ic1396 osc vs mono - a PERSONAL comparison on a single target with totally different camera sensors.

[geeklee]

4 minutes ago, powerlord said:

sii and oiii look ok ?

I think they're just visible in these stacks too:

 

[powerlord]

I do get that 'diffraction pattern' with the OSC too with the redcat. Weird isn't it ? I mean there is no lens blocking thing.. why the pattern ? is it a redcat thing ? I think I do get it on the OSC too tbh, it's just far less visible.

 

[powerlord]

Yeh, here's the extracted R from the OSC data stretched, and you can see same thing. they are so small though it's doesn't seem to be as obvious.

ha-stretched.tifit was a cheap mkl redcat, albeit one I'm happy with and that's been through Mr E S Reid's hands.

 

[simmo39]

Just to add my thoughts, Im no expert and have both an ASI 1600 mm and an ASI 2600mc. I loved my ASI1600 and the mono images it produced but I always felt I need to give a subject a lot of time to get a good image using narrow band filters. Also I was never happy with the results I got with RGB filters so I got a ASI2600 mc, I also got an optolong Enhance filter with the camera and after trying found I could get an image that I was pleased with in a lot less time. Was it as good as the ASI 1600 with a long exposure time? No but I was getting to see more targets and enjoying the images Im getting. I have since purchased an Optolong Extreme filter which I feel is giving better still results, not in the ASI 1600 narrow band filter results class but just good enough to make me happy. Im not getting rid of the ASI 1600 just yet as there are a few targets out there that i think it will really excel with but for just shear pleasure of seeing an image in a shorter time as possible I dont think you can beat the ASI 2600 mc at the moment.

[Adam J]

8 hours ago, Lee_P said:

Could the 1600 data be exhibiting microlensing? That's a known issue with the camera, although I think it's just the case with bright stars so I'm probably barking up the wrong tree.

Just would not happen with stars of this brightness. 

[Adam J]

7 hours ago, powerlord said:

I do get that 'diffraction pattern' with the OSC too with the redcat. Weird isn't it ? I mean there is no lens blocking thing.. why the pattern ? is it a redcat thing ? I think I do get it on the OSC too tbh, it's just far less visible.

 

Sorry to say it is astigmatism and would normally warrant the scope being returned. I am very shocked if it is a tested example. I would contact FLO it will be too late for WO warranty if it's a MK1. It may be caused by an overnight lens cell and so be fixable. 

Adam 

 

Edited October 10, 2022 by Adam J

[Stuart1971]

2 hours ago, Adam J said:

Sorry to say it is astigmatism and would normally warrant the scope being returned. I am very shocked if it is a tested example. I would contact FLO it will be too late for WO warranty if it's a MK1. It may be caused by an overnight lens cell and so be fixable. 

Adam 

 

It is astigmatism, i mentioned this in an earlier post, and would assume that Mr E Reid, would not see this unless he tested the scope under a starry sky, and his tests are only bench tests AFAIK, for collimation and such like….

It sometimes will not, show with certain size pixel cameras, like I said earlier, with my 2600mc I get it in one corner, but with my SXVR M25c with 9 micron pixels it’s perfect….

 

Edited October 10, 2022 by Stuart1971

[Adam J]

9 hours ago, Stuart1971 said:

It is astigmatism, i mentioned this in an earlier post, and would assume that Mr E Reid, would not see this unless he tested the scope under a starry sky, and his tests are only bench tests AFAIK, for collimation and such like….

It sometimes will not, show with certain size pixel cameras, like I said earlier, with my 2600mc I get it in one corner, but with my SXVR M25c with 9 micron pixels it’s perfect….

 

I would think that a simple test with an artificial star would show astigmatism. Its how I look for it. 

Adam 

[powerlord]

It's an old redcat I got cheap from a fellow SGLer. It had been through the wars by a previous owner (not the SGL seller) and totally screwed up. Esmond did a stellar job on it and I am very happy with what he's managed to achieve.

I'll bear in mind your comments if I ever sell it, and ensure the buyer knows about the astigmatism, but it's absolutely fine in my eyes - I'm really not a star peeper usually.

stu

[Adam J]

6 hours ago, powerlord said:

It's an old redcat I got cheap from a fellow SGLer. It had been through the wars by a previous owner (not the SGL seller) and totally screwed up. Esmond did a stellar job on it and I am very happy with what he's managed to achieve.

I'll bear in mind your comments if I ever sell it, and ensure the buyer knows about the astigmatism, but it's absolutely fine in my eyes - I'm really not a star peeper usually.

stu

It might be caused by the optics being pinched so my be fixable by backing off the centering screws. If it was my own the. I would back them all off 1/10th of a turn. But it's not without risk. 

Edited October 11, 2022 by Adam J

[powerlord]

As I say, ES Reid has calibrated and collimated it to the best of his abilities - which are far far higher than mine, so I'm leaving well alone.

stu

[Stuart1971]

13 minutes ago, Adam J said:

It might be caused by the optics being pinched so my be fixable by backing off the centering screws. If it was my own the. I would back them all off 1/10th of a turn. But it's not without risk. 

I don’t think that is from pinched optics, as that normally manifests in flares on the bright stars…🤔

[900SL]

On this subject.. I currently have an IDAS NBZ dual band filter on my 533MCP. I think this is around 12nm. Would I see an appreciable difference changing to an Antlia ALP-T dual band at 5nm? Bortle 6 ish skies...

I'm assuming I'd have cleaner frames and a better S/N but wondering how big a difference it would make quantitively

[Phillyo]

15 hours ago, 900SL said:

On this subject.. I currently have an IDAS NBZ dual band filter on my 533MCP. I think this is around 12nm. Would I see an appreciable difference changing to an Antlia ALP-T dual band at 5nm? Bortle 6 ish skies...

I'm assuming I'd have cleaner frames and a better S/N but wondering how big a difference it would make quantitively

I went from the IDAS NBX (precursor to the NBZ I think?) to the ALP-T filter on my Samyang at f3.5 and the contrast in the images is indeed more noticeable. Whether it's worth the extra cost is of course entirely up to you.

[powerlord]

I reckon a lot of it will depend on the noise pollution in your sky, moon phase, etc. for the optolong ones one of the big differences is far less star glow in oiii.