Lens flare as "contrast contol" ?

[Ken Lee]

My question is spread across 2 posts.

Given that a sheet of film can hold a lot of tonal information, I wonder if people have been right to describe flare-prone lenses as having less contrast.

Here I have started with a 16-bit image, added "flare", then removed it.


16-bit original


16-bit adjusted: flare added


16-bit re-adjusted: flare removed

We added flare (which pushed the low values up and compressed all the values together) and then removed it: There may be gaps in the resulting histogram, but they can't easily be detected.

[Ken Lee]

Here I started with an 8-bit version of the same image, added "flare", then removed it.


8-bit adjusted: flare added


8-bit re-adjusted: flare removed

Because the image is 8-bits only there are gaps in the final histogram - but on an 8-bit monitor the resulting image looks the same as the original.

If we stick with analog process or 16-bit digital capture, can a flare-prone lens serve as a valid method of controlling contrast ?

[Kirk Gittings]

From snippets I have picked up over the years (can't tell you where), many practitioners around the time when multi-coatings were invented and implemented preferred the older single coated lenses for just this reason. The newer lenses were just too contrasty.

[Old-N-Feeble]

I would like to see a test of an uncoated (or any) lens known to have lots of flair vs. a multicoated lens of the same focal length and known to have extremely low flair. Then I'd like to see the differences in prints after contrast correction via fully analog wet process.

[Taija71A]

... If we stick with analog process or 16-bit digital capture, can a flare-prone lens serve as a valid method of controlling contrast ?

__

Yes!

What you have tried to 'simulate' Ken, would be exactly the same...
As adding the proper amount of 'Pre-Exposure' of your Film (*for 'Contrast Control').
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In an 'Analog Only' workflow... This is most certainly a very, valid option.
One of the best 'treatises' on this subject... Was discussed in the Book:

"Way Beyond Monochrome" by Ralph Lambrecht.

http://www.waybeyondmonochrome.com/W...xposureEd2.pdf

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Best regards,

-Tim.
_________

[Drew Wiley]

I'm having that same schizophrenic debate in my own head right now. This time of year I sometimes covet soft open shadows rather than hard ones, and prefer
the older lens look. Guess I could pack both 360's for my Saturday walk, but my ankle sprain hasn't completely healed, so I'll need to compromise pack weight somewhat. I pampered the ankle last weekend and just shot the Nikon. Developed those negs last nite; and there are sure a couple of shots I'l like to go back and
re-shoot with the 8x10.

[Drew Wiley]

Pre-exposure or "flashing" is a rather poor option in my opinion because it muddies the microtonality in the shadows. I certainly understand it. Too blunt an instrument for me. I'd rather do more subtle controls via film development tweaks, careful lens choice, or perhaps unsharp masking. In other words, I like to have
my cake and eat it too.

[Kirk Gittings]

Pre-exposure or "flashing" is a rather poor option in my opinion because it muddies the microtonality in the shadows. I certainly understand it. Too blunt an instrument for me. I'd rather do more subtle controls via film development tweaks, careful lens choice, or perhaps unsharp masking. In other words, I like to have
my cake and eat it too.

Me too. Back when I was learning the ZS I tested that technique rather extensively and no matter how I did it I never liked the "look" of it.

[Taija71A]

... Then I'd like to see the differences in prints after contrast correction via fully analog wet process.

__

I was just wondering...

How do you propose to do this corresponding 'Contrast Correction' in the Darkroom.
Just curious...

Thank-you!
--
Best regards,

-Tim.
_________

[Ken Lee]

Here are some numbers I am pulling out of my hat. Are these right ?

Let a subject start out at 100% contrast. A lens with low flare delivers 85%. A lens with a lot of flare delivers... 75% ?

In other words, how much are we talking about anyway ?

In my digital "test" I tossed out the lower 50% of the tonal scale and got enough of it back again in the 16-bit version: that's a lot of loss and recovery. Actually, it wasn't tossed out: that would be under-exposure. Instead it was compressed up into higher 50% of the histogram.

Under darkroom conditions, I presume the same would be possible, even better perhaps since film and paper are analog, or so continuous that they appear analog.

On the other hand, if we were using a poor quality film - or a very contrasty film - or a film/developer/paper combination with limited contrast controls - then it might not be possible to spread the tones back out after such... data compression.