How to test/compare microsope lenses at best?

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macrochemistry
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Joined: Thu Jan 05, 2012 12:32 pm
Location: Kiel, Germany

How to test/compare microsope lenses at best?

Post by macrochemistry »

I've ordered 3 10x microscope lenses, one Zeiss Plan Achromat (25€, they are cheap here), one Nikon BD Plan DIC (150€) and one Nikon Finite Conjugate (80€).
They will arrive within the next ~5-10 days
I like to compare them and to resell the inferiour ones but I can't get a butterfly wing or something similar at the moment as it's winter here.

Do you know any artifical materials which can be used?
At best something which is also showing CAs and is planar, that no stacking is necessay.

I thought about using a plastic sponge or a blade sharpener as they have fine structures but I guess they are not good in showing CAs.

Any ideas?
Last edited by macrochemistry on Mon Jan 09, 2012 10:06 pm, edited 2 times in total.

rjlittlefield
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Post by rjlittlefield »

http://www.photomacrography.net/forum/v ... 7812#57812

It is glass with "smoke" from a freshly lit match.

--Rik

macrochemistry
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Joined: Thu Jan 05, 2012 12:32 pm
Location: Kiel, Germany

Post by macrochemistry »

Thanks, I knew the thread but didn't see the glass with the frehly lit match on first sight. It might be also a good start. But that also does not show much CAs and it's not as easy to see the differences as with a moth wing etc.
Last edited by macrochemistry on Mon Jan 09, 2012 10:07 pm, edited 2 times in total.

Peter De Smidt
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Post by Peter De Smidt »

rjlittlefield wrote:http://www.photomacrography.net/forum/v ... 7812#57812

It is glass with "smoke" from a freshly lit match.

--Rik
The smoked glass was a great idea!

rjlittlefield
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Post by rjlittlefield »

macrochemistry wrote:But that also does not show much CAs and it's not as easy to see the differences as with a moth wing etc.
Hhmm... The smoke crystals should be fine for lateral CA (consider the aus Jena corner, lower left HERE), so I guess you're thinking about longitudinal CA, the stuff that shows up on OOF edges?

In any case you might consider using the finest available silicon carbide sandpaper:
http://www.photomacrography.net/forum/v ... 7833#57833
http://www.photomacrography.net/forum/v ... 8056#58056

Some laser printers will also put out sufficiently small toner dots to be useful:
http://www.photomacrography.net/forum/v ... 4873#74873

The diamond sharpener I recently tested has lots of fine detail with opportunity for CA:
http://www.photomacrography.net/forum/v ... hp?t=15581

Other suggestions:
- dried hairy leaves
- hair fragments from an electric razor
- dust debris from a vacuum cleaner

And maybe it's a silly suggestion, but check all your light fixtures. It's not uncommon for little scaled corpses to sit there for months.

--Rik

Chris S.
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Post by Chris S. »

Also, there are quite a few online vendors selling dried insect specimens (preferably farm raised, to avoid depleting natural ecosystems). I've used this one a couple of times, and been pleased: http://www.butterfliesandthings.com/BNT_aboutus.asp . But you can probably find a similar vendor closer to home.

ChrisR
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Post by ChrisR »

Perhaps a Stage Micrometer.
If you can find one with 2mm at 0.01mm markings you would nearly cover the whole frame width.
High contrast (they're usually for transmitted light) with sharp edges, flat).

BugEZ
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Off the grid...

Post by BugEZ »

I have never found a shortage of fruit flies at the local grocery that specializes in produce. Best place to look is near the pineapples. In fact, the fruit flies usually can help select the ripest one. ( :D ) The only trick is to catch them without arousing suspicion with the other patrons or clerks.

Fruit fly eyes at 10X may provide a good grid pattern.

Keith

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