All Forum Comments
Comment by sorted78 posted on Scanning Negatives at 31/03/2012 - 08:19
Thanks for posting the samples - it looks as if it is in very good hands!
For completeness, here is a summary of the questions/answers referred to above:
1) The lens shows up as f/2.4 instead of f/2.5 on the camera when using it with Pepe's PK/A mount. I think that the lens showing up as f/2.4 instead of f/2.5 is a limitation of the Pentax KA mount as opposed to any of the Tamron equipment. I've used Adaptall lenses with the PK/A mount without any problem. There is more information here but effectively the KA mount has a discrete set of hard-coded aperture values and 2.4 is as close as it can get to f/2.5.
2) I think the auto-man switch on Adaptall lenses works the same way as in Takumars (Auto mode when the A is visible) but can't remember without trying it. I found the auto mode by trial and error and left it there when using it with a K or KA mount. You should be able to tell by removing the lens from the camera and setting the aperture wide open (f/2.5). In auto mode, the diaphragm should be closed, in manual mode, it should be open.
3) The PK/A mount causes the camera to intermittently display F-- when using this lens. If this is the case, you may need to clean the mating face of the PK/A mount (particularly the region around the electrical contact pins) with acetone or a similar solvent. This is a common issue with PK/A mounts and apparently is caused by thread-lock used on some of the screws in assembly leeching through and preventing electrical contact on the mating surface of the mount.
Comment by sorted78 posted on Tamron Adaptall 105 2.5 (boxed, excellent) at 31/03/2012 - 07:52
I believe (and I am not infallible, as my good friend Gareth will testify) that K lenses which survived into the M era adopted the M style of describing a lens, for example 1:4 50mm instead of 1:4/50.
I believe that this is the only difference between the 1:1.2 "editions".
Comment by sorted78 posted on FS: SMC Pentax 50mm f/1.2 at 28/03/2012 - 14:51
Comment by sorted78 posted on FS: SMC Pentax 50mm f/1.2 at 28/03/2012 - 06:09
Comment by sorted78 posted on FS: Sigma 50mm EX DG f/2.8 AF macro lens (boxed, excellent) at 22/03/2012 - 09:01
Comment by sorted78 posted on WANTED: Tamron Adaptall 2 PK/A Mount at 21/03/2012 - 17:52
What tends to get ignored in reviews is that lenses have a character and are intended for particular applications.
I think that the DXO results are interesting, but it's worth bearing in mind is that measured performance figures such as those from the tests carried out by DXO only tell you a few, very specific things about a lens. Understanding how these parameters relate to oneanother and the other parameters involved in lens design requires quite a detailed understanding of optics/lens design (more so than I have, anyway).
I work in a different branch of engineering, but from my experience, it's often very difficult to measure the things that are really useful to know, and conversely, the things you can measure easily aren't always very helpful.
As such, if it was possible to just measure the performance of a lens and know categorically how good it was, that would deprive a lot of us of the enjoyable hobby of trying them out for ourselves!
Comment by sorted78 posted on DXO test some Pentax Lenses at 21/03/2012 - 15:01
For me, the main attraction of the DA15 is its small size and light weight. I use it as part of a small, light travel kit or when taking the time to appreciate shooting with primes. The 12-24 is much more versatile in terms of FL, but is comparatively huge, so doesn't end up in my camera bag so often.
Comment by sorted78 posted on Would you swap a 12-24 for the DA15mm? at 20/03/2012 - 19:59
Thanks for looking.
Comment by sorted78 posted on Tamron Adaptall 105 2.5 (boxed, excellent) at 18/03/2012 - 05:51
Comment by sorted78 posted on FS: Pentax-M 50mm f/1.4 (excellent) at 17/03/2012 - 08:44


I found a Minolta Dimage Scan Elite 5400 in good condition that I purchased. This is a dedicated film scanner for 35mm format, and is very well respected. It ranks among the best 35mm scanners along with the Nikon Coolscan scanners.
They also have the advantage that you can load up a whole strip of negatives or a number of slides in one go. If you have a lot of film to scan, I'd certainly recommend one of the Mionlta or Nikon options, as it makes it easy to get quite good results for a lot of frames and then with a bit more time and effort, it is possible to achieve really good results on your favourites.