wtb OCA ( 1.4x - 1.6x ) - found

wucheeyiun · Post by **wucheeyiun** » Thu Oct 20, 2005 9:01 am

Looking for a 1.25" OCA for my binoviewer, or a GSO type 2" barlow where the lens cell can be taken out to be reconnected to a 2" diagonal...

rlow · Post by **rlow** » Thu Oct 20, 2005 10:31 am

Hi Chee Yuin,

I saw your pm, and I have replied to you.

BTW, I think the OCA is available at Astrobargain, you may also like to check with Joo Beng.

ariefm71 · Post by **ariefm71** » Thu Oct 20, 2005 11:51 am

both your CATs should have enough focus travel, should not need oca.
you'll need this only for refractor or newt (you're eyeing someone's refractor is it? :-) )

cheers,
arief

wucheeyiun · Post by **wucheeyiun** » Thu Oct 20, 2005 5:35 pm

The mewlon 210 does not cater for the travel, i thought it was strange, but it is true...I took the whole mirror out of mewlon to clean ( you know it is a used mewlon from markus ludes), and sure enough the focusing screw and thumb is very heavy duty looking...and weigh a lot. The mirror itself is about 1inch thick and could be dielectric coated.

rlow · Post by **rlow** » Thu Oct 20, 2005 6:22 pm

The mewlon 210 does not cater for the travel, i thought it was strange, but it is true...I took the whole mirror out of mewlon to clean

I think it is quite unfortunate if the travel is insufficient for your binoviewer; I wonder if other premium binoviewers may also have this problem.

I would have preferred to minimise taking out the mirror for cleaning. Would it be possible for you to clean it with the mirror intact? Seems like others have done that.

wucheeyiun · Post by **wucheeyiun** » Thu Oct 20, 2005 8:10 pm

Base on the TAK instruction manual, it shows how it can be done, you will be able to do the same...

Markus told be it should be remove to be cleaned twice a year... ( it getting off topic ) , Yes richard, will consider your barlow, but i am waiting for joo beng to get back to me on the 1.9x OCA.

Post by **weixing** » Thu Oct 20, 2005 8:21 pm

Hi,
:offtopic: Sorry going off topics again.

Markus told be it should be remove to be cleaned twice a year...

But I thought the general guide line is not to clean unless it is very very very dirty??? :o :o

Have a nice day.

rlow · Post by **rlow** » Fri Oct 21, 2005 3:47 pm

But I thought the general guide line is not to clean unless it is very very very dirty???

Apparently it must be really dirty lah... Chee Yiun mentioned that he even saw a feather on the mirror!!!

denebman · Post by **denebman** » Fri Oct 21, 2005 5:37 pm

wucheeyiun wrote:The mewlon 210 does not cater for the travel, i thought it was strange, but it is true...I took the whole mirror out of mewlon to clean ( you know it is a used mewlon from markus ludes), and sure enough the focusing screw and thumb is very heavy duty looking...and weigh a lot. The mirror itself is about 1inch thick and could be dielectric coated.

The dielectric coating only applies on a small (2inch aperture) and flat area, on the big elliptical mirror like mewlon 210 (220mm dia.), the stress induced by dielectric coating (<100 layers) may ruin and distort the mirror.

wucheeyiun · Post by **wucheeyiun** » Sun Oct 23, 2005 3:10 pm

Found, bought 2x 2" barlow from Rlow instead...