philip_pj wrote:
Just looking around, the same phrases appear prominently across the regular websites: 'great distortion control', 'sharp image from edge to edge without distortion'. Jono Slack adds the missing piece: 'There is little or no distortion (although this is probably corrected in software)'
And indeed it is, as pointed out by sharp-eyed Lloyd Chambers. He noticed the missing distortion data in the SL lens data sheets: 'Leica flags distortion correction as mandatory in the EXIF info, which means that the MTF charts are pure fantasy, impossible to realize once distortion correction is applied.'
'There is no distortion graph in the datasheet and the datasheet make no mention that correcting distortion (required!) will significantly degrade MTF over at least half of the frame. Leica can design a lens however they want, but they ought to at least be honest in their marketing materials.'
The MTF 'should' be post correction but who knows? BH FOV specs show a true FL of 27.99mm, post-correction presumably. The curious thing is that relative distortion is shown in the APO 35/2 Summicron-M sheet (it's a steady one percent barrel).
The SL sheets also lack vignette data, so likely another 'stage two - the s/w' deal there as well. (for comparison, the Otus 28/1.4 (2015) carries a steady gain in field distortion and peaks at 1.3% barrel. CZ have long argued for a 2% max figure for distortion.)...Show more →
Yet Chambers raves about the SL 28 image quality (except for flare). It can’t be worse than the 28 Summicron-M can it?
highdesertmesa wrote:
Yet Chambers raves about the SL 28 image quality (except for flare). It can’t be worse than the 28 Summicron-M can it?
The problem with the SL lenses I've tried (35, 50, 75) is that they have weak veiling flare resistance. So, shooting against the light robs the very high contrast they are famous for. It's more of an issue with the 35/50 and I was wondering if the 28mm is the same or worse.
Distortion is tricky on the Leica system as Leica applies distortion correction to the DNG files. Most reviewers do no notice this and think lenses have zero distortion. Having said that, both 35mm and 50mm lenses have very low distortion. I will try to find a 28/2 APO DNG file and remove the DNG correction to see the real distortion.
philip_pj wrote:
The curious thing is that relative distortion is shown in the APO 35/2 Summicron-M sheet (it's a steady one percent barrel).
Because Leica does not bake in distortion correction for M lenses. I'm still using LR6 standalone and if I want distortion correction for an M lens, I have to manually click the box and it will then pick the lens profile for correction. Maybe the current version of LR does that automatically? That said, the M does automatically apply some vignetting correction in-camera to DNG files to emulate the look of how a given lens would have vignetted on film, plus edge color shift correction.
Like the Q, the SL system's optical quality is, for better or worse, 'software assisted.' I believe all mirrorless systems are doing this.
rscheffler wrote:
Because Leica does not bake in distortion correction for M lenses. I'm still using LR6 standalone and if I want distortion correction for an M lens, I have to manually click the box and it will then pick the lens profile for correction. Maybe the current version of LR does that automatically? That said, the M does automatically apply some vignetting correction in-camera to DNG files to emulate the look of how a given lens would have vignetted on film, plus edge color shift correction.
Like the Q, the SL system's optical quality is, for better or worse, 'software assisted.' I believe all mirrorless systems are doing this....Show more →)
Hi Ron,
I am not quite sure about that. When I use LR Classic (the latest version), with my Sony Camera bodies including my A1 and my Kolari Vision UT sensor modified A7rII, for my 2 long Sony zooms and all 3 of my E-mount CV lensess I have to click to enable the lens profiles. If I do not, they are not implemented. For any of my Leica M (I believe this includes my Leica 6 Bit encoded lenses when used with the new TTartisan Leica M to NEX adapter), CV or Zeiss M mount and included R mount lenses used on my Sony bodies I have to select them for the profiles to be implemented. For any of my CV (or my Minolta CLE MC 40mm f2 M-Rokkor lenses that lack any lens Profiles I have to select the closest Leica lens profile.
This 28 mm lens handles all sorts of CA extremely well with some post-processing assistance. You can spot those residual traces of transverse CA in a developer that does not bake in a lens profile per manufacturer’s design. It’s a pity this outstanding correction comes at the cost of onion rings in bokeh highlights.
