Red cat 51

[Beardy30]

Hi all  posted this earlier in the wrong section apologies! 

as a visual hobbyist I’ve never ventured into AP however I’m tempted to jump in 

what’s the view of the following:

red cat 51

sharpstar 61 version II

or the sw 72 ed

I have no idea what hat I’m doing I’ll admit that when it come to AP!

so any help in layman’s terms most welcome - I understand that I’ll need a dslr or a cam on the guide cam and ota and some sort of computer software to process but have no idea wheee to even start 

 

cheers 👍🏼

Ps my mount is the azi gti ! And I’m intending to stick with it - I have the mak 127 I use for visual 

[Gfamily]

I've very little to say, except that the RedCat is the only one that doesn't need a Field Flattener as it's a Petzval design. 

I've observed next to someone with a RedCat and he's getting great results from it. 

[Beardy30]

11 minutes ago, Gfamily said:

I've very little to say, except that the RedCat is the only one that doesn't need a Field Flattener as it's a Petzval design. 

I've observed next to someone with a RedCat and he's getting great results from it. 

Yes must admit I’ve never heard a bad word about the red cat - seems to be a quality instrument 

[Stefan73]

I think the first thing you'd need to decide is what you want to photograph and how much money you want to sink into it.  Then the question is a bit more answerable!

The telescopes you've listed are all fine for deep space photography but anything like that, where you need long exposures, you'd need an equatorial mount really.  On the other hand you have a mak 127 so with a cheapish planetary camera (or even a mobile phone holder and a mobile phone) you could start taking pictures of the planets or the moon more or less with what you have since you can use short exposures or short videos to achieve that.

[Beardy30]

23 minutes ago, Stefan73 said:

I think the first thing you'd need to decide is what you want to photograph and how much money you want to sink into it.  Then the question is a bit more answerable!

The telescopes you've listed are all fine for deep space photography but anything like that, where you need long exposures, you'd need an equatorial mount really.  On the other hand you have a mak 127 so with a cheapish planetary camera (or even a mobile phone holder and a mobile phone) you could start taking pictures of the planets or the moon more or less with what you have since you can use short exposures or short videos to achieve that.

Hi thanks for this. Yes I agree I’ve been doing that for some time over a range of scopes but now looking at AP for deep sky imaging. Mount wise any of them will fit in the azi gti eq conversion including guide scopes and cams etc so no issue with that it’s just deciding on the quality of the ota but I think I know the answer deep down 👍🏼

[900SL]

What do you want to image (ie targets) and what is your light pollution level?  And what is your budget?

If you get a Redcat without collimation issues (it is not uncommon), it's a nice little scope. Most targets look smallish in a Redcat FOV (Andromeda here taken with a Nikon APS-C sensor for scale)

If you want a longish focal length or longish exposures you will need to track and guide, and this may overtax your GTi

If you want to capture Ha nebulosity you will need a Ha sensitive camera

The samyang 135mm is ultra widefield but very fast and more tolerant of tracking errors

Need more data to compute

 

 

 

 

 

 

Edited January 26, 2023 by 900SL

[Beardy30]

Hi Location depends where I am interns of LP my suburban garden is poo but I have access to a local dark site  

[Stefan73]

1 hour ago, Beardy30 said:

Hi thanks for this. Yes I agree I’ve been doing that for some time over a range of scopes but now looking at AP for deep sky imaging. Mount wise any of them will fit in the azi gti eq conversion including guide scopes and cams etc so no issue with that it’s just deciding on the quality of the ota but I think I know the answer deep down 👍🏼

Have a look at the field of view calculators in kstars or similar programs (or online eg https://astronomy.tools/calculators/field_of_view/) so you can check that the sort of things you want to image are going to not be too big or too small for the camera /  scope combination you're going to go for.  DSOs range massively in size from very large to very small....

Also it's worth looking for examples of pictures that others have taken with the equipment you have in mind so you'll know what's possible.

[PEMS]

If you decide on a Redcat, then the early ones were triplets at the front and flattener (or whatever) at the rear, again a triplet lens arrangement. They have collimation and set up issues. Basically I suspect just too complicated. Good when sorted, bit of a pain to get sorted.

Newer ones are doublet at front and corrector/flatter at rear is still a triplet arrangement. They are easier and as good.

Relevent if you buy used items.

Concerning the SW 72ED, I have one and will likely give it away. Just don't get on with it. Really a case of it works but only just. There seems no spare tolerance in it to make life easy. Had to have a diagonal machined slightly just so I could look through it and get a focus.

Don't know what mount you have but for AP that is most important, and as ever the mantra is "BIG". And a big mount is not user friendly.

[Beardy30]

Think I’m leaning To the sharp star 61 as it’s priced mid way and has excellent reviews - thanks all  

[jfrijhoff]

There are the 'newer' versions of the lower focal length skywatcher scopes, like the Evolux 62ED (and 82ED), but they would need the additional field flatteners for astrophotography. Same for William Optics Zenithstar 61II, and it's corresponding field flattener. I don't have experience with these, but these were the ones I came across as interesting as a next purchase. I'm currently mainly using the Rokinon/Samyang 135mm lens with good results on a start tracker without guiding.

[Beardy30]

Yes a flattener would’ve essential