Help! Question about light testing.

[Ryan282]

I recently did a fashion shoot on my Contax G2 using 35mm Ektachrome E100. I was attempting to use strobe flashes (two profoto b10s)

I was using my friends DSLR for test shots, to help me get an understanding of what the flashes were doing, before switching to my Contax using the same settings. unfortunately, the photos came out quite underexposed (and it got me in some trouble with the fashion stylist as it was hard to see the clothes in a lot of the photos!) I ws confused because it looked okay on the digital test shots.

If my understanding is correct this is because of the difference in 'exposure latitude' between my slide film and the DSLR.

My question; is there a way I can get more accurate test shots? I thought perhaps there's a way to adjust the exposure latitude of the DSLR so that it will give me a more accurate example of how the light will look on film? Or is there something else I'm missing?

Thanks for your time,
Ryan

 

[wiltw]

There should NOT have been a significant difference in 'proper exposure' for film vs. digital ...I have owned and used a handheld incident exposure meter during my days shooting weddings in the 1990s, and now with digital SLRs over the past 15 years. There is NOT a fundamental difference between exposing film for 'proper exposure' vs. exposing digital for 'proper exposure'.

Perhaps the aperture was not closing properly on the film camera's lens, perhaps the shutter speed was not correct on the film camera's body, causing a fundamental mismatch of exposure.
It might also have been an issue of using M-sync on the film camera, while triggering electronic flash.

 

[Ryan282]

There should NOT have been a significant difference in 'proper exposure' for film vs. digital ...I have owned an used a handheld incident exposure meter during my days shooting weddings in the 1990s, and not with digital SLRs over the past 15 years. There is NOT a fundamental difference between exposing film for 'proper exposure' vs. exposing digital for 'proper exposure'.

Perhaps the aperture was not closing properly on the film camera's lens, perhaps the shutter speed was not correct on the film camera's body, causing a fundamental mismatch of exposure.

Hi Wiltw, Thanks for your reply,

I would clarify that there were still some semi-useable shots, but in the shadows and highlights, I saw a quite big difference between the test shots and the slides. I also talked to the guy who scans my film and he said I should shoot at ISO80 when using the new Ektachrome because its actually more like an 80iso film. thanks again!

 

[MattKing]

I also talked to the guy who scans my film and he said I should shoot at ISO80 when using the new Ektachrome because its actually more like an 80iso film. thanks again!

That is interesting, as Kodak says that one of the benefits of the tweaks engineered into the new E100 is that it is very accurately described as a 100 ISO film.
I would be cautious using a DSLR to meter flash when you are using slide film in a film camera that uses different lenses. I would also want to familiarize myself with how the slide film and digital camera differ in rendering - if you are going to depend on the digital viewing screen to help you with exposure, you should be familiar with how it and the film you are using behave differently when used in the same circumstances.
A DSLR can be used for this, but you need to calibrate the procedure before relying on it with slide film.
I would say the same for a flash meter.

 

[Ryan282]

That is interesting, as Kodak says that one of the benefits of the tweaks engineered into the new E100 is that it is very accurately described as a 100 ISO film.
I would be cautious using a DSLR to meter flash when you are using slide film in a film camera that uses different lenses. I would also want to familiarize myself with how the slide film and digital camera differ in rendering - if you are going to depend on the digital viewing screen to help you with exposure, you should be familiar with how it and the film you are using behave differently when used in the same circumstances.
A DSLR can be used for this, but you need to calibrate the procedure before relying on it with slide film.
I would say the same for a flash meter.

Hi Matt,

How would I go about 'calibrating the procedure? trial and error?

I'm not sure if I'd be confident in shooting without first seeing a test shot, I could use the modelling light to see where the light is going, but it wouldn't be much use in situations where there is lots of ambient light. It would be helpful to know how other people know how the light will look when using strobes and a film camera.

Sorry if I sound a bit unknowledgeable - I'm new to using flashes

Thanks for your time,
Ryan

 

[MattKing]

How would I go about 'calibrating the procedure? trial and error?

Exactly, although a 36 exp single roll of film and a methodical approach toward bracketing exposures, and adjusting lighting, plus detailed note taking should give you almost all the information you need. If you have more than one lens for your Contax, you should test each lens.
You may very well find that your results will yield you to a very small offset - say an extra half stop of exposure - and that the rendering on the screen is close enough to give you a good sense of the film results.
Your biggest challenge will be that to a certain extent your tests results will be particular to that digital camera - change that and you will need to re-calibrate.

 

[grain elevator]

it was hard to see the clothes

sounds like a more serious error than just lens discrepancies. Are you absolutely certain that you had the same settings (aperture and ISO) on both cameras, maybe the DSLR did auto ISO unbeknownst to you or something like that? Can you check the digital test shots again?

 

[Dennis-B]

Ektachrome, as well as Fuji's transparency films are, by nature, a bit higher in contrast than negative films or the native settings in digital cameras. You didn't state the brand of the digital SLR, but you may want to check the contrast settings on the test DSLR to ensure they have the same (or at lest similar) contrast settings. The only way to do that is to test both film and digital side by side, and well in advance of any shooting-for-money sessions.

 

[neilt3]

Start by checking the sync between flash and camera .
It's already been mentioned about "M" sync .
That's for flash bulbs , not electronic flash .
First make sure the camera is set to "X" sync , if there is even an option .
Some cameras have two or even three settings or sockets .
Next take a test shot , without film .

Connect the camera up to the stoves via it's PC cord or wireless trigger .
Set the camera to its X sync speed , 1)60th or 1/125th second , open the back .
While looking threw the back of the camera , take a shot and see if the flash flashes while the shutter is open .
If the film is really underexposed it sounds like your only capturing ambient light , not the strobes .

How are you determining exposure ?
With a flash meter or trial and error with the digital camera ?
The DSLR was set to the right ISO wasn't it ?

 

[pentaxuser]

There are plenty of people here who can give much better help with getting the exposure right so I will leave any comment on that to others but at the risk of stating the obvious, if good shots are what you are judged on and it sounds as if they may determine whether you get used for shoots in the future from which an income may dependent then while it wastes film by definitions why not bracket and use more film until you know what exposure your camera gives the best shots at.

It sounds as if saving on film might result in losing a contract or not being used again.

pentaxuser

 

[halfaman]

For test shots I use some old digital compact camera (a Canon Powershot S95 or a Panasonic LX-3), not a DSLR. They have poor highlight and shadow latitude, more than any negative or positive film, so they are a pesimistic previews. But they ok for me to balance exposure or contrast.

 

[Pieter12]

For test shots I use some old digital compact camera (a Canon Powershot S95 or a Panasonic LX-3), not a DSLR. They have poor highlight and shadow latitude, more than any negative or positive film, so they are a pesimistic previews. But they ok for me to balance exposure or contrast.

As long as they have a manual mode and an adjustable ISO range close to the film you are using.

 

[halfaman]

As long as they have a manual mode and an adjustable ISO range close to the film you are using.

Yes, both have. Canon ISO is accurate, Panasonic ISO is about a third of a stop deviated but it has a hot shoe.