Are All m-50mm f/2 lenses the same?

*lawsonstone* · 10-30-2009, 08:07 AM

I've accumulated a handful of these old classic film kit lenses: M 50mm f/2, and one A 50mm f/2. Does anyone know if there are differences generationally in components, quality, reputation, desirability?

Lowell Goudge · 10-30-2009, 08:12 AM

I can't comment about optical formula, and lens arrangement but for sure the M50mm and A50mm are different in the aperture control lever.

The M (and K also) have the aperture diameter change linearly with lever movement, the M has the Area change linearly with lever movement/

This made the control eleectronically (through the body in shutter priority mode i.e. Tv) more controllable since area is linear with F stops and EV

MrApollinax · 10-30-2009, 08:12 AM

For DSLR purposes the "A" lenses are more desireable due to the fact you do not need to stop them down before taking a photo. Otherwise, optically they are essentially identical.

*Nowhere Matt* · 10-30-2009, 08:21 AM

Yes I would think obviously for the simple fact of the automatic aperture feature of the "A" 50mm, compared with an "M" and today's dslr users that the "A" has an advantage and is therefore more desirable to many.
I have both and although I am not a true pixel peeper, the obvious image quality is the same between the two lenses.

Oh. And one has the numbers and letters on the focus ring and the other has the numbers and letters around the front of the glass.
That is a general difference.
Well. It is. Stop looking at me like I am just some other jackass.

*lawsonstone* · 10-30-2009, 08:37 AM

My actual concern had to do with whether the shift from Japan to Taiwan in manufacture, that some think affected the K1000 for quality, affects these lenses as well. I more or less did notice the lettering is different and I understand the difference between the A and M lenses (duh!) ;-)

stevebrot · 10-30-2009, 10:20 AM

This is an interesting question. I remember a thread several months ago where it came out that there are several versions of the Pentax-M 50/1.7 out there with physical differences and different countries of origin.

Steve

georgweb · 10-30-2009, 04:46 PM

Originally Posted by stevebrot

I remember a thread several months ago where it came out that there are several versions of the Pentax-M 50/1.7 out there with physical differences and different countries of origin.

From that same thread it says there were also Taiwan and Japan versions of the M 2/50.

Dimitrov says the lens scheme from the A and M 2/50 is the same and who would doubt him.

5-element lenses have a rap of special bokeh, please post examples in the Bokeh thread :-)

Best, Georg (the other)