Originally posted by twilhelm Des and BruceBanner summed up the Pros for the 20-40 pretty well. At the last wedding I shot, I used the 20-40 on the K-1 and it worked out great (I fully tested it before to know where the sweet spots were). The 20-40 is one of my favorite lenses and I rarely leave home without it.
Not long ago I picked up a DA40 just because I wanted to try it. It was so compact on my KP that I just purchased the DA21 for the same reason. I’ll be giving the DA21 the workout in March for the Single In Group.
Yeah, I am still working out my completely safe FL and Aperture combinations in conjunction with certain LR lens correction and vignetting removal tools/settings. For awhile it looked to me like you would have to shoot a little wider than the focal length you wanted and then do the vignette treatment and then perhaps crop in slightly (losing perhaps 6mp) to completely kill the vignette. For example, say 28mm was what you have set up the shot for, then move to 26mm to give a slight safer buffer, then come editing time you will still achieve 28mm shot at a loss of 6mp.
However, recent testing and I'm not so sure. I've been testing the 20-40 on my K-1 with a 55-77mm step up ring which can take my 77mm cpl or Nd. It's too early to say but it feels as though using the lens anywhere between 25-35mm and no cropping in is necessary, complete vignette removal is possible across those ranges from f3.5 to f8 at least.
I have a landscape shot in mind today and will test further and report back.
Originally posted by nocturnal The HD DA 20-40 Limited retired every single prime I had in that focal length including the SMC DA40 f2.8 Limited, I still haven't sold the DA40 yet as it is great for astro and great wide open but it has sat in the drawer for too long now. I prefer the images from the 20-40 for all other things than astro though.
Have any of you used it close up? It is fantastic! I discovered this whilst playing with it after just getting it, I took photos of a nice glass of cider and the tins I poured it from and the 3d pop, colours and creamy bokeh were outstanding. None of the primes did any where near as nice a job
BTW I hate anyone who calls it a 'walkaround' lens
, this to me smacks of a poor photographer taking snaps of rubbish
.... I otherwise have it as one of my landscape trio trying to make proper works of art to print large.
Yes a couple of times (K-1, FF Mode);
(KP, aperture stacked);
(KP)
It really is nice for close ups on both platforms.
What many forget about crop sensors vs FF is that the aperture may stay the same and let the same amount of light in, however in terms of DoF, using the HD DA 20-40 on the K-1 has a clear advantage. If we compare the two, f2.8 on the KP is giving a DoF more akin to using the lens at f4.2 on the K-1. If using f4 on the KP it's like using f6 on the K-1. (multiply whatever aperture you have/are using with the 20-40 on the KP by x1.5). Whereas on the K-1 f2.8 or 3.5 is just that. You will always get greater subject isolation with the K-1 than the KP... because physics. For example, if using the lens on both systems below at those settings you'll get a similar FoV and depth. It's arguable that because the K-1 is stopped down more at f6 rather than f4 it will carry a higher IQ across the frame vs the f4 on the KP. Or... if we set the aperture of the K-1 to being f4 also it will give a greater shallower DoF which can be more useful for subject isolation than what the KP can achieve at it's f4.
KP+HD DA 20-40
20mm
f4
K-1+ HD DA 20-40
30mm
f6
= roughly the same FoV and Depth to an image.
KP+HD DA 20-40
20mm
f4
K-1+ HD DA 20-40
30mm
f4
= Same aperture settings and FoV however the K-1 will have a shallower depth and shot greater subject isolation (and typically greater creamier bokeh etc).
So the lens becomes really quite useful on the K-1 for those instances that this stuff matters. What I have found however is you need to take care when focusing on close range things when using the K-1. Often it will fail to lock on with AF, manually overriding it seems to show that it can focus on things quite close up it's just the AF can't.
Edit: Oh and one last thing. I think distortion is generally pretty well controlled when using on the K-1. I have a friend who has a Sigma 20-40 FF lens that he uses on the K-1, and he's done a few portraits with it and have seen some pretty extreme distortion going on, even in fairly central parts. I've seem to manage to get away with a lot more wider angle shots with the HD DA 20-40 on the K-1. It could be I am just not going quite as wide as him (perhaps keeping 25mm as my widest vs his 20mm etc), I haven't done close comparisons, but perhaps this is also a good thing and keeps the portrait stuff a little more acceptable. Some distortion examples of the K-1+20-40 (ff mode of course);
mm unknown, pretty wide though I think, about 25mm
forehead a little too long but still acceptable for the purpose of the shot
23mm, as long as the subject is fairly central distortion should be fine;
I think it's something you need to be worried more about in portrait mode than landscape shooting.