Free Shipping on ALL Products
camera reviewsbest cameraslens reviewsphotography tipscamera forumvideo toursphotography bookssupport me
It is currently Fri Apr 18, 2014 8:17 am

All times are UTC




Post new topic Reply to topic  [ 1 post ] 
Author Message
 Post subject: Zeiss Stemi 2000
PostPosted: Sat Jul 02, 2011 10:09 am 
Offline
User avatar

Joined: Sun May 25, 2008 12:48 pm
Posts: 7997
Location: UK
Something a little different here. A microscope at work. Obviously caught my attention due to the blue logo on it...

Image

This is the Carl Zeiss Stemi 2000 stereo microscope. This is similar to binoculars in that there are two optical paths, one for each eye. They're deliberately angled so you get a stereo image as opposed to two identical images. The fun part here is there is an optional camera attachment, and you can get adapters for common camera mounts. I will be using it with EOS mount.

Image

A detented knob lets you select magnifications from 0.65x to 5x at approximately 3 steps per doubling. It seems to be parfocal so you don't need to refocus when you change magnification.

Image

This fitted lens modifies the magnification and working distance. With this 0.3x option lens fitted, the working distance is a massive 285 mm. Without it, it is only 92mm.

Relating the set magnification to effective photographic magnification turned out to be rather convenient. With the 0.3x lens fitted, the optical magnification was half that of the scope value. e.g. 5x setting gave 2.5x optical. Without the 0.3x lens fitted, this increases to about 8x magnification.

Focusing is dependant on the mount. You need to move the whole scope relative to the subject to focus. Photographically there is no aperture adjustment. What you see is what you get, with limited depth of field. I suspect the microscope is providing diffraction limited images to the camera.

I don't know how big the image circle is. It easily covers the whole of an APS-C sensor.

Image

Here is one resized full sample taken without the reducing option lens fitted. The image is of a chip as may be found in tiny electronic devices, and shows the solder balls.

The scope can show longitudinal chromatic aberrations as can be seen above with the purple and green fringing, although that is a high contrast test so worst case. It is still visible in lower contrast scenes. Lateral chromatic aberration doesn't appear to be an issue, unless you fit the 0.3x option lens. I don't recall if it was a single or multiple element assembly, but it is a single assembly that fits under the two optical paths. Relative to the optical axis, it is not perpendicular to either of them. Whatever the mechanism, this gives noticeable blue/red lateral CA when in place. This is only really significant viewing photos, and not through the eyepieces.

To recap, for comparison with photographic macro lenses, this can give up to 8x magnification at a working distance of 92mm. With an optional 0.3x lens, you can get up to 2.5x magnification at 285mm working distance. I think if you want to do extreme macro, this might be a possible consideration over more extreme photographic lenses, providing you can work without adjustable aperture.

One side note: photos of the microscope here were taken with the Zeiss 2/50 makro planar.

_________________
Canon DSLRs: 7D, 5D2, 1D, 600D, 450D full spectrum, 300D IR mod
Lenses: EF 35/2, 50/1.8, 85/1.8, 135/2+SF, 28-80 V, 70-300L, 100-400L, TS-E 24/3.5L, MP-E 65, EF-S 15-85 IS
3rd party: Zeiss 2/50 makro, Samyang 8mm fisheye, Sigma 150 macro, 120-300 f/2.8 OS, Celestron 1325/13
Tinies: Sony HX9V.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 1 post ] 

All times are UTC


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  

All words, images, videos and layout, copyright 2005-2012 Gordon Laing. May not be used without permission.
/ How we test / Best Cameras / Advertising / Camera reviews / Supporting Camera Labs

Webdesign by Alphabase IT
Powered by phpBB® Forum Software © phpBB Group