Flektogon 2.4 / 35 weird or what?

[Totem]

Being new to mflenses forum, first and foremost - hello to everyone!

I started taking photos about two years ago - got myself an old canon EOS 10D, a couple of good lenses and have been a happy camper, until...
I stumbled into MF territory and was just amazed how much bang for the buck you could get from these historic babies! I purchased a pentacon (4/200) and then another one (2.8/135) and was surprised by the quality!
But then one day... along came the Zeiss! I fell in love with my Flek immediately - the colours, the bokeh, the sharpness... not to mention it was very cheap considering e-bay prices!

Now here's the problem: I've had the Flektogon for nearly a month and have been using it heavily, but have only recently noticed, that something was very wrong - I would be out shooting some architectural stuff and when focused straight upon a flat wall, the center and the entire right side were tack sharp, but the left side was sooooo very soft! The top left corner is completely distorted, even when the lens is stopped down to f5.6 or even f8! Now this isn't noticable when doing closeup work with shallow DOF, but when shooting grafitti or such, it becomes a problem! I did some testing and noticed that just by looking through the viewfinder and moving the focus ring (when focusing say.. a textured wall), the center and the right side come into focus first, then when this area goes OOF, the left side comes into focus... And this is notecable ON A CROP SENSOR!!! Could this mean that some elements of the lens are decentered? My Flek also struggles to reach infinity focus (I have to stop it down to at least f8 for the AF light to blink) and when reviewing the photos I find that objects about 5 meters away are always sharper then those far far away (with the lens set to infinity when shooting)...

Now I've grown very fond with this lens and don't want to resell it for half the price to someone who won't be bothered by these things... Is there a logical explanation for all this?


Here you can probably see the left side kind of distorted and OOF! What to do???

[F16SUNSHINE]

First of all welcome to the forum

The flek suffers often from poor quality control. Even though I like the lens after 3 copies with varying degrees of poor QC and resulting poor IQ.
My choice was to sell the lens.
If you like the style of drawing you get from the lens find a Distagon 2.8/35 to replace it.
You will not get the close focus ability but tubes can make up for that loss.
Cheers
Andy

[Spotmatic]

[ManualFocus-G]

One of your elements is a bit wonky Needs to be re-assembled and you'll have a much sharper lens

[aleksanderpolo]

For this kind of quality control I found Flek to be very overpriced on the bay, the price level has almost reached that of a Distagon. I was tempted to buy a Flek a few times before, but worry about this type of problem has kept me from buying one so far.

Hope that it won't be too difficult to fix it yourselves.

[Totem]

Thank you all for the info... I should probably take it to a specialist then and have it checked (and hope its not a costly repair), as I'm not really into fine mechanics
The next lenses on my shopping list were the MC Sonnar 3.5 / 135 and MC Pancolar 1.8 / 50, but the little Flek has really got me worried about Zeiss QC!!

[Attila]

I bought and sold at least 30 Flek 35mm f2.4 under years , none of them had any issue. They are great lens, your copy perhaps was opened by an amateur and was wrongly rebuild again. I have and had so many CZJ lenses all are at least very good lens some of them outstanding Carl Zeiss Jena had good quality control. Auto/manual technology wasn't perfect due if blades got dusts they could stop working and require cleaning.

[arhi_tectu1]

i can confirm you need to re assemble your lens

[LucisPictor]

Misalignment / decentering. Needs repair.
Somewhat typical for CZJ lenses. Quality control was not the best.

[Totem]

Thank you all for the great advice. I'll have it checked in a couple of days!

[metallaro1980]

Please attention !
I had found with an m42-to-eos adapter (with flange) similar problems.
with a m42-to-eos adapter (without flange) zero problems.
a working adapter: when i use live-view and do focus at infinity, now on the lens the line mark is very close to the infinity mark

[iangreenhalgh1]

Hello

I too did what you did and bought a cheap secondhand EOS 10D.

However, instead of buying a Flektogon I bought a Pentacon 2.8/28.

Two reasons:

The Pentacon cost me 5ukp is excellent condition, a Flektogon costs more like 50ukp for a beaten up one.

While Zeiss glass is excellent, sometimes the mechanics are not very strong so for some of their lenses, I would want to handle and inspect it before buying. Classic example of this is the Zeiss 3.5/135, it has an aperture mechanism that often fails after a few years of use, I'm not into taking fiddly apertures apart to repair them so I've never bought this lens, one day I'll get one but will have to make sure it works first. I'll buy a Pentacon 2.8/135 in the meantime and probably be quite happy with that.

If your Flektogon is going to be a costly repair, you could just get a 2.8/28 or 2.8/29 Pentacon to use while you save up to pay for the Flektogon repair, I love my Pentacon.

Some sample shots I took wide open to test the sharpness, contrast and bokeh, these were shot just after dawn on a very dull, grey day to see how the lens handled the low contrast light:






This shot shows how sharp it is wide open and I think the contrast is good too, the later MC Electric Pentacons have good coatings imho.

[Attila]

[Attila]

[iangreenhalgh1]