one more question: mitutoyo objectives

[andre reichmann]

dear micro experts , sorry , again with a begginer question

spectra services ( NY state) that i found in the web carries a lot of objectives...

1- is this dealer ok ?

2- i can see they carry both a mitutoyo BD plan apo series and a M plan apo series...
in the 10x category, the m plan is twice the price.... ( 800 vs. 400 us$)
is there any significant diference in there results for photography ?

3- what about the 20x mitutoyo... does it work nicely for photos ? would it work with a 105mm range lens to produce a 10x image ? i ask this because if it does, maybe the 20x would work as a good 20x and 10x objective ( 20mm working diatance seems ok.... )
or would the performance of the 10x be very superior to the 20x objective when working with a 105mm lens ( if it works ... )

thanks a lot once more !!!!

[rjlittlefield]

Good questions.

Short answer: I don't know.

Longer answer...

See http://www.mitutoyo.com/pdf/E4191-378_010611.pdf for a description of the objectives. Based only on experience with Nikon objectives and what I read in the brochure, I would expect the optical performance of the BD and M objectives to be similar. However, the BD has a much larger mounting thread, more like 40 mm rather than 26 mm for the M's. Also you will have to block the illumination channel in the BD to avoid catastrophic veiling glare, and either you'll have to remove the outer barrel or live with the increased diameter and correspondingly somewhat narrower gap to illuminate through.

The 20X has NA 0.42 and it would retain that NA when pushed down to any lower magnification by using a shorter tube lens. This is significantly higher than the 10X NA 0.28, which should translate to both higher resolution and less DOF.

The catch is that I don't know whether the 20X has a sufficiently wide field to keep the corners from going bad if pushed down.

Perhaps somebody who has one of the 20X M Plan Apo's can tell us about the effective field size.

--Rik

[andre reichmann]

Good questions.

Short answer: I don't know.

Longer answer...

See http://www.mitutoyo.com/pdf/E4191-378_010611.pdf for a description of the objectives. Based only on experience with Nikon objectives and what I read in the brochure, I would expect the optical performance of the BD and M objectives to be similar. However, the BD has a much larger mounting thread, more like 40 mm rather than 26 mm for the M's. Also you will have to block the illumination channel in the BD to avoid catastrophic veiling glare, and either you'll have to remove the outer barrel or live with the increased diameter and correspondingly somewhat narrower gap to illuminate through.

The 20X has NA 0.42 and it would retain that NA when pushed down to any lower magnification by using a shorter tube lens. This is significantly higher than the 10X NA 0.28, which should translate to both higher resolution and less DOF.

The catch is that I don't know whether the 20X has a sufficiently wide field to keep the corners from going bad if pushed down.

Perhaps somebody who has one of the 20X M Plan Apo's can tell us about the effective field size.

--Rik

yes, the m version seems to be more straitghforward to be used i guess...
ok, now that you are mentioning it, i realize that the lower NA or the 10x is something to be considered , i get it now ....
it takes some time to "migrate" to the "microscope objective thinking"