retroDiode upgrade question

[Rossf]

Hello peeps-does anyone know if these upgrades produce more lumens than the original lamp housing-most seem to be 800 lumens-is this definitely adequate for good darkfield and phase contrast for photography?
Are people happy with their retroDiode upgrades?
Any advice greatly appreciated
Regards ross

[Scarodactyl]

I have gotten them twice for scopes that had bad electronics, but both at a point where I'd decided to sell them so not for personal use. My limited testing has shown satisfactory results including in darkfield.

[nannoconus]

i’ve used both the regular 10w and the upgrade to 20w (which has a fan) on a bunch of Zeiss Standards & Universals for 100x cross-polarized darkfield photography, and had good results

[Hobbyst46]

I am using two slightly different versions of their 10W LED illuminators. Color temperatures are ~6500K and ~5000K. They are great for BF, DF, phase contrast. Much better than the original incandescent. And excellent service.

[apochronaut]

It depends on the microscope design, the magnification you are trying to achieve ( especially in DF) and whether the emitter is located at the original location. A 100X objective requires considerably more lumens than a 40X objective. Most microscopes that are set up to achieve 1000X DF have bulb outputs of over 2000 lumens but the filament is usually located in a separate housing at the back of the microscope, so it is relatively farther away from the object plane than it is in some other microscopes with lower output.
The model they once made for an AO series 20 for instance was inadequate for 1000X DF. I don't know if it has been upgraded
Ideally , the output of lumens should be about the same between the original bulb and the led but with the original bulb there is probably more loss from stray ray loss.