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Chipped objective question

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#26 Jobryant

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Posted 10 January 2014 - 01:02 PM

last one

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#27 SteveG

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Posted 10 January 2014 - 02:13 PM

What happened to the dew shield?

#28 dan_h

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Posted 10 January 2014 - 02:40 PM

I'm afraid the chip will affect your views. Have you taken the telescope out for a test?


Just during the day and I couldn't detect any issues caused from the chip.


In daylight, your eye pupil could be small enough that it is effectively stopping down the aperture of your scope and completely eliminating the chip. Of course, much depends on your pupil size and the powers used for viewing.

For example, with a 3mm pupil, viewing at 35X, the effective aperture of the scope is just 105mm. The chip is not going to affect this view. At 20X, the effective aperture of the scope is only 60mm.

You won't see the chip or its effects until you view at higher powers in the daytime, or at night when your pupil is larger.

dan

#29 Jobryant

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Posted 10 January 2014 - 04:54 PM

I took the original dew shield off. What you see in the pics is my homemade retractable sun shade made of flocking paper and duct tape.

Makes perfect sense Dan. I was using the scope at 20x today so like you pointed out the damaged part of the objective was more than likely not being used. Since the objective has been damaged the highest mags I have used in it has been 85x and I didn't notice any ill effects due to the chip although I didn't use the scope much at this magnification.

#30 bakerrihan

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Posted 10 January 2014 - 05:32 PM

I had the same thing in my unitron 60 mm and its fine just a reflictions some times will apear

#31 mayidunk

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Posted 10 January 2014 - 07:58 PM

Couldn't you rotate the mirror to move the scratch behind the clip?? That's what I would do if it were mine. ;) Mike

The scratch is just far enough from the edge that the clips won't cover it. It's not an issue though, because I'll never see it through the eyepiece anyway! Besides, its got Mojo now!!

:)

#32 Bill Friend

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Posted 11 January 2014 - 09:36 AM

I had a similar chip (by area) on a Towa 60mm. I blackened out the chip using a flat black magic marker and didn't really notice a difference in optical performance. I think seeing conditions and knowing that its there are the biggest factors.






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