Lemon check on used equipment (2 Viewers)

[svenh]

Hi all,

I'm new to this forum and new to the spotting scope hobby. So: Hello to everybody!

I'm looking forward to buy a used ATX / BTX Swarovski scope (85 or 95), since there is good used equipment market here in Germany. (Offers are mostly 50% off list price).

I want to know if you can give me some advice to check the optics quickly on location when it is about to buy the equipment.
I read a lot about star testing, but I'm sure that I cannot do this in a few minutes at a seller location.
Of course I would check the obvious:

• any scratches and discolouration on the visibil lenses
• does focus and zoom ring work smoothly
• is the focusing working on close and more far away objects.

Any other advices?
I'm thankfull for every hint!

Best regards,
Sven

 

[Binastro]

If the sun is shining, ball bearings reflecting the sun at say 20 or 30 metres with the highest magnification can give a good idea of the optical quality in minutes.
The tiny sun image is an artificial star.

Ideally having an excellent comparison scope and just reading a distant newspaper will show if the used scope is a lemon.

Regards,
B.

 

[svenh]

Thank you!

 

[jring]

Or a led flashlight covered by aluminum foil with a tiny pinhole (foil on glass table and apply not a lot of force) at 30m or so makes an excellent artificial star. then star test as usual

Joachim