yellow tinted mirror?

[NorthernLight (Max)]

Hi Everybody,

I recently bought a 12" GSO DOB and was wondering why the views I got were all a bit too yellowish and orange stars deeply red.

Now, when I looked down the tube under a blue sky I could see that the mirror actually is tinted slightly yellow. I have another Newton and its got Celestrons XLT coatings= no change in colour.

Question: is it normal for a GSO Newton to have that colour cast? Or do I have a Friday afternoon model?

[astro_nutt]

Hi Max.
It doesn't sound right so take it back.
Cheers!

[RAJAH235]

Any telescope mirror, new or not, should not have any colour tainting at all.
I'd take a picture which shows the dis-colouration & send a nice email to the
supplier.

Or, just return it, as mentioned.

Seasons Greetings.

[[1ponders] (Paul)]

Is it new or second hand Max?

[NorthernLight (Max)]

Hi Paul,

it is brand new and already contacted the supplier. They will send someone around to have look.
The thing is that haven`t had a Newton this big before (only 6") and it might well be that thermal currents have a different impact on a scope this size. The other thing is that the 6" has premium coatings whilst the GSO - well its aluminium isn`t it?
So there might be nothing wrong with the scope.

[GrahamL]

What do you see looking down onto the mirrors surface with a light source behind it Max ?.. a few spots of light or many ?

[astro_nutt]

Hi Max.
Thermal currents in the tube would only cause the image to wavier. As for premium coatings, I would assume the mirror has a brighter reflective coating but it shouldn't have any yellowing. GSO do overcoat the aluminium with Silicone. It might be, and I'm only assuming this, that the Silicone overcoating may be dirty and need cleaning.
Cheers!

[Satchmo]

Originally Posted by NorthernLight

Now, when I looked down the tube under a blue sky I could see that the mirror actually is tinted slightly yellow.

It would be due to an incorrect thickness of overcoating. For the price what can you expect.