Hass lens - contrast or dynamic range query

Sim2 · Mar 22, 2010

Q.G. said:
You can only have one film response per scene (per film even) though.

So image, if you will, one scene, one film, one 'processing', but (by some magic) two frames on it, one exposed through an MF lens on MF format, the other through an 35 mm format lens on 35 mm format.

What, would you say, will they both show? How, if at all, will they differ? And why?

This is more or less the point I was originally asking, perhaps better expressed than I did. :rolleyes:

Although I have not, as yet, shot the exact same scene on 35mm and MF, I have shot recently on MF similar pictures under controlled studio lighting to what I have previously shot on 35mm.

These similar scenes are on the same film, same dev procedure. Though granted not scientifically exact replications for a research paper but...

Where I have expected highlights to be "burnt out" on the 35mm neg, they are showing detail on a MF neg. Similar for shadows. Which led me to wonder if the medium format lens, as a bredd irrespective of brand, has less contrast than a 35mm lens or is it the Hass lens that has less contrast or transmits a greater range of tones.

Thanks for all the replies, will have a better read after I've had some food!

Oh, the zone system and dev'ing/printing for contrast etc are not new concepts to me and for the purposes of this discussion are not that relevant - this is the light transmitted by the lens onto the same brand of film, processed in the same procedure yielding differing results. Real world relevance may be negligible but for me, at the moment, it is interesting that I get the results I do and try to understand the reasons why.

More science welcomed!

keithwms · Mar 22, 2010

Sim2 said:
Where I have expected highlights to be "burnt out" on the 35mm neg, they are showing detail on a MF neg. Similar for shadows. Which led me to wonder if the medium format lens, as a bredd irrespective of brand, has less contrast than a 35mm lens or is it the Hass lens that has less contrast or transmits a greater range of tones.

It is unlikely that the contrast is significantly different through the two lenses. What is different is the level of tonal detail and how you meter with the two different systems.

Sim2 · Mar 22, 2010

Have just been trawling the dusty depths of my brain back to the dark ages when I started a City and Guilds photo course, in the theory section I vaguely remember a correlation between resolution and contrast for lenses. A by product of designing a lens for very high resolution was that it would inherently have a very high contrast e.g. a copy lenses. As contrast was reduced (or made manageable) for real world applications, the resolution went down. The key was to balance the desired resolution with acceptable contrast.

If this memory is correct, it could be assumed that as the resolution of an MF lense does not need to be as great as a 35mm lens, the contrast might be less i.e. greater detail in shadows or highlights.

This might have real world implications, in that the same scene shot on MF might be an N development for desired range, but due to the increased contrast of a 35mm lens that might need to be an N-1 development, all of which, other considerations aside, could be relevant in how a scene is metered, shot and dev'd. My spot meter might be better set to -4 stops for medium format rather then -3 stops for 35mm.

Not convinced but still thinking about this, might even take some pictures!

Oh and I do not believe that all lenses transmit 100% of the light, all lenses lose light in transmission, some lenses are sharper than others, some are softer than others irrespective of format.

Neil Grant · Mar 23, 2010

keithwms said:
Ok. We are making progress understanding each other

I'm still not agreeing with that. But the key to resolving our little dispute is that it may make little sense to think of the lens and the film independently. Maybe we should speak only of system resolution, to keep things simple.

Along the lines of what Q.G. was saying (and I was trying to say previously but apparently not with enough clarity), consider the following thought experiment:

Suppose that you photograph the lace of a dress from some distance. Suppose that the lace is bright white and the underlying cloth is black.

The camera with less system resolution will tend to average the two regions. The fine highlights and the neighboring blacks will tend to be averaged together to produce greys. Hence less brightness range is recorded. A TTL metering system will see grey and make an exposure recommendation based on that.

The camera with more system resolution will do a better job distinguishing the two regions, hence more brightness range is recorded.

I can't think of a way out of this effect, so again I assert, format size certainly does matter when it comes to tonal transitions.

For what you are suggesting the tonal discrimination of the system would have to be unfeasbly low, or the camera exposure criminally incorrect. No photo imaging system is going to average these out like a light meter. A better system - ie one typically recording with a larger film may show an improved dynamic range - but this is hardly likely to be a problem with your simple black/white dress/lace target (it's 2d and therefore evenly lit). A better system could be sharper (film halation/irradation less obvious) and will definitely show better tonal resolution. That is, small changes in tone (shadow, highlight and mid-tone) are all reproduced more faithfully, and it is these subtle changes that allow us to perceive depth in a 2d photo.

film_man · Mar 23, 2010

My humble opinion is that some lenses are indeed more contrasty than others. Or perhaps it should be the other way around, cheap and bad lenses are generally less contrasty and have a "worse" colour rendering due to more imperfections in the glass (and obviously are less sharp). This is far easier to determine with a digital camera as you can easily test it and I have seen it with my own eyes, put two lenses on the same camera, same scene, same exposure and the result is different sharpness, contrast, tonality and colour balance, which can be anything from insignificant to quite obvious depending what you use.

After all, you can make bits of glass that increase or decrease contrast, just think of sunglasses.

However, the main difference in the question asked is that the larger the negative the more information is recorded. If you have ever used digital you can see this easily, a smaller sensor generally has less dynamic range than a larger one. This is because, in simplistic terms, more information is crammed into a smaller space, therefore you have less information to begin with.

This is why in the digital realm people go about how "full frame" is sooooo much better than "crop" sensors. I have indeed also noticed that my 6x6 negatives will record a better range of tones and detail than my 35mm negatives and I regularly shoot both side by side, same film and using the EOS camera as a meter for my Bronica. So exposure is the same too.

Of course I might be completely wrong, but so far my understanding of this has worked out pretty well for my kind of shooting!

ruilourosa · Mar 23, 2010

Well Well

this is not a ignorance matter

Also this is not a photography matter

i would like to talk about photography, not a obvious technicality

keithwms · Mar 23, 2010

ruilourosa said:
i would like to talk about photography, not a obvious technicality

I am sure that we all eagerly anticipate the informative discussions you will start on the subject of photography and apologize for taxing you with these obvious technicalities.

Should you be generous enough to post some of your photography, I am sure that you will find that we have ample members who will appreciate it... not for reasons of proficiency in the area of obvious technicalities, but rather for its artistic merit.

Note that if certain threads containing too many obvious technicalities bore you so, you can simply click on the "ignore thread" button at the bottom of a post.

Hmm, what's that I see there, an "ignore user" button as well...

keithwms · Mar 23, 2010

Neil Grant said:
No photo imaging system is going to average these out like a light meter.

Actually, that wasn't my point. I am imagining a scene with finely detailed highlights and shadows and simply suggesting that unless you meter those carefully (i.e. not with a typically low resolution TTL in-camera meter) then the boundary won't have the snappy white/black transition. A more practical example might be a snowy landscape scene with deep shadows and bright highlights... obviously if you just rely on a meter and don't place things correctly then you get blah grey mush.

But on this subject of 'averaging' due to low resolution... if the whole system (lens and film) lacks the acutance to render the fine boundaries between white and black (in my lace example), then you will instead get grey boundaries. No?

Anyway, enough, it was just a thought problem, really.

~~~

In any case, the original poster needs to do careful comparisons under very controlled circumstances before we devote so much time to theorizing!

Sim2 · Mar 23, 2010

keithwms said:
Note that if certain threads containing too many obvious technicalities bore you so, you can simply click on the "ignore thread" button at the bottom of a post.

Hmm, what's that I see there, an "ignore user" button as well...

Lol! nice reply.

:munch:

Sim2 · Mar 23, 2010

keithwms said:
In any case, the original poster needs to do careful comparisons under very controlled circumstances before we devote so much time to theorizing!

Actually, I do agree with you here - I probably do need to do some "scientific resting of this. However, before I do that, I thought it useful to ask the opinons
of those who might have trodden this path before and could pass on the wisdom! As is normal, there seems to be conflicting suggestions from all sides. I do seem to be getting to an answer that satisfies me and my way of shooting/dev/printing which may not correlate with others experiences - it is the nerd in me that is interested in the why...
I do agree that shooting is better than philosophising about technicalities but I also know that a level of technical knowledge can assist in making the most of any artistic "vision" or intention.
Whatever, I see my exploration continuing, no doubt with more random questions - fell free to ignore at your leisure! But thanks for all the inputs. More welcomed.

Sim2.

keithwms · Mar 23, 2010

Well, I, for one, enjoy random questions

Random insults, on the other hand, I am willing to ignore....

Neil Grant · Mar 24, 2010

keithwms said:
Actually, that wasn't my point. I am imagining a scene with finely detailed highlights and shadows and simply suggesting that unless you meter those carefully (i.e. not with a typically low resolution TTL in-camera meter) then the boundary won't have the snappy white/black transition. A more practical example might be a snowy landscape scene with deep shadows and bright highlights... obviously if you just rely on a meter and don't place things correctly then you get blah grey mush.

But on this subject of 'averaging' due to low resolution... if the whole system (lens and film) lacks the acutance to render the fine boundaries between white and black (in my lace example), then you will instead get grey boundaries. No?

Anyway, enough, it was just a thought problem, really.

~~~

Your boundary areas will have a subtle transition - unless they are line-art. The rendering of this subtle transition would occur with a smaller range of changes in density with a lower res system but it will still be there. The rendering will be more 'stepped' - analagous to a pixellated photo if you like.

fschifano · Mar 24, 2010

This whole discussion got started when the OP asked if the Zeiss lenses for Hasselblad have more contrast than some other lenses. Well, maybe, maybe not. I have a few CF lenses and they do render subtle differences in tone better than some other medium format lenses I've used. The effect is particularly noticeable when there are two tones physically adjacent to each other, but without a very large difference in density. The Zeiss lenses for the 'blad seem better able to separate these tones out in a very crisp, but smooth manner. Does that mean they are capable of delivering a wider dynamic range? Not really. Dark is just as dark, light is just as light; and dynamic range is the space on the line between the dark and light. The Zeiss lenses are able to resolve the differences at a higher spatial frequency is all.

TriXfan · Mar 27, 2010

The forgotten variable -- no one has mentioned that 120 size film is not identical to 135mm film (ie, in contrast range, etc) except perhaps in certain emulsions. Therefore, even with identical development, two different sized films with the same name will not automatically give you the same dynamic range.
KB

fschifano · Mar 27, 2010

Actually no. At least when I mentioned my observations, I was doing so based on using Tri-X in both my Mamyia C220 and my Hasselblad with a variety of focal lengths. I've also used it in borrowed Mamiya and Pentax 645's, so there's no variability in the film. Exposures from all were pretty darned close to perfect, and I have a routine for developing Tri-X down pat.

TriXfan · Mar 27, 2010

I do agree with you Frank, but OP was comparing 35mm Canon lenses to his Hasselblad lenses, and therefore using different film formats.
KB
"Have got used to the replication of the dynamic range of a scene with my 35mm Canon lenses, using the same lighting set-up, film and dev on similar scenes with the Hass lens I am finding a greater dynamic range i.e. more detail in the shadows that previously would be blocked up black and tone in brightest areas that might have been "clipped" white on the 35mm."

panastasia · Mar 30, 2010

Sparky said:
... - but, well- lenses - all lenses - have INFINITE dynamic range.... QUOTE]

This statement is confusing. I think it should be restated as: - all systems (camera, lens, film, developer, etc.) are capable of producing INFINITELY VARIABLE gradations within the dynamic range - ranging from total black (Dmax) to total white (paper base color).

Infinite dynamic range implies that the number of "zones" can be extended (expanded) infinitely. Maybe it's true in theory if a "zone" was considered to be less than 1 f-stop change equivalent - infinitely small tonal changes.

Q.G. · Mar 30, 2010

panastasia said:
This statement is confusing. I think it should be restated as: - all systems (camera, lens, film, developer, etc.) are capable of producing INFINITELY VARIABLE gradations within the dynamic range - ranging from total black (Dmax) to total white (paper base color).

Infinite dynamic range implies that the number of "zones" can be extended (expanded) infinitely. Maybe it's true in theory if a "zone" was considered to be less than 1 f-stop change equivalent - infinitely small tonal changes.

If you talk about the range from one photon to gazilions photons that can come through a lens, a lens indeed has a (virtually) infinite dynamic range.

How big the range is that film or paper can record without being blank or blocking up is another matter.

You could make use of the (by comparison) very large dynamic range of the lens by exposing film to the same scene using different EV settings, though it will indeed not expand the range film will be able to record.

Hass lens - contrast or dynamic range query

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