[doc58bc]

Recently rediscovered the Tamron SP90 1:2.5 (BB52) in Adaptall mount for Pentax. Left from film days. I have been using it on the K70 in the manual focus mode (obviously). This Tamron is sharp wide open and gets to be amazing as it is closed down.
For personal carry around, non-commercial shooting, I set K70 at MF, TAv, 1/250s, F5.6, ISO Auto (100-25600). Focus through viewfinder and shoot!

[blackcloudbrew]

Nice, I have had this lens for a number of years + the matched 2X extender for it. Honestly, while I know it to be sharp etc., I've done very little shooting with it. Your post makes me wanna get it out and do some work with on my K-1. Might want to post some images you took with it.

[pepperberry farm]

I have both the previous model (52B) and the next model (72B) - and both are amazing lenses...

[Serkevan]

I have the AF version (52EP apparently?). It is a great lens and works wonders for portraiture as well. Considering I got it for 35€, I cannot be happier

[kypfer]

My #52B was acquired second-hand back in the '80's and has followed me around, with several changes of Adaptall-2 mount and the Flat-Field 2x, ever since. It's as though "Catch-in-Focus" was designed for this lens! As a "tool for the job" it just keeps delivering

[EDstrg87]

i have the 52BB version in KA mount; it's one of the lenses that i will never sale for any reason.

[pres589]

It seems like an excellent lens for portraits and just general carry as well as macro stuff. I have a copy of the 52B and found it very nice to use both on film and on APS-C digital with a little help from Live View to get focus nailed wide open. I may go looking for an AF version of the same in place of the FA 77 on my shopping list.

[Serkevan]

It seems like an excellent lens for portraits and just general carry as well as macro stuff. I have a copy of the 52B and found it very nice to use both on film and on APS-C digital with a little help from Live View to get focus nailed wide open. I may go looking for an AF version of the same in place of the FA 77 on my shopping list.

I talked myself out of a very reasonably priced FA 77 by looking at some of the better pictures I took with the 52EP. Most are portraits that I won't upload because they contain family and friends, but I guess my brother's mouse will do

The image is not the best (low light, so ISO 1600 and shutter speed 1/100 is too slow for a vibrating little ball of fluff), but it shows off the bokeh and general AF performance quite nicely.

[pres589]

Yeah, about that AF, obviously it's an older screwdrive lens from the film era, but is it overly slow? Is it pretty accurate without a lot of hunting?

[Serkevan]

Yeah, about that AF, obviously it's an older screwdrive lens from the film era, but is it overly slow? Is it pretty accurate without a lot of hunting?

It's actually pretty fast if you're "around" the area already. Infinity to MFD takes a while (more than a second): it's a 1:2 macro, and there's almost a 90º turn between the MFD of 39 cm and 60 cm. There's another 90º between 60 cm and infinity.


It's very accurate (provided AF adjust is fine) at short to medium distances, and I haven't noticed too much hunting unless lighting is pretty dim. One consideration is that at long distance, let's say focus point further away than 10 meters, accuracy does suffer and at least my copy has the hard infinity stop calibrated at... about 50-100 meters away? Shooting at infinity f/2.5 is NOT going to give you sharp distant subjects.


All in all I would say the AF is serviceable enough but nothing stellar; it wouldn't be my first choice for difficult action but it certainly does the job.

[pres589]

Very odd about the stop at infinity on your example. Mine doesn't do that at all although I can't remember when I last shot with it while shooting for distant subjects. I would imagine there's a way to fix that although it might be rather involved. Good things to think about if I do go this route.

[Serkevan]

For what it's worth, it's not really a problem; at f/5.6 or smaller apertures it's already more than good enough unless you're supremely pixel-peeping.