still part of the equation and ambient and flash are mixed everywhere. The motion blur typically only shows up in the ambient, but if there is ambient, it will appear. You either have to kill the ambient (i.e., set your exposure so ambient is so underexposed it doesn't register), or live with the blur, or use HSS to increase the shutter speed.

Yes, I agree and next time I will put more thought into capturing a motion shot. Thankfully in the shot I captured which to me was the winner of the entire series had this motion blur which added to its impact.

But HSS may not be viable in low-light situations, since the faster the shutter speed, the less light you're getting from the flash as well as the ambient.

I agree with this and am going to undertake some testing simulating speeds and flash bounce distances achievable.

[dje]

Hi Grahame

On my D610, there is a Custom Setting e4 called "Exposure Compensation for Flash". This gives a choice of "Entire Frame" or "Background Only". The effect of this setting is as follows

A. Shutter Priority

With "Entire Frame" selected, EC (which changes the Aperture) affects both the background exposure (ambient light) and the subject exposure (Flash light). With "Background only" selected, EC only affects the background exposure.

B. Aperture Prioity

The setting doesn't really have any effect because in this mode, shutter speed is varied with EC and provided that the shutter speed remains below the flash sync speed, it wont affect the flash exposure.

According to the manuals, the D810 also has this Custom Setting but the D800 doesn't.

Dave

PS: In Manual Mode, all EC does is change the exposure bar indication.

[Stagecoach]

Hi Grahame

On my D610, there is a Custom Setting e4 called "Exposure Compensation for Flash". This gives a choice of "Entire Frame" or "Background Only". The effect of this setting is as follows

A. Shutter Priority

With "Entire Frame" selected, EC (which changes the Aperture) affects both the background exposure (ambient light) and the subject exposure (Flash light). With "Background only" selected, EC only affects the background exposure.

B. Aperture Prioity

The setting doesn't really have any effect because in this mode, shutter speed is varied with EC and provided that the shutter speed remains below the flash sync speed, it wont affect the flash exposure.

According to the manuals, the D810 also has this Custom Setting but the D800 doesn't.

Dave

PS: In Manual Mode, all EC does is change the exposure bar indication.

Dave,

This is what I referred to earlier in the thread and assume Nikon realised that this could be useful in certain situations of flash use. I'll forgive them for missing out the D800

Out of curiosity, you mention that in Manual Mode on your D610, all EC does is change the exposure bar indication but are you referring to it being used with or without flash?

For info the D800 in Manual Mode works as follows;
a) With no flash, entering EC just changes the exposure bar indication.
b) With iTTL flash, entering EC changes the exposure bar indication and applies FEC.

Grahame