[barondla]

Nice info southlander. Sounds like the 135 is the one to get.
thanks
barondla

[Lowell Goudge]

I have both the M135 and the M200. The 135 is the superior lens by some margin, IMO. Quite sharp when correctly focused at F5.6 to F8. Its rendering can be very attractive.

M200 not as sharp at any aperture, tends to fringing and lots of CA in oof areas, and can struggle a bit with contrast. Though I found using a circular polarizer noticably helped contrast and saturation. With care, can take some nice photos but not the strongest card in the M series pack. Also 200mm focal length on APS-C is where the need for good tele technique seems to really kick in. On a Q though, even a 'normal' 50mm lens demands tele technique!

M200 can be OK at very close range in my experience and has nice bokeh when used that way, as long as no bright spots in background to bring out the CA's.

To me, that really seems to be the issue with any of the K/M series lenses. Finding the best for fringing and CA.

As for focal length and fringing, I have found a couple of interesting points relative to technique. The first is that when using a cheap V5 eye loupe and holding the Q like a DSLR I find the shake reduction seems over sensitive, and I get better shots with the focal length setting set down a little, I.e. I shoot between 105 and 115 for a 135 mm lens and about 160-170 for a 200 mm lens

Secondly I find fringing is most apparent on slightly missed focus shots, using the 4x focusing aid is a big help, but takes a little technique to manage 4x focus zoom with a FF equivalent lens of 750-1000mm

[southlander]

I find fringing is most apparent on slightly missed focus shots, using the 4x focusing aid is a big help, but takes a little technique to manage 4x focus zoom with a FF equivalent lens of 750-1000mm

Exactly what I have discovered with the various M tele lenses I have. You only need to have focus a little out (maybe even still just within the outer bounds of the available depth of field) and the aberrations quickly become noticable. Contrast seems to be another victim of slight mis-focus. Nail the focus exactly and aberrations diminish dramatically and contrast also lifts. A few (as in 2 or 3) millimetres on the focus ring can make all the difference. When I can I now use live view with focus magnification. That's ok if the camera is on a tripod but somewhere between damned difficult and impossible if handholding with a long lens (eg 300mm which is really 450mm on APS-C, so 9x magnification, and then layer on top of that 10x live view focus magnification so 90x magnification in total), whilst handholding the lot around a foot (30cm) in front of oneself in order to view the rear screen). Even if the K-3's focus peaking at 1x magnification makes you think a long lens is focussed correctly, shift to 10x and I generally find that further focus fine turning is necessary.

I had thought quite poorly of the M200 but then spent a day with it in Melbourne late last year. I worked hard that day on accurate focussing and discovered it was a lot better that my initial opinion.

The first half of this post on my photo blog was with the M200: Melbourne by Twilight | Photo Morsels

There's a section towards the bottom of the post where I describe the camera gear I used, and lo and behold, I commented there about the need for accurate focus!

PS I need to update my signature - I've just received a M400/5.6. Now I'm really going to get pushed on technique!

[mtux]

Oh man, I just bought the M 135mm f/3.5 on fleabay, just because of this thread.
I hope it turns out to be a good lens on the Q. Otherwise it have to be a good long lens on my K-30.

[Sidorian]

The M 135mm was the first adapted lens I tried with my Pentax Q and it has worked out great, especially for handheld shots. Keeping it at f/5.6 or f/8 limits the purple fringing which can quickly get excessive.
The other adapted lens I use is the DA 55-300. Its impressive for the ultra zoom and has allowed me to take some shots of birds for identification. However, it takes a lot of patience and skill (which I lack) to get truly worthwhile. The attached photo is an example of the DA 55-300 at 300mm.