Anything out there better than Televue 2x PowerMate?

[jpro747]

Hi all,

I'm trying to improve my setup and considering trying out a new 2x extender/barlow/teleconverter. I currently use a 2x 2" TeleVue PowerMate which I'm happy with but I'm always wondering if theres something better out there.

I should mention that I use my telescope mainly for images of aircraft flying at high altitudes and rarely for astrophotography.

My current set-up:

OrionOptics UK VX12 (12" 1200mm f4 dobsonian with flocking mod)

Televue 2x 2" PowerMate

Canon 50D

So my question is, is the televue Powermate the best piece of equipment for the job or would I be better off using a different piece such as the Canon 2x Extender iii?

Thanks,

James

[estwing]

not to my knowledge..if there is..it's been kept a secret!

[John]

Zeiss do a 2x barlow which is supposed to be as good as it gets. The cost is around $500 though and it's devilishly difficult to source one. Other than that the Powermate is probably the "top dog".

[johninderby]

Here's something even better than the Zeiss, but just a little bit on the expensive side.

All CA2 Fluorite elements

http://www.widescreen-centre.co.uk/Products/BAADER_FLUORITE_FLATFIELD_.html

John

[jpro747]

Thanks for the rapid replies.

The Baader Flatfield Converter sounds like the best, but the price!

Does anyone know if it work at 2x magnification? I cant go much further than 2x, unless I want to see what sandwich the pilot is having for lunch

I tried to find the Zeiss Barlow but could only find this one which is at 1.25", unfortunately I need the 2" which i imagine is the hard to find one?....http://www.teleskop-express.de/shop/product_info.php/language/en/info/p473.html

[alan potts]

Simple answer, no!

Alan

[HD-AP]

how about an ASTROPHYSICS 2X 2 INCH APOCHROMATIC BARLOW.

[E621Keith]

Thanks for the rapid replies.

The Baader Flatfield Converter sounds like the best, but the price!

Does anyone know if it work at 2x magnification? I cant go much further than 2x, unless I want to see what sandwich the pilot is having for lunch

I tried to find the Zeiss Barlow but could only find this one which is at 1.25", unfortunately I need the 2" which i imagine is the hard to find one?....http://www.teleskop-.../info/p473.html

Since you have a 2" 2x powermate already, do you really another 2x barlow or will you be better off with something that has lower magnification such as a 1.6x barlow?

Also I wonder if a conventional astro barlow lens / tele-extender will be better than a photographic teleconverter for imaging. After all, the Nikon and Canon photo teleconverter are matched to their cameras with the correct sensor spacing and will fully illuminated their FX format sensor. They are also designed to handle the F2 light cone coming from their 200mm F2 lens.

[michael.h.f.wilkinson]

Having dabbled in optical design a bit at university, I am given to wonder how the Baader FFC does all it claims to do. I am not so much worried about colour correction, much more about the flat field. The claim is that the field is flat regardless of the scope (F/4.5 Newtonian, F/8 APO, or F/10 SCT), These scopes have (very) different field curvature, so how the corrector manages to correct each of them (unless there is some setting dial) beats me.

[estwing]

sounds like a sales pitch to me Michael!

[Darkmatter]

Siebert Telecentric barlow lenses are said to be excellent 

[russ.will]

ES Focal Extender. Same result at half the price if you haven't already bought a TV....

Russell

[alan potts]

Very true Russell but did you notice the thread was over two years old as the poster before you hasn't. I wonder why it was dug out.

Alan.

[denis0007dl]

Harry Siebert make great telecentric barlows which are betger than Powermates, because they produce little cooler image and little better light transmittion!

[alan potts]

Denis,

I don't question what you say with regard to the Harry Siebert barlow but surely if you were concerned about light transmission and we are talking visual a dedicated eyepiece would be the first choice. If we were talking photographic the extremely tiny amount of extra light is hardly going to make any difference.

Alan

[denis0007dl]

Siebert telecentric barlows contains also 4 lenses, and same design like Poweramtes. I like that they are also much lighter than Powermates, and this sometimes helps photographers. Optics is very sharp!