MicrobeHunter.com Microscopy Forum

Just to be clear, the prism can only come out if you have loosened the four screws and removed the holder from the nosepiece.

viktor j nilsson wrote: ↑

Sat Dec 11, 2021 4:04 pm

Just to be clear, the prism can only come out if you have loosened the four screws and removed the holder from the nosepiece.

Oh ok - that's a shame, then - I misunderstood...
Thanks
Louise

Have I been wrong to put the analyser between the tube lens and the eyepiece/camera sensor all this time? Wondering if that's the reason I'm not achieving DIC... Originally, I didn't think it would matter that much but now I'm beginning to wonder. I can easily change it, if necessary. It seems logical to place it in the infinity space, but I'm not 100% sure whether it's actually essential. Maybe someone could confirm? I might try and move it tomorrow.

Cheers

Louise

I believe the distance between the top prism and the analyzer matters, thoigh I may be wrong on that. You'd definitely want to put it below the tube lens for optical reasons anyway.

Scarodactyl wrote: ↑

Wed Dec 15, 2021 11:07 pm

I believe the distance between the top prism and the analyzer matters, thoigh I may be wrong on that. You'd definitely want to put it below the tube lens for optical reasons anyway.

It could be the reason why I've not been able to get it to work as expected even though I can see both the condenser and objective dark fringes. Rathi et al. put their objective prism and analyser after their relay optics. But I suppose the relay optics changes things. However, it made me think it would be ok to put the analyser later in the train. It seems quite rare that descriptions and diagrams include infinity optics and they nearly all just show the finite versions. But I read some useful info here earlier: https://www.olympus-lifescience.com/en/ ... ightpaths/. My eyes were opened! At least now I know.

Louise

Have rearranged the tube components now so the analyser is in the infinity space. Unfortunately, one of the tube rings broke so am printing out another (stronger!) one
Hope to give it a test tomorrow. I'm also thinking of setting up an alternate, finite tube. Should be quite straightforward to do that. I've also acquired a Zeiss Inko DIC and Phase condenser (old type, single arrow, 4 prisms) . Not sure whether any of the Zeiss prisms might work with any of the Nikon objective prisms (on paper they shouldn't but you never know!). Still, the better quality condenser optics is a nice to have anyway plus it's something to play with over Christmas - if I can somehow find a way to fit it!

Louise

One thing to note - the polymer (Sanderson and other configurations) DIC prism contrast levels (maximum extinction) that I have been able to reach are less than with the quartz original DIC prisms. Effect is there but does not give the almost black DIC view. I suspect the gradients are not uniform enough in both prisms, maybe caused of thickness variations or other geometry properties.

LouiseScot wrote: ↑

Wed Dec 15, 2021 9:18 pm

Have I been wrong to put the analyser between the tube lens and the eyepiece/camera sensor all this time? Wondering if that's the reason I'm not achieving DIC... Originally, I didn't think it would matter that much but now I'm beginning to wonder. I can easily change it, if necessary. It seems logical to place it in the infinity space, but I'm not 100% sure whether it's actually essential. Maybe someone could confirm? I might try and move it tomorrow.

tpruuden wrote: ↑

Wed Dec 22, 2021 1:38 am

One thing to note - the polymer (Sanderson and other configurations) DIC prism contrast levels (maximum extinction) that I have been able to reach are less than with the quartz original DIC prisms. Effect is there but does not give the almost black DIC view. I suspect the gradients are not uniform enough in both prisms, maybe caused of thickness variations or other geometry properties.

LouiseScot wrote: ↑

Wed Dec 15, 2021 9:18 pm

Have I been wrong to put the analyser between the tube lens and the eyepiece/camera sensor all this time? Wondering if that's the reason I'm not achieving DIC... Originally, I didn't think it would matter that much but now I'm beginning to wonder. I can easily change it, if necessary. It seems logical to place it in the infinity space, but I'm not 100% sure whether it's actually essential. Maybe someone could confirm? I might try and move it tomorrow.

Hi
Well I've only been trying to implement the condenser prism as I now have a Nikon DIC nosepiece. The moving of the analyser into the infinity space doesn't seem to have made any difference. I wondered about the quality of the condenser which up to now has just been one of the cheap Abbe ones. But I now have a decent Zeiss DIC condenser which I'm working on. I'm not sure whether any of the condenser prisms will work with any of the nosepiece prisms. Will be great if they do! But, if not, the actual condenser part ought to be a big improvement. The Zeiss brightfield setting does at least give me the expected 'cross' shape with cross polarisers - my cheap condenser did not (maybe too much distortion?). It's been an interesting and educational project, if nothing else!
Louise

As I understand - changing condenser prism distance to condenser allows slight tuning and matching the shear to objective prism shear.

LouiseScot wrote: ↑

Wed Dec 22, 2021 1:58 am

I'm not sure whether any of the condenser prisms will work with any of the nosepiece prisms. Will be great if they do! But, if not, the actual condenser part ought to be a big improvement.

tpruuden wrote: ↑

Thu Dec 23, 2021 5:12 am

As I understand - changing condenser prism distance to condenser allows slight tuning and matching the shear to objective prism shear.

LouiseScot wrote: ↑

Wed Dec 22, 2021 1:58 am

I'm not sure whether any of the condenser prisms will work with any of the nosepiece prisms. Will be great if they do! But, if not, the actual condenser part ought to be a big improvement.

I can't easily change rhe Zeiss prism distance but will have some leeway with the Sanderson prism.

Thanks

Louise

LouiseScot wrote: ↑

Wed Dec 15, 2021 9:18 pm

Wondering if that's the reason I'm not achieving DIC

My Optiphot EPI DIC BD nosepiece has a lens just above the objective turret,
presumably to compensate distance added by DIC prism sliders;
Perhaps your EPI DIC M-Plan objective nosepiece has a similar lens?
That could throw off infinity objectives...

blekenbleu wrote: ↑

Mon Nov 28, 2022 3:30 pm

LouiseScot wrote: ↑

Wed Dec 15, 2021 9:18 pm

Wondering if that's the reason I'm not achieving DIC

My Optiphot EPI DIC BD nosepiece has a lens just above the objective turret,
presumably to compensate distance added by DIC prism sliders;
Perhaps your EPI DIC M-Plan objective nosepiece has a similar lens?
That could throw off infinity objectives...

Hiya

I'm not 100% certain but I don't think so - mine isn't BD. To be honest, I've not tried to do anything with it for quite a long time. I'm always getting side tracked by this and that, and life!

Louise