Finite Nikon 3x, 5x and 10x Measurescopes objectives

[Clintonwake]

Hi All

I managed to buy the Nikon 3x and 10x (toolmakers measuring lens) and still looking for a 5x measuring m/objective. The lenses have not arrived as yet and I was wondering how to use it. For example, with the finite m/objs, I am aware that if it has a marking of 210 then I stretch the bellows out to 200mm ie from sensor to start of the objective to get the desired magnification.

I am not sure how to 'measure' or ensure I get 3x or 5x or 10x with these finite measuring lenses on a bellows.

I would appreciate any advice or help?

cheers
Denis

[ray_parkhurst]

If you have a ruler with fairly small graduations you can simply adjust the extension until your field of view = sensor dimension / magnification.

[zzffnn]

To add to What Ray said, you can use a stage micrometer slide. A $12 Chinese one is good enough.

[rjlittlefield]

... use a stage micrometer slide. A $12 Chinese one is good enough.

Even better, the price tag on these things keeps dropping. I recently bought http://www.ebay.com/itm/321184672213 , $8.99 with free shipping, which beats my old one by providing two scales: 10 mm x 0.1 mm, and 1 mm x 0.01 mm. It provides a couple of small disks too, but I haven't figured out what to do with those yet.

--Rik

[Clintonwake]

Thanks Ray, zzffnn and Rik

I just ordered one of the scales.

Thanks for you prompt advice

cheers
Denis

[ChrisR]

The Measurescope objectives make a convenient mechanical combination with a conical adapter, which houses the protruding rear ends.

Note it's the M26 x 0.75 not 0.706 pitch.
You measure 210mm from the flange, as with other objectives. You can go +/- a fair bit. Of course - they are telecentric - but you do get some CA.

[Clintonwake]

Thanks Chris for the information.

I will check to see if I have that adapter.

cheers
Denis