Imaging with TS PHOTON 6" F4 Newt

[Anthony RS]

Hello,

Is anyone here using the TS Photon 6" F4 newtonian? I'm about to purchase it but I have some doubts and questions:

1- Does it hold collimation well, at least in a single session?

2- Is it impossible to balance in DEC due to its small dovetail or is it possible but harder?

3- Is the focuser rigid enough or does it introduce tilt?

4- Will collimating it be a nightmare?

5- I'm really picky when it comes to coma, should I expect some coma on edges even while using the Skywatcher Aplanatic F4 CC?

6- All in all, do you advice me to buy it or have some other option in the same price range.

Cheers!

Anthony

[RodAstro]

Hi Anthony

I am also looking at one for EAA

I have used the 8" version for several months in my observatory so have some experience.

People went on about collimation on the 8" I just think it was rough handling and not that good at collimating.

The one I used stayed in collimation for months in a fixed position, piggybacked to my main scope, in my observatory. The secondary was the most vulnerable because of the thin spider  so the 6" should be better because of the smaller diagonal and shorter spider arms but that's what you pay for having thin spider vanes.

I can see balance will be a problem depending on the camera used and I would say a small weight added to the back of the dovetail bar would be a good option, in my view better than a long springy SW/Vixen dovetail bar.

Focuser was good for the money I had no problem with it.

You are always going to get coma on a F4 newt even with a CC, maybe if you spent a few hundred more than the scope cost on a CC you may get rid of it. Visually you should not notice it if the objects you are looking at are interesting. Photography wise fix it in your processing.

As for should you get it, well there is nothing else at f4 at this price range, (other than the same scope under a different name) double that and you may get rid of the coma totally but that's a gamble.  

[Anthony RS]

18 hours ago, RodAstro said:

Hi Anthony

I am also looking at one for EAA

I have used the 8" version for several months in my observatory so have some experience.

People went on about collimation on the 8" I just think it was rough handling and not that good at collimating.

The one I used stayed in collimation for months in a fixed position, piggybacked to my main scope, in my observatory. The secondary was the most vulnerable because of the thin spider  so the 6" should be better because of the smaller diagonal and shorter spider arms but that's what you pay for having thin spider vanes.

I can see balance will be a problem depending on the camera used and I would say a small weight added to the back of the dovetail bar would be a good option, in my view better than a long springy SW/Vixen dovetail bar.

Focuser was good for the money I had no problem with it.

You are always going to get coma on a F4 newt even with a CC, maybe if you spent a few hundred more than the scope cost on a CC you may get rid of it. Visually you should not notice it if the objects you are looking at are interesting. Photography wise fix it in your processing.

As for should you get it, well there is nothing else at f4 at this price range, (other than the same scope under a different name) double that and you may get rid of the coma totally but that's a gamble.  

Thanks for the info! I actually decided to go with the TS UNC 6 inch F4. which is a step above the photon. I own the Skywatcher F4 Aplanatic coma corrector, do you think it's good enough to eliminate coma in an F4? I really hate coma.

[RodAstro]

Hi Anthony

Thats nice.

I don't think you will remove the coma totally but you will do a very good job of it, I have used a Teleview Parracor and that cannot get rid of all the coma at F4.

I think you would be looking at a ASA reducer corrector or a Row Akerman unit both costing more than the scope and Sw coma corrector and having never used them I would not guarantee they would be perfect although images seem to show they do a good job but you don't know how much has been done with post processing. As I say for imaging you can remove the final bit of coma in your processing software.