Dreamspy wrote: Saul wrote:
Dreamspy wrote:I'm looking for ... darkfield as well...
Are they 28mm in diameter and 3mm thick ?
Not so sure... can I measure these lengths somewhere on the microscope?
If I understand correctly then darkfield is a mask you put on the light, right? In that case the diameter is much more than 28mm (of the light), and the thickness can be anything really, since there is a lot of empty space between the light and the collimator lens before the sample. Or am I misunderstanding something here?
Nope, the darkfield stop must be placed at the condenser as close as possible to the diaphragm. For different magnifications (actually NA) you need different stop diameters.
I don't know the particularities of your condenser. If it has an slot to place a phase ring this is the best position. If it has not that slot and the diaphragm is placed at the lower part of the condenser and it has a filter holder just under the condenser this is also a good place.
Phase contrast is more delicate: you need to get phase objectives and to put at the condenser matched phase rings for each objective. You need a condenser with a slot to place a phase ring at the right position or a dedicated phase condenser.
As beginner my advice is to calm down a bit. For example you can do decent pol work with cheap filters and then buy more expensive ones if you get hooked. Phase contrast if already you do not have phase objectives will be expensive while oblique illumination contrast is also excellent and can be done with little money if any.
For now I would concentrate in taking the best of your microscope with brightfield and also experimenting with dark field, oblique and pol (low cost way). Most of us can be equipment geeks but your technique with the microscope and sample preparation is often more important.