QHY268M has arrived

[Xiga]

8 hours ago, tooth_dr said:

Thanks Ciaran.

Actually that is a crop of the centre, binned 1x1, and not downscaled.  I did consider binning during capture or afterwards though, but wanted to try it out full size.  Guiding was sitting around 0.5"/px, using an OAG.  The full image has some nice detail in the small background galaxies.

Trying to work out the spacing - does it need some more or less spacing?

 

 

 

 

Amazing how sharp that looks at full size. Given what i'm seeing, i'd say you probably don't need to bin or downscale, the resolution is unreal. It doesn't have that soft look that can come from oversampling. 

Bring on Galaxy season! 😀

[tooth_dr]

A small gap in the clouds last night, 30mins on M81 M82, seeing was pretty bad last night.  Quick calibration and stack in APP:

Edited to add: havent sorted the spacing yet, and this is pretty much the FOV at 1200mm (slight edge crop)

Edited March 14, 2021 by tooth_dr

[teoria_del_big_bang]

Thats some detail for such a short exposure time 🙂 

I must admit when I took the dog out late last night with everything so wet I was amazed that quite a few stars were visible and was tempted to get the rig out but I thought maybe not a great idea after a bottle and half of red wine and so bed it was. 🙂 

Steve

[tomato]

Yes, great detail for 30 mins of data. Sky transparency was great last night, when there were no clouds in the way.

[tooth_dr]

Cheers @teoria_del_big_bang and @tomato It’s a bit over sampled but I’m absolutely loving the old 10” f/4.7 reflector for imaging. 

[SyedT]

Just my luck! Changed over to the Edge HD 8 for galaxy season, and the 268M gave up. Connecting fine but no image download and no cooling. QHY support suggested the cooling board needs to be replaced. Contacted Bernard at Modern Astronomy who has been incredibly helpful and is trying to push for a replacement camera instead of repair as the timeline for repair is fairly lengthy.

Back to the trusty Atik 490EX it is!

[tooth_dr]

21 minutes ago, SyedT said:

Just my luck! Changed over to the Edge HD 8 for galaxy season, and the 268M gave up. Connecting fine but no image download and no cooling. QHY support suggested the cooling board needs to be replaced. Contacted Bernard at Modern Astronomy who has been incredibly helpful and is trying to push for a replacement camera instead of repair as the timeline for repair is fairly lengthy.

Back to the trusty Atik 490EX it is!

Thats not very good at all.

[SyedT]

17 minutes ago, tooth_dr said:

Thats not very good at all.

Yep. Just something to keep an eye out for. If it starts to suddenly play up it's probably not you!

[nfotis]

9 hours ago, SyedT said:

Just my luck! Changed over to the Edge HD 8 for galaxy season, and the 268M gave up. Connecting fine but no image download and no cooling. QHY support suggested the cooling board needs to be replaced. Contacted Bernard at Modern Astronomy who has been incredibly helpful and is trying to push for a replacement camera instead of repair as the timeline for repair is fairly lengthy.

Back to the trusty Atik 490EX it is!

If I am not mistaken, this particular copy was just a few months old?

If yes, it should be under warranty.

N.F.

 

[SyedT]

33 minutes ago, nfotis said:

If I am not mistaken, this particular copy was just a few months old?

If yes, it should be under warranty.

N.F.

 

Yeah, I only received it in February so it's well within warranty. Repair would be free of cost as it's clearly a manufacturing defect, but I'll hopefully get a replacement instead.

[Starflyer]

23 hours ago, SyedT said:

Yeah, I only received it in February so it's well within warranty. Repair would be free of cost as it's clearly a manufacturing defect, but I'll hopefully get a replacement instead.

I'd expect a replacement for an almost new camera that clearly has a manufacturing defect.  Check out the Consumer Protection Act 2015.

If you reported the fault within 30 days of it being delivered to you then you have a right to reject it and get a full refund, although the retailer will most likely prefer to replace itif you point this out.

If you're outside the 30 day period for rejecting goods and getting an immediate refund these two points would apply and I'd still ask for a replacement or refund;

- a repair or replacement would cause you significant inconvenience
- the repair would take an unreasonably long amount of time

[rsarwar]

On 02/03/2021 at 11:50, tooth_dr said:

Seems to be working fine last night, apart from mist/cloud issues.  I’m only cooling to -10 deg C though.

I just wanted to add an update on attaching the camera to an Atik EFW3. Currently the only way was to use the M48 adapter, which added 5mm. This meant the total back spacing of the camera is 19.5mm

The Atik EFW3 is designed to mount directly to an Atik 16200 camera. Both seem to have a similar spacing of bolts.

Indeed it’s very close and in fact I only had to widen the holes by 0.15mm using 3.5mm drill bit) to let me screw the EFW3 plate directly onto the QHY268.

5mm doesn’t seem like much, but it means I can use my ZWO OAG (16.5mm) and Atik EFW3 (22mm) with my Baader MPCC mk1, and still maintain the correct back spacing (56mm).

Plus it is a secure flat fit 👍🏻

 

 

Hi.

 

I am in a similar situation and want to keep using my zwo ewf, which means I will be increasing the sensor to efw distance to 17.5mm.

 

I was wondering if you saw any problems with your 19.5mm spacing? I guess I should prepare myself to drill some wholes as well.

[tooth_dr]

7 hours ago, rsarwar said:

Hi.

 

I am in a similar situation and want to keep using my zwo ewf, which means I will be increasing the sensor to efw distance to 17.5mm.

 

I was wondering if you saw any problems with your 19.5mm spacing? I guess I should prepare myself to drill some wholes as well.

I never tried it at 19.5mm, just assumed at 5mm over the correct spacing there wouldn’t be any point. 

[tooth_dr]

Hi guys

Any suggestions for gain/mode/exposure time for H-alpha imaging. 
 

I grabbed a handful of H-alpha subs last night 300s/gain 56/photographic mode and thought they looked a bit noisy.  Are these the right settings for narrowband?  I’ve attached an uncalibrated stack of 11x300s

 

Thank you!

Adam

 

[rsarwar]

I have been testing as well. using Astronomik 12 nm Ha filters. 

both of these are 1 hour integrations. 50% moon. Thinking of trying gain 80 and see how well it goes. but yes a bit noisy.

RM=1, Gain=56, Offset=25, subs=600

RM=1, Gain=56, Offset=25, subs=300

[tooth_dr]

4 minutes ago, rsarwar said:

I have been testing as well. using Astronomik 12 nm Ha filters. 

both of these are 1 hour integrations. 50% moon. Thinking of trying gain 80 and see how well it goes. but yes a bit noisy.

RM=1, Gain=56, Offset=25, subs=600

RM=1, Gain=56, Offset=25, subs=300

Those both look better, smoother than mine - are those calibrated integrations or just raw stacks?  I was using a 7nm filter, and it last night so a slightly bigger moon.  Maybe 600s subs are the way to go?

[rsarwar]

12 minutes ago, tooth_dr said:

Those both look better, smoother than mine - are those calibrated integrations or just raw stacks?  I was using a 7nm filter, and it last night so a slightly bigger moon.  Maybe 600s subs are the way to go?

Yes, 600 sec is probably worth the try with gain 56.  

 

also you are in "photographic mode " which is mode 0? I think you should probably try mode 1/high gain. lower read noise and far better DR. 

 

I am having a horrible time getting anything on OIII/SII though with these settings- first time trying narrowband and i am not sure what to make of it. that is why i am thinking of trying out 80 gain. DId you try them? i am using 130pds

Edited April 22, 2021 by rsarwar

[tooth_dr]

2 minutes ago, rsarwar said:

Yes, 600 sec is probably worth the try with gain 56.  

 

also you are in "photographic mode " which is mode 0? I think you should probably try mode 1/high gain. lower read noise and far better DR. 

 

I am having a horrible time getting anything on OIII/SII though with these settings- first time trying narrowband and i am not sure what to make of it. that is why i am thinking of trying out 80 gain. DId you try them? i am using 130pds

Thanks for the reply.  I was shooting in photographic mode (I think yes that is mode 0).  I am not used to the modes.  Previously I used a CCD, and the only thing you could change was time    I'm using a 250px, which is a 10" reflector with a focal length of 1200mm at F4.7.  Tonight is looking clear too.  I will try mode 1.

[rsarwar]

yes, it has been very clear last week or so in oxfordshire too. i think it is clear tonight and tomorrow as well.

with mode 1, your gain will reduce by a factor of 1.5. but you should see less noise. and your DR range will increase 20% and your full well by 300%. you would definately need that for 600 sec shots. 

May i suggest you try both 300 and 600 sec and share the comparision. Honestly I did not expect much difference when i took the pictures i took, so would be nice to have them confirmed by you , 

Edited April 22, 2021 by rsarwar

[tooth_dr]

1 minute ago, rsarwar said:

yes, it has been very clear last week or so in oxfordshire too. i think it is clear tonight and tomorrow as well.

with mode 1, your gain will reduce by a factor of 1.1. but you should see less noise. and your DR range will increase 20% and your full well by 300%. you would definately need that for 600 sec shots. 

May i suggest you try both 300 and 600 sec and share the comparision. Honestly I did not expect much difference when i took the pictures i took, so would be nice to have them confirmed by you , 

I'll set up a sequence of 300+600s subs, and run a dither every other sub.

[Spongey]

Mode 1, Gain 56, Offset 10, 300s subs is what I use for narrowband, and it's been giving me pretty good results. 600s subs would probably be better but I'd rather take the small hit to noise and have more subs for pixel rejection to play with. I'm using 3nm filters for reference.

I'm not super experienced when it comes to NB imaging (this is my first mono camera), but an integration of a few hours has been enough for me to work with.

As I'm currently scope-less (although hopefully not for too much longer!), I've been using my Samyang 135mm at f/2.8 for imaging, but I did try the same settings at f/5.5 on my Esprit 100 before it was returned to good effect. I'm working on a widefield narrowband cygnus mosaic at the moment and I'm very happy with the results so far.

Cheers 

Edited April 22, 2021 by Spongey

[tooth_dr]

51 minutes ago, Spongey said:

Mode 1, Gain 56, Offset 10, 300s subs is what I use for narrowband, and it's been giving me pretty good results. 600s subs would probably be better but I'd rather take the small hit to noise and have more subs for pixel rejection to play with. I'm using 3nm filters for reference.

I'm not super experienced when it comes to NB imaging (this is my first mono camera), but an integration of a few hours has been enough for me to work with.

As I'm currently scope-less (although hopefully not for too much longer!), I've been using my Samyang 135mm at f/2.8 for imaging, but I did try the same settings at f/5.5 on my Esprit 100 before it was returned to good effect. I'm working on a widefield narrowband cygnus mosaic at the moment and I'm very happy with the results so far.

Cheers 

Cheers.  I'll try the mode 1 tonight, and will go with 600s.  In the past I've been using 1200s subs along with calibration data, and this removed the bad pixels etc and dithering cleaned up what even was left.  Maybe you arent taking many frames in the mosaic?  You need at least 16 for the sigma clipping to work isnt that right?

[Spongey]

5 minutes ago, tooth_dr said:

Cheers.  I'll try the mode 1 tonight, and will go with 600s.  In the past I've been using 1200s subs along with calibration data, and this removed the bad pixels etc and dithering cleaned up what even was left.  Maybe you arent taking many frames in the mosaic?  You need at least 16 for the sigma clipping to work isnt that right?

I have been taking approximately 4 hours per panel in each channel so far, so just under 50 subs/panel/channel. I dither after every frame, calibrate with darks and bias subtracted flats, and this works excellently. As for the exact number for sigma clipping to work I don't think there is a threshold as such, but more is always better.

My master frames are very clean, I'd happily send one across to you for inspection if you'd like?

Cheers

Edited April 22, 2021 by Spongey

[tooth_dr]

1 minute ago, Spongey said:

I have been taking approximately 4 hours per panel in each channel so far, so just under 50 subs/panel/channel. I dither after every frame, calibrate with darks and bias subtracted flats, and this works excellently. 

My master frames are very clean, I'd happily send one across to you for inspection if you'd like?

Cheers

No I was just wondering about you saying about the need for pixel rejection.  I thought maybe you had a very small number of frames to work with.  But even at 600s, you would still have 25 subs, I would have assumed that was plenty for the rejection algorithm to work effectively.

[tooth_dr]

To clarify the 1200s subs were with a CCD, not this camera.