Review: Pentacon auto 50 mm f/1.8 Multi Coating - phillipreeve.net (2024)

Pentacon auto 50 mm f/1.8 Multi Coating

The Pentacon auto 50 mm f/1.8 Multi Coating is a small and very cheap 50 mm lens with an unusually close focus distance of 33 cm. Is this “nifty fifty” worth adapting to a modern full frame camera?

Specifications

You can buy the Pentacon 50 mm f/1.8 MC for a little over €20,- at ebay.de (affilitate link) or for around $45 via ebay.com(affilitate link).

Versions

The Pentacon auto 50 mm f/1.8 MC is a very small vintage 50 mm lens. It is the direct descendant of the Meyer-Optik Görlitz Oreston 50 mm f/1.8. There are a lot of different versions of this lens in m42 and Practica B mount.

• The oldest version has silver stripes on the aperture ring and is branded “electric” or “auto”.
• The second version has no stripes on the aperture ring but has two silver rings at the front of the lens.
• The third version still has one silver ring at the front, the focus ring of third version has a spiked profile.
• The last version is all black. This review is about the last and most common all black version.

Here you can find some more information about all versions.

As far as I know, all versions are identical optically, the most important difference is the lack of multi coating of the older versions with the hill/valley type focus ring. Since flare is already a big problem with the multi coated version I would recommend to stay away from those older versions unless you like a lot of flare for creative reasons.

Adapting to E-mount

Depending on the mount you need either a M42-NEX adapter or a Practica B-Nex adapter. The K&F adapters work good enough in my experience and do not break you bank.
M42: Amazon.de | Ebay.de | Ebay.com (affilitate links)
Practica B:Amazon.de|Ebay.de | Ebay.com (affiliate links)

Build quality and handling

Compared to modern lenses build quality is very good, almost every part is made from either glass or metal. Compared to other vintage lenses like the Minolta Rokkor 55 mm f/1.7,build quality is less good, tolerances seem to be somewhat higher.
This is also reflected by some common problems that can be found in these lenses nowadays. I come across the Pentacon very often in thrift shops and flea markets and encounter the same issues with these lenses quite often. I have seen quite some lenses with either stiffened focus rings or focus rings that came loose. So if you buy this lens make sure to check for these issues.
All markings on the lens are engraved and filled with paint. The black finish shows some wear but does not look too bad for a 40 years old lens.

My sample is in good condition and still functions as it was supposed to, and handeling is very good. The focus ring has a pleasant resistance and travels about 320° from minimum focusing distance (MFD) to infinity, about 180° from MFD to 60 cm, 90° from 60 cm to 1.5 m and another 50° from 1.5 m to infinity. This is a very long focus throw for a standard lens, nevertheless it does not bother me as you can focus very precisely at close distances (which is what you probably want to use this lens for).

The aperture ring has soft clicks, 5/6 stop from 1.8 to f/2.5, and after that 1/2 click stops. To my taste resistance is a bit on the low side but high enough to prevent accidentally changing the aperture. It is also easy to set the aperture in between the click stops.

Vignetting

The Pentacon auto 50 mm f/1.8 shows quite some vignetting wide open, though stopping down helps a lot. At f/2.8 vignetting is already reduced to 1.2 stops. From f/4 vignetting is negligible and not visible in real world shots.

Flare resistance

Flare resistance is among the worst I have ever encountered. Ghosting and veiling flare are very visible even in less challenging situations.
With a bright light source just outside the frame you can observe extreme veiling flare and contrast loss. Shading however does a wonderful job as can be seen below. I shaded the lens with my hand, this was wide open.

With the sun in the frame some red and purple ghosts can be observed. Stopping down reduces the size of the ghosts a bit, but they become more saturated and much more obtrusive. Veiling flare improves when stopping down.

However, in some situations you can use the terrible flare resistance in your favor:

Sharpness

Infinity

f/1.8 The center shows good resolution, but contrast is low and there is some glow caused by spherical aberration. Midframe is soft and the corners are very soft.

f/2.8The center improves, the glow is gone and contrast improved a lot. Midframe and corners improve a bit but are still soft.

f/4In the center contrast decreases a bit, sharpness is nevertheless equal. Midframe and corners improve a little bit.

f/5.6 Contrast decreases a little bit more in the center. The midframe reaches OK levels. Corners are still soft.

f/8 The center is a bit less sharp due to diffraction, contrast is a bit lower. Midframe reaches good levels. The corners are still somewhat soft.

f/11 The center is a bit softer due to diffraction. The midframe is very good now. Even the corners look good.

Wide open the center is already quite good and usable despite some glow caused by spherical aberration and low contrast. The midframe and corners are soft. Stopping down to f/2.5 already boosts contrast and eliminates most glow, therefore I would rather use this at f/2.5 than at f/1.8. Astigmatism is obvious in the midframe and corners wide open. Even at f/11 you can see it in 100% crops.
If you want to shoot landscapes with this lens I would certainly stop down to f/8 or even f/11.
However, field curvature does affect corner and midframe sharpness quite a lot, see below

Field curvature

The Pentacon 50 mm f/1.8 shows quite a lot of field curvature on my a7II. When focusing on the corners one can get decent corner sharpness stopped down a bit. Below you can see how much of a difference focusing on the corners makes at f/1.8 (before = focus on center, after = focus on corner).

For landscape photography with important structures in the corners I would recommend to stop down to f/11 and focus on the corners. At f/11 focusing on the corners improves corner sharpness quite a bit at the expense of only a bit contrast loss in the center.

Close-up sharpness

f/1.8 The very center of the image is quite sharp from wide open, contrast is very low though and there is some glow caused by spherical aberration. Midframe is very soft.

f/2.8 Contrast is boosted. The center is very sharp now and glow is gone. The midframe improves a lot but is still soft.

f/4 Again a boost in contrast is visible, the center is as sharp as it can get. The midframe improves a lot.

f/5.6 No difference in the center. Midframe improves a little bit and is almost OK now.

f/8 Center is a tiny bit less sharp due to diffraction, midframe is OK to good now.

f/11 Diffraction is visible in the center and sharpness decreases. Midframe is very good now.

Corners: When focused on the center the corners never get sharp due to field curvature, however focusing on the corners improves corner sharpness a lot. Wide open the corners are soft even if you focus on them, however from f/4 on things look much better. At f/5.6 you can get OK sharpness in the corners if you focus on them, at f/8 you can get good corner sharpness. So if you want to place your subject in the corner near MFD it is wise to stop down to f/5.6 at least and focus on the corner.

Bokeh

This lens shows the well known “soap bubble” bokeh in some situations, not very surprising as it is basically aMeyer-Optik Görlitz Oreston. This means bokeh has strong outlining in some situations and can be very harsh, in some situations even some swirl can be observed. Whether you like the rendering depends on your taste. I personally don’t like the strong outlining in general but there are a few situations I think it can work.

In some situations the background still has some structure which I like in some situations but not so much in others.

Bokeh near MFD (background is a few meters away) f/1.8 and f/2.8:

CA

Longitudinal CA is corrected very well, wide open LoCA is mostly masked by the glow. At f/2.8 LoCA is reduced a bit and at f/4 it is gone completely.
In the corners some lateral CA is visible, see the example below.

Coma

Wide open there is quite some coma, stopping down to f/2.8 reduces it a lot. At f/4, coma is completely gone. See the comparison below: Before = f/1.8, after = f/4.

Distortion

The Pentacon 50 mm f/1.8 suffers from a slight amount of barrel distortion, as you probably will not use this lens to photograph architecture it is not relevant.

Sunstars

Sunstars are definitely a weak spot of this lens. It takes stopping down to f/16 to get defined sunstars. Due to the 6 bladed aperture the lens draws 6 pointed sunstars. I prefer the 10 pointed sunstars of the Loxia lenses, as this is a matter of taste you might want to check out this article. Unfortunately the sunstars come with a lot of ghosting and contrast loss. However, with less light city lights you can get well defined sunstars. At f/11 they are most defined.

Alternatives

There are a lot of very cheap vintage 50 mm lenses, I can not discuss them al so I made a small selection below of lenses I have used myself or have similar rendering.

Minolta MD 50 mm f/2

The Minolta is even a bit smaller and lighter. Build quality is quite similar but the Minolta feels a bit more robust. Contrary to the Pentacon, the Minolta has a very flat field and it is already quite sharp to the corners wide open. The Bokeh of the Minolta is nothing special but also not distracting. In case you are looking for a (cheap) general purpose lens I would certainly get the Minolta instead of the Pentacon.

Revuenon MC 50 mm f/1.7

The Revuenon is another small 50 mm lens. In terms of sharpness it is comparable to the Pentacon, it also suffers a bit from field curvature. The Revuenon has less busy bokeh but still its own character. Build quality is not very good though. As you can get the Revuenon very cheap as well it might be worth trying if you like the rendering.

Canon nFD 50 mm f/1.8

The Canon FD is another vintage 50 mm lens. It is sharper from wide open than the Pentacon. Flare resistance also is much, much better. The MFD of 60 cm however is below average and limits the amount of possible background blur. The Canon’s bokeh is quite smooth even at longer distances. Unfortunately the Canon suffers from onion ring bokeh which is visible in some situations like city lights.

Meyer-Optic Görlitz Oreston 50 mm f/1.8

Optically the Oreston is the same lens, the most important difference is the fact that its not multi coated. The Oreston has another housing though, like more Meyer-Optic lenses from that era the feature the “zebra” design. If the zebra design is important to you this might be a good choice for you, otherwise get the much cheaper Pentacon.

Conclusion

The Pentacon auto 50 mm f/1.8 multi coated is certainly not a lens for everybody, though with a little patience and effort one can create good images with quite a special rendering.
There are some very serious flaws like terrible flare resistance and serious field curvature, but you can mostly work around them. Don’t see it as your only fifty but more as a special purpose lens for the times you want its special bokeh rendering.

If you like the looks of “classic” harsh bokeh bokeh, the ability to focus close, and if you can live with the flaws this might be a lens for you.
On top of that it is dirt cheap so trying it out certainly won’t break your bank!

If you buy the lens please consider using our affiliate links, we will get a small commission and it wont cost you anything extra.
You can buy the Pentacon 50 mm f/1.8 MC for a little over €20,- at ebay.de (affilitate link) or for around $45 via ebay.com(affilitate link).

More samples

Most images in the review can be found in high resolution in this Flick album.

Pentacon 50 mm f/1.8 @f/1.8

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