First proper test with my triple Samyang 135mm system

[Chris-h]

So I FINALLY got not one, but TWO nights of "clear" sky (transparency was a bit variable on night 2). That meant I could finally give my new system a good test! I did run into some weird problems with the EAF's. Everything would be working fine in the beginning, but then when it was time to refocus an hour later, the ASCOM drivers had suddenly decided to either swap the focusers around, or assign the same focuser to both instances. It looks like when you have two of the same thing, ZWO's ASCOM drivers are a bit flaky. ZWO are looking into it. Other than that, it seemed to run well with 3 NINA instances and synchronized dithering.

Over the two nights I collected 16+ hours of OSC and 4 hours of Ha (and Oiii, but none showed up in M31, so I didn't use it). I might add a bit more Ha, as I'm now starting to pick it up in the background!

3x Samyang 135mm f/2 @ f/3.3
2x ZWO ASI585MC @ Gain 100 og 252
1x Player One Uranus C @ Gain 100
Baader IR/UV Pass filter
Altair 6nm HA/Oiii DualBand filter
OSC: 16.2 hours (324x180 sec)
Ha: 4 hours (80x180 sec)

Thanks for looking! 🙂

Edited September 4 by Chris-h

[WolfieGlos]

Really nice M31, and lots of Ha in the spirals as well as the background too, nice job.

There is OIII in there too, there was a recent image showcasing it.

A triple Samyang rig, wow you’re going to gobble up that sky in no time! Any pictures of your rig by any chance?

Out of interest, was your Dualband filter on the 585mc or the player one? I get horrible star halos with my 585mc and SY135, with two different filters (Askar C1 and Optolong LeNhance) at gain 252, I’m wondering if it’s the filter or the gain. Noting that you used a different gain makes me wonder if it’s the culprit! 

[TiffsAndAstro]

1 hour ago, WolfieGlos said:

Really nice M31, and lots of Ha in the spirals as well as the background too, nice job.

There is OIII in there too, there was a recent image showcasing it.

A triple Samyang rig, wow you’re going to gobble up that sky in no time! Any pictures of your rig by any chance?

Out of interest, was your Dualband filter on the 585mc or the player one? I get horrible star halos with my 585mc and SY135, with two different filters (Askar C1 and Optolong LeNhance) at gain 252, I’m wondering if it’s the filter or the gain. Noting that you used a different gain makes me wonder if it’s the culprit! 

From what I have gleaned from reading about filters and halos, might be worth moving filter further away from sensor if you can.

Also some filters only have anti reflective coatings on side side, so try flipping it?

Edited September 1 by TiffsAndAstro

[Chris-h]

Thank you Chris.

Well you know how it is, we need speed in this country with all the clouds!

I know there is OIII in there, but 4 hours just wasn't enough time to bring it out.

The Altair's are halo free on both cameras. I know the Optolong will show haloes, not sure about the Askar.

I started out using gain 252, but soon switched over to gain 100. The 585 is a great short exposure camera, but not a good long exposure camera. Images are just way to noisy at HCG and longer exposures. For narrowband I still use 252 though

[WolfieGlos]

26 minutes ago, Chris-h said:

Thank you Chris.

Well you know how it is, we need speed in this country with all the clouds!

I know there is OIII in there, but 4 hours just wasn't enough time to bring it out.

The Altair's are halo free on both cameras. I know the Optolong will show haloes, not sure about the Askar.

I started out using gain 252, but soon switched over to gain 100. The 585 is a great short exposure camera, but not a good long exposure camera. Images are just way to noisy at HCG and longer exposures. For narrowband I still use 252 though

Interesting, I've not experienced the "way too noisy" at HCG but then I have come from a DSLR, so any improvement in noise is appreciated  Generally I'm at 120/180s broadband at gain 252, and 300/360s "narrowband" at gain 252. Operating at f/5.6 on the main scope kind of leads me to HCG to reduce exposure time and maximise dynamic range. I've had no issues so far with it, other than halos in dualband.

Thanks for the info, I might have a play with different gains and see what happens.

Look forward to seeing your image when you add more Ha to it  The triple rig will also make mosaics a breeze.

[Chris-h]

Hehe, i guess i notice it more coming from cooled cams.

I'm still sorting out the cables, but here is a quick pic of the setup.

[Elp]

How have you addressed getting the same alignment issue for each lens?

[Chris-h]

Both the right and left lens are on a Skywatcher guidescope mount. The hardest part is actually getting the camera rotation correct.

Edited September 1 by Chris-h

[Elp]

It's a bit difficult because of the way yours is setup with eafs etc, I simply rotate the lenses and have even devised something else though haven't tested. It all adds up to setup time, but yours looks mounted permanently so you don't get this issue.

[Chris-h]

Yes, I have to rotate the lenses before the belts are attached, praying things won't move. Unfortunately they do. But I have ordered some rotators from China now, so hopefully they will solve the problem.

So you tear down every night? Knowing how little it takes to knock things out of alignment, that would drive me insane! 🤣

[Elp]

I've put in the rotators but mine only allow 90 degree rotation, but from experience I usually start off with the sensors in "portrait" if the setup is in home position, because any east/west RA will inevitably change them into some degree of diagonal orientation, then theoretically the rotator only needs a slight rotation to get them all orientated the same, then lens centre alignments to do etc etc.

Yes, I setup and breakdown every time, but I've kind of reached a point where I think I can store it with near enough the same setup (minus cables), the lens alignment needs to be done every time because it's too fine a movement to be able to disturb the setup by handling it every time and expect them to keep alignment.

The other issue is I use airs, so lose at least 30 mins of data per lens when dithering but making up for it via fewer sessions.

Also, so many cables, but they're needed.

[Chris-h]

30 min loss on each lens? Ouch!

The cables drive me mad! I probably have to get some custom made ones to tidy things up. Or buy a Pegasus Powerbox Ultimate. But I don't really want to spend the £540...

[Elp]

If you need 12v only the Deep Sky Dad 12v hub is far cheaper.

[callisto]

10 hours ago, Elp said:

If you need 12v only the Deep Sky Dad 12v hub is far cheaper.

I'll second that 👍

[geeklee]

On 01/09/2024 at 03:10, Chris-h said:

3x Samyang 135mm

Very nice proper first light image Chris and what a fantastic setup 😍

On 01/09/2024 at 03:10, Chris-h said:

Other than that, it seemed to run well with 3 NINA instances and synchronized dithering.

Even thinking about this makes me prefer to admire from afar rather than try the same!  Well done getting this set up and working efficiently.

[Vroobel]

Hi, 

That's a great project, so I have full respect for the effort put into this. As a DIY/ATM enthusiast I know what that means. 👍

I have one question: if you use MC cameras, why three setups instead of two? From my experience with MC, Optolong L-eXtreme and IDAS LPS-P2 were used. In case of mono cameras you could use separately Ha, SII and OIII filters or R, G and B which makes more sense for me. 

Presently, one of my setups is a Sigma 40mm F/1.4 Art @ F/2.0 with an ASI2600MC Pro equipped with a ZWO filter drawer and EAF and controlled by an ASIair Plus, guiding by ASI120MM mini @ Svbony 30mm. A lot of Arca-Swiss clamps, rails and brackets is used for a flexibility and convenience. I spent so much time on details around the setup that I would get insane if try to triple the work plus the alignment. That's why I understand and appreciate your work. 👍

 

Edited September 2 by Vroobel

[Elp]

26 minutes ago, Vroobel said:

Ha, SII and OIII filters or R, G and B which makes more sense for me

This is how I'll use mine, or RGB/OSC and 2x mono lum. Literally one project done per night.

[Chris-h]

Thanks all.

Why colour? Well I had a lot of the equipment already, like two ASI585's and a set of Altair Ha/OIII and SII/OIII filters. So I decided to use what I had 🙂 I've bought another Ha/OIII filter, and I have borrowed a third one. So basically all 3 lenses now shoot Ha and OIII at the same time. Or I can colour. Or mix and match.

I've also gone down the mono route twice, but always returned back to OSC. With today's sensors, Dualband filters and software, there really isn't that much difference between mono and colour anymore. Some, yes. But not as big as 5-10 years ago.

I'm also lazy! With OSC, I can just dump everything into SIRIL (well I have to crop the Player One image first, as it has a few extra pixels compared to the ZWO), and let it chug away.

Now, I might go back to mono once I've played with the system for a while. This was more of a 'Can I pull this off, and will it work' kind of project 😁

 

Edited September 2 by Chris-h