No tool required?

[Plasmid]

Question

What effect is there if one were to remove the diffuser filter on a microscope below the field diaphragm..... Said filter is held in place by a large ring with two small indentions/slot on opposite sites of the diameter , what tool is used to remove this ring?

[dtsh]

Perhaps a snap ring? If so there are special plier sets for them, frequently encountered in automotive and other mechanicals.

[hans]

Sounds like a threaded retaining ring. Search "spanner wrench optics" for example shows some of the types of tools available. I have not tried the inexpensive ones sold for camera lens repair but they look kind of flimsy for use on older stuff where the retaining rings are often seized up. So far all the retaining rings I have needed to get out were reachable using two slotted screwdriver bits held in a pair of locking needle-nose pliers. Awkward to get the bits clamped in the right position but very rigid once locked.

[MicroBob]

Does it look similar to the rings that hold the glass in camera filters? These are usually screwed in as Hans has described. I somtimes clamp slot screw bits in a machinist vise in the right distance and set the part onto them from above. Before you start working you might put a disc of cardboad or plastic on to of the cleaned glass filter so you don't scratch it as easily.

[dtsh]

I wasn't visualizing what you were describing!

Thats a type of spanner like this:

23cb90f1b57f4e95a7c93f829f017354.jpg (32.19 KiB) Viewed 2919 times

I have sometimes been able to spin them loose with a pin or screwdriver in one slot and gently pushing to make it rotate, but it's easy to slip and scratch things that way.

[apochronaut]

If the slots are on opposite sides , it is likely a threaded retaining ring. I have a epecialized set of needle nose pliers that have the jaws bent at a right angle and ground to a finer point for many of those. I also bought a lens ring spanner on ebay for 12.00. It has two reversible bits in it. s!ot on one end and point on the other. It gets down to about 1/2cm.
Hans' system is also a good one, if you have the bits and needle nose vicegrips.

If the ring has holes close together it is a kind of circlip. Dedicated spring loaded circlip pliers with expandable or contractable jaws bent at various angles are available. I bought a cheap set of 4 years ago and they are very good about what I would call mid-grade. Nice drop forged jaws. A lot for 6.00. I haven't come across a circlip that I can't get out since. I had to emery the points down a little.


I just saw dtsh's post. That is a similar spanner to mine.

[Plasmid]

Awesome, thank you all, the rink seems to be pretty stuck, I've considered the flat head tap tap tap approach but don't want to damage it I got a pair of spare compression ring pliers that I'll probably modify the tips like mentioned above.

[Plasmid]

I remember reading that ND filters need to be changed from time to time, how does one know when the filter is shot? And is there any other alternatives out there as in different opaque levels and or other filters lile lambda or retarder plates that can be used?

After removing the ND filter the images under polarize light become more contrasted and brighter, but it renders the 4X objective due to uneven illumination.

[dtsh]

I remember reading that ND filters need to be changed from time to time, how does one know when the filter is shot? And is there any other alternatives out there as in different opaque levels and or other filters lile lambda or retarder plates that can be used?

After removing the ND filter the images under polarize light become more contrasted and brighter, but it renders the 4X objective due to uneven illumination.

Sounds to me like the ND is dispersing the light some. I know some microscopes (AO for example) use an auxiliary lens to change the cone of light for lower power objectives, that might be an option.

auxiliary_lens.jpg (93.87 KiB) Viewed 2875 times

[Plasmid]

Aahhh yes , I have one of those 1087 in a drawer somewhere, thank you will report back.