Page 1 of 1
Olympus BH-2 question
Posted: Wed Apr 22, 2020 6:55 am
by david_b
I have an Olympus BH-2 BHS with a flip-top condenser.
There is no swing out filter holder or slide.
How can I attach patch stops for darkfield, oblique illumination etc.?
Re: Olympus BH-2 question
Posted: Wed Apr 22, 2020 11:22 am
by photomicro
I *think* they made a 'plug-in' filter, like the one shown in the pictures. I have no idea what make this is.
This is a blue filter, but can support other discs such as stops.
Of course whether this is the ideal place for such a stop depends on the design of the condenser.
Another forum member also 3-D prints a device that fits these condensers, and is raised further up into the condenser body, so bringing stops nearer the iris.
I am sure he will join the discussion at some point.
- DSC06422.jpg (53.89 KiB) Viewed 4594 times
- DSC06421.jpg (83.46 KiB) Viewed 4594 times
Re: Olympus BH-2 question
Posted: Wed Apr 22, 2020 2:55 pm
by dtsh
Something like thus?:
http://earth2geologists.net/Microscopes ... bstage.jpg
Found from
http://earth2geologists.net/Microscopes ... Scopes.htm
Unless I am missing something, that looks to be the easiest solution. If you have access to a 3D printer, something like that could be whipped up pretty quick.
Edit: If you're brave, you could drill and tap the mount and secure a filter holder directly underneath the condenser to pivot on a bolt threaded into the hole.
Re: Olympus BH-2 question
Posted: Wed Apr 22, 2020 4:46 pm
by Saul
photomicro wrote: ↑Wed Apr 22, 2020 11:22 am
...Another forum member also 3-D prints a device that fits these condensers, and is raised further up into the condenser body, so bringing stops nearer the iris. I am sure he will join the discussion at some point....
David asked me this question through another channel ...
Initially I answered, no, nothing will keep insert inside because of the conical shape. Even simplified insert (no magnets, flat base) will not help - condenser base is hanging in the air...
But...morning is smarter than evening - I have very thin big size steel washers (bought for the initial testing), if they are right size, they can be glued (double tape) to the base of the condenser, and my type insert (has to be designed for this condenser) can be attached to this condenser. If it sounds logical, I need some
exact dimensions in mm, at least one number after coma (attached) and distance between bases of the cone (not along the side wall but perpendicular):
Re: Olympus BH-2 question
Posted: Wed Apr 22, 2020 7:41 pm
by david_b
Good information, thank you.
Re: Olympus BH-2 question
Posted: Wed Apr 22, 2020 7:48 pm
by PeteM
Three other options:
1) Recollection is that the dovetail base of the condenser comes off with a few screws. Can't recall if extra care is required to keep the iris leaves in place as it's removed - replacing those requires a bit of patience. Anyhow once off, the inside can easily be machined, parts can be epoxied on, etc. For example, I've modified some Olympus condesers to fit and try DIC prisms up inside as close to the iris plane as possible.
2) Another possibility for darkfield is to be on the lookout for a proper darkfield or olique condenser and fit it to the BH2. A Loma oblique, for example, ended up OK on a BH2.
3) You can also support something from the base of the BH2, perhaps made of camera extensions and adapters to get just below the condenser height.
Re: Olympus BH-2 question
Posted: Wed Apr 22, 2020 8:05 pm
by david_b
Saul wrote: ↑Wed Apr 22, 2020 4:46 pm
David asked me this question through another channel ...
Initially I answered, no, nothing will keep insert inside because of the conical shape. Even simplified insert (no magnets, flat base) will not help - condenser base is hanging in the air...
But...morning is smarter than evening - I have very thin big size steel washers (bought for the initial testing), if they are right size, they can be glued (double tape) to the base of the condenser, and my type insert (has to be designed for this condenser) can be attached to this condenser. If it sounds logical, I need some
exact dimensions in mm, at least one number after coma (attached) and distance between bases of the cone (not along the side wall but perpendicular):
Thanks I'll measure up and send you a PM.
Re: Olympus BH-2 question
Posted: Wed Apr 22, 2020 8:13 pm
by david_b
PeteM wrote: ↑Wed Apr 22, 2020 7:48 pm
Three other options:
1) Recollection is that the dovetail base of the condenser comes off with a few screws. Can't recall if extra care is required to keep the iris leaves in place as it's removed - replacing those requires a bit of patience. Anyhow once off, the inside can easily be machined, parts can be epoxied on, etc. For example, I've modified some Olympus condesers to fit and try DIC prisms up inside as close to the iris plane as possible.
2) Another possibility for darkfield is to be on the lookout for a proper darkfield or olique condenser and fit it to the BH2. A Loma oblique, for example, ended up OK on a BH2.
3) You can also support something from the base of the BH2, perhaps made of camera extensions and adapters to get just below the condenser height.
Thank you, 3) sounds like the easiest option.
Alternatively, it looks like this type of BH-2 condenser could be adapted and is relatively inexpensive. Is it any good?
Re: Olympus BH-2 question
Posted: Wed Apr 22, 2020 9:52 pm
by PeteM
The Olympus 1.25 na condenser isn't bad. But your .90 na Achro condenser is better color corrected and better able (with the top lens flipped out) to fully cover the field of a 4x objective.
Re: Olympus BH-2 question
Posted: Thu Sep 01, 2022 3:56 pm
by carlh6902
