Cheap Microscope Objectives

Jem · Post by **Jem** » Fri May 27, 2011 2:41 am

Hi All

Does anyone want any cheap microscope objectives...

Edmund Optics are having a clearance sale...

http://www.edmundoptics.com/onlinecatal ... 1#products

I've snagged myself some of the 30x that i've been trying to get hold of for so long, I never thought i'd get them this cheap

Lots of other goodies in their sale so it's worth a good look around and not just the page i've linked to above.

Cheers

Jem

rzeheb · Post by **rzeheb** » Fri May 27, 2011 6:35 am

Hey Jem, thanks for the link! I, too, picked up a few of the 30X objectives. They should be perfect for my holography table and have proven to be hard to find. Much thanks!!

Ron

holomaker · Post by **holomaker** » Fri Jun 03, 2011 5:18 am

i grabbed a few as well, they arrived and the are all some weird thread size, Edmund admitted thier mistake in the description and refunded my $$$

Jem · Post by **Jem** » Fri Jun 03, 2011 5:53 am

Yep, unfortantely these have a small (~14mm) thread instead of the more usual 20mm thread. However, it's very easy to make an adapter if you have any old standard thread objectives laying around that have got scratched etc and are useless ( I had a few

). Oh, did I mention you need a lathe as well?

Anyway, you just cut up the old objective (about 5mm from the thread shoulder), turn the edge flat on the lathe, mill or turn a 15mm hole (at the opposite end to the thread

). You can then glue the new smaller objective in there and it works a treat

.

Note: hole is a bit rough on this one as my cutting tool was blunt and was vibrating

, i've now bought a 15mm end mill. Not really a problem though as it gives the glue a good key

Sorry the photo's a bit rough as it was taken at clsoe range with my phone.

Jem

holomaker · Post by **holomaker** » Fri Jun 03, 2011 6:41 am

My lathe isnt set up at the time but ill make mine work using a drill press, great idea Jem thanks.......

PS if you complain to them about misrepresentation (this is by no means a "standard" size), chances they will refund you $$ and allow you to keep the items! Dag-nabbit! i should have ordered more!

Jeffrey Weil · Post by **Jeffrey Weil** » Fri Jun 03, 2011 10:02 am

Hello Everyone,

If you have a lathe why are you using glue? Make a threaded adaptor that just screws onto the new objective.

Jeffrey Weil
NorthBeach Holography Inc.

BobH · Post by **BobH** » Fri Jun 03, 2011 10:13 am

Don't read this one Jeff! Use a hacksaw to cut off an old objective as above, drill it out some way, paint it black inside, and glue the new one in place. Do a neat job (file after hacking) and it'll look AND work good as store bought.

Jem · Post by **Jem** » Fri Jun 03, 2011 1:07 pm

Jeffrey Weil wrote:Hello Everyone,

If you have a lathe why are you using glue? Make a threaded adaptor that just screws onto the new objective.

Jeffrey Weil
NorthBeach Holography Inc.

Don't think i'd trust my lathe (or me) to do screwcutting

Glue is much easier

Paulos · Post by **Paulos** » Wed Jun 15, 2011 2:04 am

Unfortunately cheap by all means.
They are rather objectives for cheep school microscopes.
I have ordered a few 10x, 20x and 30x and just measured the transmission:
Every fourth photon cannot pass through these objectives, only about 75% of the beam is transmitted.

rzeheb · Post by **rzeheb** » Wed Jun 15, 2011 8:52 am

I agree. They are very poor lenses, and cheap as they were, they were a mistake to buy. The optics were so poor that I could not even clean the beam up very well with my spatial filter. I used a 25 micron pinhole which was probably not the best match (20 or 15 microns might have worked better), but for a while I actually thought my pinhole might have been dirty as an explanation for why the beam looked so uneven after filtration. Careful examination of my pinhole with a microscope showed it to be just fine.