ZM85 focus test

FanMan

FanMan

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Dear fellow ZI/ZM users,

last weekend I made some test shots with the ZM85 and wanted to share the results.

Please be aware that my test was only a user test and is - of course - far from being scientific in precision. I only wanted to know, whether I have to consider a similar front focus as with my C-Sonnar.

My test was done on a tripod, with my ZI placed approx 1 meter from the "focus here" line, and at an estimated angle of 45°. I focused on the "focus here" line by moving the camera and cross-checked the distance with a ruler. On the ruler it was a distance of 98 cm.

The shots are scanned by my local lab without any post processing.


Here we go with the test shots taken with apertures: 2.0 - 8.0. I think that there is a vignetting with 2.0 - but that might be not an issue of the lens itself, since I have an UV-filter attached to the lens.

Film used was Ilford's "XP2 super"

Aperture 2.0

http://farm3.static.flickr.com/2162/2252679144_2db765049c_b.jpg

Aperture 2.8

http://farm3.static.flickr.com/2303/2252679372_d560f67dd5_b.jpg

Aperture 4.0

http://farm3.static.flickr.com/2289/2252679564_d15fff6dc6_b.jpg

Aperture 5.6

http://farm3.static.flickr.com/2079/2252679834_c9978574ac_b.jpg

Aperture 8.0

http://farm3.static.flickr.com/2355/2252680082_d409a99523_b.jpg
 
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here I have another shot - aperture used was 5.6, focus was on the center of the picture (I used the camera's AE mode).

2251920579_2d68e4e1c1.jpg
 
Focus accuracy looks great. There may or may not be the slightest trace of front focus but if so, it's negligable. It may have more to do with the optical characteristic of the lens design or the rangefinder calibration may be coming into play. Nice lens and should give the 90/2 AA a run for the money.
 
Nice image of the chairs, this looks to be a darn nice lens. Tempting to sell the 90/2 AA and go for this, but isn't it a real beast? Could you post a shot of it on the camera?
 
Oh man, that piece of junk is front focusing just like all those blasted Zeiss lenses.
I'll never buy one of those.
Nice bokeh, though.

😀
😉
 
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Focus looks almost spot on to me. Where can I download a copy of that focus test chart? Im having problems with a a RF 40mm Sonnar focusing behind the correct focus point and wouldn't mind doing a similar test to be certain what the cause is.

That's a beast of a lens by the looks, what meter is that on top of the Ikon?
 
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FanMan
This lens has no focus shift, and the test is probably 2mm off, which is well within the human error limits and is totally insignificant. From the look of your test chart I can tell you, the ony lens that gives me this kind of sharpness and contrast is the Makro Planar 100/2 ZF, so you have a great tool in your hands. From your chair shot the bokeh looks nice - if you make any shots at wider apertures make sure to post them please !
 
Captain said:
Focus looks almost spot on to me. Where can I download a copy of that focus test chart? Im having problems with a a RF 40mm Sonnar focusing behind the correct focus point and wouldn't mind doing a similar test to be certain what the cause is.

That's a beast of a lens by the looks, what meter is that on top of the Ikon?
Click to expand...

Captain -

you will find the test chart here:

http://focustestchart.com/chart.html

The meter on the top plate is a Sekonic Twin Mate L-208.

Michael
 
I'm interested in the bokeh, any shots wide open would be appreciated, thanks in advance.

Todd
 
I furthermore tried to test the accuracy of the 85mm framelines in the ZI‘s viewfinder. In the following shot I have chosen the distance to the window pane in the photo, so that the window approximately filled 100% of the 85mm frame. As you can see the actual photo covers more than the viewfinders‘s framelines. It seems that the framelines are more like „90mm“. Again, only a very simple user test. But it shows indeed that the framelines are only an indicator - not as exact as an SLR's viewfinder.

2253651358_544939c03b.jpg
 
visiondr said:
Seriously, that is one sweet lens. I'm not seeing any focus shift.

Michael, why the sekonic on your ZI?
Click to expand...
when I did the test shots I mostly relied on the camera's build in meter (i.e. used the ZI in AE mode) but sometimes I crosschecked the accuracy with the Sekonic.

My Nikon F3 cannot be used in AE mode with the 105mm or the 200mm lens. With AE mode the results are overexposed shots. Therefore with a tele lens attached to the Nikon I set time and aperture manually - based on a measurement with the zoom lens set to 35mm (reflected light) or with a handheld meter (incident light measurement) - that gives me the best results.

The ZI and the 85 mm: the metering was nearly the same. It seems that the build-in meter is also acceptable with the 85mm attached to the camera. But in case of doubt I would always rely in incident light measurement.
 
Nice looking lens! Pity its way way way out of my price range, but looks like a keeper.

Also I dont see any focus shift in that lens, looks really nice.
 
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