28mm Lenses

Back to 1981/1982 again and some 28mm lenses compared, and I think one common misconception turned on its head.

Lens name - MTF value at 10 lpm - MTF value at 40 lpm

Canon FD 89% 42%
Zeiss Distagon 92% 57%
Hoya HMC 87% 47%
Leitz Elmarit-R 86% 34%
Makinon 86% 31%
Nikon E 86% 40%
Pentax-M f2.8 88% 51%
Sigma 88% 40%
Tamron f2.5 83% 38%
Vivitar f2.8 83% 39%
Tokina 87% 47%
Zuiko 91% 51%

The best lenses in the group were the Zeiss, Pentax, Tokina and Olympus. The misconception I refer to is the commonly stated belief that the Pentax 28mm f2.8 design is not a good one. This test confirms my own experience of the lens, that it is in fact excellent. It's interesting that Tokina were excelling themselves as well and are well on a par with the "big boys".

Pentax 28s have always been very good. I have two. An 'A' f2.8 and an 'F' f2.8. The latter is the standard prime on my ist D. The A is nicely made. The F, while being optically excellent is, like all the F series, rather ugly and cheap looking, being made of rather nasty grey plastic!

The Hoya did very well too, I see. Those HMC lenses are much underrated and can be found on ebay very cheaply. I got a 135mm for £7.

Interesting as my personal experience with the 'M' and 'A' series 28s has been slightly dissappointing. I used to have a K mount Vivitar that I much preferred. John do you have decentering figures for the 28s ?

Regards - Steve

No decentering figures unfortunately, but you're right to mention that. Lenses do vary and if we only had one sample each then some of us would be very pleased and some less so.

It would be equally possible for these lens testers to have received an almost perfect Pentax lens and a rubbish Leica one, so skewing the results.

But short of thoroughly testing several samples of every lens, what alternative is there? I don't think anyone, apart from the factory, would have any time or inclination.

John, I agree with your comment, but at the time of these test in the early 80's I think people paid far more attention to these figures and so you would presume that the manufacturers were very diligent in ensuring that 'good' copies were sent for test. Also 28mm was a very popular focal length at the time, so considering the volume sold I would have expected the manufacturing process to be very well tuned.

Do you have anymore comparisons 85mm , 135 ect ?

Regards - Steve

More to follow.....

I have the Pentax A 28/2.8 which is totally uninvolving compared to several of the Vivitar 28mm lenses I own. It's probably the only poor Pentax lens I have come across. Of course, since there are so many different Vivitar variants, the results means little without knowing exactly which they were testing.

Besides, what aperture were these tested at? Some lenses naturally perform better wide open (e.g. Sonnar) while most do not.

Robin - curious to know what you don't like about the 28mm SMC-A - I rather like mine, but I have no experience of other 28mm primes to compare?

One thing I do notice is that - given it is a "standard" length on APS-C - there is a little more distortion than you would expect. But hardly surprising given it was originally designed as a wide angle lens. I'm not saying it's the outstanding lens in my collection, but given I picked it up for £30 I've been pleasantly surprised....

Best wishes,

Jon

They were tested wide open and two stops down, but I have only quoted the two stops down figures.

Hey Jon, I'd have to try it out again; it was a while back. But I just recall being uninspired by the rendering. But I do like the 28mm focal length on APS-C.

Thanks for posting the test results for these 1980's lenses - very interesting.

I haven't used any Pentax 28 mm lenses but I do have the SMC A 24/2.8 and it's a beaut (in my book anyway). I'd love to know what the testers thought of that lens back in the day. Any 24 mm test results from your old mags would be much appreciated!

Thanks,
J

The 28mm lens is the same as the one tested here, just re-released as an A series version.

And as you pointed out, perhaps rather better than its reputation too!