Review: ferider modified Pentax 50/1.4 in M-mount adapter

[paulfish4570]

RFF member ferider (Roland) kindly offered to modify an SMC Pentax-M 50/1.4 lens for use of a Kipon Leica M-mount adapter for me use on my Bessa R2m. After two rolls of film, one in c-41 color and one in BW, I have to say the kit works beautifully. Here are some thoughts and photos:

Lens with adapter fits the R2m snuggly and confidently.
The lens and adapter - and camera - look good together.
Focus is silken.
Lens/adapter/cam combo is well-balanced, and comes to hand nicely.
The front of the lens intrudes into the viewfinder field at the bottom right corner, but barely conceals anything in the bottom right corner of the 50mm frame lines. It is not a factor in my composing.
Focus is dead on, from inside three feet to infinity.
The SMC Pentax-M 50/1.4 is sharp with a capital S, but not too contrasty. The OOF field, I think, is a big plus: it is smooth and orderly. There is nothing dramatic about the OOF that would detract from what is in focus.
Half-stop clicks on the lens are handy, as the R2m’s TTL meter uses half-stop increments.
Metering is perfect through the lens, according to my two rolls worth of experience, both with ISO 400.
Framing is accurate.
Rendering fits the way I see things very, very well.
Conclusion: this lens stays on my R2m.









cam at infinity:


cam at closest focus:


For those of you who are interested in Roland’s engineering of this kit, which requires modification of the lens before it fits the Kipon adapter, see this link. http://www.rangefinderforum.com/foru...d.php?t=113676

And for those of you interested in obtaining this lens/adapter combo, you will have to contact Roland ... J
The Bessa grip, which you might have noted in some of the pics. was provided by Roland. It immediately became a treasured - and mandatory - accessory.

Some sample color pics made with the kit:









Some BW:

f1.4 (gonna takes lots of shots to nail focus at this DOF), handheld at 1/60 or 1/125:

[raid]

The lens has always been awesome, Paul, and now you have it a mount that fits your other non-Pentax cameras.

[paulfish4570]

thanks, raid. i am tempted to buy an mx or me and another copy of the lens so i can have a matching slr kit ...

[raid]

I use my SMC 50/1.4 mainly on a Spotmatic F. Is the MX the small sized body that comes with the pancake 40mm lens?

[paulfish4570]

yes, the mx/me series is very compact, like the om series.

[raid]

I have a black MX with the pancake lens. It is a small combo.

[ampguy]

Great image quality. That setup is smaller than I expected. Impressive engineering work. Maybe someday we'll all be 3D printing our lens adapters at home! Maybe the lenses too!

[CNNY]

Thanks for posting these images. I remember the original thread, and was intrigued. It looks like a relatively simple project. The resulting lens looks like it is not oversized, and well suited to an M mount camera. It seems really usable.
How accurate is the focussing?

[jsrockit]

Originally Posted by CNNY

Thanks for posting these images. I remember the original thread, and was intrigued. It looks like a relatively simple project. The resulting lens looks like it is not oversized, and well suited to an M mount camera. It seems really usable.
How accurate is the focussing?

Christian, thinking about doing this? I have a 50mm f/2 Pentax you can experiment with...

[CNNY]

Originally Posted by jsrockit

Christian, thinking about doing this? I have a 50mm f/2 Pentax you can experiment with...

Perhaps, but it is low on my project list. I'm not sure that is the right lens though. Do you even have an M body nowadays?

[paulfish4570]

focus is dead on ...

[CNNY]

Originally Posted by paulfish4570

focus is dead on ...

Great! Very impressive.

[Mablo]

The image quality is awesome. Makes me think of 50/1.4 Summilux quality. Great review, thank you Paul and Roland.

[paulfish4570]

thank you, Mablo.

[Michael Markey]

Very nice Paul...looks good on the Bessa.
I use Pentax when not using an RF.
The 50/1.2 is very good .
The 50/1.7 is sharp and has more contrast.
Of the short tele lenses I like the 100/2.8.
I`m currently trying a 35/2.8 .....

[semilog]

Oh, how I'd like one of these. I don't suppose Ferider is doing this on a regular basis?

[paulfish4570]

am waiting for him to chime in ...

[gb hill]

Outstanding Paul. I have a Spotmatic that was given to me. The lens is yellowed but I've been sitting it in the sunlight. It's almost clear now, but have forgotten about it until this post. I'd need one in 39mm ltm but think I'll keep it for the Pentax.

[gb hill]

Since Brian is no longer posting maybe Ferider can take over Brian's forum.

[Jamie Pillers]

Hi Paul, very cool. And just to comment on the photos... your low-light landscapes are always fantastic! You should make MORE!!

Roland... VERY cool modification - thanks for trying it! Just to be clear: the modification is essentially adding the focusing 'cam' to the slr lens so that it pushes the rangefinder wheel in the camera... correct? And can I assume that its not a minor exercise to calculate the dimensions of the cam.. correct? And regarding focus distance: the pentax lens normally has a close-focusing distance of something less than a half a meter. Can the Leica M rangefinder mechanism accomodate this shorter distance, or is the modification limited to 0.7m?

[ferider]

Thanks for the review, Paul, and also for posting pictures of the lens on the Bessa - they make a great pair together. And like Jamie, I'm a fan of your B+W landscapes ....

Originally Posted by Mablo

The image quality is awesome. Makes me think of 50/1.4 Summilux quality. Great review, thank you Paul and Roland.

Thanks, Mablo. And I agree with you - I've shot my pre-asph v2 next to the Pentax lens and the images look very similar. Not surprising, since the optical designs are closely related. Even better, the Pentax lens distorts a little less, and has a minimum focus of 0.7m; on the other hand, the Summilux is more compact which is why I'm keeping it.

Originally Posted by Jamie Pillers

Roland... VERY cool modification - thanks for trying it! Just to be clear: the modification is essentially adding the focusing 'cam' to the slr lens so that it pushes the rangefinder wheel in the camera... correct? And can I assume that its not a minor exercise to calculate the dimensions of the cam.. correct? And regarding focus distance: the pentax lens normally has a close-focusing distance of something less than a half a meter. Can the Leica M rangefinder mechanism accomodate this shorter distance, or is the modification limited to 0.7m?

Hi Jamie: the cam is made from a brass pipe by hand, with saw and file. Only in the end is accuracy needed, when I grind it with a stone to match infinity on my reference camera, an M3.

The Pentax SMC lens is a "lucky coincidence", since it's focal length matches the Leica RF standard of 51.6mm. This, I measured before I modified my first copy (a donation from a friend). It guarantees that focus is right at both close focus and infinity. When the lens focuses closer than the camera's minimum focus (0.7m), the RF cam simply decouples.

Enjoy your lens Paul. BTW, it also has a tag in the flickr Leica M forum

Best,

Roland.

[paulfish4570]

greg, that yellow does nothing to IQ, IIRC.

[paulfish4570]

jamie, close focus is about 2.5 feet. and the way i understand the engineering, you are correct on that, too.

[Jamie Pillers]

So now we have to try to talk Roland into inventing a modification of the rangefinder mechanism itself! :-)

[paulfish4570]

jamie, thanks for the landscape compliment.