Objective Upgrade?

Claytown · Post by **Claytown** » Tue Feb 27, 2018 2:08 pm

After comparing the eyepiece to the DSLR adapter, I'm starting to think maybe just going the afocal route would be an upgrade in and of itself. It also sounds like I'd have more options for objective upgrades. What sort of mount would I need? I have a Canon T2i and a series of lenses including a 100mm macro and a 50mm f/1.8 (which sounds like the way to go).

Ichthyophthirius · Post by **Ichthyophthirius** » Tue Feb 27, 2018 2:50 pm

Claytown wrote:What sort of mount would I need?

This is a very good and widely used setup:

http://www.photomacrography.net/forum/v ... 647#224647

- Zeiss clamp adapter for a monotube with outside diameter approx. 25 mm (good price would be around $30; alternative is a Pentax microscope adapter to M42: https://www.pentaxforums.com/forums/mem ... 48806.html )
- dovetail adapter (the original might be difficult to get; you can replace it with this one https://www.ebay.com/itm/142376786985 RafCamera T2-DT43.5)
- adapters to filter thread
- 50 mm camera prime lens is OK; 40 mm is better as it gives a larger field; old analog camera lenses are more mechanically robust; I recommend the Pentax SMC 40/2.4 https://commons.wikimedia.org/wiki/File ... ancake.jpg but can definitely make a start using the 50/1.8); lens has to be dust-free
- you almost certainly need a mini-tripod or similar support for the weight of the camera

+ 10x high eyepoint /glasses eyepiece matching your choice of microscope objectives

ChrisR · Post by **ChrisR** » Tue Feb 27, 2018 3:44 pm

There's a Konica Hexanon 40mm f/1.8 Pancake(ish) too, which I have been told works well.

Ichthyophthirius · Post by **Ichthyophthirius** » Tue Feb 27, 2018 5:02 pm

ChrisR wrote:There's a Konica Hexanon 40mm f/1.8 Pancake(ish) too, which I have been told works well.

The flange focal distance of the AR mount is too short (40.5 mm vs. Canon EF 44.0 mm). On an EOS 550D, it would require a special adapter with optics to focus to infinity. Is there an M42 version?

https://en.wikipedia.org/wiki/Flange_focal_distance

A lot of others work with simple mechanical adapters, like Nikon F, Pentax K, Olympus OM, Prakticar B (PB) and M42x1.

ChrisR · Post by **ChrisR** » Tue Feb 27, 2018 5:14 pm

I see what you mean. That extension would mean (assuming the adapter were zero length) the lens focusing at 396mm. If there's only one eyepiece (no parfocality issues), would that matter much? I remember focusing on a the desk with the other eye to draw things while looking down the scope - I assume both eyes were focused at the same distance?

Ichthyophthirius · Post by **Ichthyophthirius** » Tue Feb 27, 2018 6:00 pm

Hi Chris,

I have only focused away from infinity once before because of a hotspot. It was still usable. However, you don't actually buy a mechical adapter AR to EOS, never mind a short one (had a quick search).

The Pentax starts at $60, the Konica at $40. There's not a lot of money to be saved.

Claytown · Post by **Claytown** » Tue Feb 27, 2018 11:27 pm

Ugh, I'm getting a headache trying to weigh my options. Doing some more side by side comparisons of the dslr vs shooting through the eyepiece, there doesnt seem to be much noticeable difference, or at least not that I can tell in my crude tests.

I think I might just go for a solid objective and see where that gets me with the dslr adapter. At least then I'll have a nice piece of glass and if I'm still not getting the results I'm after, I can change over to an afocal setup.

I found this objective on ebay. Does it happen to be a CF of CFN?
https://www.ebay.com/itm/Nikon-Plan-Apo ... Swax5YyBre

Are there any Nikon CF of CFN objectives that are plan flourite?

Pau · Post by **Pau** » Wed Feb 28, 2018 1:41 am

Claytown wrote: I have a Canon T2i and a series of lenses including a 100mm macro and a 50mm f/1.8 ...

If you have a tripod or a repro stand you can test the afocal approach before buying any part: just put the 50mm in manual focused to infinite full open placed with the front lens well centered and very close to the eyepiece.
You will get 2X relay magnification, the same than with you adapter, so you can compare them very well.
Did you see the first page of my afocal thread?
http://www.photomacrography.net/forum/v ... hp?p=99265

I found this objective on ebay. Does it happen to be a CF of CFN? ...

Not sure, but it seems old pre CF style.
You can download the CF catalog stored by our forum fellow Charles Krebs
www.krebsmicro.com/Nikon_CF.pdf

Claytown · Post by **Claytown** » Wed Feb 28, 2018 2:20 am

Ichthyophthirius wrote: P.S.: Don't forget you can also stich together several fields of view, which gives nice images for large prints.

I'm considering giving this another shot after reading about some of the various pitfalls involving parallaxing.

Now my main question for is, would I better off getting a cheap Plan Achromat like this: https://www.amazon.com/AmScope-Plan-Ach ... omatic+10x

or

going for the Wild Fluotar (provided my stage goes high enough, which it looks like it does. Is there an optimal way of figuring that out?)
https://www.ebay.com/itm/Wild-Heerbrugg ... 1438.l2649

My thinking with the cheap Plan is that the images will stitch together more accurately and easily

My thinking with the Fluotar is that the colors might line up better and produce the better image especially while focus stacking. It would also just be nice to achieve a crisper image without stitching. However, the tiles might not stitch together as easily around the edges? I'm not really sure if my thinking is correct here

ChrisR · Post by **ChrisR** » Wed Feb 28, 2018 3:51 am

Ichthyophthirius wrote:Hi Chris, ...
The Pentax starts at $60, the Konica at $40. There's not a lot of money to be saved.

Much bigger ££ difference in the UK, none here near $60!. I thought the same about the AR mount but I believe it's the "Konica Minolta", and MD adapters are common. Can anyone confirm?

Claytown - there are fluor Nikon CFs, though not many. There's a 10x NA 0.5, but I haven't seen any comments about it. Plan apos have very small image circles so I'd avoid those. A known well bahaved plan achro, stitched as necessary, would be the way I'd go.

Pau · Post by **Pau** » Wed Feb 28, 2018 4:07 am

Chris, I want to point that here we are speaking about the use of microscope objectives as designed in a non wide field microscope. Any objective will cover the 18mm (maximum 20mm) field of the eyepieces.
In macro setups and direct projection where people want to fill sensors bigger than 18-20mm diagonal is where image circle limitations arise

Ichthyophthirius · Post by **Ichthyophthirius** » Wed Feb 28, 2018 4:22 am

Claytown wrote:I found this objective on ebay. Does it happen to be a CF of CFN?
Nikon CF Plan Apo 10/0.40

Are there any Nikon CF of CFN objectives that are plan flourite?

That's a Nikon CF Plan Apo 10/0.40; the early-style CF version. I haven't tried this one but I have tested the CF 20/0.60 and it is very good in brightfield but not in Pol. If you buy it (it is a bit expensive), make sure you test it in Pol and can return it if you don't like it. This is a good seller; there is a 14 day return period which is nice if you are in the US.

The poor performance in Pol not a defect; early Planapo objectives often perform poorly in Pol. The later CFN Plan Apos were better performers (in my experience).

The CFN Plan Fluor look similar to the CFN Plan https://www.ebay.com/itm/372043416559 but they are quite rare and usually expensive. They were only made for a short time before Nikon switched to infinity objectives (CFI60).

There are also CF Fluor objectives (non-plan), see the Pau's link. I tried to buy a CF Fluor 10/0.50 twice; both were full of dust on internal lenses and I returned them. This particular objective seems poorly constructed. The CF Fluor 20/0.75 is great (but not plan). https://www.terapeak.com/worth/nikon-mi ... 400561482/

Ichthyophthirius · Post by **Ichthyophthirius** » Wed Feb 28, 2018 4:37 am

ChrisR wrote:Plan apos have very small image circles so I'd avoid those.

This shouldn't be an issue for use on this microscope. It will be used either with a 2x DSLR adapter or with afocal (10x eyepiece, 40 mm lens) which easily covers the sensor.

The CF Plan Apo should be sufficient to cover field number 26.5 (CFUW 10x/26.5 eyepieces) on Nikon's ultra widefield microscopes of the time?

Ichthyophthirius · Post by **Ichthyophthirius** » Wed Feb 28, 2018 5:02 am

The Pentax starts at $60, the Konica at $40.

18 Feb 2018 https://www.ebay.co.uk/itm/323068106980
17 Feb 2018 https://www.ebay.co.uk/itm/391976890529
22 Jan 2018 https://www.ebay.co.uk/itm/152870294398
16 Jan 2018 https://www.ebay.co.uk/itm/152862213151

In the UK it starts at £40 with cosmetic damage; £60 for lens in good condition. The Pentax is quite affordable and suited perfectly to afocal adaptation so I tend to recommend it. It tested well: http://www.mikroskopie-forum.de/index.p ... #msg147136

Claytown · Post by **Claytown** » Wed Feb 28, 2018 8:43 am

Ichthyophthirius wrote:
That's a Nikon CF Plan Apo 10/0.40; the early-style CF version. I haven't tried this one but I have tested the CF 20/0.60 and it is very good in brightfield but not in Pol. If you buy it (it is a bit expensive), make sure you test it in Pol and can return it if you don't like it. This is a good seller; there is a 14 day return period which is nice if you are in the US.

The poor performance in Pol not a defect; early Planapo objectives often perform poorly in Pol. The later CFN Plan Apos were better performers (in my experience).

What kind of poor performance would I be looking out for on a Plan Apo? Even if the Pol performance was similar to your experience with the CF 20/0.60, how much of an improvement (or lack of improvement) would it be for me compared to my current stock lens?

ChrisR wrote: A known well bahaved plan achro, stitched as necessary, would be the way I'd go.

Can you recommend a known well behaved plan achro?