Pentacon 50mm f2.4 Prakticar "Pancake" Lens

Ballu

As I wrote in other message, I bought 2 lenses, one is Tamron 28-70mm.
The other lens is Praktica B-mount Pentacon 50mm f2.4 Prakticar "Pancake" Lens.
The lens doesnt fit on EOS system and no adapters are available.
Only option is to change the mount to EOS (replacing current mount with M42-EOS adapter).

Any idea about this lens... and how easy/difficult will be conversion...

I paid $25, too much for me.. but I am little crazy about pancake lenses... or say small lenses...

Ballu · Posted: Tue Feb 26, 2008 7:18 am Post subject:

Small update.. got the lens... almost new... but not really pancake (not of Industar 50/3.5 category).. I think the best focal length for fast pancake lens for full frame slr cameras is 45mm (register distance)...... at 50mm, only slow lenses can be minimized in size...

But the lens is little smaller than Nikon series E 50mm f1.8 and little faster than Industar...

I can live with these specs, although an expensive path ($25)...

Now update on conversion, the mount can not be replaced directly with M42-EOS adapter (like done for Minolta). The screws on the original mount on the protruded part of mount, so those screws fall within the M42 thread diameter....

Seems like only option is, try the mount from some broken Canon EOS lens... I have one broken lens.. will try in next few days...

else, it will be a long path to find/create some sort of mount by keeping the focus to infinity...

montecarlo · Joined: 04 Apr 2007 Posts: 1865 Location: Romania

Congrats for the lens and good luck with your work . As I read that pancake was asambled a log time ago, here, in Romania Smile

( http://www.praktica-users.com/lens/blenses/pp2.4_50.html )

Ballu · Posted: Tue Feb 26, 2008 7:42 am Post subject:

montecarlo · Joined: 04 Apr 2007 Posts: 1865 Location: Romania

Well here says: "4 elements in 4 groups" not like on the other link http://www.praktica-collector.de/Pentacon_Prakticar_2.4_50.htm . What to believe?... and here http://www.praktica-b.org/p_2.4_50.htm "5 Elemente in 4 Gruppen" .

peterqd · Expire: 2014-01-04

Ballu, I have a feeling we discussed this before but I can't find it in search. Apologies if so, but would the lens fit a K-mount to EOS adapter?
http://photo.net/bboard/q-and-a-fetch-msg?msg_id=00MJZe

Neil Purling · Joined: 12 Oct 2009 Posts: 37

Has anyone actually used one of these full-bore on a 'B' series Praktica or a full-frame sensor DSLR?
Back in the day one of the photo magazines used to test lenses by shooting at a vessel on the Thames, presumably because it was visible from their offices. Another mag actually printed lines per mm at centre & edge with various apertures.
I don't recall the 50mm pancake getting the test treatment, but around 1985 or 1986 they were wondering why Pentacon had introduced this lens.
I wonder why, rather than the B mount version of the Tessar that exists as prototypes. Maybe if it has five elements it would have been expected to have better performance?
I have got one of these lens, but it needs to be rather 'loose' on it's mount. All the assembly wobbles about.
The lens isn't in that bad shape. Maybe worth having fixed if there's a guy in the UK and avoid the ebay gamble.

papasito · Joined: 09 Jan 2015 Posts: 1658

Here you can find an information of the lens.

Perhaps can help you in any way.

http://zeissikonveb.de/start/objektive/normalobjektive/prakticar%202%2C4.html

Neil Purling · Joined: 12 Oct 2009 Posts: 37

What is the average value of one of these lenses? I just want to know what is the best move: Gamble on another ebay lens or have the present example repaired that would come with a guarantee?
It is very interesting that the lens design dates from 1968, but the Zeiss Tessar was already being used. I wonder if there are prototype 'zebra' 50mm f2.4 lenses in M42 screw?
Another interesting matter is that Meyer knew that their triplets had been forced beyond the limits of the Cooke design.
I think that a Praktica user of the sixties could have told them that!
I didn't know the 50mm f2.4 was such an old design, nor that it was the base option lens when the B200 came out in 1978. The first version lens has the focus ring in the same material as the B200 body is covered with. I think the lens was mentioned in a B series camera test in the early-mid 1980's and I thought Pentacon had produced the lens as a cheaper alternative to the 50mm f1.8 Pentacon (Oreston). Was the Carl Zeiss Jena Prakticar 50mm f1.4 around then? Just wondering, as there were several choices for the screw mount Prakticas.

luisalegria · Expire: 2018-01-18

Interesting.

There seem to be two models here - one is 4 elements in 4 groups and another longer version is 5 in 4

As per the diagram in the link the 4 in 4 is not a Tessar at all (4 in 3), but something else entirely.

Neil Purling · Joined: 12 Oct 2009 Posts: 37

What are these lenses like on film or with a full-frame sensor between f2.8 and f8?
Mine has mechanical 'issues'. Something wants to be tightened up inside.
Just wondering before I pluck up the courage to go diving into it or simply buy another example.

Neil Purling · Joined: 12 Oct 2009 Posts: 37

The Prakticar is not fantastic at f2.5 around the edges which is to be expected.
However I don't yet know if the other available alternatives would be any better if used at their wide-open apertures & further tested at f4 & f5.6. I have bought a 50mm f1.8 Prakticar
The Tessar for the screw mount has a recessed front element, wheras the Industar 50mm does not. The Industar needs a lens hood.
I wonder what the thinking was in producing the f2.5 Prakticar when there was a Tessar type 50mm PB mount lens in prototype form.
Was physical size a prime concern?

Still missing ORWO NP15. Even though Kodak Tech Pan blew it into the weeds on grain performance.........

y · Joined: 11 Aug 2013 Posts: 304 Location: EU

Neil Purling · Joined: 12 Oct 2009 Posts: 37

I don't know how the Romanian f2.4 'pancake' Prakticars can be identified. The one I am using has the 2 rows of soft squares. It suggests an early lens from a B200 or B100 that matches the body covering. Unless the late f2.4 Prakticars never had the hard plastic focus ring as per the later f1.8 Prakticar, with two rows of the bevel-edged squares.
Did ALL the later 50mm PB lenses have multi-coating? I am sure a 50mm f1.4 Prakticar looked brownish. Yup I had a BX20 with a 50mm f1.4 & like a mug I traded it against a Pentax K1000. You don't have an 'idiot' emoji do you?
For the sake of a tiny light loss I wonder whether a f2.8 Tessar would give a visibly different result on test against a f2.4 Prakticar.
I have no idea how far you could enlarge the resultant negative before the edges & corners become unacceptably soft when viewed on a print.

koji · Expire: 2012-12-27

Two Prakticar 50/2.4 images:

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The right one is plastic one, the left is original metal version.

Neil Purling · Joined: 12 Oct 2009 Posts: 37

The plastic version appears slightly taller. The difference looks to be accounted for by the front bezel being deeper.
Were the optical elements still made in the DDR, or in Romania? If German, then would that be the Meyer factory at Gorlitz?
The Praktica users link is broken: The domain is for sale.

You can have a fast 'pancake' lens: The 50mm f1.8 Nikkor ais. The registration depth is greater............

A 50mm f1.8 Prakticar is huge by comparison. I just got one of those. I will see what that monster shoots like at a half stop down from open.
I wonder if it would be much better? One way to find out.... I have some Technical Pan left & I can mix up POTA easily.