Hi,
Maybe somone can help with my question. I have Zeiss C-Apochromat 40x water immersion objective on olympus microscope. Unfortunatly I am getting aberrations in corners,centre is sharp and looks good.
This is infinty corected objective, do you need matching eypiece to properly use this objective? Maybe somone had an exerince with this objective?
Thanks for your help!
Zeiss C-Apochromat 40x 1.20W Sharp Centre
Moderators: rjlittlefield, ChrisR, Chris S., Pau
Zeiss infinite corrected objectives need aberration compensation at the tube lens while Olympus UIS and UIS2 don't.
The Olympus tube lens focal length is 180mm while the Zeiss is 165mm, so magnification will be a bit smaller although this is not very important. *
So their right use is with a Zeiss Axio stand.
Because the radial CA seems similar to the finite Zeiss objectives I think that the image correction will improve if you use compensating eyepieces in your Olympus microscope.
I don't know if there are any Zeiss 30mm compensating eyepieces but there are the Leitz Periplan GW series
For photo the problem seems more difficult to solve at least if you don't use an afocal setup. Shooting raw you must be able to correct the issue at least in a big part during raw conversion with the adequate software like Photoshop
* https://www.microscopyu.com/microscopy- ... al-systems
https://www.zeiss.com/microscopy/int/so ... asics.html
The Olympus tube lens focal length is 180mm while the Zeiss is 165mm, so magnification will be a bit smaller although this is not very important. *
So their right use is with a Zeiss Axio stand.
Because the radial CA seems similar to the finite Zeiss objectives I think that the image correction will improve if you use compensating eyepieces in your Olympus microscope.
I don't know if there are any Zeiss 30mm compensating eyepieces but there are the Leitz Periplan GW series
For photo the problem seems more difficult to solve at least if you don't use an afocal setup. Shooting raw you must be able to correct the issue at least in a big part during raw conversion with the adequate software like Photoshop
* https://www.microscopyu.com/microscopy- ... al-systems
https://www.zeiss.com/microscopy/int/so ... asics.html
Pau
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Hi,
Just as Pau said. The Zeiss ICS has a special tube lens that precisely compensates the CA: https://books.google.co.uk/books?id=IKc ... &q&f=false
The Olympus tube lens doesn't have to do that because CA is corrected within the objective.
The C-Apo 40x/1.20 W gives an outstanding image. You should try to get a Zeiss stand for it to use it's full potential.
Regards, Ichty
Just as Pau said. The Zeiss ICS has a special tube lens that precisely compensates the CA: https://books.google.co.uk/books?id=IKc ... &q&f=false
The Olympus tube lens doesn't have to do that because CA is corrected within the objective.
The C-Apo 40x/1.20 W gives an outstanding image. You should try to get a Zeiss stand for it to use it's full potential.
Regards, Ichty
Hi Guys, thank you very much for your reply. I will have a think about this, will probably get a Zeiss tube lens / trino as this objective works well with DIC set up on Olympus. I attached couple of photos, they could be sharper but was in rush when taking them.
And can confirm Olympus objectives can project a perfect image directly on camera sensor, no need for tube lens or trino, I thought that Zeiss will be the same.
Cheers!
And can confirm Olympus objectives can project a perfect image directly on camera sensor, no need for tube lens or trino, I thought that Zeiss will be the same.
Cheers!
One other point about Zeiss in general - is that their image circle does not hold up well past 18mm. They are beautiful within this FOV, but other vendors are better at covering an APS or even full frame sensor sizes without additional optics past the tube lens. Especially considering a new C-APO like this retails for >$12K.
So if you are using an SLR or mirrorless camera with a sensor larger than 1" - you will get increasingly poorer image quality the farther you move from the central optical axis.
This is why many of Zeiss' own SLR adapters increase the magnification by 1.6-2.5X.
So if you are using an SLR or mirrorless camera with a sensor larger than 1" - you will get increasingly poorer image quality the farther you move from the central optical axis.
This is why many of Zeiss' own SLR adapters increase the magnification by 1.6-2.5X.
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- Joined: Thu Mar 07, 2013 5:24 am
Hi,zed wrote:Zeiss in general
I can see on your website that you've done a lot of imaging with Zeiss instruments. Do you have an example for the loss of quality past FN18?
Because this absolutely doesn't match my own experience. There are some Zeiss objectives that don't have a completely flat field (in favour of higher transmission; that's also the case for the other companies) but those that are rated for flat field and FN25 like the Plan-Apochromat series are absolutely crisp all the way to the edge.
What instrument did you test this on? Zeiss own adapters have a bit of additional magnification, so they might not perform all the way up to FN25. The only fair comparison would be with a direct projection setup, which is difficult as the intermediate image is hard to access on the stands I know - it might work with a mirrorless camera.
Regards, Ichty
Hi Ichty,
If you are using a Zeiss microscope along with an SLR or mirrorless camera of some sort (does not matter) - you are likely already using a photo eyepiece or some other optic that reduces the field of view - so the comment that the ‘Plan-Apochromat series are absolutely crisp all the way to the edge' means that you are likely not sampling from the entire image circle to begin with. If you were - you would have a camera setup that was direct coupled with no optics between the camera and tube lens.
You can test this easily by measuring your FOV with a stage micrometer. With an objective like this (40x/1.2) you would theoretically expect a FOV of 625 microns with a FN25 - but you likely have less than this. And if you are really measuring optical performance using point spread functions the acceptable FOV is less than half of this.
I digress because most in this forum don't particularly care about sub micron optical performance of their microscope - they just want to see nice clean images from edge to edge. I am interested in this as well - and have attempted to couple a full frame DSLR (Nikon D850) to the latest generation AxioObserver, AxioImager, etc. With no additional magnification, the image sensors from these types of cameras are just too large for the image projected from the tube lens directly. I don't have any examples images unfortunately because the results were so bad that I abandoned the project almost immediately. Granted, at the time I was building a microscope from scratch that used lower resolution optics (up to 50x/0.55 NA) - and even a tube lens salvaged from an old Axioskop 2 FS performed identically to the newer models.
I am a little bit bias in these types of conversations because I prefer the lowest magnification with the highest NA I can possibly get - so maximum field of view for any given objective is very important to me. This is especially true when using high resolution sensors on SLRs. These sensors are way overkill for something like a 40x/1.2 optic - but knowing this I want to have the lowest mag possible to minimize the potential of diffraction limiting resolution and more importantly destroying contrast.
Personally, I am very big Zeiss proponent. I have used their systems for over 20 years, worked for their advanced imaging group for 13 of those years and continue to use their instruments in biological research today. While their optics and engineering are second to none in my opinion - they just make very rigid and unfortunate decisions in their designs that make them difficult to work with when you are custom building or modifiying things like many in this community. I once saw a guy at the Marine Biological Laboratories in Woods Hole (won't name names) that had an old t-shirt that said 'Zeiss is nice - at twice the price'. I just hate to see people spending tons of $$ on these components and have them be so inflexible.
Cheers!
-Jason
If you are using a Zeiss microscope along with an SLR or mirrorless camera of some sort (does not matter) - you are likely already using a photo eyepiece or some other optic that reduces the field of view - so the comment that the ‘Plan-Apochromat series are absolutely crisp all the way to the edge' means that you are likely not sampling from the entire image circle to begin with. If you were - you would have a camera setup that was direct coupled with no optics between the camera and tube lens.
You can test this easily by measuring your FOV with a stage micrometer. With an objective like this (40x/1.2) you would theoretically expect a FOV of 625 microns with a FN25 - but you likely have less than this. And if you are really measuring optical performance using point spread functions the acceptable FOV is less than half of this.
I digress because most in this forum don't particularly care about sub micron optical performance of their microscope - they just want to see nice clean images from edge to edge. I am interested in this as well - and have attempted to couple a full frame DSLR (Nikon D850) to the latest generation AxioObserver, AxioImager, etc. With no additional magnification, the image sensors from these types of cameras are just too large for the image projected from the tube lens directly. I don't have any examples images unfortunately because the results were so bad that I abandoned the project almost immediately. Granted, at the time I was building a microscope from scratch that used lower resolution optics (up to 50x/0.55 NA) - and even a tube lens salvaged from an old Axioskop 2 FS performed identically to the newer models.
I am a little bit bias in these types of conversations because I prefer the lowest magnification with the highest NA I can possibly get - so maximum field of view for any given objective is very important to me. This is especially true when using high resolution sensors on SLRs. These sensors are way overkill for something like a 40x/1.2 optic - but knowing this I want to have the lowest mag possible to minimize the potential of diffraction limiting resolution and more importantly destroying contrast.
Personally, I am very big Zeiss proponent. I have used their systems for over 20 years, worked for their advanced imaging group for 13 of those years and continue to use their instruments in biological research today. While their optics and engineering are second to none in my opinion - they just make very rigid and unfortunate decisions in their designs that make them difficult to work with when you are custom building or modifiying things like many in this community. I once saw a guy at the Marine Biological Laboratories in Woods Hole (won't name names) that had an old t-shirt that said 'Zeiss is nice - at twice the price'. I just hate to see people spending tons of $$ on these components and have them be so inflexible.
Cheers!
-Jason