Would a MPCC help with a newtonian for prime focus work

[Chris Southby (Chris)]

Hi all
I am begining my travels in astrophotography. I am currently experimenting with prime focus work with a DSLR.
My question is whether a Baader MPCC would be useful, all I have read so far seems to suggest that they are mostly used with eyepieces and not with prime focus photography.

Any suggestions would be appreciated.

cheers

chris

[Gama]

Short answer, yes.
But, its most benificial when used on fast scopes, like f5, f4 etc.
The MPCC is used for both astro imaging and viewing, and works well.

Theo

[White Rabbit]

It depends on the type of scope, refractors dont need them, but newts do. If you dont have one on you newt you end up with egg shaped stars. This is due to the mirror being parabolic in shape, this causes different focal lenghts at the botton of the mirror curve than the top.

[Chris Southby (Chris)]

Thanks guys
I have an F5 Newt so it looks like I'll be after an MPCC sooner or later than.

Cheers

Chris

[toryglen-boy (Duncan)]

Originally Posted by Chris Southby

Thanks guys
I have an F5 Newt so it looks like I'll be after an MPCC sooner or later than.

Cheers

Chris

Chris

I use an MPCC on a 200mm F5 newt for imaging, it works wonders

[multiweb (Marc)]

Originally Posted by Chris Southby

My question is whether a Baader MPCC would be useful, all I have read so far seems to suggest that they are mostly used with eyepieces and not with prime focus photography.

Get a baader MPCC. Definitely a keeper.

[TheDecepticon]

Originally Posted by White Rabbit

It depends on the type of scope, refractors dont need them, but newts do.

I believe that statement to be somewhat incorrect. It is not uncommon for a refractor to need a field flattener of some sort.

[peter_4059 (Peter)]

I thought the MPCC was intended to correct coma in Newtonians rather than be used as a field flattener in a refractor?

"The only Newtonian Coma Corrector that does not change (increase) the focal length of the telescope in any way. f4 Newton optics will remain f/4!"

http://www.baader-planetarium.com/pdf/mpcc_e.pdf

[peter_4059 (Peter)]

Originally Posted by Chris Southby

Hi all
I am begining my travels in astrophotography. I am currently experimenting with prime focus work with a DSLR.
My question is whether a Baader MPCC would be useful, all I have read so far seems to suggest that they are mostly used with eyepieces and not with prime focus photography.

Any suggestions would be appreciated.

cheers

chris

Also have a look at the Televue universal paracorr - I've been very happy with mine.

[AlexN]

Originally Posted by peter_4059

I thought the MPCC was intended to correct coma in Newtonians rather than be used as a field flattener in a refractor?

"The only Newtonian Coma Corrector that does not change (increase) the focal length of the telescope in any way. f4 Newton optics will remain f/4!"

http://www.baader-planetarium.com/pdf/mpcc_e.pdf

I'm using a Baader MPCC to flatten the field of my TMB F/6 refractor. I looked at many other options (and spent quite a lot of money testing them...)

I finally decided I did not want any focal reduction (most flatteners are a 0.8x or 0.85x reducer as well) I was told by the previous owner of my refractor that an MPCC would flatten the field provided the distance from the chip to the MPCC was exactly the right distance.... I thought, it can't hurt to try it out... Gave it a go and have been using the MPCC since.. Perfectly flat field without any focal length reduction..

[peter_4059 (Peter)]

Originally Posted by AlexN

I'm using a Baader MPCC to flatten the field of my TMB F/6 refractor. I looked at many other options (and spent quite a lot of money testing them...)

I finally decided I did not want any focal reduction (most flatteners are a 0.8x or 0.85x reducer as well) I was told by the previous owner of my refractor that an MPCC would flatten the field provided the distance from the chip to the MPCC was exactly the right distance.... I thought, it can't hurt to try it out... Gave it a go and have been using the MPCC since.. Perfectly flat field without any focal length reduction..

Alex,

Sounds like an added bonus for the MPCC - it also works as a field flattener for refractors!!

ps the Televue paracorr increases focal length by 15%

[White Rabbit]

I new that refractors needed a field flattener but I did not know that an MPCC would do the job. I suppose it makes sense as the problem is the same for both types of scope but the cause is differnet.
I'll need to try that on my ED 102...

Thanks

[Chris Southby (Chris)]

Thanks for all the info.
Due to limited funds I can either afford to get a Baader MPCC or a GSO 2 inch 10:1 microfocuser at the moment. The other will have to wait until later. The current focuer is the standard Skywatcher crayford that comes with the Blackdiamond Newts.

Any recomendations on which one would be the most useful to begin with. I'll get the other one some time later.

Cheers

Chris

[multiweb (Marc)]

Originally Posted by Chris Southby

Thanks for all the info.
Due to limited funds I can either afford to get a Baader MPCC or a GSO 2 inch 10:1 microfocuser at the moment. The other will have to wait until later. The current focuer is the standard Skywatcher crayford that comes with the Blackdiamond Newts.

Any recomendations on which one would be the most useful to begin with. I'll get the other one some time later.

Cheers

Chris

I'd bite the bullet and get the MPCC. You can improve your focuser down the road.

[toryglen-boy (Duncan)]

Originally Posted by multiweb

I'd bite the bullet and get the MPCC. You can improve your focuser down the road.

agreed.

i use the MPCC with the SW Crayford, and while its not fantastic, its still a very workable solution.

[Benno85 (Ben)]

Originally Posted by toryglen-boy

agreed.

i use the MPCC with the SW Crayford, and while its not fantastic, its still a very workable solution.

Does the MPCC assist with reachiong focus? At present I can't focus my Canon through my 8" Newt, will the MPCC correct this or did you have to modify your tube?

[multiweb (Marc)]

Originally Posted by Benno85

Does the MPCC assist with reachiong focus? At present I can't focus my Canon through my 8" Newt, will the MPCC correct this or did you have to modify your tube?

That's the good thing about the MPCC. It won't change your focal length so focus will be in the same spot or extremely close. If you have an in-focus problem you might want to use a barlow.

[pmrid (Peter)]

Originally Posted by AlexN

I was told by the previous owner of my refractor that an MPCC would flatten the field provided the distance from the chip to the MPCC was exactly the right distance..

And the $64Million question is ..... what is that distance? Is it the magic 55mm?

Peter

[toryglen-boy (Duncan)]

Originally Posted by Benno85

Does the MPCC assist with reachiong focus? At present I can't focus my Canon through my 8" Newt, will the MPCC correct this or did you have to modify your tube?

i find in general the MPCC moves focus in slightly, that is, i dont have to rack the focuser out as much as without it

[peter_4059 (Peter)]

Originally Posted by pmrid

And the $64Million question is ..... what is that distance? Is it the magic 55mm?

Peter

Peter - it would appear so - have a look at the instructions in the link I posted earlier in this thread.

Peter