Can different lenses affect the dynamic range?

Can different lenses used on digital camera affect the dynamic range of the shot being

recorded? For example, can a better nikon lens provide more stops of recorded

information than a cheapo nikon lens?

At the same aperture, no. But in situations that are not DoF-limited a faster lens in low light will allow to work at a lower sensitivity, which will get you a better dynamic range.

Sure they can! Some lenses flare more than others, raising the value of the darkest parts

of a frame and washing out the brightest. Unless it's a really crappy lens, though, I don't

think it could affect it much - not nearly a stop. However, Ansel Adams noted that he

sometimes used his uncoated lenses to much the same effect as a pre-exposure i.e. to

increase the values of the lowest parts of a scene.

 

With modern coated lenses, though, it doesn't really seem that you'd see much of a

difference if any. With a junker or no-name uncoated or single coated lens you may well

see a lowering of contrast.

A good lens does not increase dynamic range but a bad one does reduce dynamic range (e.g.: internal flare , Spherical aberration and etc) in certain situations.

Oh yeah, what Andrew said, though it's not specific to digital photography so I took it as a given. The edge case of pre-exposure doesn't apply to digital photography as far as I can tell.

Pre-exposures seem unnecessary with digital cameras (at least with RAW files) because

there's a ton of data even below Zone 0. I would figure that there's 4-6 stops of data in the

blackest parts of my 10D and R-D1 files that can be gently massaged into visibility. I

haven't experimented, though. It may be a useful technique.

As Andrew just said there is a lot of information in the black which can be accessed even without using RAW although with degradation at extremes like getting effectively 64,000 ISO

Preexposure, postexposure, and even concurrent exposure has no useful effect with digital. I tested it with a rig that I used for concurrent exposure with film cameras, essentially the same setup I use for epi-illumination of macros, but with the beam splitter rotated so that it sent the illumination into the camera instead of through the taking lens.

 

So, latensification will die with film...

See <a href=http://www.luminous-landscape.com/reviews/lenses/fastlensreview.shtml>Sean Reid's article on Luminous Landscape</a>

 

<p>Briefly: The dynamic range of a scene is fixed, the dynamic range of your sensor fixed - but a lens converts from the range in the scene to the range that gets put on the sensor. Very contrasty lenses expand the range of the scene and may push the highlight and shadow details too far out and you end up losing details at the extremes of the range. A lower contrast lens compresses the dynamic range of a scene. A lens with good coatings which is less contrasty will compress the visible dynamic range (without suffering from flaws like flare), possibly pulling highlight and shadow details into the range your sensor can handle.

<I>Very contrasty lenses expand the range of the scene and may push the highlight and shadow details too far out and you end up losing details at the extremes of the range. A lower contrast lens compresses the dynamic range of a scene.</I><P>

 

Obviously a poor quality lens with lots of flare can degrade dynamic range by washing out shadow detail.<P>

 

But if you think a lens can <B>expand</B> dynamic range (increase the ratio of bright to dark in a scene beyond what it actually is) or <B>compress</B> it (reduce the ratio by either attentuating the bright parts more than the dark parts, or selectively boosting the dark parts), then you got some 'splainin' to do.<P>

 

What would you imagine the physical principles to be?

As a practical matter, lenses with many element groups, zooms fer instance, no matter how well coated, are apt to have more flare than simpler designs. IMO, that's the reason people often prefer primes. Though they are often slightly sharper, what people are really reacting to is the improved contrast. Also, though I don't remember the reason why, mirror lenses are pretty awful in the contrast department.

Peter,

A lens necessarily modifies the image that comes in as it projects it onto the sensor/film surface. This should be self-evident, otherwise there would be no difference between good lenses and bad lenses, and even among good/great lenses there would be no difference in character. As far as explaining the actual physical laws in effect, I am not into optics or physics so I will not try to BS my way through that. At the same time, you don't need to know the underlying laws of physics in order to observe the properties of lenses.

 

I suggest you read the article referenced, especially where the second paragraph in the section "Canon 50/1.4, Nokton 50/1.5 and Summilux 50/1.4".

<I>Peter, A lens necessarily modifies the image that comes in as it projects it onto the sensor/film surface. This should be self-evident, otherwise there would be no difference between good lenses and bad lenses, and even among good/great lenses there would be no difference in character. As far as explaining the actual physical laws in effect, I am not into optics or physics so I will not try to BS my way through that. At the same time, you don't need to know the underlying laws of physics in order to observe the properties of lenses.</I><P>

 

Yes, but I <B>AM</B> into optics and physics so I'm challenging you to back up your claim.

I agree with peter, a lens can not "increase" the contrast of a scene only "decrease" it through artifacts and aborations. A better, simpler lens will generally have "higher contrast" because it has fewer shadow detail robbing faults. While the faults can be most often seen in the shadows, they also increase the noise floor for the entire image leading to loss of contrast and fine detail.

Peter - I once again refer you to Sean Reid's observations on this, where he claims (apparently with the images to back it up) that the summicron's images have more contrast than the sensor can handle, while less contrasty lenses don't have that problem.