I also have the Tamron SP 60-300 f/3.8-5.4. I used it frequently on my Nikons (FE2, FE, F2, EM, FM) during the 80s and 90s and it played nicely with all of them. Image quality is OK. Better IQ in the short end of the range. For long time, this was the only truly long lens I owned so I used it quite a bit for the 300mm capability. At this end of the zoom I found IQ to be adequate for my needs. Some of my disappointment with images at 300mm is due to me and my technique. Sometimes it was just my lack of skill/ignorance using too slow shutter speeds handheld. Sometimes it was because I had no other option than to attempt handheld at 1/60sec (at 300mm). However, images from those times when I used the tripod, good shutter speed, good light, etc. the images were reasonably good, sometimes downright great. Often a bit lower contrast than my "better" lenses (that I've acquired more recently). On film, sharpness was good in center, and good enough toward the corners (for a cheapskate like me). On digital, I found sharpness is less, across the zoom range. Still a usable lens given its useful attributes (zoom range up to 300mm, reasonable sharpness, tolerable weight, 62mm filter size, and adaptall-2 flexibility). I bought it and used it for wildlife photos -- 300mm was the key selling point. I know I've used the macro capability on that lens, but don't remember nuthin about performance.
I have other Tamron adaptall lenses. Mostly zoom, but a couple primes as well. The only other zoom I can recall right now is the 35-135 f/3.5-4.5. I used that one quite a bit on the Nikons duirng 80s and 90s as well, but can't remember anything particular about performance. I just remember it delivered satisfactory images and I used it quite a lot. I do remember it never gave me images with the sharpness and/or contrast quality I was getting with some of my prime lenses, or with my Minolta HiMatic-E. The Himatic (40mm f/1.7) really stunned me. On my Nikons, I would use my 50/1.8 (amber coating) or 50/2.0 and they gave better sharpness and contrast than the Tamron 35-135. So did the 35/2.8 and 105/2.5 Nikkors. But these are not fair comparisons, are they? I bought the Tamron 35-135 back in the mid 80s to be a standard walking-around lens. The camera bag would often just contain the FE2 with 35-135 attached (and some filters, cable release, batteries, tiny notebook). For some reason, back then I didn't go for a Nikon zoom in that range and just got the Tamron. I've acquired some Nikon zooms since then
Now, the little Tamron 28mm f/2.5 is definitely not up to my standards. I got it back in the late 80's as well and used it with film. I've also tried it on digital more recently. I like the size and handling of this little lens. The 49mm filter size is convenient. and I really want to like this lens, but image performance makes that untenable. It's just too soft. Sharpens up a bit with smaller apertures, but for a 28mm prime lens from a manufacturer that has demonstrated their ability to make a genuinely sharp lens, it never quite delivers. I suspect that the softness at f/16, maybe even 11 is from diffraction? Regardless, the end result is more softness than I'd like. While it's not fair, I compared an image made with my Tamron 28/2.5 and my Elmarit v4 28/2.8 just to quell my ADHD brain and the need to see a satisfying image from a 28mm prime. Ahh, that's better now.
Truly the most disappointing of all Tamron lenses I've ever tried is the autofocus SP AF 20-40mm f/2.7 (in Nikon mount). But, that one's not an adaptall-2 lens. Whew! Because it's truly awful awful awful.
I can already tell I'm going to search through the lens cupboards and find my other adaptall Tamrons. Might be a fun walk down memory lane.
