I thought I understood this, but after further consideration, it is more than a bit confusing to me. If I use D-23 in a non-replenishment mode, it is essentially the first bath in Thornton's 2-bath. AIUI, Sodium metaborate in the replenisher is used to buffer the leftovers of earlier processing. What does it do all by itself in the 2nd bath after the 1st bath is gone?
It seems to me using problematic lenses to improve problematic film is a problematic approach. Why not just use a film without excessive contrast and virtually any lens manufactured in the last fifty years?
You are indeed no expert on this, otherwise you would not ask me this question.
It really does not matter at all which lens I have used for this test, because a different lens would not have changed the results at all.
When I am doing the evaluation of the characteristic curve I photograph the 18% grey card with even, diffuse light from behind.
And then the results are the same no matter whether you are using an uncoated, single-coated or multi-coated lens.
The characteristic curve is a film-typical characteristic.
And you cannot solve the problematic characteristics of this film by using other lenses.
Well then let me go on not being an expert:
How can you measure for shadow detail, if you just shoot a 18% grey card?
And even with diffuse light from behind a multicoated lens should give higher contrast than single- or uncoated.
Again, for evaluating the HD-curve it is irrelevant whether your lens is multi-coated or single-coated. That will not change the curve shape!!!
I am just doing what every good BW photographer is doing: Evaluating the characteristic curve / HD curve of the film.
By exposing a complete Zone series from Zone I to Zone X. So from - 4 stops underexposure over correct exposure (Zone V) to + 5 stops overexposure (Zone X).
This curve tells you everything about real film speed, shadow detail, tonality and highlight detail.
It is just simple basic knowledge for BW film photography! And if you don't know about it, just buy a book, read and learn this essential basic knowledge. It is really worth it, and you will benefit from it very much.
Again, for evaluating the HD-curve it is irrelevant whether your lens is multi-coated or single-coated. That will not change the curve shape!!!
If you are testing several film-developer combinations it is only relevant that you are using the same test procedure (including same lens) for consistency and comparison possibility.
Now what if you did match subject contrast to the film+dev. by using a different contrast lens? Do it the other way round?
Now what if you did match subject contrast to the film+dev. by using a different contrast lens? Do it the other way round?
As already explained by faberryman, Cubao and me above. That does not work!!!
You cannot change the curve shape of the film by using a different lens.
Period.
Please do yourself a favour and learn the basic essentials of BW film developing and evaluating of the characteristic curves of films.
Interesting idea. Why don't you acquire lenses having different contrasts, take photographs with them in lighting of different contrasts, and let us know how that works out. To be honest, I'll probably just continue to adjust development time to control negative contrast, but often there is more than one way to accomplish a task.
I know that coating of a lens has an effect on contrast.
I`m aware that the curve is independed of the lens used - its just there because its the characteristic of the film.
But if the curve is the way it is with P30, reducing shadow detail and blowing highlights, what would happen if you don`t use a high contrast lens - but a lens brightening up shadows and reducing highlights?
The curve would remain the same, but what would the picture look like, what would happen to shadow detail and highlights? Would the picture look more correct, though the curve still is the same as with a high contrast lens?
No, that does not work. The lens cannot "brightening up" shadows. Only additional light can that.
And the contrast range = difference, is determined by the curve shape, which cannot be changed by the lens.
That was my thought too after testing P30 with modern contrasts Zeiss glass. It seemed to me that the film might give vintage lenses a little needed punch. I was going to try it with the 120 size but it hasn’t arrived yet.
A single- or uncoated lens will produce flare, which will be spread across the entire neg during exposure.
As bright areas will be several times brighter than the flare (sometimes a 100 times brighter), you won`t notice brightening of bright areas - but with dark shadows a brightening can happen, as lens flare is additional light.
As i said several times now you don`t need to change the curve and i don't want to change the curve - all i want is to give the curve the subject-contrast it gets along best with. But, i`m afraid, you seem too focused on the curve to see my point.
This does apply to my theory i presented a few days ago: As P30 was formulated in a time where there were no multicoated lenses, single-coated were state of the art and uncoated still in use, they maybe designed the curve to match single- and uncoated lenses by intention.
Today most use multicoated lenses and find shadows dropping and highlights blowing. Maybe P30 will give better results with single- and/or uncoated lenses.
No, that is not generally the case. You have flare only in certain conditions, but not always. In diffuse daylight or with the light source behind you you won't have any flare. I have used enough old non-coated and single coated lenses to know their characteristics.
See explanation above. And please don't ignore the physical fact that lens coating is increasing and improving light transmission through the lens.
Your statement that uncoated lenses will give you "additional light" is not true.
No, your problem is that you don't understand that uncoated lenses cannot solve the original problem with this film. And that you unfortunately don't know what a characteristic curve really is and what it is showing. And your object contrast / subject contrast is determined by the lighting conditions on that object, and not by the lens.
If you could significantly influence object contrast by lens choice our photography techniques would be very, very different to what we are using for decades!
Sorry, but that is really esoteric wishful thinking. And ignoring physics: E.g. Because of the better light transmission multi-coated lenses have better shadow tone separation, and not "shadows dropping".
As you are so extremely convinced of your "theory", then go, buy some uncoated lenses, make comparison tests with modern multi-coated lenses and evaluate the characteristic curves, show the results and give evidence that you are right.
But I can guarantee you: It will be a total waste of time, and you will fail. Because you are ignoring physics.
This means as soon as there is light passing through the lens, there will be reflections, no matter what light or light source there is - even with a multicoated lens. If a light source does shine directly into the lens, there will be visible artifacts which usually are called lens flare, but there also is a different kind of flare which could be described as an even fog laying above the entire picture - and because of that isn`t that obvious or not obvious at all.
This is what i mean when i was talking about flare, not obvious reflections of the aperture or multiple images of light sources. Think of it as a fogged lens, it will produce flare even if there is diffuse light comming from behind.
Now as a single coated or uncoated lens does produce flare (fog) any time, there will be additional light be shed on the shadows during exposure. Light that would not be shed (respectively much less) onto the shadows with a multicoated lens, as this does produce way fewer flare (fog).
This additional light on the shadows of course is not comming out of nowhere. A single- or uncoated lens does not have higher light-transmission and there are no extra openings in the lens barrel to let in additional light, no this flare (fog) is created by the lens elements reflecting light. That's what i meant by "stealing light from the bright areas of the subject". Light of the bright areas will be reflected between the single elements, it will be converted to flare (fog) and spread even above the entire neg.
O.k., the correct technical term for that is light transmission, and not flare.
A single- or uncoated lens will produce flare, which will be spread across the entire neg during exposure.
Today most use multicoated lenses and find shadows dropping
See explanation above. And please don't ignore the physical fact that lens coating is increasing and improving light transmission through the lens.
Because of the better light transmission multi-coated lenses have better shadow tone separation, and not "shadows dropping".
9% is what each element of a uncoated lens does reflect, with single-coating did reduce reflections to about 3% and multi-coated is about 1% per lens element.
O.k., the correct technical term for that is light transmission, and not flare.
That is also measured by the T-stop value (in addition to f-stop), which gives you the real "light-power" of a lens.
Uncoated or single-coated lenses have lower / worse light transmission than multi-coated lenses, and therefore also a worse T-stop.
I think you may be referring to something else. AFAIK @Harry Callahan is talking about flare, in the sense of 'veiling glare', which does indeed reduce overall contrast by illuminating shadows that would otherwise remain darker.
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