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Lens contrast and dynamic range

Taz

Active Member
Could it be that lenses with the most contrast are not what is really important on digital camera?
If a non multicoated lens like a old Helios lens is used to photograph a high contrast scene it adds light to the shadows and takes away a bit from the highlights. This is much like what you get with a high dynamic range image prior to tone mapping.
The low contrast of the lens allows a greater illumination range to be captured by the limited 12 bit digital capture of most cameras.
In post processing the low contrast can be restored along with the details in the shadow areas. This is easy with the x3 fill slider or other high dynamic range tone mapping software.
I think the important characteristics for lenses on digital cameras is good micro contrast, sharpness , low CA, and the least amount of distortion.
 

su_chan

Member
helios lenses

I don't want to say too many words...
Here are some results made with SD14 and russianmade Helios44 58mm Lense:
1,2 and 3 are f2, ___ 4 and 5 f11.
I adore old glass on new cameras..
 

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su_chan

Member
very interesting indeed as far as technical terms are of interest.
It helps understanding how lenses are made
The results however are estimated by human eye. And that is what counts
in my opinion. Lense flare though is an interesting effect
and uncoated glass gives sharper results however. I personally prefer
aplanat type lenses: Symetric 2 pairs of same achromats. They work so well!
And they achieve great microcontrast. My 135mm is 100 Years old now
and still best choice for Macrophotography with bellow...
 

Taz

Active Member
Very interesting. I always thought the Helios images were special. I did a lot of pixel peeping and discovered that there is more contrast in areas of detail but less contrast overall. None of my brighter coated lenses are as sharp.
 

jesito

Well-Known Member
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Taz, this may be due to the fact that old lenses were designed for 35mm film. This means that being digital sensors smaller (not talking about FF) some parasitic light can flow around the sensor thus reducing contrast. In some other camera forums, I've seen people adding some kind of frames to reduce the backside of the lenses/adapters to avoid the parasitic light coming into. According the results, it seems to improve the overall contrast and bokeh.

A pointer to a Olympus spanish forum where they describe the framing (Olympus suffer more of that effect because the smaller 4/3 sensors):

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Regards,
Jes.
 

ombud

Member
Your images surprise me regarding the excellent bokeh and almost no Chromatic Abberations...which you usually get from older anlaog lenses a lot.

The sharpness is fantastic though.

Well Done !
 
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