You haven't mentioned a Macro lens, and if you're interested in macro photography maybe a proper macro lens would be beneficial?

lemmy, is that an ironic statement or a serious one?

Anyway, let's diffuse the emotional aspect by supposing that we were Exakta fans. The Exakta was defunct many many years ago, but there are still masses of cameras and lenses available on the second hand market. In fact a couple of years ago I saw a camera fair stall full of unused camera bodies and lenses, as a collection was released for sale.

The point I'm making is that possibly 40 years after the last Exakta rolled off the production lines, we could still use them today to make photographs, if we should so wish. Far fetched? Well I know someone whose main camera is a Periflex.....

There are so many Pentax cameras and lenses in circulation that the future of being able to indulge in Pentax photography is secure for many decades to come - dare I say for longer than any of us will care about it?

Now I admit that the DSLR may not last as long and could be a stumbling block, but we can't be sure that in 10 years any of the marques will still be with us. Canon and Nikon are losing money. Leica look very dodgy to me. Rollei are gone or all but gone. Samsung are dabbling at the edges but their survival is as part of a huge company, as with loss making Sony.

There could be little advantage in worrying about all of this. What will happen will happen and we'll deal with it when we get there.

In the meantime I'm enjoying my photography and getting on with making the images I like.

In terms of prestige, the Pentax is a product very well made but costed to be affordable in a wide market. In many cases, these sort of products can actually have features or qualities that the more expensive ones neglect or don't do well.

So, for example, the Contarex and Voigtlander SLRs of yesteryear were arguably better made than any of the Japanese products, but in terms of design they were heavy, clunky and out of step with the world. And unaffordable.

The Spotmatic worked slicker, had great lenses and was made well enough to sweep the board clean. It was also smaller, lighter and affordable. Still not cheap though!

I was looking at SLR lenses in the 1980s and when the Pentax ones were as smooth as silk, the Contax ones were very stiff to operate and were not finished as well, regardless of whether or not they were better lenses optically.

But Skoda? No, not even close.

Out of this mass of information then, the percentage MTF value for a few lenses at 10 lpm and two stops down. This shows the high contrast performance of a lens rather than the detail resolution.

f1.7/f2 lenses:
Canon 93%
Chinon 91%
Hexanon f1.7 89%
Hexanon 40mm f1.8 85%
Summicron-M 94%
Summicron-R 95%
Rokkor f1.7 91%
Nikkor 93%
Nikon Series E 93%
Zuiko 94%
Pentax f1.7 91%
Pentax f2 91%
Pentax 40mm f2.8 93%
Ricoh f1.7 88%
Planar 92%

f1.4 lenses:
Canon 87%
Chinon 87%
Hexanon 86%
Summilux-M 88%
Summilux-R 90%
Rokkor 89%
Nikkor 89%
Zuiko 87%
Pentax 83%
Ricoh 99%
Planar 88%

f1.2 lenses:
Canon 81%
Canon L 80%
Noctilux 73%
Rokkor 83%
Nikkor 74%
Noct-Nikkor 80%
Zuiko 90%
Pentax 75%

Yes, the f1.2 was the K lens. My typo, not the magazine's!

To explain decentering, when lenses are made up of many elements these elements need to be in the correct locations and their centres lined up perfectly. Decentering can be measured and shows how far out of line some of the elements are. The higher the figure, the worse the lens.

5% is very acceptable in any lens.

Those figures show the accuracy of centering of the elements. I'll leave it at that for now while we absorb that information.

Clearly the star is the SMC Pentax-M 50mm f1.2, with virtually perfect construction.

Average decentering figures for some 50mm lenses:

Canon f1.8 8%
Chinon f1.7 5%
Konica Hexanon f1.7 5%
Konica Hexanon 40mm f1.8 15%
Leitz Summicron-M f2 16%
Leitz Summicron-R f2 3%
Minolta Rokkor f1.7 15%
Nikkor f1.8 12%
Nikon Series E f1.8 7%
Olympus Zuiko f1.8 8%
Pentax-M f1.7 2%
Pentax-M f2 6%
Pentax-M 40mm f2.8 12%
Ricoh Rikenon f1.7 13%
Zeiss Planar f1.7 3%

Then the f1.4 lenses:
Nikkor: 5%
Zuiko 7% Pentax-M 11%
Rikenon 7%
Zeiss Planar 8%

And the f1.2 lenses:
Canon 9%
Canon L 7%
Hexanon 7%
Leitz Noctilux f1 5%
Rokkor 16%
Nikkor 2%
Noct-Nikkor 5%
Zuiko 5%
Pentax-M 1%

I have in front of me the 13 issues of Creative Photography from 1981/1982. The thing still of interest here is the extensive lens tests included, which I think were originally produced by a Swiss magazine.

The X-Ray photographs of Pentax, Leica, Nikon and Canon 50mm lenses are interesting in that the canon stands out as being almost totally plastic. All the others are held together with a mass of metal under the plastic exteriors. The designs are very different for sure!

The tests measure many things, such as MTF values at 10, 20 and 40 lpm, MTF graphs, decentering, distortion and MTF graphs as well.

I'm going to follow up this post with a few figures for you. These are what I really call lens tests!

I'm always happy to help people, and from time to time I run Saturday morning beginners sessions at ADAPS. If I were to do it for non-ADAPS members then I would have to hire the rooms and make a small charge per person to cover the costs.

We're talking West Manchester here and probably a Saturday morning from 10am to 12noon, although there's not a sharp cut off time. I have laptops and a digital projector available so most things can be covered.

If enough people were interested we could lay something on. A couple of intensive hours can cover quite a lot of ground.

On here the facility already exists. Do what some already do - if you need some specific help, send me a PM so I can assist before you "go public" on the forum.

Makinon was one of the low cost brands of the 1970s and possibly 1980s. There were hundreds of different 135mm f2.8 lenses available, some good, some not so good.

If you get a good example of any of them it will no doubt be acceptable or maybe quite good in some cases.

It could be a very useful portrait lens if it makes the skin tomes more flattering.