[CarbonR]

Pentax lenses all have a reddish glow.
The 140F TC is not that exceptionnal, my simplier Vivitar which is shorter (seems to be 3 elements) has the same performance. I am surprised by the Telemore ones : this is not the 7 elements multicoated (7KMC) which is the best one with the Tamron.

[angerdan]

I'm missing fundamental informations:

• Lens model names
• Teleconverter Model names
• Distance from sensor to focus point

Can you please describe what was your motivation for this comparision and what conclusion you have?
What recommendations would you give following your conclusion?

[CarbonR]

Indeed you are right, I've done the process in two separate times and did not add enough info on the lenses :
Pentax K 200/2.5
S-M-C Takumar6x7 400/4
S-M-C Takumar 500/4.5
Tamron 60B 300/2.8

The goal was to see if the Tamron can replace all of these lenses, so all shots are taken with the same view (= different distances) to simulate what we could do on wild birds. With the process done I see taht it is at least similar with the 500/4.5 when on TCx2 (500/4.5 is my short tele for sunsets), with a x1.4-1.5 it is roughly equivalent to the 400/4 I used for sports, and without TC it is better than the 200/2.5 which is at equal distance between Samyang 135/2 and Tamron 300/2.8, so this is useless for me to keep it on a shelf. These tests (I have issued several of them) are done primarily for me according to my needs but I share them if it can give answers to others who would have similar questionnings

[angerdan]

Thank you for sharing the test )

So what do you think how well the Pentax User Review ratings match with your tests?

• SMC Pentax 200mm F2.5 Reviews
• S-M-C Takumar / Super TAKUMAR / Takumar 6x7 400mm F4 Reviews
• SMC Pentax 500mm F4.5 Reviews
• Tamron Adaptall-2 SP 300mm f/2.8 LD IF - 60B Lens Reviews

[CarbonR]

To be honest, I did not read these tests, because the Pentax/Takumar lenses were bought for collection (so I would have bought them being good or not), and the Tamron is my second, the first one had been bought for pure curiosity years ago but I was too fond of the Takumar and did not want to keep the Tamron unused. At this time I only had the K100D which is less demanding on lenses quality and I did not see the difference. Some months ago I remembered of this lens and wanted to give it a second chance.

The other point is that each individual lens has a history, out of factory they can have light variations and after decades these variation can improve, so you can have a bad chance and get a lens that is not at the level you can expect. By testing in my conditions of usage I ensure to know how the lens I have handles, not how the average lens should handle in average situations