[pinholecam]

Pentax M20/4; A50/1.7; M85/2 a very versatile travel kit at a very small size

I do think the M20/4 is the closest in size.
Its also wider, 20mm vs 22.5mm eq.
Surprisingly, less field curvature compared to faster f2.8 20mm lenses.
Perhaps last 1/10 of the frame is less sharp at f8.
No real issue at f11.
Corners are not good at f8 but imo f11 its do-able.
I even printed a shot at f11 to confirm. A4 size print.

Use of aspect ratios like 5x7 or 8x10 immediately removes any of the concerns regarding corners too.
The edges and corners also get cropped off when using distortion correction in LR.
Which in my actual real use, I found to be often the case.


The FA20 is a nice smallish lens.

Here it is compared to a Canon FD20 (roughly same lineage type lens) and the size difference is apparent.


and we are not even talking A20 or M20 here.

I commented on its performance here.
https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/285043-what...ml#post3108556

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Last edited by pinholecam; 02-05-2015 at 05:01 PM.

[Sandy Hancock]

Keep an APS-C body and your DA15, along with any other favourite DA lenses. It will add reach for telephoto shots and there will always be a time when a smaller kit is wanted.

[pinholecam]

I largely agree with the comments on K24/2.8

There is a noticable resolution falloff off center.
Maybe 2/5 of the frame per side.
A lot of this can be mitigated somewhat as its field curvature.
So use the off center to focus and f11.
On 36mp FF, I do think it will most likely struggle.


However, nothing is black and white.
The K24 got very good micro contrast and a pop to the images.
Nice colors too.
At f2.8-f4, it does give a subject isolation 'pop' to the subject and I believe that the field curvature has to do with this.
Its also small, inexpensive and f2.8


To me, on 24mp FF, its still a nice lens that I uses regularly.

[lytrytyr]

But is that a function of the A7 or the lens? Could be either, or a bit of both.

The K and A 24/2.8 are retrofocus DSLR lenses,
with a good long register distance,
so they should be telecentric enough
to avoid the problems of the Gauss type wide-angle lenses.

---------- Post added 02-05-15 at 09:07 PM ----------

When I read the thread title, I thought of the Voigtlander and Zeiss primes

Zeiss? Smallish?

When Zeiss have a small lens, like the ZK 18/3.5 or 50/2,
they put it in a really big barrel just because they can!

---------- Post added 02-05-15 at 09:13 PM ----------

and we are not even talking A20 or M20 here.

Aren't the FA 20 and A20 pretty much the same size?

[yusuf]

Tokina 17mm is pretty cheap and small, not a great lens though but not bad too.

[pinholecam]

Aren't the FA 20 and A20 pretty much the same size?

Pretty close.
A20 is just smaller by a bit.
It's the M20 that is really small.

[robjmitchell]

Just use the da15ltd in crop mode!

[clackers]

Just use the da15ltd in crop mode!

You'll lose most of your pixels, Rob...

[robjmitchell]

You will still have 16mp of 15ltd loveliness to play with though!

[chickenandavocado]

Thanks for the responses, I may first try the m20 as it seems to tick the right boxes.. and then see how it compares to da15 in crop mode if I want to sell it!