Old vs New

Your right there Andrew a lot of purple has been added to the 100% crops? It's still there in the galvanized posts on the original, but the worst part (and I can't see if you have any) is usually black paint it turns purple so do gray roof tiles. Setting WB to shade or even daylight might fix it. I'm going to try after with my f/1.7. Some of the old M series also add a lot of purple. My 28mm f/2.8 does.

i have a pentax-a 70-210 f4 and a 18-250 pentax DA

the old defeat 10-0 by sharpness colours the new one...
I know they are simply two different lenses... the 18-250 have too many compromises BUT...
I think your 55mm is just a lemon...
I have for example, a takumar 50mm 1.4 first version that's SUPER SHARP already from 1.4

http://www.flickr.com/photos/elpimps/4743122245/

check that photo... k10d + 50mm 1.4 AT 1.4 ....

It's possible that the Kood grey grad might not be completely neutral too.

Andrew

Tried the Ricoh f/1.7 and the Pentax A f/1.7 outside and the Pentax is much better for sharpness. Used f/5.6 throughout.

The Ricoh does go purple with AWB, but isn't too bad set on Daylight although still too much green/blue.

I was surprised that the Pentax was better at AWB rather than Daylight. Seems a bit yellow/green at daylight.

Ricoh
AWB : Daylight
Pentax
AWB : Daylight

So ........ have I got this right?

* the 18-55mm kit lens is sharper than a Pentax 50 (for some folks)
* a Pentax 50 is sharper than a Rikenon 50 (for some folks)
* a Rikenon 50 is sharper than a 18-55mm kit lens (for some folks)

I suspect that the reality is that all we've proven is how hard it is to test lenses and get reliable results.

Andrew

Part of the problem is likely to be variation within a particular lens type. Some people have ditched their kit lens quickly, and some people (including me) continue to be amazed at how good it can be.

With older lenses we also have the issue of how the lens has been treated in the 30 years or so since it was made.

K.

Yes, this is the correct result. It is what we call "user error" or subjective variance.

Because, overall, the 18-55mm kit lens is demonstrably NOT sharper than an FA 50, or any other Pentax 50mm for that matter. Comparing MTF measures we find that the 50mm beats the kit at f/1.4, f/2, f/2.8 (er, naturally) and also at f/4. At f/5.6 and f/8 they are much the same, so long as we don't take the kit wider than 35mm. But in that case why use the zoom at all?

Some might find the differences to be negligible for their purposes. But I saw distinct improvements even in going from the kit to the DA 16-45. So I'm one of those people for whom lenses do matter. For me, shooting at f/8 to make differences between lenses negligible is to completely miss the point.

(Note: I am referring to the kit Mk I, since I have not used Mk II.)

I think, Robin, that people are referring to the second version of the 18-55.

The second version was introduced specifically to make it sharp enough to use on the K20D, and it is this version that people are talking about. Reputedly, it is significantly sharper than the first version.

G

Well at least a few myths have been laid to rest, and we have all learned a bit more about these lenses from what were only very short elementary tests. Full resolution tests can probably be obtained from Oldtimer cameras.

There was a website with a full test between a 50mm f/1.8 Olympus lens, which is very similar to the Pentax M f/1.7 and a modern lens and it really showed how lens design has advanced in the last 10 years leaving the Oly lens lacking in many areas. Unfortunately I can't find it and can't remember what the other lens was.

I've done several tests between the 18-55mm ALII kit lens and two different (not-Pentax) 50mm lenses. Providing the subject has enough fine detail (trees in winter at 100m away are good); the camera is on a tripod; it's triggered by cable; the 2sec delay timer is used to lock the mirror up and several shots are taken of the same subject, refocussing between each and then picking the best then results for photos taken at f5.6 are repeatable. They will not look the same, because in the time it takes to do all this, the light will have changed - but the 50s are consistently and obviously sharper than the kit when displayed on-screen at 100%. The differences between the kit lens and any other (that I have access to) within its focal range and at f8 onwards are as near to non-existant as makes no difference - not worth taking the kit off the camera.

I know a lot of folks have reservations about lab tests and MTF curves and they can't tell you anything about colour rendition, but in my view they are the best guide to lens sharpness - providing of course you ignore the portion of the curves beyond about 15mm from the centre if you are using a crop-sensor camera.

Only at the borders and not enough (apparently) to make it better than the DA16-45mm. I think it is possible to extrapolate from the first version to the second with some degree of confidence.

Stumbled across it completely by accident link

They compare Olympus F.Zuiko Auto-S 50 mm f/1.8 versus Olympus ZD 50 mm f/2.0 Macro and you can see quite clearly that the old lens is behind modern standards.

Interesting to compare old and new, but we can't extend that comparision to the Pentax 50mm f1.7 as this was a better lens in its day than the Olympus.

Not all 50mm lenses have the same design parameters.

I had both the M 50mm f/1.7 and f/1.4 and the Oly f/1.8 (two versions one marked MC although the other was multicoated as well)and the Oly f/1.4 in the late 70's and I couldn't tell which was best after hours of trying. It was only when I got the A f/1.7 that the Pentax seemed much better.

Quite a lot of top photographers used Olympus such as Brian Griffin as well as nearly all the fashion photographers such as Bailey. They did make some top lenses many of which were unique to Olympus especially in the macro area.

They did for a while and the picture of them all gathered together looked pretty impressive in the advertising. They all went back to Nikon and/or Pentax 67 though. I heard that the Olympus kit wasn't up to the rigours and they were fed up of it failing in heavy professional use.

In those days the field leaders were Pentax and Nikon, with Canon coming up strongly behind them....