cl: no f-stop exif with coded lens and m adapter

[eev776]

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You cannot see f stop on Leica CL from M lenses. 

I wonder if you can see f-stop on SL2 though.

Edited April 29, 2020 by eev776

[scott kirkpatrick]

An L-mount camera corrects for distortion (barrel, pincusions, moustache -- corrections which change depending on distance from the center of the image) by putting correction parameters into the DNG file, where post processing may use them to provide a correction.  Adobe tends to do this automatically; Capture One lets you evaluate the correction and decide how much of it you wish to use. DarkTable default and Sandy McGuffin's AccuRaw let you skip this postprocessing.  But I don't think of that as being "in" the raw data -- it's a post processed correction.  In the JPEG it is automatically applied.  Vignetting and color shifts at the edges are applied in the raw data before it is written to the DNG file.  The reason for the different handling is that the distortion corrections need to be applied separately (and perhaps differently) to the R, G, and B planes of the demosaiced image, which is most easily done in post processing.  DNG has a standard field, WarpRectilinear, where this data is stored.  The vignetting corrections can be applied to the intially gathered pixels.

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[lct]

41 minutes ago, motard said:

I can`t see any distortion ( neither barrel nor cushion distortion ) in any of them. Hard / impossible to find distortion if there are no straight lines like the marking of the parking place in my picture

I would watch more carefully. 

[nicci78]

2 hours ago, eev776 said:

You cannot see f stop on Leica CL from M lenses. 

I wonder if you can see f-stop on SL2 though.

You can. But it is a bad estimate. Through the external light sensor guessing. 
APS-C cameras such as TL2 or CL do not need to apply different software corrections according to real aperture. 
However full frame one such as M10, SL or SL2 do need to apply a different one for each aperture. Because vignetting will be stronger wide open than close down. 
Hence the additional external light sensor. 

[Boojay]

2 hours ago, eev776 said:

You cannot see f stop on Leica CL from M lenses. 

I wonder if you can see f-stop on SL2 though.

Could we just make this less complicated by remembering that changing aperture on a M lens is a purely mechanical action, as such there is no communication to the camera body (any body be that CL SL or an M) to know what the actual f stop is.

 

 

 

 

[gteague]

24 minutes ago, Boojay said:

Quote

Could we just make this less complicated by remembering that changing aperture on a M lens is a purely mechanical action, as such there is no communication to the camera body (any body be that CL SL or an M) to know what the actual f stop is.

 

 

it would have simplified it for me if i had realized there's nothing electronic in an m lens. which i should have known, but for some reason i associated the coding with contacts. now i see that all the coding does is tell the camera which lens it is--it's only an identification number.

i just now mounted the 75mm m lens onto my panasonic s1 and although the manual focus works much the same way in that on the s1 you press a button to get magnification, the peaking is quite a bit better than the cl although that might be due to the gorgeous evf on the s1. on the cl, if you magnify the image, it's nearly impossible to see peaking dots as there might only be a half-dozen or a dozen spread out over the whole image but on the s1 at the same magnification, there's plenty of dots.

i took two dozen shots on a walk last night with the cl and the 75mm and i plan to make the same walk and shoot the same stuff with the s1 and the 75mm and we'll see what the results are. one of the absolute best features, for my purposes, on the s1 is the ex.tele function which, at the press of a function button, lets me cycle from normal fl to 1.4x to 2.0x meaning the 75 will be a 75, a 105, and a 150mm. in my semi-rural area with paranoid landowners, that's a big benefit to have the extra reach at the sacrifice of resolution instead of quality as a digital zoom does.

anyone using m lenses on an s1 or sl2?

/guy

Edited April 29, 2020 by gteague

[eev776]

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1 hour ago, nicci78 said:

You can. But it is a bad estimate. Through the external light sensor guessing. 
APS-C cameras such as TL2 or CL do not need to apply different software corrections according to real aperture. 
However full frame one such as M10, SL or SL2 do need to apply a different one for each aperture. Because vignetting will be stronger wide open than close down. 
Hence the additional external light sensor. 

That is great news! 

I need to see f-stop on my M lenses, it makes me wanna get SL2 for sure.

[dau]

26 minutes ago, gteague said:

have the extra reach at the sacrifice of resolution instead of quality as a digital zoom does

You do realize that this is exactly what a digital zoom does, don't you?

[gteague]

3 minutes ago, dau said:

You do realize that this is exactly what a digital zoom does, don't you?

maybe i should have said image size. the teleconverter function on panasonics is most definitely not the 'digital zoom' fake pixels mode found on other cameras although panasonic offers it as an option. if they were the same, why separate them?

/guy

Edited April 29, 2020 by gteague

[Boojay]

56 minutes ago, eev776 said:

That is great news! 

I need to see f-stop on my M lenses, it makes me wanna get SL2 for sure.

Please see my reply to you above.  

1 hour ago, Boojay said:

Could we just make this less complicated by remembering that changing aperture on a M lens is a purely mechanical action, as such there is no communication to the camera body (any body be that CL SL or an M) to know what the actual f stop is.

 

 

 

 

 

 nicci78 said  You can. But it is a bad estimate. Through the external light sensor guessing.

In case you are still in any doubt I have an SL2, today for example I was shooting with 135mm 3.4 apo, wide open, possibly took around 20 shots without changing aperture once, exif on SL2 reported 3 or 4 different apertures, not once was it correct at 3.4.  

 

Edited April 29, 2020 by Boojay

[eev776]

20 minutes ago, Boojay said:

Please see my reply to you above.  

 

 nicci78 said  You can. But it is a bad estimate. Through the external light sensor guessing.

In case you are still in any doubt I have an SL2, today for example I was shooting with 135mm 3.4 apo, wide open, possibly took around 20 shots without changing aperture once, exif on SL2 reported 3 or 4 different apertures, not once was it correct at 3.4.  

 

Well, I guess Leica going to work on improving this to be accurate in SL2.

[nicci78]

8 hours ago, eev776 said:

That is great news! 

I need to see f-stop on my M lenses, it makes me wanna get SL2 for sure.

Don’t be excited. It is a rough estimate. And it is very very inaccurate. 
Leica stopped writing f/ stop estimate with M10 for this reason. Even if the camera has to guess it anyway, to function properly. 
 

For example, it was frequent for the SL2 to report f/0.95 to f/2.0 when Summilux-R 80 is used at f/1.4 
Any change of lighting condition can trump the light sensor. 
When you close down an M or R lens, the estimate will go wrong for sure. 
 

 

[jankap]

 I have bought a Metabones lens booster for Canon EOF lenses on Sony 6500 (APS). The booster supports the lens functions like AF, f-stop, but even calculates the equivalent focal length. The 50mm is a 35,3mm in the Exif data.

[frame-it]

10 hours ago, eev776 said:

Well, I guess Leica going to work on improving this to be accurate in SL2.

and how would they do that if the lens is mechanical ?

[Boojay]

1 hour ago, frame-it said:

and how would they do that if the lens is mechanical ?

Exactly... I gave up trying to make that clear.

[ramarren]

Stepping back a little from the discussion of how the various Leica cameras embed the lens aperture into EXIF data: I've often looked at the lens opening in Lightroom but, honestly, it's never really made any difference at all to my photography what lens opening I used after the fact.

Why is what the EXIF data contains with respect to lens opening such a big deal? Exhibition audiences, clients, and photo buyers are concerned with what the photographs look like, not with camera information. I need to know the lens opening when I'm making an exposure, not afterwards.   ...??... 

G

[nicci78]

It’s just to know, you see ? 
No big deal. 
No need to know afterwards, except for statistics. But no real world use really. 
 

[dau]

1 hour ago, ramarren said:

I need to know the lens opening when I'm making an exposure, not afterwards.

That may apply to you when you know what you're doing. We beginners would like to have the critical settings on record, so that later we can see on the monitor how our decisions affected the resulting image.

[lct]

1 hour ago, dau said:

That may apply to you when you know what you're doing. We beginners would like to have the critical settings on record, so that later we can see on the monitor how our decisions affected the resulting image.

Manual lenses are made for beginners as well but there is a learning curve. Oldies like truly yours remember approximately the aperture they use or record them in a notebook or elsewhere. Too painful? Better choose L lenses then.

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[ramarren]

Dau: Perhaps I simplify too much. I nearly always remember my lens opening ... It's always two stops down from wide open, as a rule. I only go to wide open when I need more light to get a shorter shutter time, or stop down a lot to increase DoF, and I can tell both of those situations from the photos I make. When I make adjustments like that, it's rare that I need to remember it much later since I remember the principle of what I'm doing rather than the specific settings... 

G