33 replies to this topic

[Jim Svetlikov]

Geeze Jeff - I'm surprised you want to sell that TV barlow - I use mine all the time - its one of my best eyepiece accessories.

[Tom L]

Jeff, I have an older TV 1.8x barlow that is an interesting piece and I like it a lot...but find myself using the TV 3x exclusively. Probably keep it though...I also bought the GSO 2" 2x barlow that I haven't tried out yet...it was an impulse buy when I bought the 30mm (they shipped together and I got it at a good price). Don't know if I'll ever use it though.

[jmoore]

Geeze Jeff - I'm surprised you want to sell that TV barlow - I use mine all the time - its one of my best eyepiece accessories.

You'd think it would be a keeper, wouldn't you, Jim? But:
1) In my 80mm Pentax, nothing will focus when using a 2x Barlow...I can only focus EPs with a 2.5x Powermate
2) In my 5" Mak, I don't need a Barlow to get high powers. 6mm EP gives 256x. 5-8 zoom (which I'm about to buy), and 3-6 zoom (recently bought) take me unnecessarily high.
3) I used to use the 2x a bit with my 8" Newt. For example, 2x with 9mm ortho gave 222x. A real winner. But as mentioned, I just picked up the 3-6 zoom, which ranges 167x-333x. Just don't need the 2x anymore, unless I find myself wishing for 400x, or for future photog purposes, but I'll cross those bridges later. For now, I'd rather have the $85 back in my pocket. My credit debt is dangerously high, thanks mainly to this hobby.

jeff

[Jim Svetlikov]

Too bad it doesn't focus in the Pentax. But I have a Speers-Waler zoom and use the zoom in combination with the TV barlow with excellent results, even when the zoom is at 5mm.

But of course, if the credit card is bulging at the seams, you have to give up something.

The TV zoom is definitely a cash cow but probably worth every cent. I hope to try it one day and compare it to the Speers.

[jmoore]

Jim...in what kind of scope do you use the SW-zoom/2x combo? It would be tempting to have this setup rather than the Nagler zoom (for cost reasons), but I'm assuming:

1. this is a pretty bulky setup that might cause some balance issues (especially with a small grab-n-go package)

2. that the visual quality of a SW zoom with 2x Barlow just wouldn't approximate that of the Nagler zoom. The SW shouldn't quite match the Nagler to begin with, and with the 2x, you're talking a heck of a lot of glass in the light path.

But you seem to use this combo with great success (and Dave Knisely has said as much also), so I'm interested in hearing more.

jeff

[Jim Svetlikov]

I use it in my 10" dob - see ATM forum for pics of new chassis recently completed.

1. It is bulky and heavy but I've accounted it for with counter-balance - you can do the same thing.

2. I agree there is probably more glass in this combo than the Nagler zoom, but the Speers zoom offers more field of viewand the TV barlow does not seem to take much of the light away.

And besides, the cost of a Speers zoom and a TV barlow are much less than a Nagler zoom. I paid $250 CDN for the zoom. (about $185US)

Although I haven't looked through the Nagler zoom, I can't see it being that much better image quality than the Speers, but again, the Speers offers a much larger field of view.

I would suggest hanging on to the TV barlow until you get a chance to fully experiment with the Speers zoom and TV barlow as there is a better range of magnifications.

Who knows, you might wind up selling the Nagler zoom instead and keeping the Speers/TV barlow combo.

[Tom L]

Where did you find the S-W zoom for $185? The TV3-6 zoom is too much power for my scopes.

[Jim Svetlikov]

Tom

I bought it through Astromart from a local fellow - he occasionally has them for sale now and again. I don't know where he keeps getting these things but they are brand new and have not been used.

If I see one of his ads up again, I'll post it here.

Please remember, I saved some in shipping and insurance by picking it up myself.

[Tom L]

Thanks Jim...I keep my eyes open on AM for just this eyepiece (just like Jeff!). Haven't seen one for quite a while.