Relief Contrast

[photomicro]

I have an odd filter pair labelled ‘Relief Contrast’ that I am led to believe is perhaps for a DMiL inverted…any ideas?

I show it below;

[MicroBob]

I would suggest that they are not made to be used together. They do the same, offer some kind of oblique lighting, but are probably for use in different microscopes. What are the diameters?
The mount looks professionally made. Does it look as if the filter is also profesionally made, or have they been combined later?

[photomicro]

I would suggest that they are not made to be used together. They do the same, offer some kind of oblique lighting, but are probably for use in different microscopes. What are the diameters?
The mount looks professionally made. Does it look as if the filter is also profesionally made, or have they been combined later?

They were in the same bag, and are both professionally made.

the larger part is around 28mm diameter, the smaller 19mm

[MichaelG.]

They were in the same bag, and are both professionally made.

the larger part is around 28mm diameter, the smaller 19mm

I would guess then, that the 19mm is an insert for an eyepiece, and the 28mm fits onto the condenser.

MichaelG.

[zzffnn]

I cannot see clearly from those photos. Does the 28mm filter have two semitransparent areas, in addition to the opaque half? How about the 19mm filter?

Without semitransparent areas, if the 19mm can be placed at objective back focal plane (which is usually not difficult for low power, but difficult for high power), and the 28mm placed at condenser back focal plane, then you can run schlieren contrast:

http://www.microscopy.cz/html/2514.html

But it seems that the 28mm has two more semitransparent areas, which are usually not used for schlieren contrast (light lost would be way too much).

With true "relief contrast", you usually use only one. But some people out one at condenser back focal plane and rotate another one on field iris to fine tune contrast. That 19mm is slightly too small for that, but may still work.

[MichaelG.]

If the results are as good as illustrated here; finding out how best to use them would be very worthwhile:
https://sciencellonline.com/blog/how-to ... -pictures/

MichaelG.

[photomicro]

I cannot see clearly from those photos. Does the 28mm filter have two semitransparent areas, in addition to the opaque half? How about the 19mm filter?

Without semitransparent areas, if the 19mm can be placed at objective back focal plane (which is usually not difficult for low power, but difficult for high power), and the 28mm placed at condenser back focal plane, then you can run schlieren contrast:

http://www.microscopy.cz/html/2514.html

But it seems that the 28mm has two more semitransparent areas, which are usually not used for schlieren contrast (light lost would be way too much).

With true "relief contrast", you usually use only one. But some people out one at condenser back focal plane and rotate another one on field iris to fine tune contrast. That 19mm is slightly too small for that, but may still work.

Apologies for late reply to this, I have been away for a few days.

In relation to the 28mm part, the one half is silvered so that no light passes, the other is in 3 sections, of which the outer two are silvered such that light does pass through. The middle one in-between these is clear.

I attach a picture of the small bag they were in, to see if the numbers make any sense.

[coominya]

If the results are as good as illustrated here; finding out how best to use them would be very worthwhile:
https://sciencellonline.com/blog/how-to ... -pictures/

MichaelG.

Pretty good link MG, a lovely synopsis of Focus, Exposure, and the need to configure the scope correctly.

So which area of the cell should you focus on? For phase and relief contrast that use transmitted light to view the entire cell, you often want to focus down on the thinnest part (Figure 4A) and not up on the cell body (Figure 4B). In order to do this, look at the outermost perimeter of the cell and adjust the fine focus knob until that region is sharp.

I'll give this a go and see what the results look like.
Fascinating hobby.