Televue NP127 has arrived and the optics look a little... Hmmmmmmm

[Joves]

Hi guys,

I purchased a second hand NP127 from a fellow in the states a few weeks ago, which arrived today. Beautiful looking scope, for sure, and for the most part in very good condition. However, the main objective has some discolouration/marks in the coatings. In fairness, I knew these existed when purchasing, so this is in no way a gripe against the seller or buying used scopes in general, but as you know, these things can be hard to properly see or measure in photographs of objective lenses. I was hoping, when buying, that they'd possibly simply be moisture marks or something of the like, which could possibly be cleaned if one so desired. Upon personal inspection, it would appear that they are here to stay. I was told by the seller that they have absolutely no impact on the view, which was confirmed by Al Nagler himself in a phone conversation they'd had, and that, as such, he had never tried to clean them off. Looking closely though, it is clear that someone HAS at some point in time tried to clean them off and, in doing so, have put a few fine scratches in the coatings. They don't look anything too major, but they are definitely there.

So, my long winded question is this... What impact, if any, should I expect some fine marks on the lens coatings of a scope of this quality to have when the skies finally clear and I get a chance to get it out for first light? This, as with my other scopes, will be used primarily for visual, unless I suddenly get the urge to dabble in imaging in the future, which isn't an impossibility, but certainly not likely any time soon.

I'm hoping the answer is "nothing" and that the marks, whilst cosmetically discomforting, should have no impact on the views, but I'm also realistic enough to know that we must all be fanatically protecting our lens coatings for SOME reason other than wanting them to look pretty?!

Thanks guys. As always, I appreciate your feedback and advice.

Cheers,

Aaron

[NGC 1502]

Hi Aaron. You have acquired a fine scope that many would aspire to own.

I do know how most of the astronomy community worries about marks or issues on their optics, including me. Most of us worry for nothing.

On fainter objects, it's highly likely that no issue will be seen. I'd view Jupiter while it's still on view, as it's on very bright

objects that any fine scratches 'could' perhaps, show some flaring, but if 'Uncle' Al Nagler has given his opinion, then his opinion is

more valuable than anyone elses.

Let us know how you get on with this wonderful scope.

Regards, Ed.

[Joves]

Thanks Ed. Your response is helpful. I assumed the likely effect of minor scratches to coatings, if any, might some flaring on brighter objects. That's good advice. I'll test it on Jupiter when I get a chance and see how it goes. Hopefully there's no noticeable issue, as the cost of sending the entire scope back to the states and having the primary re coated would not be cheap!

Let's hope the conversation with Uncle Al actually did take place and that all is good as gold. Will let you know how it goes.

Oh, and thanks, it sure does look and feel to be a lovely scope. Looks like quite a beast compared to the Genesis and and absolute monster beside the TV76!

Aaron

[ChrisLX200]

I guess you're the best person to judge rather than us, and if Al says there's likely to be little impact then it's difficult to know what else to add. I would be curious to know how such marks got there in the first place though (other than the cleaning effects I mean). It is a large and surprisingly heavy OTA, and mine is even heavier with a Pronto on top. To be honest I've never even looked through mine, it's just had a CCD camera attached and that's all

ChrisH

[Joves]

I guess you're right, Chris. Although,without comparing two (mine with marks and another without) side by side, I guess I may never know. Absolutely, if Al says it's not a problem, then I'd bet it's not a problem. Only issue is... Who would know if that conversation ever took place and, even if it did, to what extend were the marks explained?

I guess I'm just thinking out loud at the moment. I look forward to checking it out for myself and seeing if my imagination will start seeing problems, just for problems sake

I agree, it is a surprisingly heavy OTA... I could only imagine mounting my TV76 on top of it. How've you found it for AP so far? You should take a look through an eyepiece and let us know your thoughts!!

[ChrisLX200]

I've barely had chance to use mine since I got it because the weather has been so bad. Just twice its been outside, once a complete failure to achieve anything useful (too many other issues to sort out) and the second was its first light where I snagged a couple of images of M82 and the Leo Triplet before the clouds moved in. However, hopefully most of the technical issues are resolved now (all but plate solving which I think works but yet to try it for real) and tonight is said to be clear for a few hours... Give me clue how you fit an eyepiece in it?    Seriously though, my eyesight is not what it was, astigmatism in one eye and load of floaters in the other, I don't do much visual work now so my opinion on the view through it would be worthless.

ChrisH

[ollypenrice]

It's always worth remembering that a thumping great secondary mirror right in the middle of the light path does not appear in the eyepiece....

My standard one-liner on matters like this is to say, 'Look through your optics, not at them.' I would be surprised if you saw any sign of these marks whatever. In the unlikely event that this isn't so then TV will repair the lens coating, I'm sure. I've spoken to them on the phone and they are just great, really helpful.

Glorious scope. Enjoy it.

Olly

[Joves]

Thanks Olly, that's a great way of looking at it. The marks are gonna irk me, no doubt, but not as badly as if I had made them myself!

[swamp thing]

It's always worth remembering that a thumping great secondary mirror right in the middle of the light path does not appear in the eyepiece....

My standard one-liner on matters like this is to say, 'Look through your optics, not at them.' I would be surprised if you saw any sign of these marks whatever. In the unlikely event that this isn't so then TV will repair the lens coating, I'm sure. I've spoken to them on the phone and they are just great, really helpful.

Glorious scope. Enjoy it.

Olly

^^^^ This.

Great post

[StarryEyed]

From reading your email I would suggest your biggest problem is how you feel about it much more than any impact they might have which in reality might not be significant and likely that you will ever know.

Keep the scope and if in a few years time it bothers you send the scope of to have the problem resolved.

But You need to let it go or sell the scope if you think it will make you unhappy.

Best of luck.

[Joves]

Haha... Good advice, thanks Starry. I'm not really THAT bothered by it. Like I say, I knew there were some marks before buying it. Was more curious as to what impact small scratches are likely to have on the views.

Thanks for the advice though. I'll stick with it and at least take a look through it, I suppose

[StarryEyed]

Ed Ting did a nice article about an 8 inch sct with a cracked objective which is an interesting read.

[John]

My TV Nagler 31mm has some marks on the coatings of the eye lens. They were there when I bought it (used) and the seller was open about them. They make no difference to the views through the eyepiece at all as far as I can see and I have compared the eyepiece to unmarked ones such as my Ethos 21mm, Pentax XW 30mm, Nirvana 28mm etc, etc. As the eyepiece only cost me £200 I'm perfectly relaxed about them

Enjoy the 127 - it's a fantastic scope I'm sure

[Baffa]

Hehe, I love this article. http://www.lensrentals.com/blog/2008/10/front-element-scratches

Sent from Xperia Z1 using Tapatalk.

[HumptyMoo]

At the levels you describe it is going to be psychological way way more than anything else. Olly has it bang to rights imo.

[Joves]

Thanks folks, really appreciate the replies. Sounds like I really don't have too much to worry about. Which is funny, considering the lengths we go to keep our lenses pristine. Prevention is always better than a cure though, I guess!

That was a great article, thanks Baffa... Certainly put things into perspective!

I took a couple of quick snaps of the main objective, which I'll post on here so you have some idea of what caused the worry in the first place.

Thanks again.

Aaron

[Joves]

Ok, here are a few shots. The first shows the coatings. You can just see the discoloration, but can't really make out the fine scratches, which I guess only further confirms that they're really not that major.

Also attached a couple of pics with it mounted beside the Genesis and little 76. Excuse the mess in Televue corner

[ChrisLX200]

What you need is an ME II so you can bolt all those scopes together on it

ChrisH

[Joves]

Would look kinda cool, don't you reckon! Haha

[StarryEyed]

You know the best person to ask would be Al. Send him the images and ask him for some advice. Should be a qualative answer.

[HumptyMoo]

From the pictures it definitely looks like the neighbour might be up to something interesting

[Joves]

From the pictures it definitely looks like the neighbour might be up to something interesting

Haha... No wonder they keep their curtains closed!

"HOOOOONEY... the weirdo across the road has another telescope pointing at us!!!"

[Rrrrronnn]

Hi Aaron, I agree with Olly's post. I think you would have a lot more to be worried about if the blemish or scratch was on your diagonal mirror, or on one of your eyepieces. Generally, the further away it is from your eye, the less of an effect it should have. Years ago I had the Genesis SDF, the grandfather to the NP 101. The views were outstanding.  Your "big brother" to the NP101 is fantastic!  I hope you enjoy your scope!

It's always worth remembering that a thumping great secondary mirror right in the middle of the light path does not appear in the eyepiece....

My standard one-liner on matters like this is to say, 'Look through your optics, not at them.' I would be surprised if you saw any sign of these marks whatever. In the unlikely event that this isn't so then TV will repair the lens coating, I'm sure. I've spoken to them on the phone and they are just great, really helpful.

Glorious scope. Enjoy it.

Olly

[alan potts]

A lovely set of scopes Arron, and how many eyes do you have.

I am with Olly on this one we try to clean things too much. I also think as it is a top quality scope and I know you like high quality things try to get it re-worked by Televue at a later date, it will cost a bit I am sure but I think in the long run it will be worth it.

If you fall out of love with it I would be happy to pay shipping to take it from you, Oh I may throw in a few bob for a cold one.

Alan.

[Joves]

Thanks Rrrronnn. That makes sense. Fortunately, my eyepieces are tip top! the genesis in the pic is an SDF. I agree, the views through it are outstanding. Haven't had a chance to look through the NP 127 yet. If the views are as sharp, combined with the added aperture, I'll be a happy camper!

Alan, thanks. They are lovely scopes. Still only have two eyes, last time I checked I think you're spot on with what I will do. I'm imagining I'll be pretty happy with the new scope once these darn clouds clear (might even allow me to split the Pup, with a little luck), so I can see myself sending it off to Televue for a lens re-work in the future if it appears to be a long-term keeper.

Thanks for the generous offer to take it off my hands AND cover the cost of shipping if I happen to fall out of love with it. Reassuring to know that someone might like the old piece of junk!

Aaron