Diatoms with my new Canon 600D camera

Jean-marc · Post by **Jean-marc** » Sun Jan 20, 2013 3:19 pm

Arturo, You're welcome,

Hello Dave,

Thank you for the email adress, it will certainly useful for me.
to answer about the CA with the vario orthomat, I do not see any. I used NPL and PL fluotar PL Apo, but also Splanapo Olympus. I do not see any CA. I have to check for the flatness aberration with non Leitz Lens.

Jean-Marc

naturephoto1 · Post by **naturephoto1** » Sun Jan 20, 2013 4:51 pm

Jean-marc,

Beautiful well done set of diatoms.

Rich

Pau · Post by **Pau** » Mon Jan 21, 2013 2:00 am

Cactusdave wrote:One possible issue with the Vario-Orthomat, not mentioned here is chromatic aberration. I've never been clear what, if any additional compensation for CA the Vario-Orthomat applies. I've sort of assumed that as a Leitz eyepiece it might be similar to the compensating Leitz Periplan eyepieces in this regard, but I have no evidence to support this. I have only ever used the Vario-Orthomat with Leitz objectives, and have done very little with highly corrected objectives such as high power plan-apos that might show this issue up. I have no idea whether CA might be a significant problem when the Vario-Orthomat is used with highly corrected objectives from another manufacturer.

Jean-marc wrote:to answer about the CA with the vario orthomat, I do not see any. I used NPL and PL fluotar PL Apo, but also Splanapo Olympus. I do not see any CA. I have to check for the flatness aberration with non Leitz Lens.

Leitz objectives need a considerable amount of eyepiece compensation. About at half XX century the need of correction was also implemented in low power objectives in order to avoid the need to change eyepieces when changing objectives, so all the objectives of the same maker and series are designed with the same need of eyepiece corrections.
You can do the test as I did: put a low power Leitz objective on bellows to make direct projection at the camera sensor and you will get a good image center and a very poor periphery.
The Vario-Orthomat lens is marked Periplan and designed to work toghether with viewing Periplan eyepieces, and all of you say that the image is CA free, so... despite I'd never tried this optic I'm sure it is a compensating one.
Another test to find if an eyepiece is CA compensating is to look just at the limit of the field of view (better outside the microscope pointing to a diffused light source): Compensating ones do show and orangeish halo

(corrected to add info)

discomorphella · Post by **discomorphella** » Mon Jan 21, 2013 2:14 pm

Ok, I suppose I should not just lurk here. I have been using my Vario-Orthomat with its 0.32X lens in a home-machined mount on
my D300 for several years now. You can see some pictures of it in the older post
http://photomacrography.net/forum/viewt ... highlight=

I also have another version that replaces the film back with just a delrin spacer (with room for more optics) for where I don't need the Leitz shutter. In fact, with flash, I almost always use the "shutterless" mount.
I also use the simpler mount with my portable SM-LUX for doing video demonstrations for schools.
Both have a 0.32X lens mounted at the appropriate distance to focus the image onto my D300 sensor. I use this adapter on both an orthoplan
and an Olympus BX-60. Its parfocal with both, and I have never encountered any noticable CA, using Olympus SPlanApo objectives.
One thing I would like to try, once I have time, is to replace the 0.32X /83 mm lens with an ~70 mm FL lens as Charles has suggested.
Since I was not planning to use a more complicated relay system, e.g, a single lens, I will probably choose a very highly corrected lens,
such as one of the Edmund aspherized achromats

http://www.edmundoptics.com/optics/opti ... enses/2953

I will post the drawings (just hand drawings) that I used to machine my holders.
Regards,

Dave

Pau · Post by **Pau** » Tue Jan 22, 2013 9:32 am

discomorphella wrote:...Both have a 0.32X lens mounted at the appropriate distance to focus the image onto my D300 sensor. I use this adapter on both an orthoplan
and an Olympus BX-60. Its parfocal with both, and I have never encountered any noticable CA, using Olympus SPlanApo objectives.

Because new infinte Olympus objectives don't need compensation and Leitz ones do, your observation is very surprising.

discomorphella · Post by **discomorphella** » Tue Jan 22, 2013 6:40 pm

Hi Pau,

I certainly have not been actively looking for CA, such as a proper optical measurement. But I have been using UPlanApo objectives with my BX-60 and the Vario and have not noticed any CA, at least not at a troublesome level. I don't know how corrected the Vario-orthomat zoom lens is compared to other eyepieces. I will try to find out.
Regards.
Dave

Jean-marc · Post by **Jean-marc** » Wed Jan 23, 2013 4:23 am

Hi Pau, Dave,

With the many tests and setup I will operate the next weeks, I will tell you about CA and flatness aberration. As I am using Leitz and Olympus objectives with GW 10/26 leitz and 10/20 olympus eyepieces, I think I have many tests to try with the Vario orthomat

Regards

JM

Jean-marc · Post by **Jean-marc** » Mon Jun 03, 2013 8:15 am

Hello,

First of all, I was busy with my new setup but I followed all the wonderful pics you post here, congratulation for this rich forum.

I have nearly finished my setup with my DSLR Canon 600D, on my Leitz vario. I have choose to use a canon objective between the vario and the reflex. It is easier and I keep the parfocality even I change the magnification of the vario. The tests with some 70-80mm focal lens, are not easy.
I will post soon a new subject in technical discussion forum.
Here is some new pics, shot with my new setup. some are with inside electronic flash. (my new YN460, it seems that my vivitar 285HV has passed out)
Hope those pics are the firsts of a good set !

NPL fluotar 16/0,45; 25/0,55 and Splanapo 40/0,95

Regards

JM