CZJ Biometar 2.8/80 on Sony a850

iangreenhalgh1 · Expire: 2014-01-07

This is the early 'Star Wars' finish, with nasty plastic focus grip, in P6 mount and using a P6-M42 adapter to mount on my a850.

I always really liked this lens on 6x6 BW film, on digital it doesn't immediately win me over, but I need to try it further. The bokeh and rendering are very nice, but the images are a little flat. Sharpness is good but a little less good than most CZJ lenses for the 35mm format. All these samples are wide open.

#1

100% crop:

#2

#3

#4

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#5

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#6

#7

#8

#9

Lloydy · Expire: 2022-01-01

There's a lot of sharpness there Ian, impressive sharpness. Nice bokeh and rendering as well - as you say. Are they "a little flat"? I wouldn't say they are, they might not have the dramatic punch of many ( popular ) lenses, but what it does have is an honesty about its colour rendition, I'd say it's "natural" - and that's not a bad thing.

RSalles · Posted: Thu Sep 11, 2014 10:39 pm Post subject:

Ian,

Seems to be a really nice lens to my eyes also,

Cheers,

Renato

Gerald · Joined: 25 Mar 2014 Posts: 1196 Location: Brazil

I have 4 copies of Biometar CZJ 80mm F2.8. In terms of performance they are among the best lenses I have. A notable characteristic of the Biometar is a virtually zero lateral chromatic aberration. The Biometar is also an excellent macro lens when used with extension rings or bellows.

The definition of the Biometar wide open is only reasonable. There are subtle traces of residual spherical aberration, but many people will just find this feature interesting for portraiture. At F4 the definition increases considerably, and at F5.6 the lens becomes exceedingly sharp in most of the image. At F8 the definition is absolutely irreproachable from corner to corner. F11 is more or less equivalent to F8, and these two apertures are the best for landscape. At F16 the sharpness drops, but not much, because of the diffraction effect.

A technical and historical curiosity:
The Biometar is a simplified double Gauss lens with five elements, where the rear doublet was replaced by a very bent meniscus. This optical scheme has been used in many lenses, including macro and enlarging lenses. It was used by Canon, Elgeet, Fuji, Leica, Meopta, Minolta, Nikon, Olympus, Schneider, Tomika, Wray, Zeiss Jena and Carl Zeiss Oberkochen.

Minolfan · Joined: 30 Dec 2008 Posts: 3437 Location: Netherlands

Gerald · Joined: 25 Mar 2014 Posts: 1196 Location: Brazil

iangreenhalgh1 · Expire: 2014-01-07

These examples were cherry picked, the overall impression from the shots I made was that the lens produces results that are less sharp and more flat than other CZJ lenses for the 35mm format. This is an early copy, I expect later copies, especially with the MC coating are sightly better.

I'm not saying it's not a good lens, just that this copy doesn't particularly inspire me and many of the shots with it were just flat, lacking somehow.

It does display CA on bright highlights, BTW.

Gerald · Joined: 25 Mar 2014 Posts: 1196 Location: Brazil

As I said before, according to my experience the lateral chromatic aberration of the Biometar 80mm F2.8 is virtually nonexistent. On the other hand, there is some longitudinal chromatic aberration, but it is moderate.

A good way to test a lens for longitudinal chromatic aberration is photographing specular reflections of strong light sources. This type of reflection often occurs in chromed metal parts.

The photograph below shows the reflections from a kitchen faucet. The first crop is from a picture taken with F2.8 aperture. It is possible to see red and cyan fringes around the strongest reflections. Note also a little of glow and softness caused by the residual spherical aberration. This behavior is characteristic of many fast or semi-fast lenses. In the second crop the aperture was reduced to F5.6, virtually eliminating the chromatic aberration. Note also how sharpness improves much when the lens aperture is closed by 2 only stops.

Full image:

100% crop - F2.8:

100% crop - F5.6:

iangreenhalgh1 · Expire: 2014-01-07

Only pedantic people care about such minutiae, even moreso today when there is a button in adobe camera raw to click that will remove CA. Very Happy

Also, it is a waste of time to use a singular example of a lens to make sweeping statements about all other copies of the same design, especially if they are not made at the same time and may well represent different calculations of the prescription, a lens like the Biometar that remained in production for decades no doubt went through several iterations.

Gerald · Joined: 25 Mar 2014 Posts: 1196 Location: Brazil

I'm afraid you do not know the difference between lateral and longitudinal chromatic aberration. The longitudinal chromatic aberration can not be easily removed by post-processing.

Too bad you got a bad copy of Biometar ... Sad

memetph · Joined: 01 Dec 2013 Posts: 942 Location: Poland

iangreenhalgh1 · Expire: 2014-01-07

Newfie · Joined: 04 Mar 2014 Posts: 242 Location: Austin, Texas

Hi guys and gals,

I'd say that it is a very capable lens Ian, the colors are spot on. That last shot is a bit of an inspiration I would say.
An old but goddie lens indeed.

Cheers,

Gavin

Oldhand · Posted: Sun Sep 14, 2014 10:22 am Post subject:

There is no doubt that the CZJ Biometar renders in a unique way and yours seems quite good to me.
I have this lens in later MC variant and I, too sometimes think it looks "flat" for want of a better word.
But it is excellent for sharpness, and I find that the bokeh needs careful "managing" - ie you have to be conscious of the kind of background that it is subjected to.
The old world pastels are one reason to own and use this lens.
On a related topic, I understand that in the shooting of the movie "Saving Private Ryan", there was a considered effort to locate and use older lenses to give an authentic 1944 feel to the D-Day landings cinematography.
Anyhoo, we choose different lenses and their rendering for the joy that they give us in reproduction.
Horses for courses so to speak.
OH

uddhava · Expire: 2021-06-21

Some nice shots there, Ian. I like the last one the best.
I have said this before, you have some beautiful countryside where you live!

Igor · Posted: Wed Sep 17, 2014 7:50 pm Post subject:

very sharp and nice bokeh, great set !