pentacon 29mm/2,8 --- Why are one border unsharp?

[padiej]

Good day!

A question:

I have two copys, both are unsharp on one side, good sharpness in the center and on other side, unsing aperture 5,6 or 8,
by using aperture 16 or 22, all is sharp, include the dust on the sensor

why ???

Is this a focus-problem or disturbances into the lens?

The 6 blades are silver, is this a source of blurring?

I will test the pentacon again and show the pictures.
I must use a good hood, becouse the blades are reflecting so much.

What do you mean about this effect?



regards Peter

[Orio]

The Pentacon 2.8/29 is a cheap lens with a cheap build. The copy variation is an issue. My first copy was so horrible that I had to sell it. My second copy is ok and I am keeping it. The positive side is that the lens is so cheap that one can afford to try several in order to find a good one.

if your problem is identical with two different lenses, however, I would investigate other possibilities also, such as possibly defective adapter.

[Flor27]

Orio is right, and the main problem is misalignment of lenses elements : lens element could be cut un-centered or if not, badly placed in the barrel.

[padiej]

Thank you!

adapter works good by other lenses, must be the lenses, the glass

it´s ok, the price is low,

but why is the lens sharp by aperture 16 or 22 ???

regards peter

[Orio]

[Sandie]

I feel the Meyer versions of the 29/2.8 and 30/3.5 have better QC than their pentacon counterpart.

[Attila]

On many lenses Meyer version is better than Pentacon, Pentacon was driven by Mr. Honecker trully Built quality most of them crapier than Meyer and sometimes optical quality too.

[estudleon]

Pentacon and meyer - the same maker with different brand for marketing- used the same glases (not schott like zeiss). The first - meyer- had better built and in the cases of the "same" lens (ie orestegon and pentacon 29mm F/2, that have differents optical's rendition, it may occur in the poor built of pentacon way and in the different rendition of the MC glasses in comparation with the single coat ones (remember here that some lenses rendition not be improved with the MC, although the contrast may be better. Some designers said the the mc coat need a reformulation of some design because, among others causes, altered the distance and reflexion of the elements of the lens, and some design don't support this changes without less qality).

[padiej]

Thank you all !

We can resume:

Meyer-Lenses are on a higher level
(-yesterday I tested the Lydith 3,5/30 - it is better then pentacon 29mm)

my Pentacon 29mm are half-lenses - I have to cut one border of the picture to get sharpness over all




When the rain in austria is over (we have a kind of monsun-rain), then I will make a test meyer 30- pentacon 29- takimar 28

regards Peter

[Orio]

[padiej]

Now, my inside test, becouse the rain is so massive

Pictures 100%





I have two pentacons to sell

The pentacons are for the rack, they are duds.

The bigger pentacons are good, leastwise a success

and the meyer lydith 30/3,5 (zebra) - a dream, I like it, is a good lense, all is sharp

There is a big difference between pentacon and meyer, I see, too.

Thank you, for helping!

regards Peter

[padiej]

Pentacon 29mm is a very good lens, you must find the right way to use it:



respectfully Peter

[Farside]

[A G Photography]

I can concur that the Meyer Lydith is very nice lens, it's almost sharper than the 35mm Flek (I must do some tests just for fun). Actually I have pretty a crush on Meyer lenses, they're so undervalued but they always delivered more than I expected from them.