Topic: Anyone want to give me some free advice?

[Jeff Warden]

I started the weekend thread with this picture.



That dark curtain in the background is dragging me down (I want it to be full black) but I can't seem to get the exposure right. The exposure is about five seconds on FP4 and the curtain is a good twenty feet behind the performer. The flash is six feet to the left of the camera and aimed to not illuminate the curtain.

My next attempt will be with PanF, but I get the feeling if I achieve the black background I'll also lose the performer's movement that I desire. It's a puzzle. If you've ever tried something similar and have suggestions I'd appreciate it!

 

[Bryan]

If you can move the black curtain farther from the subject that would help, especially if it's beyond the depth-of-field.  Less light hitting it and some blur will hide it better.  The light on the subject should be the only light in the room.

[Jeff Warden]

If you can move the black curtain farther from the subject that would help, especially if it's beyond the depth-of-field.  Less light hitting it and some blur will hide it better.  The light on the subject should be the only light in the room.

Thanks for your thoughts, Bryan. I think you're right and I'll try to control what I can. We are as far from the curtain as we can get and with my current lighting (natural light from windows and the one flash) I need f/16ish for the long exposures so I've had trouble blurring out that rear curtain.  It would be nice to have a hot light and completely darken the room otherwise. Hmmm.

[Bryan]

I shot the photo below with a Rolleiflex using Ilford Pan F Plus 50.  I had to wait until after the sun set to get the room dark enough. 

Zeiss Ikon Movilux 8A by Bryan Chernick, on Flickr

This was done with one of those fancy new electronic cameras but it's the same concept.  A completely dark room with a black cloth a good distance behind the subject.  It's a long exposure using a handheld light.  I waved the light around to help eliminate shadows while making sure it wasn't pointed at the background.  If you just use one light at an extreme angle to avoid illuminating the background you're going to get harsh shadows.  A few lights at different angles would be better.  You may want to do a little experimenting with a still life to get the lighting to work.

Zeiss Ikon Super Ikonta 531/2 by Bryan Chernick, on Flickr

[Francois]

You should use a black flag on the light to control the exposure (think foamcore).
Also, take a reading off the back. If you expose the front for a middle gray, make sure the back is a good 4 stops darker.
Also, printing to a higher contrast would help. It would give something a bit like this

[Pete_R]

I need f/16ish for the long exposures

A neutral density filter would let you use a wider aperture.

[Francois]

That too. It would definitely help cut down the overall amount of light quite a bit.

[Francois]

I forgot to ask a few questions about your flash.
Is the flash on or off camera?
Is the flash manual, automatic or TTL?
Knowing these things would be helpful.

[zapsnaps]

Bryan: those are great photos & not just because I'm a Zeiss fan

[Bryan]

Bryan: those are great photos & not just because I'm a Zeiss fan

Thanks Zapsnaps, that's a really nice little compact 8mm projector.  It's a bout the size of a large purse when it's all folded up with the cover on.

[Jeff Warden]

I forgot to ask a few questions about your flash.
Is the flash on or off camera?
Is the flash manual, automatic or TTL?
Knowing these things would be helpful.

Hi Francois, and thanks for your thoughts.

It's off the camera and about six feet to the left of it, aimed so it doesn't hit that rear curtain. It's a Nikon SB-600 firing at full power, which is flashed manually when the performer is in the right position.



Here's that same room with the same black curtain, and using ambient light from the window, i.e. no flash. When it's an image like this and the performer isn't moving (probably 1/30th sec exposure) it's easy to get rid of the curtain. It's only with these long exposures that I'm struggling.

[Jeff Warden]

I need f/16ish for the long exposures

A neutral density filter would let you use a wider aperture.

I like this idea a lot. If the curtains are still slightly visible at least they would be blurred. Thank you!

[Jeff Warden]

I shot the photo below with a Rolleiflex using Ilford Pan F Plus 50.  I had to wait until after the sun set to get the room dark enough. 

That's beautiful, Bryan.

[Francois]

Using a flag will probably fix the problem.
Even just taping a bit of black cardboard to the flash head could be enough provided that the light goes out at a relatively shallow angle to the curtain.

[BernardL]

Also, take a reading off the back. If you expose the front for a middle gray, make sure the back is a good 4 stops darker.

+1. Look at your negative. If the background is at base+fog density, this is why you can't print it darker. In other words, the negative does not reflect the dynamic range of the scene if the background is below the toe of the film. And no amount of baffling or snouting the light source will change that. Even if background is halfway on the toe you do not have full dynamic range captured on the film. Advise to re-do with +2stops of exposure, shutter or aperture according to your other constraints.

[Pete_R]

Advise to re-do with +2stops of exposure, shutter or aperture according to your other constraints.

There is some logic to this, if the exposure on the curtain was on or very near the toe, as long as highlight detail isn't sacrificed.

But the main area of issue is where the dancer passes in front of the curtain so adding exposure to that area (sort of pre-flashing the film) and in that area the exposure isn't on the toe as there are significantly darker areas in the image (top corners).

Francois is right that getting sufficient contrast between curtain and foreground is the answer but it may need to be more than 4 stops because of the exposure added by the dancer as she passes in front of the background. If your flash is already on full power then a more powerful flash might be needed to increase the contrast. Assuming you do manage to stop any flash spilling onto the background of course.

I think the main issue, though, is the folds in the curtain which makes them obvious. If it was a perfectly flat background, I don't think it would matter if it received a small exposure. Maybe you need to look at a different background or throw it out of focus with a wider aperture as previously discussed.

[Jeff Warden]

Also, take a reading off the back. If you expose the front for a middle gray, make sure the back is a good 4 stops darker.

+1. Look at your negative. If the background is at base+fog density, this is why you can't print it darker. In other words, the negative does not reflect the dynamic range of the scene if the background is below the toe of the film. And no amount of baffling or snouting the light source will change that. Even if background is halfway on the toe you do not have full dynamic range captured on the film. Advise to re-do with +2stops of exposure, shutter or aperture according to your other constraints.

Thank you Bernard, I appreciate your advice. I'll be trying again today and will report back.  :-)

[Jeff Warden]

Advise to re-do with +2stops of exposure, shutter or aperture according to your other constraints.

There is some logic to this, if the exposure on the curtain was on or very near the toe, as long as highlight detail isn't sacrificed.

But the main area of issue is where the dancer passes in front of the curtain so adding exposure to that area (sort of pre-flashing the film) and in that area the exposure isn't on the toe as there are significantly darker areas in the image (top corners).

Francois is right that getting sufficient contrast between curtain and foreground is the answer but it may need to be more than 4 stops because of the exposure added by the dancer as she passes in front of the background. If your flash is already on full power then a more powerful flash might be needed to increase the contrast. Assuming you do manage to stop any flash spilling onto the background of course.

I think the main issue, though, is the folds in the curtain which makes them obvious. If it was a perfectly flat background, I don't think it would matter if it received a small exposure. Maybe you need to look at a different background or throw it out of focus with a wider aperture as previously discussed.

Thanks Peter,

Naturally my concern is that achieving blackness in the curtain might also mean that I lose the long curves of the motion blur, which is important to these images. And you're right about those folds in the curtain; If they weren't there I would have a dark gray behind the moving performer and I wouldn't mind that at all. It's the vertical lines that are bothering me. Perhaps having helpers hold the curtain taught would be one solution.

I don't have a ND filter for this lens but I may try taping one on there today to get less depth of field.

One of the challenges is that each exposure is quite different. The dancer may take four seconds to go from left to right, and then it might be seven-ish seconds the next try, even though she's trying to do the same thing. I'm just closing the shutter when she's out of the frame rather than when a light meter says I should.

I'll try again today. Thanks for the advice!

[Pete_R]

Naturally my concern is that achieving blackness in the curtain might also mean that I lose the long curves of the motion blur,

You're right. That's an extra factor to take into account and because you're using window light to expose the movement there's not much control over it. Maybe a studio flash with a modelling lamp might be an option and avoid using the window. Or rig up some other continuous light source (LED maybe) close to the flash. If you can get the right balance between modelling lamp and flash output it also means you only have one light source to control and to mask from hitting the backdrop.

[Jeff Warden]

Naturally my concern is that achieving blackness in the curtain might also mean that I lose the long curves of the motion blur,

You're right. That's an extra factor to take into account and because you're using window light to expose the movement there's not much control over it. Maybe a studio flash with a modelling lamp might be an option and avoid using the window. Or rig up some other continuous light source (LED maybe) close to the flash. If you can get the right balance between modelling lamp and flash output it also means you only have one light source to control and to mask from hitting the backdrop.

Yep, aside from having little control of the light, and practically no control over the dancer or the exposure, I'm in complete control of things.   

So far I like the flag idea, and the ND, slower film, and using controlled light not from the windows. Today I'll try all of that except the lights.

[Jeff Warden]

The free advice paid off.  Thanks again everyone.

I did some experimenting in the studio before the dancers arrived, opening and closing and repositioning curtains to block the daylight, and found I could reduce the light hitting the rear curtain by a full stop compared to last week, while still illuminating the dancer. Metering my hand at iso50 and f8 was a half second, and the rear curtain was 30 seconds so I was pretty sure it would disappear without the need for the ND filter, even with the longer exposures. So I skipped the ND filter and exposed a test roll of PanF at F11 and F16 with my normal out-of-control 3-7 second exposures, and my flash assistant cupped her hand while flashing to keep the light from hitting the rear curtain. The backgrounds were for the most part all featureless blacks, which is just what I want.

There'll be more experimenting with the flash, which is now a bit too bright in most of the images, but at least the curtain issue is solved and I'm feeling more confident.  Score.

:-)

[MiguelCampano]

Veeeeeery nice!

[Jeff Warden]

Veeeeeery nice!

Thanks Miguel,

I'm glad I have the opportunity to spend so much time capturing these dancers, and it's a happy coincidence that all my photography right now is happening in air conditioned comfort.  :-)  But yeah, I'll be ready to walk the streets again with a camera when this chapter closes. I may not be a studio guy. 

[Francois]

Studio work is just a learning thing. Once you have it down, you can pretty much do what you want. The only downside is that assistants are often welcome (though you can do a lot with simple stands.