I'm using several SMC Pentax-A 645 lenses on my dual Mirex A7r outfit with excellent results. One of my lenses is the 45-85mm zoom. It's an excellent lens, especially at the wider end. The problem is that it's very heavy. It's not the carry weight that's the issue. Rather, the Mirex adapter tilt mechanism uses friction rather than gears to hold the lens in position, and this lens is so heavy that it drags out of position unless I really crank down on the screw that is supposed to lock the tilt in place. I can work around the problem... but I have spoiled some shots due to not noticing unwanted tilt.
I'm toying with the idea of adding a smaller, lighter SMC Pentax-A 645 55mm f2.8 into the mix. That would give me lighter 645 lenses at 35mm, 55mm, 75mm and 150mm -- a nice range of focal lengths for what I do.
Unfortunately, there's not much information out there about the SMC Pentax-A 645 55mm f2.8 lens. There are a few user reviews at the Pentax Forum. Some of these comment on field curvature issues. I'm curious to know if people who've used the lens are also seeing this: http://www.pentaxforums.com/lensreviews/SMC-Pentax-A-645-55mm-F2.8-Lens.html
Have you used this lens enough to be able to comment?
* Is the field curvature issue really as pronounced as suggested at the Pentax Forum (above)?
* Do you think field curvature will be less of an issue because I'm not (mostly) using the whole image circle?
* I'm really happy with the other SMC Pentax-A lenses I use. Is this one in the same league?
I can't answer your specific A 645 55mm lens question, but being a Mirex user myself, surely you've been able to rotate the adapter so that the lens must be tilted up?
That way, in landscape mode, gravity works to your advantage. Forgive me if you're already working this way.
Apologies if this rather lateral suggestion is off-topic however my experience with the Pentax 67 55 f4 SMC lens has been so good that I wanted to add that into your mix. Clearly such an approach would require a 67 to 645 adapter. My experience is with it on the P645D and also P67 II film camera.
I also agree with your findings on the FA45-85, however I often turn to the P67 55 since it is such a good performer (and available at great prices).
sirimiri, turning the adapter sideways is my go-to solution for most cases. There are some situations where I need it in the default position, and it's a small pain keeping it "sideways" because you have to rotate it back to neutral to release the lens. These are small complaints in the grand scheme of things, that's true.
lenticular11, I looked very long and hard at the 67 55mm f/4 lens, and would love to try it one of these days. I've heard nothing but good things. Unfortunately, it's almost as heavy on its own as the 45-85, which defeats the purpose of cutting down the load on the adapter! Out of curiosity, have you tried the Fotodiox 67 to 6545 adapter?
The 55 f4 SMC with genuine P67-645 adapter, filter but no hood is 845g. I don't have the hood within 'finding distance' just now but it's pretty light. 😃
45-85 with filter and hood is 985g
Another fantastic lens to consider is the A35 f3.5, weighing only 517g.
Photos of all lenses attached.
So, essentially you are correct!
I have seen some views on the Fotodiox adapter on the Pentax Forums MF section and they seemed generally favourable.
Incidentally, I've just watched the Olympic 4x200 Womens' 200m Freestyle Relay: congrats to the USA, Australia 2nd!
I have an SMC Pentax-A 645 55mm f2.8 that I originally bought to use on my Canon (with Mirex). As I recall I wasn't too impressed and it went into hiding in my photo cabinet. I just took it out and I'll make an effort to take some shots with it over the next few days on my A7r2 with the Mirex and a EF-E adapter.
I took a chance, and a near mint SMC Pentax-A 645 55mm f2.8 is winging its way to me right now from Japan. I'll also post results from my own testing to the thread when it comes in. It's also going to be used on a Mirex adapter (two actually -- one for P645 to EOS and one for EOS to Sony E) so the collective feedback and results on this thread may be a useful resource for people who are looking at this lens in future.
The side-by-side photo of the P67 55 f4 next to the P645 A35 f3.5 is a bit daunting! That 55 is massive! I've heard nothing but good things about it, so I'm sure it's worth hauling around.
This is the back end of the Basilica of Our Lady Immaculate in Guelph, Ontario. It came like this out of the camera because I was able to get 17mm of rise and about a degree of swing out of the dual Mirex adapters. That much rise is really pushing it, but with two adapters you can avoid mechanical vignetting by splitting the rise between the two adapters. There's a bit of distortion at the top of the steeple, but I don't find it objectionable. The little bit of swing I applied makes the whole face of the Basilica nicely sharp.
Just as I had the shot lined up was ready to go, an elderly parishioner pulled up and parked right in the middle of the frame bottom! This was late on a Saturday afternoon, so the ENTIRE parking lot was empty. She didn't even realize I was making a photograph, and was happy to relocate....
My copy of this lens arrived from Japan recently. I had a chance to do some extensive testing and to use it in a real world setting.
I posted my thoughts over at the Pentax forum in case anyone is interested in closing the circle on this post. The bottom-line is that this is actually a good lens in my setup (Sony A7r with Mirex tilt-shift adapters). I can't speak at all to its performance on the medium format camera for which it was designed! However, if you need to cover 55mm in a tilt-shift scenario involving a full frame sensor, and you want a prime lens, then you won't regret getting this lens. It's a keeper. Mind you if you want the flexibility of a slow zoom, the SMC Pentax-A 645 45-85mm f/4.5 is excellent too (just a lot heavier and bulkier).
