Looking for opinions on mirror artefact

YunDog · #1 11-08-2010, 06:23 PM

Hi guys,

I recently tried getting into some ameture astronomy having recently moved down to The great southern region of WA - fantastic night sky down here.

I bought myself a Celestron 114 SLT.

On a very cold morning I was examining the telescope mirror and the condensation from my breath showed these pull marks on the mirrors coating.

http://members.westnet.com.au/rogun/screenies/P6110021.JPG
http://members.westnet.com.au/rogun/screenies/P6110022.JPG
http://members.westnet.com.au/rogun/screenies/P6110025.JPG
http://members.westnet.com.au/rogun/screenies/P6110029.JPG

After several weeks of waiting Celestron finally came back saying they were marks from cleaning fluid that they apply to the mirror once it has been coated in a protective film. They said there is NO FAULT with the mirror and all there scopes have this.

So they say they are fluid marks! - Looks more like the film coating hasnt applied evenly to me, I cant think that this can be helping my viewing of the night sky.

anyway, I opted for a refund and got a 10% penalty from Ozscopes because according to Celestron there was 'nothing wrong with the scope'.

My questions are:
do you agree with Celeston Tech teams appraisal?.

I am looking for a good beginners scope for around 1.2k AUD
I dont particularly want all the computer starfind guidance stuff as I found that to be a bit of a waste ie. by the time Ive aligned it I couldve pointed the scope to what I was looking for. Should I get another Celestron?

Also looking for a reliable supplier for the scope as I think Ive done my dash with Ozscopes.

Yes I have racheted back my expectations having looked at Saturn through the C 114.

Really looking for a solid beginners scope with no frills
want the best view of the planets I can get of coarse
not interested in looking for minute pin priks of light
wanted to attach some sort of digital camera device to the eye piece and hopefull blow up the shots on a PC..

am I dreaming?

wasyoungonce (Brendan) · #2 11-08-2010, 07:01 PM

Quote:

Originally Posted by YunDog

anyway, I opted for a refund and got a 10% penalty from Ozscopes because according to Celestron there was 'nothing wrong with the scope'.

My questions are: do you agree with Celeston Tech teams appraisal?.

All I'll say is thanks for the heads up..I know which scopes and where from not to buy.

It's a crock. That mirror is unusable and they deduct 10% saying nothing was wrong or this is normal.
It looks as if the new distributor for Celestron is working out to to be a treat!

.

Anyway at this moment cut your losses. I won't suggest any scope ATM as the price range is really at the low end of the market. Here is a suggestion..I know it's another Celestron (but a decent scope and ok mount) and its more pricey but the selling price is very attractive for this package.

Sorry to hear Celestron & their re-sellers treating people like this.

edit;

An welcome to IIS..I hope thing are looking up for you from this onwards.

asimov (John) · #3 11-08-2010, 07:17 PM

I'b be wanting a FULL refund. As I've said once before: Celestron Tech support couldn't 'tech' their way out of a wet paper bag.

rcheshire (Rowland) · #4 11-08-2010, 07:22 PM

Is it a Newtonian that your looking for, or am I off the mark?

multiweb (Marc) · #5 11-08-2010, 07:26 PM

That mirror doesn't look right at all and I don't think you should have been penalised asking for a refund. Not good. I have a 130SLT and it looks nothing like this, even after 3yrs in the dew on the field.

bmitchell82 (Brendan) · #6 11-08-2010, 07:27 PM

I will let you know that my 10" skywatcher mirror DOES NOT HAVE THAT... that mirror is stuffed. If they wont give you all of your $$$ take it to fair trading as the goods are not as described when received. don't cop a 10% restocking fee for something that isn't your fault and you would have been happy if it wasn't in this condition. Stand up and fight it dude!

YunDog · #7 12-08-2010, 12:08 AM

Quote:

Originally Posted by rcheshire

Is it a Newtonian that your looking for, or am I off the mark?

its the Nexstar 114 SLT I think its a newtonian reflector that I had? Not necessarily looking for this type again.

Honestly, the several types of telescope are fairly daunting for a newbie to try and figure out which to get for a first scope.

I guess this should be the first thing I need to figure out and then look at what is available in that type.

Yeh I should fight it out but that means Im sitting waiting even longer for my refund and without a telescope.

Or I can wear the 80bucks and learn a hard lesson about purchasing telescopes over the internet.

The whole thing has left me fairly jaded (given that it was a 40th Bday present from my family) - now that their tech team has come back with No Fault report - I would have to prove there is a fault, and spend a heap of my time filling in complaint reports to the fair trading.

I think Ill just wear it and be more cautious before purchasing next time

Thanks for the replys

wasyoungonce (Brendan) · #8 12-08-2010, 10:40 AM

Well in cases like this there is no need to be cautious. The dealer is supposedly reputable and so is the brand...yet it appears they fobbed you off.

Even the village idiot could see that this product is defective. Lets hope they do not try to sell this to the next poor unsuspecting person.

Serves as a warning to others! I like the retailers return policy..."Our Guarantee..we want you to be 100% satisfied with your purchase"!

Obviously nice words that mean little not that that is any comfort to you.

Depending upon where you are try to go to a shop like Bintel. At least they have fllor stock you can touch and fully support their products.

Screwdriverone (Chris) · #9 12-08-2010, 11:44 AM

Hi Yun Dog,

I recently bought an 8" (200mm) Black Diamond reflector on an HEQ5 (this is Skywatcher by the way) from Andrews Comms for $1349. Check out my post for a pic of the beast. Here is an example of what a DSLR can do through it too. (my second ever Astro Pic)

Slightly more than your budget, BUT, VERY easy to use and set up, the scope is big enough to get details on planets and also has mounting capability for DSLR's for pictures etc You can use a webcam and get decent planetary shots too.

Well worth the money and this is my THIRD scope, but the best in my opinion. (even considering my $1500 12 inch dobsonian).

Can't go wrong with this baby, its almost good enough for me to contemplate selling the big dob as its now gathering dust.

See what you think

Cheers

Chris

YunDog · #10 12-08-2010, 11:49 AM

Looking around the forum - it appears the 10" Newt reflector, Dobsonian mounts seem fairly popular and the price isnt too bad at around 800-900.

How does that flat base go on the uneven ground?

I think I want to get the best optical bang for my buck and worry about star tracking later - certainly I found goto to be a waste of money for the time Im out there.

What about the Mak Cass scopes?

btw I linked Ozscopes support here to show them 'public opinion'

YunDog · #11 12-08-2010, 11:59 AM

Quote:

Originally Posted by Screwdriverone

Hi Yun Dog,

I recently bought an 8" (200mm) Black Diamond reflector on an HEQ5 (this is Skywatcher by the way) from Andrews Comms for $1349. Check out my post for a pic of the beast. Here is an example of what a DSLR can do through it too. (my second ever Astro Pic)

Slightly more than your budget, BUT, VERY easy to use and set up, the scope is big enough to get details on planets and also has mounting capability for DSLR's for pictures etc You can use a webcam and get decent planetary shots too.

Well worth the money and this is my THIRD scope, but the best in my opinion. (even considering my $1500 12 inch dobsonian).

Can't go wrong with this baby, its almost good enough for me to contemplate selling the big dob as its now gathering dust.

See what you think

Cheers

Chris

Chris,

That is a quality looking scope - that pic was fantastic - even viewing something like that would be a dream let alone getting a pic. Did you use stacking and digital processing?, did that shot require star tracking? Do you have the SLR attached directly or was that through the eye piece? Sorry for all the questions.
Its a little more than I had budgeted but hopefully this will last me a long time.

Thanks for that reply it has rekindled my interest. I was starting to think I was out of my depth.

Steffen · #12 12-08-2010, 12:10 PM

I'd say that mirror has been poorly cleaned/dried after cleaning. Condensation from breathing or dew will show up those cleaning marks very clearly. It does not mean the mirror is defective or underperforming in any way. The only way to gauge its performance is a star test.

Celestron or their agent should have offered a professional clean at the least, though.

Cheers
Steffen.

Screwdriverone (Chris) · #13 12-08-2010, 12:14 PM

Quote:

Originally Posted by YunDog

Chris,

That is a quality looking scope - that pic was fantastic - even viewing something like that would be a dream let alone getting a pic. Did you use stacking and digital processing?, did that shot require star tracking? Do you have the SLR attached directly or was that through the eye piece? Sorry for all the questions.
Its a little more than I had budgeted but hopefully this will last me a long time.

Thanks for that reply it has rekindled my interest. I was starting to think I was out of my depth.

Hi YD,

You wont see this sort of colour (or pretty much any colour) through the eyepiece as our eyes are not sensitive to colour in the dark. You can still see these sort of details, but they are more black and white / grey than colour.

I took 9 x 30 second pics through the scope using a Canon 1000D DSLR connected via a T ring adaptor that screws straight on to the focuser of the scope. These pics were stacked using registax and then slightly adjusted in registax (realy only played with gamma and levels) to produce this pic. NO eyepiece used as the camera was at prime focus in the focuser (no lens on the camera either)

I only had the scope lined up with the south celestial pole and the 3 star alignment done and then attached the camera and fired off 9 shots at 30 sec each to get this.

As for the planets, I am impressed with how much I can see on Jupiter and Saturn through this scope, especially with tracking, it tends to help a lot as the image doesnt fly by like the dobsonian does because it stays on target for as long as you want to look at it.

Well worth the money and should last me (and you, if you get one) a LONG time as its a very versatile setup.

Cheers

Chris

DavidU (Dave) · #14 12-08-2010, 12:26 PM

I agree with Steffen. "stretch" marks or stresses in glass can only be seen under polarized light on uncoated glass.

Quote:

Originally Posted by Steffen

I'd say that mirror has been poorly cleaned/dried after cleaning. Condensation from breathing or dew will show up those cleaning marks very clearly. It does not mean the mirror is defective or underperforming in any way. The only way to gauge its performance is a star test.

Celestron or their agent should have offered a professional clean at the least, though.

Cheers
Steffen.

YunDog · #15 12-08-2010, 12:52 PM

David,

I dont think the stress marks are in the glass of the mirror - I think the stretch marks are in the protective coating (presumably some sort of plastic film) on the mirror. They look too straight to me to be cleaning fluid, but I could be wrong - hence why Im looking for opinions. I guess what Im saying is it looks to me like the protective film hasnt been applied evenly and looks more like the sort of job I would do putting cling wrap on my lunch. I mean thats what it looks like to me - ever put cling film over a bowl, those are the exact patterns you get!

With regards the professional clean - they might have offered had I not expressed no wish to have the telescope back, given that I had been told by the supplier that the scope was obsolete and no longer supported by Celestron - I dont think its surprising that only 2 months after purchase - I didnt want a brand new unsupported scope, cleaning fluid or stretch marks not included.

DavidU (Dave) · #16 12-08-2010, 01:21 PM

The protective layer is never a plastic, it is very hard semi metalic oxide like SiO2. Be sure it's not dust in a pattern due to static electricity.

YunDog · #17 12-08-2010, 01:45 PM

David,

I dont think you can be referring to the same coating Celestron are talking about otherwise how can it be transparent?

an exerp from the email from Ozscopes
I have spoken to the service department in detail and the reason why there were markings on the Mirror is because of the manufacturing process. The Mirrors are cleaned before applying the Celestron coating and in the process of cleaning the mirror, the liquid used to clean the mirror may not have been applied evenly. However, they have assured me that this does not affect the Telescope at all. This uneven layer can be found in all Celestron Reflector scopes.

and the Celestron report

http://members.westnet.com.au/rogun/screenies/Celestron.jpg

The Mekon (John Briggs) · #18 13-08-2010, 06:01 AM

Get the best refractor your $1200 will buy.

I am amazed that you can get ED doublets for less than this money these days.

YunDog · #19 13-08-2010, 10:24 AM

Hi Mekon,

Can I ask for a little more opinion about why you recommend a refractor. I agree that I think I need to go for the most visual bang for my buck I can get, and worry about the growth of the hobby (into astrophoto etc) later. So atm I comparing the 12" dob (1k, Pro: good visual, easy to use) vs the 8" black diamond Newt that Chris has (pro: good for photography, con: EQ mount may be difficult for a beginner). So far no one has mentioned the Mak Cass but I heard they are one of the best (con:expensive).

cheers

Mark

erick (Eric) · #20 13-08-2010, 11:20 AM

Quote:

Originally Posted by YunDog

How does that flat base go on the uneven ground?

As long as it it not strewn with boulders or is a massive slope, no problem. They normally sit on three feet that provide a solid support. Just sweep any stones, twigs etc. out of the way with your boot before you plonk the base down.