Rheinberg filter test

Jan l'Amie · Post by **Jan l'Amie** » Thu Nov 17, 2011 1:18 am

Just this week I noticed Rheinberg filters for the first time so I made some the usual way with this result. I bought a couple of sheets of foil and circle cutters they use for scrapbooking so I can make a lot of different shapes. I will try to make some like yours. Thanks very much.

Wim van Egmond · Post by **Wim van Egmond** » Thu Nov 17, 2011 1:42 am

Jan, Some time ago I wrote some articles for Micscape that may give some suggestions. After I wrote the articles I started to use polar filters for the inside stop.

http://www.microscopy-uk.org.uk/mag/art ... trast.html

http://www.microscopy-uk.org.uk/mag/art ... iydic.html

Wim

Jan l'Amie · Post by **Jan l'Amie** » Thu Nov 17, 2011 2:02 am

Very interesting Wim. Thanks very much. Results will follow.

Jan l'Amie · Post by **Jan l'Amie** » Thu Nov 17, 2011 7:34 am

I don't untherstand it anymore !!

Today I made those two filters, 32 mm with 16 mm stop.
For both I used the same materials, the base is transparant acrylat foil,
black is black sticky foil, blue is transparant blue sticky foil.

With these results. Photo 1 is made with ,,your,, filter, photo 2 is made with the moonshaped. Photo's are made with a Plan 10/0.25 objectiv.

Schiet mij maar in een pudding.

Litonotus · Post by **Litonotus** » Thu Nov 17, 2011 8:15 am

it is not the same I posted. My old circular filter has something like darkfield stop with a transparent part inside, that is important.

I made a lot of black circles and I looked through the eyepiece to find the correct diameter for each objective. If I remember well 16mm is way to much for 10/0,25 objective, it was about 4-6mm, and it was hard to cut that very little circle for the coloured part inside of it.

Jan l'Amie · Post by **Jan l'Amie** » Thu Nov 17, 2011 8:20 am

I don't think the small black segment has so much effect but I will make another one. At this moment I have only circle cutters for 32 and 16 mm.
This photo I made with the same moonshaped filter and a Plan 40/0.65 objectiv.

Litonotus · Post by **Litonotus** » Thu Nov 17, 2011 8:26 am

Jan l'Amie wrote:I don't think the small black segment has so much effect

It has. the more light goes from the center of the filter the weaker relief/DIC like effect you get.

I printed black circles on the foil (diameters 4, 5, 6, 7 mm etc).

Jan l'Amie · Post by **Jan l'Amie** » Thu Nov 17, 2011 10:35 am

I made another one. The same as before but now with a 3 mm black segment next to the blue stop. I have now a sharper colour view but no DIC effect at all.
I read once somewhere that the open light segment never may be wider than half the diameter of the filter. In your filter is this the blue centre stop plus the open segment seperated only by the little black segment so it is much over the centre of the filter.
Could it be the difference between your and mine microscope ?
My filtertray is direct unther the condenser.
I also made two new blue stop (so only a small blue circle on the transparant filter) filters. One from 8 mm and one from 10 mm.
I made this small circles with sharpened pieces of aluminium pipe and a hammer but this worked only once.

The 8 mm works great for the 4x objective and a little for 10x, but not for
25x and 40x.
The 10 mm works for 10x and a little for 25x.
The older 16 mm one works for 10x and 25x but just a very little for 40x.
I think I have to make a 20 mm one for the 40x.

Litonotus · Post by **Litonotus** » Thu Nov 17, 2011 10:47 am

one more thing. the one on the left is the 32mm diameter filter. on the left is what is seen through the eyepiece.

I don't remember precise dimensions, I gave up making those filters months ago after inventing the universal one.

It requires experiments, I remember colour foil pieces all around my desk...

Mitch640 · Post by **Mitch640** » Thu Nov 17, 2011 10:54 am

I made this small circles with sharpened pieces of aluminium pipe and a hammer but this worked only once.

Punch Set?

Jan l'Amie · Post by **Jan l'Amie** » Thu Nov 17, 2011 11:16 am

Litonotus, I know what you mean. I'm just making them for 3 days and allready now is everything foil pieces. Ik will try to make some with a printer, maybe this gives a difference. I also will try to make your universal filter. Could this also work with colours ?

Mitch, I have two scrapbook circle ponses now for 32 and 16 mm and I'm looking for smaller ones.

Litonotus · Post by **Litonotus** » Thu Nov 17, 2011 11:28 am

my universal filter works great with colours too, I will show the new version soon (:

Mitch640 · Post by **Mitch640** » Thu Nov 17, 2011 11:31 am

Jan, that set starts at under 4mm and goes to just smaller than 20mm.

Jan l'Amie · Post by **Jan l'Amie** » Thu Nov 17, 2011 11:37 am

Do you have more info about that and where to get it ?
I live in The Netherlands.

Mitch640 · Post by **Mitch640** » Thu Nov 17, 2011 11:42 am

Only that you can order it from Amazon.com. Do you have that there?