Coma correctors for Skywatcher 150 pds

[Chrissh]

Hi everyone

I have recently acquired a 150pds and need some advice on coma correctors, currently using a unmodded canon 70d and have read quite a few reviews on the said item, some negative some positive. the model I have been interested in is the Baader Mark-III MPCC Coma Corrector - Photographic, but I noticed there are a couple of the skywatcher models as well. So I am after your advice as I really don't want to buy one and then find it is not all that good especially nowadays with the price of things. Any advice most welcome.

Many thanks

Chris H

[cajen2]

I'm told the StellaLyra one is very good VFM and has the option of connecting via a T 2 or M48 thread.

[Louis D]

The GSO made StellaLyra CC is very good visually for the money.  It also helps to flatten the field somewhat.  I've no idea how well it works for prime focus photography, though.  If you are also a visual astronomer, it could serve double duty for you.

[adyj1]

I have a 150PDS and have used a skywatcher 0.9x coma corrector with a Canon DSLR (modded and unmodded) for a few years without complaint.

[Elp]

I did a rough test with a GSO one with a 130pds here:

Certainly helps, but it's not essential.

[barbulo]

I went for the Baader MPCC MkIII and I will not say that I regret but I wouldn’t buy it again. For a similar price I’d go for the Skywatcher.

[adyj1]

7 hours ago, adyj1 said:

I have a 150PDS and have used a skywatcher 0.9x coma corrector with a Canon DSLR (modded and unmodded) for a few years without complaint.

I have had a  reflection from very very bright stars if they are in the centre of the FOV, though (alnitak as an example) - but I was only taking that as an alignment shot and it has never troubled me through my normal dso imaging (the horsehead and flame was fine) 

[Chrissh]

OK Guys thanks for all the help,

Chris

 

[Altair8389]

Sorry to revive this old thread again. ! I have a Skywatcher 150pds and decided to go for the StellaLyra coma corrector (from FLO) for a reduced price. I did this as the Baader and Skywatcher CC were more expensive. However, I am not interested principally in visual, just for imaging e.g. with a dSLR Canon 100D. How do you set the StellaLyra CC for dSLR imaging on the Skywatcher 150pds. Just insert the coma corrector and insert the dSLR (with Tring and 2 inch camera adaptor into the coma corrector) ? Or is there additional spacers and other stuff to worry about ?

 

I did read the CloudyNights thread but that seemed mainly for the visual (eyepiece) adaptions, I am not really bothered for what my eye can see as my eye is not perfect anyway.

Many thanks.

 

Magnus

[Louis D]

You'll need about 75mm of space between the back of the CC optics section and the DSLR's imaging plane.  If you're using a T-ring, that alone gets you to 55mm spacing.  Thus, you'll need approximately 20mm of additional spacing.  I would think an M42 to M48 adapter would also be necessary plus some spacer ring(s) to get your to that 20mm.  I would invest in a spacer ring kit to fine tune the separation.  These kits say M42, but mine came as an M48 kit.

Edited February 13, 2023 by Louis D

[R26 oldtimer]

What Louis said, I've got the GSO one and works really good. I think that a 5mm length m48 to m42 adapter is already included, meaning you'll need aprox 15-20mm spacer to fine-tune the distance. You will unscrew the eyepiece holder part and screw your t-ring with spacers to the CC's main body which houses the optical elements.

The focal plane will also be shifted aprox. 20mm outward of the focuser which means that newtonians that normally won't come to focus with a DSLR (unless you move the primary mirror up) will focus with this cc as they would with a Barlow.

Gave up mine for a Lacerta GPU which is a bit better but far more expensive.

Edited February 13, 2023 by R26 oldtimer

[Altair8389]

Thanks R26 oldtimer. I will do as you advise and get the dSLR fired up with the Stellalyra CC soon. I think I have enough spacers to do the appropriate spacings.

 

Magnus