DA and some elder lenses on Pentax K-1
As there is some speculation on which DA lenses that will work on the Pentax K-1 Full Frame, I will present some photos showing the extent of dark corners with some of the popular DA zoom lenses. As one can see, all DA zoom lenses have some degree of
vignetting. Some will give dark corners all through, while some, like the 12-24 and 16-45 will be less affected towards the long end. In fact, the 12-24 is fairly good already at 17 to 18 mm.
By zooming in one step (1,4 on the K-1) the dark corners
are gone on all images presented. One can, of course, choose the auto-crop function on the camera, but that gives a smaller image than necessary. I would recommend to shoot at FF and resize on your machine. That is if you are able to evaluate what to cut while
looking through the finder. If you always want to be on the safe side, then turn on the crop mode.
I have added some primes and zoom lenses from the film era, some dating back to the first K-bayonet lenses from the mid-70s. I am also testing
M 42 Takumars from 1957 and on. The test photos may be presented on the Takumar pages.
For more about the variety of lenses for K-1: see Pentax K-1 FF: 2016-
Please note that these comments are for those not using D FA lenses. So far, I have tested the D FA 100/2,8 Macro, the D FA 28-105 3,5/5,6 and the D FA 150-450/4,5-5,6. They are
all high-quality lenses with fast AF, beautiful colours, and extreme sharpness! AND WR.
K-1 + DA 12-24/4:
An 18-24 wide angel on full frame. Tested at 20mm against the FA 20/2,8 and the DA 16-45/4. It looses against both in sharpness, but not by much.
K-1 + DA 16-45/4:
This lens needs cropping from 16 to 22 mm. So, it is recommended as a 22-45 wide angel on K-1 FF. Problems with shadows on built-in flash images made it less suitable on K-3 and elder built-in-flash-cameras on wide angles.
Tested for sharpness
on 20mm against FA 20/2,8 and DA 12-24/4. Very sharp, especially at 5,6, and keeps good results even in corners.
K-1 + DA 17-70/4:
Usable when cropped, but not recommended on FF compared to the 16-45. Functions as a 26-105 zoom when cropped, which is a good range. However, it is known for a hunting SDM AF. Mine is useless on AF at 70mm.
K-1 + DA 18-135/3,5-5,6:
Good on aps-c, usable on FF, but not the one I would pick first, as it needs more cropping than any of the other DA lenses presented here.
K-1 + DA* 50-135/2,8:
A very sharp lens, though soft wide open. Better at 4, and shines from 5,6. Needs cropping all the way.
AF: SDM system on this lens is known to be a problem on items produced before 2012, as it is very slow or even nonworking. I had given
it up, as it seemed dead. BUT: With the K-1, it started to work again! It sometimes needs to be kickstarted, but once alive, it works like a dream!
K-1 + FA 20 2,8:
To compare, here is a prime 20 mm from the early '90s. Good sharpness even wide open, but improves step by step. Excellent for keeping sharpness from foreground to background. Mine comes out a bit light compared to other lenses, making it seem to lack
some contrast, at least wide open. Better from 5,6.
Some vignetting even here. Disappears from f 4.
K-1 + FA 28-70/4:
Here is another FA lens, produced from 1991. Sharp from f 6,3, but not as good as the FA 28-105/3,2-4,5. It even loses against the F 28-80, though not by much. Some vignetting at 28 and 35.
K-1 + F 28-80/3,5-4,5:
A not so highly valued F-lens from 1987: the F 28-80 macro zoom. But tested against the FA 28-70/4 and the FA 28-105/3,2-4,5, it comes out with a bit higher center sharpness than both at 35 and 50mm. On the long and short end, it needs 6,3 or 8. Loses
sharpness towards corners. No visible vignetting.
K-1 + FA 28-105 3,2/4,5
Another FA zoom from the early 90s. Praised for its colour rendition. Sharpness is average to good, while a hunting AF (on some samples) made the total score rather moderate on Pentax Forum. However, we are talking K-1 here, and AF is fast and accurate,
although more noisy than D FA lenses.
The 3,2-4,5 works like this: 3,2 from 28-30, 3,5 from 30-40, 4 from 40-80 and 4,5 from 80 and up.
As a walkaround lens for the K-1, it outperforms the FA 28-70 and the F 28-80 from 50mm+ and has better corner
sharpness all over. And no dark corners.
However, I repeat: these comments are for those not owning the D FA lenses. Compared to the D FA 28-105 3,5/5,6, this FA lens very clearly looses in sharpness from center to corners. Once one compares,
this is highly noticeable.
K-1 + K 24/2,8:
Produced from 1977 till 1984. Known to be good at shorter distances, but a bit soft on eternity. This seems to be verified here. Plus too little contrast. DA 16-45 would be a better choice.
K-1 + A 50/1,4:
A highly praised normal lens from 1984. But it needs 2 or 2,8 to shine, and keeps improving at least to 8,0. Manual focus.
K-1 + M 200/4:
A very sharp lens from 1976. Good colour tones and contrast. All manual. Tested for sharpness against F 100-300/3,5-4,5, F 70-210/4-5,6, FA 28-200/3,8-5,6, DA 18-250/3,5-6,3 and DFA 150-450/4,5-5,6, all at 200mm. Beats all except the latter, but comes
out about even with the DFA from 5,6!
K-1 + FA*300/4,5:
This lens has impressed me since I got it back in the 90s. Easy to use, good AF, though a bit noisy. Very sharp.