Beginners questions

[UncleChip]

For objectives like the MITUTOYO M Plan Apo 2.5x 5x 10x

Is there an advantage of setting up a tube lens arrangement with the Raynolds 150 over using a standard lens?
I have a Carl Ziess contax 80-200f4 sat gathering dust, it’s exceptionally sharp at 200, this could be left as the objective lens

For full frame do I need to get the separate objectives and use them at 200mm? Do I loose sensor coverage with say the 10x at 100mm?

Is there a cheap alternative at the low end of magnification, for me to have a play with before I commit?

Thanks
Steve

[rjlittlefield]

Steve, welcome aboard!

For objectives like the MITUTOYO M Plan Apo 2.5x 5x 10x

Is there an advantage of setting up a tube lens arrangement with the Raynolds 150 over using a standard lens?

I have a Carl Ziess contax 80-200f4 sat gathering dust, it’s exceptionally sharp at 200, this could be left as the objective lens

I assume that you're asking about the Raynox DCR-150. The main advantage of the Raynox is that typical setups do not vignette at all and image quality remains good even out to the corners of a fullframe sensor (36x24mm) . Ordinary telephoto lenses are liable to vignette, even on APS-C, and usually worse with zooms than primes. But there is no way to be sure what will happen except by experiment or finding a test report for the exact same conditions that you care about.

For full frame do I need to get the separate objectives and use them at 200mm? Do I loose sensor coverage with say the 10x at 100mm?

The Mitutoyo objectives differ in their usable image circle. The 10X is pretty good, but you would be hard pressed to get good corners on fullframe with only 100 mm tube lens.

Is there a cheap alternative at the low end of magnification, for me to have a play with before I commit?

I suggest the Nikon CFI BE 4X NA 0.10. Like all Nikon CFI's it is designed to give 4X with a 200 mm tube lens, but it covers APS-C at 2X on 100 mm tube lens, better with its hood removed as shown at viewtopic.php?t=18182 . My initial test report is at viewtopic.php?p=101380#p101380 .

--Rik

[UncleChip]

Thanks for this,

With the MITUTOYO M Plan if I stick to 200mm will they all cover full frame? And is the same for the Nikon flour?

I think it makes more sense to get the best objective I can afford, attaching it to the lens is just 2 cheap adapters so it makes sense I do that first while I put together the tube,

[Macro_Cosmos]

Full frame circle is 42mm, Mitutoyo states 30mm and Nikon objectives top out at 25mm. Yes it will likely "cover" full frame but the corners will see degradation and acceptability of the degradation depends on the person.
I am pretty sure there is no M Plan Apo 2.5x.

[rjlittlefield]

The Mitutoyo's are officially rated at 30 mm image circle, but all reports I've heard are that in practice they cover 43 with not much degradation, given a suitable tube lens. (Note my tests at viewtopic.php?t=23898 , showing that not all tube lenses are equally good in the corners.) The Nikon CFI BE that I mentioned will cover full frame also.

You wrote "Nikon flour", and I do not know if that refers to some different lens. I suspect you intended to write "Nikon fluor" (as In "fluorite"), but the CFI BE 4X NA 0.10 is just an ordinary plan achromat.

--Rik

[UncleChip]

Thx again, I did say I was a beginner

What are the advantages of an infinity objective over a standard objective?

[Sym P. le]

Infinity microscope systems extend opportunities for analyzing images without distorting them. The space between the objective and tube lens is referred to as "infinity space" and this space is utilized to place various optical components within the optical path.

For those of us not availing ourselves of this valuable opportunity, there is no practical difference. In fact, it just creates more work to establish the system. However, since the latest and greatest (all this and then some) is being poured into these objectives, its hard not to go with the flow.

[Macro_Cosmos]

The Mitutoyo's are officially rated at 30 mm image circle, but all reports I've heard are that in practice they cover 43 with not much degradation, given a suitable tube lens. (Note my tests at viewtopic.php?t=23898 , showing that not all tube lenses are equally good in the corners.) The Nikon CFI BE that I mentioned will cover full frame also.

I have found out that it really depends. I can accept the corners of a 10x Olympus (26.5) but I know people who cannot and thus stick to projection eyepieces.
The corners of 4x (2x and 5x, Olympus and Nikon) are just horrible, no mechanical vignetting but even I cannot accept it.

Mitutoyos are far better in that regard, even the 2x is exceptional, provided a good tube lens and adequate mounting is used as illustrated in your thread and several others.


>Standard vs. Infinity
I assume standard means finite.
Practical differences exist but it depends on what you want and what your initial investment figures look like. Infinity is more expensive. For most, it will be similar. If you are going to examine chemical crystals under polarised light or wafers with coaxial, then infinity is the clear way to go.