Coma Corrector

[drumsolo]

What does this do and how much difference will it make to imaging through my dslr?

Many thanks.

Stuart

[ollypenrice]

It is a lens which corrects an off axis (edge of field) defect inherent to Newtonians. This defect, coma, produces trailed, comet like, stars away from the image centre.

As a DSLR has, by astronomy standards, a large chip it will make a big difference to your mage quality. A CCD with small chip would not reach so far into the affected part of the light cone but would lose field of veiw.

Some coma correctors are too long, in my view, and set the camera too far out from the tube. This leverage can pull the camera out of square and produce new artefacts. However, I think the SW and Baader ones are good but I don't know from first hand. Someone will come in on this, I'm sure.

Olly

[Digz]

I completely agree with what Olly says above.

I have the Baader MPCC and it does a good job. Admittedly I havent done a direct comparison but have noticed a difference in my shots between using it and not.

If you are using a DSLR and newt scope then a coma corrector is essential IMO.

I dont know how good the SW one is but there are several people here with it. What I like about the Baader MPCC is that it comes with a series of spacers and rings so it can be used in almost any situation.

HTH

[Sparrow]

I'm desperately waiting for an injection of funds to get the Baader COma Corrector. There's no doubt that it will improve my images once I get it. I hate those elongated stars at the edges at the moment - my only temporary solution is to use the lens distort filter in Adobe to correct the image but it's a poor substitute.

[Digz]

What I like about the Baader CC (not sure in the skywatcher is the same, I guess so) is all the spacers you get so focus etc can be achieved, but I can also just attach my T adapter direct to the CC thus have a direct connection between DSLR and CC this then slots into the draw tube. That means my connections are effectively 2" and I think I should be able to attach a filter in there at some point. But Im not quite that far into yet for filters.