Macro lens test rail set-up - a photo on Flickriver

            This is a piece of gear I put together for testing supplemental lenses used on my camera mounted lenses. Using this rig I can test any add-on lens for flatness of field, working distance, field width, depth of field, and other lens characteristics. Here my D40 is set up with a Nikon 105mm f/2.5 AI-S lens. Reverse-mounted for testing on the front of the 105mm is a kodak 7 inch f/3.5 Projection Ektanon lens from a dead Kodak Carousel slide projector. The test subject is a banknote (Clydesdale Bank One Pound) clamped beneath a thin glass plate.  The camera is mounted on a support that provides rotation, allowing the lens to swing in an arc left and right. The stage on the right is set up to enable a mounted subject to swing in an arc left and right as well as up and down. Test subjects are usually bank notes with fine engraving. The stage is set horizontally for mounting a bank note beneath a thin glass plate, which is then carefully clamped in place. The table is then swung down into a vertical position facing the camera. The camera is positioned so that the lens faces straight down the rail, then its support is locked. The stage slide lock is loosened allowing the stage to be moved until the surface of the glass plate contacts the barrel of the lens or component being tested. With the stage's horizontal and vertical rotation locks loosened, the table is carefully manipulated until the full circumference of the lens ring is in contact with the glass. Once this happens, the camera back is absolutely parallel, vertically and horizontally, with the surface of the bank note beneath the glass plate. The stage rotation knobs are then locked and the stage moved back down the rail away from the camera. While you look through the viewfinder, the stage is slowly moved back toward the camera until the bank note image is at its sharpest, then the stage is locked in position. Now it's a simple matter to set a speed and aperture that will produce a decent image. I always use the self timer when working with this set-up. Lighting is provided by overhead fluorescent bulbs, with exposures running from about 1/2 to four seconds depending upon the ISO and aperture used. 
 The "heart" of this setup... the flat rail with lockable articulated sliding stage, is a Baird Stereo Bar, a device used for shooting stereo image pairs, one side at a time, by shifting the camera position between exposures to produce separation, the "stereo base" determined by the focal length of the lens used. I bought this back in 1977 and used it to produce stereo images for a number of years. It has adapted well for use as part of this test rig, and can be ready in minutes for shooting stereo images by removing the temporary bottom supports. 

DSC-8334
   

Taken on: December 27, 2016

Tags:

lens testing

lens hacking

test rail

lens evaluation

supplemental lenses

diopters

closeup

optical

test

add-on

macro

Lens stacking

Lens reversing

Kodak

projection

Ektanon « less

Sets appears in: • Macro-modifications

Groups appears in: • *DIY Photography Equipment • ★★★Shutter Bug - Tips & Tricks★★★ more » • Kodak Projection lenses « less

Camera: Nikon D60, f/11.0, 0.8 sec, 20mm (=30mm), ISO 200 (more info) (hide info)

Camera:	Nikon D60
Aperture:	f/11.0
Exposure Time:	0.8
Focal Length:	20mm (35mm equivalent: 30mm)
ISO:	200
Exposure Bias:	0 EV
Flash:	No Flash
Exposure Program:	Manual
Exposure Mode:	Manual
Metering Mode:	Multi-segment
White Balance:	Manual
Light Source:	White Fluorescent
Color Space:	sRGB
Software:	Adobe Photoshop Elements 6.0 Macintosh
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