Jump to content

 

1825338873_SNRPN2021banner.jpg.68bf12c7791f26559c66cf7bce79fe3d.jpg

 

Objective Lens Scratch (tiny) - Should I worry?


Recommended Posts

HI all, I've just recently picked up a C80ED-R from off the forums here, and overall it's in great nick, but there does appear to be one very small scratch on the objective. Now my gut feeling is that this wont affect the performance one little bit, but it'd be nice if someone more knowledgeable could confirm that for me. :D

Thanks in advance.

post-16299-133877454339_thumb.jpg

Edited by samtheeagle
Link to comment
Share on other sites

I think thats very small to have any type of real effect, mind you I have seen worse.

BTW the C80ED & C100ED's are legends, too bad it's just the focuser which lets the scope down, but you could add some teflon pads to the drawtube or change the focuser altogether.

Nadeem..

Link to comment
Share on other sites

:D Thanks Nadeem. I spent an hour or so stripping the scope down last night. It was fairly dusty, and there was a scary amount of metal shards from the manufacturing process floating about in there. It's pretty immaculately clean now, and it's only really that small scratch that is a bit of a concern. Just using it visually on some distant trees I couldn't see any kind of problem caused by the scratch, so I assume that imaging probably wont be affected either.

I've only ever had rack an pinion focusers, so I guess I don't know what I'm missing out on, but as R&Ps go this one seems quite nice. And yup, I've already regreased and added teflon strips to the rails inside the focuser. It's rather more solid feeling now :D

Just wish that this cloud would clear off for a night!

Link to comment
Share on other sites

my gut feeling is that this wont affect the performance one little bit

Your gut is perfectly correct. If the scratch was considerably worse than this, there might be a barely noticeable loss of contrast. A scratch that small will have no effect whatsoever, unless you wish to use the scope for a coronagraph, when scattered light is at an absolute premium.

Link to comment
Share on other sites

Thanks guys, my mind is suitably at ease now :D

Nadeem, as a C80 veteran I might have to pick your brains as to accessories! Not that I can afford any right now, but high up on the shopping list is a flattener / reducer. I think you've said previously that the WO FFII is a good match, but they're hard to come by these days. What do you use? In fact does the scope even need a flattener?

Link to comment
Share on other sites

The WO Flattener is a good match for it, but their hard to get hold off as thet have been discontinued. The next best thing which is meant to be optically matched for the scope is the SW 0.85x Focal Reducers, Steve from FLO, is meant to be arranging some 2" push fit adaptors to fit onto the reducers so they can be used with other scopes. Or you can try a televue reducer... Tell you the truth, I never imaged without the reducer, so I cant comment what the effects were without one.

Nadeem..

Edited by Deneb
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.