BX system and field number (FN) for different configurations

[erikwetterskog]

Hello,

Im wondering if anyone has a clear idea on how the field number of FN26.5 objectives are affected by accessories in the beam path.

For instance, I have a fluorescence arm and want to add another confocal unit on top (UCFU). Will this reduce the field number?

I use direct projection to a m43 camera, am I getting the full FN26.5 from the cmount adapter in the basic configuration (only fluorescence arm + standard trinocukar head)?

Or does the field number only apply to the eyepieces? Does the projected image circle vary with the choice of trinocular head?

What I’m wondering, will I get more image circle if I change to a super-wide head (with regards to the camera)?

Second question is if I waste the super wide head if I install more than one accessory in the beam path? In this case it’s a confocal spinning disc, but I guess the same would apply to a Bertrand lens, or a photo adapter for a second camera.

All my objectives are 26.5, it seems reasonable to want to be able to utilize all the available image circle.

[PeteM]

You'll typically lose a bit of field after stacking several intermediate accessories. Leica provides guidance for their various heads and the number of intermediate pieces. I don't recall seeing the equivalent from Olympus, though it's likely out there somewhere. I'd think you could place one element (say your fluorescent illuminator) without a problem. Two? Someone else may know how much, if any, you'll lose. It's also possible that your confocal unit doesn't scan a 26.5mm field.

[erikwetterskog]

Hello,

Thanks for the info Pete! I guess I have to try my hand with combining stuff.

I’m contemplating getting a second stand just for EPI, since the confocal does not support fluorescence anyway.

[Scarodactyl]

I use direct projection to a m43 camera, am I getting the full FN26.5

No. The diagonal of your sensor is 22mm, it can't capture 26.5mm.

[erikwetterskog]

I use direct projection to a m43 camera, am I getting the full FN26.5

No. The diagonal of your sensor is 22mm, it can't capture 26.5mm.

Scarodactyl, I understand that. The regular trinocular tube projects only 22 mm to the eyepieces, but I do wonder if the tube lens delivers 26.5 mm to the trinocular portion. Someone told me there is a difference in the image quality of the superwide head (26.5 mm to eyepieces) and the wide head (22 mm). Question is, do they deliver the same FOV to the trinocular port?

[wabutter]

Two Points,
If you have a confocal system, Don't you already have fluorecent capability?

Yes, the higher you stack the system there is likelyhood, you will lose FN. Both Visually and to the camera port. I don't know enough about the Olympus design, but if the they have a WF tube for the 26.5 FN, you can probalby get one or two intermediate pieice in the optical path. As PeteM stated, I have not seen a table laying out the limitatino on the Olympus, but do know first hand from AO and Leica experience, that vinetting will occur if stacked too high.

[Scarodactyl]

The regular trinocular tube projects only 22 mm to the eyepieces

It projects a larger image than that even to the eyepieces. The trinocular port can cover aps-c no problem as my test showed, the quality is just a bit lower in the corners than the ultra widefield tube lens. You could probably use a m4/3 speedbooster to get a wider field on a 22mm diagonal sensor.

[erikwetterskog]

The regular trinocular tube projects only 22 mm to the eyepieces

It projects a larger image than that even to the eyepieces. The trinocular port can cover aps-c no problem as my test showed, the quality is just a bit lower in the corners than the ultra widefield tube lens. You could probably use a m4/3 speedbooster to get a wider field on a 22mm diagonal sensor.

Hello,

Yes I thought about that. Also it would be useful for the Blackmagic pocket, which has an even smaller sensor than m43, though it uses the same mount. I might upgrade to the 4K edition later in life though. They're expensive though, but a more flexible and universally useful solution.