Lighting Technique Question

[lensman_nh]

So, I recently got the Interfit honey badger 2 light setup and have been having a blast learning lighting. I'm also having some ups and downs along the way, with way more ups than downs.

Over the weekend I was playing with still life in high and low key lighting.

I'm metering the flash with a Sekonic l-358. When using my digital body, the exposures given by the L-358 are pretty spot on, so the meter is good. It works well outdoors too in normal incident mode.

When shooting film however, the given EV is about 2 stops underexposed on Fujicolor in high and low key situations. ISO matches on the Meter, digital body and film. This batch of film gives normal, very printable, negatives when used for typical daylight stuff outside when exposed at box ISO. It is home processed in Kodak C-41 Flexcolor chemistry. It could be my processing, but the fact I get repeatable outdoor results at box speed suggests that's not a key factor.

This effect is really noticeable in the low key examples. The base is pretty clear, which is what you want in a low key situation. To print for maximum black, the exposure is 10 secs at f16 for a 10x8. Less than that it isn't black, more than that and it gets no darker. This is about ballpark for RA-4 8x10 prints with my equipment.

Using that exposure, it is the EV+2 negative that prints correctly for the subject and with a black background. Using the thinner negative at EV+0 and printing for the subject won't give a black background.

So, forgive the long preamble, but I have a couple of thoughts I would like to bounce off the community.

Firstly, I belive that high and low key lighting with film is brutally unforgiving of technique, and will ruthlessly expose any flaws.

My second thought is that high and low key scenes end up using the toe and heel of the response curve, and make those extremes a critical part of the image. I think that this is what is driving the need for EV+2 exposure. If the scene was more tonally compressed into the middle of the response curve the EV+0 exposure would be printable. Isn't this what the zone system is intended to do for B&W, compress the tonal range into something printable?

I'm repeating the test with HP-5+, but would appreciate any thoughts on this. Is this something others have notices, or does my technique suck?

J.

 

[MattKing]

sn't this what the zone system is intended to do for B&W, compress the tonal range into something printable?

It is also intended to expand the tonal range into something more easily printed if the scene's tonal range is unusually narrow, such as in low key and high key situations.

 

[RalphLambrecht]

So, I recently got the Interfit honey badger 2 light setup and have been having a blast learning lighting. I'm also having some ups and downs along the way, with way more ups than downs.

Over the weekend I was playing with still life in high and low key lighting.

I'm metering the flash with a Sekonic l-358. When using my digital body, the exposures given by the L-358 are pretty spot on, so the meter is good. It works well outdoors too in normal incident mode.

When shooting film however, the given EV is about 2 stops underexposed on Fujicolor in high and low key situations. ISO matches on the Meter, digital body and film. This batch of film gives normal, very printable, negatives when used for typical daylight stuff outside when exposed at box ISO. It is home processed in Kodak C-41 Flexcolor chemistry. It could be my processing, but the fact I get repeatable outdoor results at box speed suggests that's not a key factor.

This effect is really noticeable in the low key examples. The base is pretty clear, which is what you want in a low key situation. To print for maximum black, the exposure is 10 secs at f16 for a 10x8. Less than that it isn't black, more than that and it gets no darker. This is about ballpark for RA-4 8x10 prints with my equipment.

Using that exposure, it is the EV+2 negative that prints correctly for the subject and with a black background. Using the thinner negative at EV+0 and printing for the subject won't give a black background.

So, forgive the long preamble, but I have a couple of thoughts I would like to bounce off the community.

Firstly, I belive that high and low key lighting with film is brutally unforgiving of technique, and will ruthlessly expose any flaws.

My second thought is that high and low key scenes end up using the toe and heel of the response curve, and make those extremes a critical part of the image. I think that this is what is driving the need for EV+2 exposure. If the scene was more tonally compressed into the middle of the response curve the EV+0 exposure would be printable. Isn't this what the zone system is intended to do for B&W, compress the tonal range into something printable?

I'm repeating the test with HP-5+, but I would appreciate any thoughts on this. Is this something others have noticed, or does my technique suck?

J.

with an exposure of 10s at f/16, you have to consider low-intensity reciprocity failure(easily responsible for a two-stop underexposure)

 

[lensman_nh]

The ten second exposure is to print the negative for maximum black. The actual exposure to make the printable negative under strobes was something like 1/125 at f8 or so.

the meter gave me about f16.

 

[spijker]

The 2EV difference seems odd to me. I shoot digital and BW film with studio flashes and the exposure has always been consistent for me. What film camera are you using? Does it have a leaf shutter or a focal plane shutter? A leaf shutter that opens a bit late could explain it but that's just a wild guess.

 

[MattKing]

There are some flash meters which give varying results when the shutter speed set on the meter is changed. Could there be a disconnect arising from that?
And of course, are you sure there isn't a filter on the lens?

 

[Adrian Bacon]

So, I recently got the Interfit honey badger 2 light setup and have been having a blast learning lighting. I'm also having some ups and downs along the way, with way more ups than downs.

Over the weekend I was playing with still life in high and low key lighting.

I'm metering the flash with a Sekonic l-358. When using my digital body, the exposures given by the L-358 are pretty spot on, so the meter is good. It works well outdoors too in normal incident mode.

When shooting film however, the given EV is about 2 stops underexposed on Fujicolor in high and low key situations. ISO matches on the Meter, digital body and film. This batch of film gives normal, very printable, negatives when used for typical daylight stuff outside when exposed at box ISO. It is home processed in Kodak C-41 Flexcolor chemistry. It could be my processing, but the fact I get repeatable outdoor results at box speed suggests that's not a key factor.

This effect is really noticeable in the low key examples. The base is pretty clear, which is what you want in a low key situation. To print for maximum black, the exposure is 10 secs at f16 for a 10x8. Less than that it isn't black, more than that and it gets no darker. This is about ballpark for RA-4 8x10 prints with my equipment.

Using that exposure, it is the EV+2 negative that prints correctly for the subject and with a black background. Using the thinner negative at EV+0 and printing for the subject won't give a black background.

So, forgive the long preamble, but I have a couple of thoughts I would like to bounce off the community.

Firstly, I belive that high and low key lighting with film is brutally unforgiving of technique, and will ruthlessly expose any flaws.

My second thought is that high and low key scenes end up using the toe and heel of the response curve, and make those extremes a critical part of the image. I think that this is what is driving the need for EV+2 exposure. If the scene was more tonally compressed into the middle of the response curve the EV+0 exposure would be printable. Isn't this what the zone system is intended to do for B&W, compress the tonal range into something printable?

I'm repeating the test with HP-5+, but would appreciate any thoughts on this. Is this something others have notices, or does my technique suck?

J.

If you're metering accurately, there should be no difference between digital and film, though, remember that film usually only has 4-5 stops below middle grey before you hit film base plus fog, whereas with digital you usually have at least several stops before noise starts to become a concern. You may have noticed a difference between film and digital because of this in your exposures.

How much ambient light is there in the scene when you're taking the meter reading for the flash? Most Sekonic meters require some amount of ambient light in addition to the flash in order to return accurate meter readings. This is because the reading it returns is ambient + flash. That is because when you're shooting flash, you're making two exposures: you're exposing ambient, and you're exposing flash. If you're shooting with flash in a studio, all you usually see is the flash exposure because the ambient exposure is at least 4-5 stops down and in the black part of the image, but in order for your Sekonic meter to return an accurate exposure reading, there needs to be enough ambient light that the meter will return a reading if just taking an ambient reading instead of returning UE (under exposed). If you turn your flashes off and just take an ambient reading what does it say? Add enough ambient light that you at least get a reading, then build the flash exposure on top of that. If you want that ambient part of the exposure to not show up in the visible part of the image, simply add enough flash power so that your flash exposure is at least 4 stops (6+ is better though) above the ambient reading.

If you do that, you should see no difference between digital and film, assuming you're fitting your tonal contrast range into what each can capture.

All that being said, what I typically do is select the part of the scene where I want to maintain shadow detail and take an incident reading from there and subtract two stops from that reading. If that area is particularly dark (reflectively speaking, like black clothe), I sometimes will only subtract 1 stop to make sure that it registers something instead of sinking into film base plus fog. I then shoot the rest of the scene with that exposure knowing that with film, the other parts of the scene will handle whatever that exposure is easily. If I'm shooting it digitally, I simply meter where the key light is primarily lighting the subject knowing that I have lots of shadow latitude for the darker parts of the image, though sometimes, if I have a camera that is not as clean in the shadows as I'd prefer, I'll do the same thing as I would with film, but adjust the tonal contrast range (super easy to do since you're shooting with flash) so that my highlights and speculars don't clip out on the other side.

Your other alternative is to simply know that with film, you only have 4-5 stops below middle grey before film base plus fog, so add light in the shadows to keep it in that range, though what I described above tends to be simpler as you can simple set up your lights how you want to light the scene, then meter from the darkest part, then add light until you have the aperture/DOF that you want.

 

[lensman_nh]

Thanks all, some things to definitely digest here.

I'm getting a similar effect with HP-5+, but that difference only appears to be about a stop. I'm also re-running my temperature calibration tests for my C-41 process, to rule out underdevelopment of the Fujicolor tests. Right now that is still a possibility for the Fujicolor. Also, this was done using 2 different bodies and lenses.

Something I have never done before, but am doing as part of this is deliberately printing for maximum black, DMax, as Anchell talks about it in the darkroom cookbook and also at https://www.halfhill.com/speed2.html. Curiously the speed2 link rates HP5 just about where I'm seeing it too.

What is interesting to me is the more "normal" scenes with more normal tones outside the really high and really low key stuff are printing OK. This kind of points to box speed really being for "normal" subjects with a more compressed tonal range. Still learning new stuff after all these years...

J.