Redcat 51 with ASI533MC pro

[Martthebass]

I’m currently using a 90mm triplet apo with a 533MC and would like to look at doing some more wide field views than that offered by the 432mm reduced focal length offered by my existing setup so I’m considering looking at adding a Redcat 51 to facilitate this. I’m not exactly flush with cash and so will have to persevere with the 533 at least for a while which I’m aware isn’t technically a good match. Does anyone have a good experience (or bad) with this arrangement?

Edited May 29, 2023 by Martthebass

[Elp]

If you want to go wider and much faster consider the Samyang 135mm F2.

[Adam J]

16 hours ago, Martthebass said:

I’m currently using a 90mm triplet apo with a 533MC and would like to look at doing some more wide field views than that offered by the 432mm reduced focal length offered by my existing setup so I’m considering looking at adding a Redcat 51 to facilitate this. I’m not exactly flush with cash and so will have to persevere with the 533 at least for a while which I’m aware isn’t technically a good match. Does anyone have a good experience (or bad) with this arrangement?

You would get as much additional FOV by selling the 533 and buying a rising cam 2600 equivalent and have more change left over than buying a redcat. 

 

Adam

[scotty38]

What about doing some mosaics, won't cost anything but time and yes I know someone will mention clear nights 🙂 🙂

[Martthebass]

3 hours ago, Adam J said:

You would get as much additional FOV by selling the 533 and buying a rising cam 2600 equivalent and have more change left over than buying a redcat. 

 

Adam

Good idea but I’d be completely lost without my AAP 😂

[licho52]

11 hours ago, scotty38 said:

What about doing some mosaics, won't cost anything but time and yes I know someone will mention clear nights 🙂 🙂

Yes because mosaics are fundamentally and dramatically turning down the speed of your setup.  On one hand people fall over themselves to get f/2 and whatever hyperultraspeed setups, on the other they casually mention doing mosaics with them, which are an absolute slog to capture, normalize and process.  Mosaics are evil and should be avoided by anyone who has limited time/clear sky which is most people.

 

To answer OP's question, it should work very well, I'd recommend drizzling 2x because you'll be undersampled.

[Adam J]

21 hours ago, Martthebass said:

Good idea but I’d be completely lost without my AAP 😂

Why would you not be able to use APP? Assume Astro Pixel Processor would work just fine with Rising Cam?

Adam

[Martthebass]

Sorry, typo, meant AAP

[Martthebass]

Well a Redcat 51 v1.5 came up for sale at a very reasonable price locally so I took the plunge. The sky is looking ominous at the moment but ‘Clear Outside’ assures me it will be clear by 9pm for a good few hours. So, I’ve swapped out my SM90EDT and put on the Redcat for a hopeful first light.

[Elp]

Looks snazzy when it all matches.

[Martthebass]

18 minutes ago, Elp said:

Looks snazzy when it all matches.

Some of the ZWO red bits are starting to go pink 😂

[Dark Raven]

Welcome to the RC51 club. It is fine and durable instrument. I'm sure you you will have amazing time with it. AM3 would probably be more suited as AM5 is a bit of an overkill but they work well together.

If you polar align well enough, guiding will be spot on and you'll have sharp stars across the entire field.

I went with uncooled ASI585MC at 2.9 um in order to reduce the undersampling and avoid the need for large, heavy battery while backpacking.

 

In hindsight, perhaps it was over cautious on my part. I'll go wider with my next cam and I'm sure 533 will give you great results.

Do show what you get with it.  

Edited August 6, 2023 by Dark Raven

[900SL]

533 will be fine. At 3'/px a touch undersampled but you won't notice unless you pixel peep. The small sensor cuts down the FOV of course. 

My Redcat is spot on but some have decentered elements, a star test will soon tell you if all is well. 

Edited August 7, 2023 by 900SL

[Simon Pepper]

On 06/08/2023 at 21:30, Dark Raven said:

Welcome to the RC51 club. It is fine and durable instrument. I'm sure you you will have amazing time with it. AM3 would probably be more suited as AM5 is a bit of an overkill but they work well together.

If you polar align well enough, guiding will be spot on and you'll have sharp stars across the entire field.

I went with uncooled ASI585MC at 2.9 um in order to reduce the undersampling and avoid the need for large, heavy battery while backpacking.

 

In hindsight, perhaps it was over cautious on my part. I'll go wider with my next cam and I'm sure 533 will give you great results.

Do show what you get with it.  

What are those funky green parts? Actually gives the Cat some sexiness? 

[ollypenrice]

On 31/05/2023 at 01:42, licho52 said:

Yes because mosaics are fundamentally and dramatically turning down the speed of your setup.  On one hand people fall over themselves to get f/2 and whatever hyperultraspeed setups, on the other they casually mention doing mosaics with them, which are an absolute slog to capture, normalize and process.  Mosaics are evil and should be avoided by anyone who has limited time/clear sky which is most people.

 

To answer OP's question, it should work very well, I'd recommend drizzling 2x because you'll be undersampled.

I think you may be over-simplifying the mosaic versus single panel alternative. Suppose you want field of view 'x.' You can shoot it in low res, fast F ratio, short FL widefield in one go or shoot it in 4 panels in higher res, slower F ratio, longer FL. (Obviously you could also shoot it in super fast F ratio, larger aperture, longer FL, but not for the same approximate price!) If you go for the mosaic, and resample downwards, you do not need 4x the exposure because you can downsample each panel to a quarter of its area, so boosting the S/N ratio of each panel.

The choice really is a complex balancing act and is a very target- and intention- driven one.

An irony which constantly amuses me is that I never mosaic with my longest FL setups and almost always mosaic with my widefield ones. 

Besides, until you have spent a week of 8 hour days grappling with a 35 panel mosaic, you haven't lived!!! 

Olly

 

[tomato]

I do quake at the prospect of any mosaic over 4 panels but if you are fortunate to have a set up that goes deep quickly (e.g. RASA) then with modern software to stitch them together, a 4 panel mosaic is IMHO not too onerous. Sure, they will consume quite a bit of clear sky time, but then any serious imaging project will.