Another cult lens

From test roll #2. An example of the lens's rendering wide open.

1/15s exposure (hence a bit of motion blur). Superia 200 processed at the drug store, scanned quick-and-filthy on my V500.


Jenny & Joe by Semilog, on Flickr
 
I am loving this lens in a way that I never loved my old gen. IV Summicron — a lens that I tried and failed to love for a decade. The Summicron and I filed for divorce a couple of years ago. I'm happier without her. I hope she's happier without me, too…wherever she is.
 
jsrockit said:
Cool, but not practical. Cool anyway.
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Totally practical. The lens is lightweight, built to great mechanical standards, and draws magnificently. Ergos are excellent and there is almost no finder blockage. SMC optical coatings are as good as any including Zeiss, and the lens renders vastly more beautifully than my old gen IV Summicron.

Did I mention that I sold the Summicron for just under $1000, and that this project cost $200? More than $700 in my pocket. Now that's practical.
 
Not impractical at all. BTW, Semilog, the new M-Nokton is not much smaller than the converted SMC. Takes the same filters, too.
 
Would suggest vinyl electrical tape for covering up red dots, the residue is much easier to remove. Gaf tape has no residue for a while, then it turns into this hardened stuff. Bad.
 
semilog said:
SMC optical coatings are as good as any including Zeiss. . . .
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Yes, it is well known in the astronomy world that the Pentax eyepieces and optics, with their special coatings, are premium.

It's the backwards focus from Leica/Canon that keeps me away from Pentax.
 
jim_buchanan said:
Yes, it is well known in the astronomy world that the Pentax eyepieces and optics, with their special coatings, are premium.

It's the backwards focus from Leica/Canon that keeps me away from Pentax.
Click to expand...

Understood. As a longtime Nikon user that doesn't bug me.
 
Ranchu said:
Would suggest vinyl electrical tape for covering up red dots, the residue is much easier to remove. Gaf tape has no residue for a while, then it turns into this hardened stuff. Bad.
Click to expand...

Thanks for the heads-up. I've actually been meaning to paint the dot flat black and now that I have a can of flat black spray paint (purchased for this project) I'll do it.
 
The side that mates with the back of the lens is machined for a press-fit.


upload by Semilog, on Flickr

Now the focus adapter is painted absorptive black. The paint is nonreflective, designed for camouflage use. After spraying it and letting it dry I baked it in the oven for an hour with the exhaust fan running. This was to drive off any volatile crud that might otherwise have off-gassed into my camera bodies.


upload by Semilog, on Flickr



upload by Semilog, on Flickr
 
Very, very nice, Semilog. Cool that you used a lathe for adapting the tube.

Can you check for vignetting at infinity, please ?
 
ACROS & XTOL, this time. More quick & dirty V500 scans.


Test pictures with SMC Pentax-M 50mm f/1.4 adapted to Leica M mount by Semilog, on Flickr


Test pictures with SMC Pentax-M 50mm f/1.4 adapted to Leica M mount by Semilog, on Flickr


Test pictures with SMC Pentax-M 50mm f/1.4 adapted to Leica M mount by Semilog, on Flickr


The veiling flare in this last one is probably due to the fact that the focus coupling tube tube was not yet painted flat black; it just had some electrician's tape on the inside to cut down on reflections.


Test pictures with SMC Pentax-M 50mm f/1.4 adapted to Leica M mount by Semilog, on Flickr
 
holy ****. this is amazing work from both of you! i have a 50 1.4 (pre SMC, K) that i picked up for $50 because of a little chip in the front element, which, from what i can tell, has no real effect on IQ. this is a great and very practical idea, as the cheapest 1.4 lens you can get for any M body is the CV 40 1.4 which can be pretty harsh looking. for what you pay for a pentax 50 1.4, adapter, and parts, it's probably still cheaper than the CV 40 1.4.

i love the K 50 1.4 because of how beautiful it renders everything, but i don't use my k1000 nearly enough because the meter doesn't fare too well in low light. reall inspiring stuff guys!
 
My Pentax M-Conversion is now almost complete.

Thank you for your inspiration and advice, Roland!


First I modified a KIPON Pentax K-Mount to Leica M-Mount adaptor to show the 50 mm frame in the Rangefinder of a Leica M.


IMG_4731 von thomas.78 auf Flickr


After unscrewing the last element I thinned down the brass tube with a lathe to fit the "step" of the ring holding the last element:


DSCF3812 von thomas.78 auf Flickr

Then the brass tube was glued to the ring of the last element, sawn to the calculated lenght + 0.2 mm and then I used emery paper to trim the tube down until the rangefinder at my Berra R3A matches at infinity.



IMG_4834 von thomas.78 auf Flickr


With the KIPON adapter:


IMG_4833 von thomas.78 auf Flickr


Together with my Bessa R3A:



IMG_4831 von thomas.78 auf Flickr



I did some test shots both at ininity and 1 m distance.
The resolution at infinity is ok.

If I do scale focusing at 100 cm, I get the focus at about 94 cm at f/1.4.
If I use the rangefinder at a "real" distance of 100 cm it shows me something a bit less than 100 cm at the scale and I get the focus somewhere between 92 and 94 cm.
So it looks as my lens gives me some front focus using it wide open at close distance.

Now I am wondering if I should adjust the coupling tube to give me spot on focus at 1m and f/1.4 as I want to use the lens primary for available light portraits.
The drawback ist that this procedure would shorten the tube and thereby be irreversible....
 
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