[southlander]

I tested the 20mm on my A7-II, but this was just a short test between M20/4, FA*24/2, DA15/4 (on A7-II in crop mode). Except from the size I was not convinced by the M20/4, however, since it was really just a short test I decided not to give up and repeat this although a bit more thoroughly. I really liked the output (colour, flare, microcontrast, distortion) of the DA15, but for my taste it's simply not sharp enough for stunningly sharp landscape shots, and it's not a full frame lens. I happened to also have my 31 with me, and this lens is nearly perfect, I wish we would have such a gem in the 19-21mm range weighing maximum 400 grams. I guess the new 15-30 will be stunning, however, weighing that much is not an option for me since I am mostly on foot and in the mountains. Has anyone a comparison M20mm f/4 vs FA 20-35mm f/4 on full frame?
I have also considered using the multimount (I guess it it fullframe compatible) and giving either the Voigtländer SL II - N 20 mm / F 3,5 Color Skopar or the Zeiss Distagon T* 21mm F/2.8 (which is 600 grams) a try.

I'll test the M20 vs the FA20-35 next week on a Sony A7 when back from my trip to Japan. Based on what I know to date, the 20-35 will be a clear winner on resolution particularly beyond medium distances. But the M20 can do such amazingly saturated colours. My M20 is only really ok on resolution through to mid distance. It struggles at infinity and isn't landscape grade at infinity. Possibly sample variation, I can't say with only the one copy to test. But good for images where the point of interest is in the foreground bcause of the colours.

[GeneV]

I remember being happy with my copy in the film days. I need to put it on the A7R a bit more. I'd love to find a 20mm color Skopar from the time Voigtlaender was making them for PK. The 40mm was my go to for street shooting on film.

[CreationBear]

Be sure to check out the K20/4 if you're really drawn to primes--it's a big lens, a little shorter but a bit heavier than the FA 20-35, I think. They don't come up for sale often, but there was one here on PF that lasted a lot longer (and went for less money) than I would have imagined.

[bassek]

Any Pentax made 24mm or 28mm would perhaps be better price/performance. But they are not 20mm...

Seb

[northcoastgreg]

My M20 is only really ok on resolution through to mid distance. It struggles at infinity and isn't landscape grade at infinity. Possibly sample variation, I can't say with only the one copy to test.

Yes, it could be sample variation, as I don't have the same issue with my M20. While my FA 20-35 is a tad sharper than my M20, the differences are slight and probably not significant. My FA 20-35 does have better contrast, with intense FA-style color rendering. My M20 has a more subdued and subtle palette, with lovely Pentax old-school rendering. I have no idea how either lens performs on FF, but as to corner sharpness, my money would be on the FA 20-35. Both lenses suffer from a fair amount of distortion, which will only be worse on FF.

[southlander]

I'm somewhat tempted to retrade my current M 20 and try to buy another one, but with the current full frame frenzy, I'll stick for now with the bird I currently have in my hand. I did have one go at adjusting the infinity stop in case that was out, but didnt seem to have any significant improvement. I might have another go at that when testing on the A7 this coming week.

Interesting in the palette obsevations Greg. My M 20 is one of the most colourful lens I have!

I just love my FA20-35 on the K-3. It relegated my Tamron 17-50 to the shelf. The copy I bought on Fleabay didn't come with the matching hood and the hood is damned hard to find. I was in a small suburban Tokyo camera shop yesterday morning and lo and behold I found a used FA20-35 hood in an oddments box. Missing the polariser hole cover but the right hood all the same. What was the chance of that!

And my son held up something from another oddments shelf and asked what it was. Replied, a teleconverter. On closer inspection it was a Pentax mount Kenko PZ-AF 1.5x converter in top condition. Nice find for around USD15 equivalent. He also found a clean working K1000 for next to nothing. Looks like it just needs the foam around the mirror box replaced.

---------- Post added 30th Apr 2016 at 08:39 AM ----------

I can point someone in the direction of a K 18mm I spied a couple of days ago in a tiny pokey secondhand camera gear shop in Tokyo if anyone happens to be passing by that way!

Wasn't real cheap, asking price was around 35,000 yen (USD350) or so.

[Abbazz]

Has anyone a comparison M20mm f/4 vs FA 20-35mm f/4 on full frame?

I have posted a quick and dirty comparison there: Comparison between a Few 17-21mm Lenses

The Pentax-M 20/4 is a wonderful little lens. Its main drawback is that it doesn't deliver sharp extreme corners on a full-frame image unless stopped down to F/16. Of course, the lens has many other qualities besides corner sharpness and most of the time there is no point in having tack sharp corners in a picture anyway!

Cheers!

Abbazz