Contrast and Optics

[steve_levine]

Can a lens be "too contrasty"? Just curious. Is there a suitable level

generally accepted? I know from experience that there are many older lenses

that are flat in the contrast dept.

 

My testing wasn't thorough or under any tight controls. But using the same

film/lab combo for my C41 B&W (scanned to CD). I've noticed that my CV Skopar's

are much more "snappy" than my various 50-60's Japanese glass. In fact my CV

21/F4 is almost too sharp and too contrasty!

[john_gleason1]

I suppose there's a fair bit of room for personal taste here. No doubt, many modern lenses are going to deliver higher contrast than many lenses designed and built in, say, the 1950s or 1960s.

 

But, whether that "improved" contrast is really an improvement is another matter. Some images just seem to work better with lower contrast, I'd guess. It's likely part of the reason that some folks prefer the look of older lenses. Nothing wrong with that, I reckon.

[jonathan_reynolds]

I've struggled to comprehend this idea, which keeps re-surfacing. Older lenses had lower contrast because they allowed stray light into the shadows. In order to improve shadow definition, modern lenses had to control this stray light better. So the shadows are deeper relative to the highlights, but all tones are resolved better. To my mind this can only be good. You can always discard shadow detail later if you want to.

 

In B/W at least, if you apply the same exposure and processing with lenses of both eras, one set of negs will be unsatisfactory. You have to adapt your technique. If you do that, I can't see how contrast is a problem.

 

You might think higher contrast could be an issue with colour slide material, where you have a smaller exposure latitude and less control in processing. But then, modern slide emulsions are designed for modern lenses. I've rarely had well saturated colours using any older generation glass.

[charles_stobbs3]

New formulations of glass have appeared over the years which may also have increased contrast.

[frank uhlig]

Contrast of a given scene is a given by the prevailing light. Period.

 

Can we record more contrast than we see? How could this be done, physically? Are other

glass gremlins that put darkness into portions of the scene, and bright light into other

sections?

 

Some here think this is now possible through "modern glass". I am not aware of any light

enhancing glass at all. Glass is passive, just like an audiotape, somethings will get lost in

every recording, so the contrast of a taken pic can never exceed the one of the original

scene, nor can the sound of a recording ever achieve the original sound space.

 

The less the contrast is diminished by a lens, the better the lens. Period. But the original

contrast (that normally exceeds our media's 5-8 contrast range by a factor of around 10

anyway) cannot be added to. Sorry.

[dave_s]

<i>Older lenses had lower contrast because they allowed stray light into the shadows.</i>

<p>

A theoretical advantage would be in taming contrast in a very long-range scene. In one of his books, probably The Negative, Adams describes how preflashing the film gives a similar result to using an older uncoated lens-- it wakes up the shadows and gets them off the toe of the film curve.

<p>

I agree it would be pretty darn rare that anyone would actually choose to do this in practice.

[doug herr]

"<I>Can a lens be "too contrasty"?</I>"

<P>

No. The recording medium's limited dynamic range can make photos look too contrasty, but the lens cannot deliver more contrast to the film or sensor than is present in the original scene. I've gotten the best results when using a lens that degrades contrast as little as possible along with a recording medium that can handle the dynamic range. This gives me maximum highlight & shadow detail along with good tonal gradation.

[Rob F.]

There seems to be an oft-repeated belief to the effect that lower contrast lenses are best for black & white (you see this repeated a lot); while the high contrast ones are best for color. While I think there is some merit to this position, higher contrast will give the picture more "snap" and "sparkle" whether shooting in B&W or in color. A lower contrast lens will open up the shadows somewhat; and it will do that with both B&W and color.

 

Given that color transparency film has less latitude than negative films, it would not necessarily follow that "higher contrast is best for color." I think a better habit is to use the higher contrast lens unless shooting in a situation where the luminance range of the scene exceeds the latitude of the film, and you need/want to preserve some shadows without blowing out the highlights. Another reason for using the lower contrast lens is to create a softer look.

[doug herr]

In my experience a lower contrast lens does not open up the shadows, it just makes them look muddy along with reducing color saturation throughout the photo.

[jonathan_reynolds]

Thank you for saying that, Douglas! This has been such a persistent myth that I had begun to doubt my own eyes.

 

Frank, no-one above has suggested that a lens can deliver more contrast than the scene has. That would be silly.

[vivek iyer]

<i>In fact my CV 21/F4 is almost too sharp and too contrasty! </i>

<p>

That lens is very contrasty alright, especially under sunny skies and f/8. :)

[bob_sunley]

Actually, Steve implied that in the first post by saying a lens is almost too sharp and contrasty, but with scanning and post processing reducing the dynamic range of the image and whatever else it did to the image, I can understand what he is implying.

 

Just remember, all lenses are subtractive devices, they only reduce the quality of a theoretical image by lowering sharpness and saturation, and add all sorts of distortion to the image.

[alex_lofquist]

Contrast is also a characteristic of the photographic emulsion. It is usually defined by the slope of the H&D curve which relates density to log intensity. (This is sometimes called Gamma.) Most color films have slopes less than one, but many scientific and commercial emulsions (like Microfile) can have slopes as high as two, or more. It all depends on what you require.

[sandor_a._feher]

To me contrast also should have good defenation with resolution.

The attchments show these clearly wher resolution also will provide good contrast. I agree that you can not get more contrast then what is there but what contrast do when their is no resolution just make the image in the shadows more unrecognizable.<div></div>

[sandor_a._feher]

Other photo that is more contrasty with good resolution w/o any adjusment. The optics is the key to sucess.<div></div>

[sandor_a._feher]

Sorry for the above comment here is the photo:<div></div>

[paul_neuthaler]

What lense(s) Sandor?

[l_dasousa]

<b>Douglas Herrprolific poster, Mar 27, 2008; 11:07 a.m.<p>

 

In my experience a lower contrast lens does not open up the shadows, it just makes them look muddy along with reducing color saturation throughout the photo.</p>

 

Jonathan Reynoldsphoto.net patron, Mar 27, 2008; 11:12 a.m.<p>

 

Thank you for saying that, Douglas! This has been such a persistent myth that I had begun to doubt my own eyes.</p> </b>

 

Yes, I agree. I read many times where it is suggested a low contrast lens is advantageous in high contrast light, such as bright overhead sun, but in my experience all it gave me was flare and washed-out color with murksy shadow area.

[andrewlamb]

"I agree it would be pretty darn rare that anyone would actually choose to do this in practice."

 

According to the British Journal of Photography, pre-flashing was a very common practice

amongst press photographers at football (soccer, if you must) matches.

[sandor_a._feher]

Old Town Winthrop:Canon MKII, f9@1/800sec, ISO400, Sigma 50-500mm, FL@130mm.JPEG, adjusted in PS 5LE.

Portrait of Kandur:D2h, f6.7@1/180sec, ISO400, Nikon 105mm 2.8 VR,ISO400, unadjusted.

 

Sorry not Leica equipment.

[john_hicks5]

I don't understand how a lens can be too contrasty. If the shadows are empty, expose more and develop less so the scene doesn't exceed the contrast range of the materials.

 

In reference to digital, the material, in this case the CCD, simply has a limited range, not much different than when serious photographers shot Kodachrome.

[doug herr]

"<I>In reference to digital, the material, in this case the CCD, simply has a limited range, not

much different than when serious photographers shot Kodachrome.</I>"

<P>

I find the DMR has much more usable range than Kodachrome.

[dave_s]

<i>"I agree it would be pretty darn rare that anyone would actually choose to do this in practice."

<p>

According to the British Journal of Photography, pre-flashing was a very common practice amongst press photographers at football (soccer, if you must) matches.</i>

<p>

Should have said pretty darn rare that I would do it in practice. Having said that, I can think of a few extreme negatives I have that would have benefited from a pre-exposure.

<p>

I've heard the old time press photographers used to rack out their Speed Graphics (MPPs, if you must :>D) and put an out-of-focus sky exposure on Zone I or II.

[lutz]

<i>"I agree it would be pretty darn rare that anyone would actually choose to do this in practice."</i><p>

It has also been common practice with newsreel cameramen shooting reversible ("slide") stock. Plus, on the other end of the analog processing chain, before Multigrade I used to pre-flash b&w paper in the darkroom to better bring out detail in the highlights. As far as overall advantage/disadvantage of pre-flashing goes, it all depends on whether you expect the result to be perfect out of the box (straight from the slide/neg) or if you allow for tweaking in the post processing. By allowing for the latter results will certainly improve.

[winfried_buechsenschuetz1]

Of course no lens can compensate high contrast, nor can it add more contrast.

 

As others mentioned, it is often believed that old uncoated lenses have "nicer contrast" than modern lenses because the shadows are not that deep. But these lenses cannot add details to deep shadows, they just lighten them up a bit on the film (not in reality!!!) and thus they appear less deep. You can achieve a similar result by using low-contrast paper when printing, or by swaying a brush across the shadowy parts to reduce exposure time during printing.

 

Compared to what we are used to see from older and non-multicoated lenses, the contrast resulting from modern lenses may seem too high... but they just "transfer" reality better to the film. The question is whether we want a "real" image or one that looks good. There is no general answer to this question, it's the aim of the photographer which sets the standards, i.e. it's his decision or will whether he/she wants higher or lower contrast. The lens designer just can contribute a device which transfer everything to the film.