Tele Vue Paracorr Type 2 Comma Corrector

[bartonv]

I am thinking of purchasing this item form Orion for my 10" reflector with the primary purpose of shorting my focal length. I want to do some astrophotography and cannot reach primary focus(within 2-3 mm). Does anyone know if it will do this if at all? My focal length is 1200mm. I know a barlow will but I also want to get the comma correcting effect.

Thanks

[Stargazer_00]

Paracorr t2 has a 15% barlow effect I believe which lengthens the focal length.

[alan potts]

The only member I know uses a Paracorr is Moonshane, he knows about these things. I thought a PC only increased the focal length myself. I do not know if he is a SGL 8 as many site members will be, so you may have to wait a while for an answer.

Televue will be a good choice but pricey

Alan

[swamp thing]

Hi

The Paracorr is not designed for this purpose. The Paracorr is a coma corrector and as has been said actually lengthens the focal length. It sounds to me like you need to move the primary mirror up the tube.

[Daniel-K]

either do as steve said or get a low profile focuser

[Moonshane]

I have the T1 paracorr but I think they are the same in this respect. the focal length is actually increased by 15% so your scope would become a 1380mm f5.5. rather bizarrely, the paracorr also takes the focal plane IN by about 18mm. therefore if you just need a bit more in focus it might help but it won't create a wider field (in fact the opposite).

moving the primary up the tube is a cheaper way to get in focus but if you want a wider field, for AP, you'd be better buying a smaller frac or newt and in fact a 10" newt is not really a great tool for AP unless you have a seriously good mount.

[Moonshane]

you can I think buy focal reducers for newts but these are incredibly expensive. e.g. http://www.teleskop-express.de/shop/product_info.php/language/en/info/p4685_ASA-2--Newtonian-Corrector---Reducer-0-73x.html

[cs1cjc]

The Sky-Watcher coma corrector is 0.9x, while the Baader MPCC (new version coming soon?) has no barlow effect, see: http://www.firstlightoptics.com/coma-correctors.html

[Stargazer_00]

How does the MPCC work? Considering this myself as I dont have paracorr money. Want to see how the eyepieces I have in the post perform first but I suspect I might want a coma corrector if it's something I dont have to screw to every eyepiece like a filter.

[cs1cjc]

I have no experience with the MPCC. The older verison was not well suited to visual use, but the new one should be a good as any. It may be possible to configure it up like the GSO coma corrector which I wrote about here but spacing is going to be more critical because of the smaller back focus distance, 55mm vs 75mm.

[bartonv]

Thanks everybody for your input

[ivan-sh]

Hi all!

After a lot of reading here and there, I am still not sure if the TV Paracorr Type-2 is worth it (in terms of price/performance ratio) for imaging.

It seems that pretty much everybody is using it mainly for visual...

At first, I was considering the Baader MPCC Mark III, but it seems it is not that good at all:

http://www.pleiades.hu/tesztek_csillagaszat/korrektorok_1.html

The Paracorr 2 is pretty pricey, but if it is worth it... I am currently leaning towards it.

I intend to use it with a SW Quattro 8s + TSOAG9 + Canon EOS 600Da

So, what do you think about the Paracorr 2 for imaging?

PS: I am currently imaging with a SW 200p + SW CC and when there is some bright star in the FoV, I get some nasty reflections. How is the Paracorr performing in that aspect?

Thanks!

Ivan

[Don Pensack]

A general rule of thumb about coma correctors is that magnification is added to reduce spherical aberration.  SA isn't important for imaging, but it definitely counts in visual observing.

Baader MPCC-0% increase in focal length

Explore Scientific HRCC--6% increase (requires 32mm of in-focus)

GSO/Astrotech coma corrector--10% increase

TeleVue Paracorr--15% increase

All the latest versions of the above are usable below f/4.

[RAC]

I use a TeleVue Paracorr type 2 for imaging with a 10" f4. I was very unhappy with the Mk3 MPCC. I find the Paracorr very VERY good! You can see a few of my newer shots with it on my Flickr page.

https://www.flickr.com/photos/46302893@N02/

Here's a full size image of M83 using it.

[ivan-sh]

Thanks a lot! The Paracorr 2 is already on its way...

PS: And that is one cracking image of M83 by the way! Good job.

[Skynovice]

Impressive photos.

S.