M mount Black&White sensor

[Artur6]

While the GXR can't make a guess about the aperture used, because there's no external light sensor like on the Leicas M8,M9, I noticed that the color shading is practically constant across the aperture range. Obviously, isn't so with pure vigneting and some compromise has to be made for finding a 'quiet good' setting for the most used apertures of each lens.
I haven't done serious tests or controls and my settings below were decided at a glance, so to speak, and probably could be improved :

MY1 - CV Heliar 15/4.5 - periph. ilum: +3 ; Color shading : R= +1 ; B= -2 ( all corners ) Distortion : 0
MY2 - Zeiss ZM 25/2.8 - periphf. ilum: +2 ; Color shading: R=0; B= -2 ( all corners ) Distortion: 0
MY3 - Zeiss ZM 35/2 - periph. ilum: +1 ; Color shading: R=0; B= -1 ( all corners ) Distortion : 0

 

[Tom Caldwell]

Thanks Artur,

Good to see someone posting some settings they have used for lenses. I think everyone understands that this is a work in process. Therefore it is taken for granted that there will be some cross testing and exchange of ideas. Possible refinement.

I started buying up Russian lenses for a Samsung N10 in anticipation of the A12 mount release. By the time the A12 arrived it had grown to an obession. Originally LTM lenses it morphed into M42, then FD and PK (I already had some PK slr lenses from yesteryear).

Having far too many lenses ever to even remotely fit on the present version of the GXR lens database I simply did not try. However a quick look tells me that the setting can be applied generically outside the modes and therefore remembered in the PASM settings for the lens actually installed. Must have a play with them for my own interest.

Somewhere it wa noted that you can use the lens settings not only to "correct" an individual lens but also to deliberately create an effect. So I suppose in-camera created "fish-eye" and vignetting with or without colour halo is possible. Not that this is big-deal as it is easy in post processing these days. More "just interesting to know".

Tom

 

[Katsunami]

That is two "confessions" already
...
So who does individually set up lenses?
Tom

So, I lied. I do have lens profiles, but not for correcting lens problems. (First, I assumed that this is what you meant by using lens profiles.)

The only difference between them is the name / focal lenght for the EXIF data, and the possible slowest shutter speed I've set:

CV 15mm/4.5 (eq 23mm): 1/30 sec
CZ 21mm/2.8 (eq 32mm): 1/30 sec
CZ 35mm/2.0 (eq 52mm): 1/60 sec
CZ 50mm/2.0 (eq 75mm): 1/60 sec
CV 75mm/2.5 (eq 112mm): 1/125 sec

All profiles use Auto ISO 1600 and Aperture Priority. This way, I set the aperture, and leave the camera to do the rest. The ISO will stay at 200, unless the camera reaches the set slowest allowed shutter speed. Then the ISO will be increased up to 1600. Only then, if need be, will the shutter speed get any slower.

So, basically: the shutter speed is always as fast as possible, while the ISO is as low as possible. For general shooting, that's exactly what I want. Shutter speed does not have influence on most pictures (unless you want to play with freeze/blend stuff like water and movement) and ISO must always be as low as possible to avoid noise.

That's how I use lens profiles, but I've not set up any vignetting or color corrections. I simply didn't find it necessary yet. I've not seen any disturbing color shifts or vignetting yet. If I shoot white walls or bright blue sky, I may see some needed corrections, but I don't. Maybe I'll look into it some day.

If I get a new lens, I just load one of the profiles, save it to a new slot, and adjust the shutter speed and name/focal length and that's it. If I get many lenses, I may name one of the profiles "Random Lens", set the focal lenght and aperture to 1, and minimum shutterspeed to 1/60.