low_contrast VS high_contrast lenses

[poilu]

I checked back my files and it seems the contax file I used for the comparison was a modified one so all this theory was based on sand.
Sorry

[Nesster]

Thank you for this illustration - the contrast differences are clear in the histograms and photos.

So putting your statements together: a low contrast lens, when auto contrast in pp is applied, can give the appearance of a high contrast one, but at the price of lost information.

[KhanX]

Thanks for your test

[kds315*]

Thanks for that very good point + explanaition!

This is what Zeiss made so famous: high sharpness + high contrast = high acutance. Today it might even way too much for some DSLRs...

[Orio]

[Nesster]

Now that I'm thinking of it - perhaps flare is one of the differences in contrast behavior. I have an old hazy lens Franka which simply refuses to give anything but thin negatives... because the internal flare is so high it destroys the contrast towards the left side of the histogram. I see that sort of behavior in the three examples.

Towards the right, I'm not sure what would cause a drop in the peak with the Jup?

[Orio]

[LucisPictor]

[ChrisLilley]

[F16SUNSHINE]

The comparison of these three lenses is quite striking. I think Carsten nails it.

[luisalegria]

Very interesting comparison !

And this has changed my thinking, it does not seem that low contrast out of the lens can be completely compensated by post-process.

[poilu]

[Rob Leslie]

[poilu]

[poilu]

[Orio]

[Rob Leslie]

[quote="poilu"]

[estudleon]

Tha high contrast of the zeiss, may can confusion about the sharpness of the three lenses.
Zeiss always expresed that the sharpness is different to the contrast and, with pictures, emphasized that the contrastier image seemed to be the sharper, but didn't it.
I not say that the zeiss isn't contrastier, I put over the table that the image form the jupiter have more detailes in some areas. Look at the red area in the center, all of the things (plants and the wall) present more detail in jupiter's image. I can see more in the jupiter's picture than in the zeiss one in the red area. And then, Because the jupiter is less contrast than zeiss is less sharp too? I don't think so. May be, as in the zeiss illustrations, that jupiter is sharpness but less contratier than the zeiss.
The high contrast of the zeiss impede me to know the real sharpness of that lenses.

[poilu]

[Rob Leslie]

I think such tests of lenses are useful but to prove any theory or judge a lens one has to do ones best to produce an image that ‘Matches’ whatever other one you are testing it against.
To do the same RAW conversion or a ‘Default’ one will of course always produce a different result. The difference may be the lens, it may also be a very slight change in the light you did not notice, or could be a silly as the camera shutter speed being different by a few percent.
Digital exposure is very sensitive so shooting in any auto setting could produce a different result. If (More likely) the shots were done in manual, then who says f8 on one lens is exactly the same as the other lens? And again how do you know that light hasn’t just changed by 1/6 of a stop?

The present example shows that the 3 example images all have a very slightly different FOV, so are in fact recording 3 different scenes. Such a slight difference is enough to say that the exposure for all three cannot be exactly the same. A look at the three histograms confirms this difference in exposure. IMO it isn’t showing anything else.
You don’t think that dark land mass top of frame in the first two shots is going to alter any recorded exposure?
I think all the ideas and theories put forward are very good and well worth considering, however it does seem the simplest and most obvious one has been ignored?

[Nesster]

Here's a good short article on flare and contrast:
http://www.luminous-landscape.com/columns/sm-03-01-12.shtml

I note that in older lenses, Zuikos had the reputation of using higher contrast to compensate for a slightly lower resolution. How much of that is slander, I'm not sure, but I do get a different feel from Zuikos than e.g. Nikon or Takumar. In modern AF lenses, I feel the Pentax 16-45 does this sort of thing - it hides its lack of resolution with contrast.

[estudleon]

Yes, Nesster.
Not only zuiko. LEICA did it too. My personal tests said me that elmars and olds summicrons were better in constrast than in sharpness (never matched the 90 pairs of linesp/mm) while eg the Konicas hexanon 50/1,7 at F/8 matched the 110 pairs of lines in the center - down to 80's in the borders, and had low contrast
If you look to the rendition of the summiluxes at the borders, they are bad in sharpness but so-so in contrast, and the same with the summicrons 50/2 collapsibles (not the rigid that is best).

[estudleon]

Rob Leslie
I think that all of us know that the talent is better than any lens. But in the forum we trait this themes to know more of the characteristics of each lens. Play the game.

[patrickh]

This has been an incredibly informative thread and I think I even understand some of it. I think at least part of the problem is that the sensors involved have relatively limited dynamic range and that is where future developments have to go if they are to keep us moving forward. We need the histograms to stretch further and have fill in both extremes (detail in the shadow and highlights). At that point we will be able to make some fairly definitive comments on "micro" and "macro" contrast, resolution and acutance. The main effect for me of these samples is to demonstrate that mid-day sun offers a dynamic range that is much too wide for any sensor to handle properly - all of these shots have blown highlights and impenetrable shadows. There is a strong color cast to the Jup that conceals some of its strengths. The Zeiss still manages to show its class. The canon makes me wonder where modern development of lens design has really moved forward.


patrickh

[Orio]