Closeup of the Tadpoles from a RASA 8 wide field

[gorann]

1 minute ago, ollypenrice said:

There's no tendency for mirror flop in TEC 140s either but it still doesn't work...

Olly

But that is more than twice the FL - what was it Oddball said in Kelly's Heros about sending out them negative waves......

[ollypenrice]

11 minutes ago, gorann said:

But that is more than twice the FL - what was it Oddball said in Kelly's Heros about sending out them negative waves......

Why would FL matter? Surely the issue is resolution. I don't know your resolution in arcsecs per pixel, nor do I know at what point it becomes a problem, but I do know that a dual rig works for me painlessly at 3.5"PP and not at 1.1. (Or 0.9 on one side and 1.1 on the other.) Maybe tube length and bending moment come into it but I suspect it's resolution. I know of others who've found two high res instruments problematic. Of course, short CMOS sub lengths would be a big help. I see a considerable difference in trailing on the slave scope between 10 min and 15 min subs. 3 minutes would be great!

Olly

 

Edited December 17, 2020 by ollypenrice

[gorann]

11 minutes ago, ollypenrice said:

Why would FL matter? Surely the issue is resolution. I don't know your resolution in arcsecs per pixel, nor do I know at what point it becomes a problem, but I do know that a dual rig works for me painlessly at 3.5"PP and not at 1.1. (Or 0.9 on one side and 1.1 on the other.) Maybe tube length and bending moment come into it but I suspect it's resolution. I know of others who've found two high res instruments problematic. Of course, short CMOS sub lengths would be a big help. I see a considerable difference in trailing on the slave scope between 10 min and 15 min subs. 3 minutes would be great!

Olly

 

Ah, there we have what may save me Olly. The Light grasp combined with the new CMOS = short exposures. For this one it was 83 x 2 minutes. For the Squid I whent to the extreme and used 5 minute exposures😉.

Edited December 17, 2020 by gorann

[ollypenrice]

7 minutes ago, gorann said:

Ah, there we have what may save me Olly. The Light grasp combined with the new CMOS = short exposures. For this one it was 83 x 2 minutes. For the Squid I whent to the extreme and used 5 minute exposures😉.

That might, indeed, be a key factor.

Olly

[gorann]

1 minute ago, ollypenrice said:

That might, indeed, be a key factor.

Olly

The draw back is of course that with 2 minute exposures one ASI2600 collects 30 x 52 Mb of data per hour, which after debayering becomes 30 x 313 Mb, so 9 Gb. Two of them will collect 18 Gb per hour. So stacking takes more time than collecting, so external hard drives are a necessity.

[ollypenrice]

7 minutes ago, gorann said:

The draw back is of course that with 2 minute exposures one ASI2600 collects 30 x 52 Mb of data per hour, which after debayering becomes 30 x 313 Mb, so 9 Gb. Two of them will collect 18 Gb per hour. So stacking takes more time than collecting, so external hard drives are a necessity.

Indeed. I met this issue processing Yves' 32 panel full frame Cepheus/Cygnus mosaic. Fortunately I have a fast machine. (Not my Royal Enfield...🤣)

Olly

[Alien 13]

47 minutes ago, ollypenrice said:

Indeed. I met this issue processing Yves' 32 panel full frame Cepheus/Cygnus mosaic. Fortunately I have a fast machine. (Not my Royal Enfield...🤣)

Olly

Your Royal Enfield is a beauty, I am sure its "the journey" thats the important part.

Thankfully in the scheme of things fast PCs are relatively cheap in astro terms.

Alan 

[ollypenrice]

9 hours ago, Alien 13 said:

 

Thankfully in the scheme of things fast PCs are relatively cheap in astro terms.

Alan 

They are, it's true, and a fast one does make processing even more enjoyable.

Olly

[wimvb]

13 hours ago, gorann said:

If I ever do it I will virtually bolt them together. Good thing is that there is no tendency for mirror flips in the RASA and the short FL and wide field makes them easy to align to a sufficient degree. And I would not be a pioneer. Just wish I have had a chance to tell him to arrange his cables better - he will get a mess of star spikes:

https://www.dpreview.com/forums/post/62471743

Never mind the cables, as long as they go parallell to the sides of the cameras. The cameras edges will produce star spikes in this configuration.

[wimvb]

Btw, that rig with six RASAs reminds me of the ED-209 unit in the 1987 movie Robocop.

Edited December 18, 2020 by wimvb
might as well use that double post

[wimvb]

On 16/12/2020 at 12:51, gorann said:

At this closeup the stars looks a bit odd, dimond shaped.

That's easy to fix:

Morphological Transformation in PI to the rescue. Without putting too much effort into it.

Edited December 18, 2020 by wimvb

[gorann]

34 minutes ago, wimvb said:

That's easy to fix:

Morphological Transformation in PI to the rescue. Without putting too much effort into it.

Great! There is always new things to learn in this game

[wimvb]

On 17/12/2020 at 21:48, gorann said:

But that is more than twice the FL - what was it Oddball said in Kelly's Heros about sending out them negative waves......

Have a little faith, Göran. Have a little faith.

[gorann]

1 minute ago, wimvb said:

Have a little faith, Göran. Have a little faith.

I have a lot of faith in a RASA 8 double rig with my ASI2600MC for dual band or RGB on one and an ASI2600MM for Lum on the other, except there is no ASI2600MM procued yet😰