SD14 and Praktica B bayonet mount compatibility?

[Arvo]

I recently read on russian Sigma forum, that someone had accidentally got Jena Flektogon in Praktica bayonet mount instead of M42 and to his big surprise that lens fitted SD14 very well.

Searching google about this fact I didn't find anything sensible. But there were some pages about Pentax K-mount and Praktica B, where users had success using Praktica lens on Pentax after removing some metal from Praktica mount (but I couldn't understand, where exactly).

Can anyone on this forum sched some light at that? If some SD14 user had any Praktica B lens, it would be easy to check, can these lens mounted on SD14 or not.

Be careful to not hit IR filter/dust protector!

 

[notfound]

I got some praktica B lens on hand, I've tried to put it directly on the SD14, but the aperture preview lever on the lens just need to be removed before mounting on the body. I think trimming the aperture preview lever should make the lens work on SD14.

I'll pick one of the lens and have a go, let you know if I've any luck.:z04_cowboy:

 

[Arvo]

I hope that lever can be removed without destroying it? Anyway I'll be waiting for your results, thanks a lot!

 

[notfound]

I've tried to cut the lever, but the problem I've found is that the PB mount's teeth is too thick to fit in a SA mount, also the rear element's tube is too long that hitting hit the IR filter(lucky only the plastic part). Therefore, some more mods need to be taken to use a PB on a SA mount.

 

[dirk]

Hi Arvo,

I did a kind of conversion of a Pentax K lens to the Sigma mount some time ago. Just for the fun. But in the end, you will not be able to focus to infinity properly.

Images and descriptions are in our German Sigma Forum:

http://sigmaforum.de/forum/showthread.php?t=141&highlight=pentax

If you want to, I can upload them also here. But I would rather recommend instead to try to buy a good value Sigma 2nd hand lens at ebay

Except for the fun of trying it out, there is no real advantage for you. Especially if you use very old lenses. Ssame with old M42 lenses. They are not designed for DSLRs and you will always have disadvantages compared to a modern lens. Even if that modern lens is not the best quality, it will be able to hold up well EASILY against old M42 lenses

So if image qualiyt is the focus and saving money, go for a newly designed lens 2nd hand at ebay. If the fun of experimenting is what you are looking for, then go for those conversions of old M42 et alii lenses

Or try something new and use the adapters and modification offered by experts (i.e Nikon mount conversion etc.). But the you will use again newly designed Nikon lenses with it sooner or later

Best wishes

 

[Arvo]

I've tried to cut the lever, but the problem I've found is that the PB mount's teeth is too thick to fit in a SA mount, also the rear element's tube is too long that hitting hit the IR filter(lucky only the plastic part). Therefore, some more mods need to be taken to use a PB on a SA mount.

Well, many thanks for information!
Seems that this guy on russian forum actually didn't get his Flektogon in Praktica mount, otherwise your results would be different.

Thus no direct use of Praktica bayonet lens on Sigma.

@dirk

Are Pentax K and Praktica B compatible? Reading forums there are similar problems like notfound encountered.

What about M42 - I like these old lenses Although I can agree that they are not designed for DSLRs and often give nasty effects, sometimes they are enough cheap to experiment with.

Image from M42 Chinon 55/1.7, you may count the pine needles (+ for sharpness), but don't look at bokeh (- for some green fringing, although not very distracting on this image):

http://www.stv.ee/~donq/sigma/SDIM1129.jpg

 

[Arvo]

I wanted to change link in previous posting to uploaded image, but timeout expired

Crop from image above attached.

View attachment 1828

 

[notfound]

Excellent quality, the bokeh is not bad though. For a old lens at low price, it perform well!

 

[dirk]

...
@dirk

Are Pentax K and Praktica B compatible? Reading forums there are similar problems like notfound encountered.

What about M42 - I like these old lenses Although I can agree that they are not designed for DSLRs and often give nasty effects, sometimes they are enough cheap to experiment with.
...

Hi Arvo,

I do not know the Paktica B mount, so I can not say anything meaningful about it.

I use mnyself M42 lenses. But only the newly designed Carl Zeiss lenses which Zeiss is offereing also with Nikon, Canon and Pentax mount. They are called Zeiss ZS (ZS=M42 mount). They are excellent. They are designed for digital photography. BUT they are expensive. Especially if you reflect that they are manual focus and usable only in A-Mode or fully manual.

I do think that the modern Sigma lenses like i.e. the Sigma 50/1.4 (not so much the Sigma 30/1.4) are really good. Maybe not as good as Zeiss in some respects, but they have AF, all program modes and are desigend for fullframe too.

The old M42 lenses of the 60ies and seventies are basically a bet. You can win and you can loose. But in my experience, if you count in the time to find good ones, the prices all added together, I nowadays much rather prefer to save a little more time and add 50.- USD on top of that to get a newly designed lens (either 2nd hand or new) without any worries, risk and anger

 

[Ille]

Hi everybody,
I do not own praktica B mount lenses, but I did adapt some old Pentax K lenses (50mm f/2, 28-80 Macro f/3.5-5.6, Tokina 35-200). I had to cut the aperture lever, and shave or remove the back element tube (light shield). I also had to add a 1.5mm washer between the lens and its mount. But now everything works good (well the 50mm is one of my favorite, the 28-80 Macro was broken, so I use it as a macro only lens, the tokina was - and still is - unusable but as a soft lens.).

EDIT: I just bought a brand new Samyang 85mm f/1.4
I will convert it to SA mount in the next few days. Hope to post some images soon.

Regards