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Coding for CL lenses


huwm

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I have my Pentax-L 43mm Limited coded as a Summicron-M 35mm f/2 ASPH because its age and lens design seems pretty similar. It renders beautifully. 

You can see what if any corrections affect the Summicron-C 40mm by doing a test setup and making the same exposure uncoded and coded to whatever profiles you think will work. Then pick what works best for you and note what will be embedded in the EXIF. The Summicron-C 40 is most similar in lens design to a pre-ASPH Summilux 35 or Summicron 35, I would imagine. Test and see what works. :D

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3 hours ago, huwm said:

I've just acquired a Summicron - C  40mm f2 for my digital CL on the basis of size/quality and have opted to set for 35 f/2 11310/11311

Is that the best bet? 

Newbie

I doubt if lens corrections applied by coding it as 35/2 make any real difference as the lens is being used on an APS-C sensor and most of the corrections will apply to vignetting and other mostly peripheral issues. As Jaap says, coding is really only useful in identifying the lens when you are looking at images in the future ..... in which case choose whatever you fancy. 

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I read jaapv saying this all the time, but in my first hand, empirical testing I see major differences in the DNG files for some lenses and little for others. So i’ve come to set what gives me what I find to be the best profiles for my lenses, based on testing with and without. And I recommend that for everyone who cares. 

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49 minutes ago, jaapv said:

Some lenses, yes, but most lenses need few if any corrections on APS-C. Unfortunately Leica profiles do not correct distortion, which, in practce, is the most useful aspect.

There's definitely some geometric distortion correction between the Super-Elmar-R 15 and the Macro-Elmarit-R 60 ... I was starting a copy session with the CL and realized I had the wrong profile set...  Changing the profile from the SER15 to ME60 had a very large effect in the viewfinder. In general, however, I think Leica's primary thrust in the implementation of lens profiles is to preserve the original rendering intent of their lenses' design on all the various imager chips that they use, rather than to correct all geometric aberration. The gross artifacts of various short focal length lenses are of course the immediate high-visibility target, but more of the corrections are much more subtle compared to that.

I see this on all the M and R lenses that I use. 

The TL and SL lenses use correction with a different intent. These lenses are designed from the ground up to be used with software correction, so they typically have fairly strong simple aberrations when processed without correction. The notion is that simple aberrations are very easy to correct in software compares to complex aberrations (like the infamous "mustache shaped rectilinear distortion" you see so often with ultra wide zooms) and it is much more beneficial to the user to rely upon the software to quell simple pincushion or barrel distortion, or lateral chromatic aberration, than to spend a whole lot more money on more exotic lens designs to achieve zero distortions optically. The Micro-FourThirds lens mount protocols pioneered this approach in the consumer market, and it's been a winning solution to the question of how to get high quality performance to users at the best price, so far. 

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7 hours ago, lct said:

You mean on M lenses, TL lenses or both? Just curious knowing the huge native distortion of some PanaLeica lenses. 

On M lenses, admittedly I'm extrapolating from the way M cameras behave. Ramarran reports differently on the CL.

If that goes for the  SL as well, it makes those two the better platform for M lenses.

I don't see significant distortion on Panaleica lenses, but then I use them as intended with the full hybrid correction. There are some bloggers who weirdly removed half the design by looking at the optical corrections only, but that is tantamount to removing one element from a traditional fully optical corrected lens and then complaining. They are not designed that way, a lens is not just glass and metal any more :rolleyes:.

 

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2 hours ago, jaapv said:

I don't see significant distortion on Panaleica lenses, but then I use them as intended with the full hybrid correction. There are some bloggers who weirdly removed half the design by looking at the optical corrections only, but that is tantamount to removing one element from a traditional fully optical corrected lens and then complaining. They are not designed that way, a lens is not just glass and metal any more. 

Too bad for sharp corners then unless you crop a lot. Here is how a PanaLeica file looks like before correction:

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You will notice if you compare a "PanaLeica" lens of whatever focal length to any lens NOT designed for hybrid optical/software lens correction that the apparent optical focal length of the PanaLeica lens is a fair bit shorter than the nominal focal length if you do not let the software lens correction operate. The software lens correction effectively increases the focal length while doing the rectilinear correction to the nominal focal length marked, eliminating the hard vignetting seen in your example image as well as straightening the rectilinears. 

In comparing edge/corner resolution between optical only lenses and PanaLeica lenses, I would have to say that in most cases the PanaLeica lens was superior, not inferior, but that the wide angle distortion (the stretching effect off-axis on circles and other shapes) was more pronounced. You can't have perfect rectilinear correction without some of that due to the geometry of the physical situation you're trying to photograph being mapped to a plane. One of the best corrected ultrawides of all time, the Hasselblad SWC with Zeiss Biogon 38mm f/4.5 T* lens, does the same thing. 

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9 hours ago, lct said:

Too bad for sharp corners then unless you crop a lot. Here is how a PanaLeica file looks like before correction:

Perfect proof of my post: using a lens with only half of the correction...🙄 You are not supposed to remove the factory digi-optical correction, let alone starting to fiddle with cropping and corrections yourself.

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2 hours ago, jaapv said:

Perfect proof of my post: using a lens with only half of the correction...🙄 You are not supposed to remove the factory digi-optical correction, let alone starting to fiddle with cropping and corrections yourself.

Cover up that breast, it's not meant for my eyes! I was sure you would say that :DLet's robots fix other robots in other words. Iridient Developer result below. Bad robot i guess...

 

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I don't know Iridient, but that looks nothing like any Panaleica lens I know. I'm sure that is not the embedded profile. I guess that is the real drawback of hybrid designs - non-supported  raw developers - or user settings- can screw things up.

When I get home in a couple of weeks I'll shoot a few shots with the DG Summilux 15 and post them.

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11 minutes ago, jaapv said:

I don't know Iridient, but that looks nothing like any Panaleica lens I know. I'm sure that is not the embedded profile.

Never say never. It is indeed. Surrender you cannot win :D.

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I have no idea what you did  as I don't use Iridient but if that were my DG Summilux 25 I would return it to Panasonic immediately. Mine does nothing like that. In fact, it has a weird unsharpness all over the image. Have you dropped it and is it decentered?

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