TV Naglers for an 8" SCT

[strutsinaction]

I have a Celestron NexStar 8SE and am thinking of buying 3 'quality' EPs. My short list at the moment is:

TV 26T5 (x78)

TV 13T6 (x156)

TV 9T6 (x225)

I'm expecting these to be long term 'keepers' so would like to make the right decision now. I understand that less expensive EPs may suffice with this f/10 SCT, but I do intend upgrading the scope at a later date and don't really want to upgrade the EPs again - famous last words ;-)

So, has anyone used these EPs with an 8" SCT? Can I expect sharp focus across the entire FOV? Is the 26mm/13mm/9mm combination a good choice?

Thanks for any advice!

Regards

John

[Kai]

If its Televue's your after have a look at this link , From the man himself

http://www.televue.com/engine/page.asp?ID=222

[John]

I use the 13mm T6 and 9mm T6 Naglers in scopes much shorter than F/10 and they are sharp right across the field

Naglers and other Tele Vue designs are tested to perform well down to F/4 so F/10 is a piece of cake for them.

I've also found that Naglers barlow well so you might want to take that into account in selecting your focal lengths.

John

[strutsinaction]

I've ordered the 13T6 and 9T6, and now need to decide on the low mag wide field EP.

The 8SE has a baffle size of 32mm and the 26T5 has a field stop of 35mm. So, do you think I'll notice some form of vignetting with this EP, or will this not really be an issue? It's likely that I'll order the 26T5 anyway, as I'm sure the supplier will exchange the EP if it's a problem.

[MartinB]

Thinking about eyepiece options normally scrambles my brain. As you've said, the SCT doesn't really benefit a great deal from the expense of a set of Naglers although the wide field of view will be just the job. A Moonfish 30mm UWA will perform wonderfully but will not be that impressive at the edges with the faster scope you may have in the future. I never got any vignetting with the C8 30mm UWA combination.

It doesn't seem sensible to be having a 13mm a 26mm simply because the 26mm will barlow up very nicely to 13mm.

The other thing with a C8 is that you have a long focal length scope. The 9mm will be of use for nothing other than bright planets and the moon. The C8 will have run out of steam for DSOs at this point. I looked at a few bright globs with my C8 and a Pentax 10mm XW but things are really getting too dim at x250 for deep sky viewing. A 9mm Nagler isn't the ideal planetary scope (more glass than necessary). Better on the moon but you might be better sticking with some simple plossls.

So, if the Moonfish is out it would be a 26mm T5 and 17mm T4 (Rated by many to be the finest EP Nagler have produced up until the Ethos) and a 2" x2 powermate. Then get something like 10mm and 6mm plossls - no need to spend too much, or better still if you don't wear glasses, for planetary viewing get a couple of orthoscopics which give superb planetary views. I've never tried the Radians but they are supposed to be very nice to use with good eye relief. I was only able to get use from a 6mm EP on nights of super fine seeing, on one glorious night I am convinced I could make out the Encke division in Saturn's rings with my C8.

[strutsinaction]

Thanks, Martin - consider my brain well and truly scrambled :? I've cancelled my order for the Naglers whilst I review my options. I don't think the 2" 26T5 is the right EP for the 8SE due to inherent field curvature/coma with the SCT design, and the fact that the field stop of the 26T5 is 38mm and the 8SE baffle size is only 32mm. At least that's what I'm led to believe. £400 is a lot of money to spend on an EP that gives blurred, dim stars at the edge of the FOV - the WO 33mm SWAN can do that for a lot less

If anyone has actually used a 26T5 with an 8SE and had pin sharp performance across the *whole* FOV then please speak up! Al Nagler recommends the 24 Panoptic for the 8SE, BTW.

[strutsinaction]

Well, after much deliberation, a TV 24mm Panoptic is now on its way.

Regards

John

[John]

Well, after much deliberation, a TV 24mm Panoptic is now on its way.

Regards

John

You won't regret buying a 24mm Pan John - I'm delighted with mine and it and the Nagler T6 13mm are my favourite eyepieces

John

[James]

I'll echo Johns sentiments regarding the 24mm Pan - a fantastic eyepiece even in fast scopes.

James