12 Minute M42 with ASI294MC Pro

[Budgie1]

The ZWO ASI294MC Pro camera has been getting a bit of a bashing of late in various threads, mainly about the difficulties getting decent Flats, which I know can be a pain and more so if you're using one of the duo-band filters.

So I thought I would post an image I took on the 10th February (my second clear night so far this year! ) to show that this camera isn't all that bad and can produce some surprising images.

Now, my main target for the night was M33 and I managed nearly 4 hours on that, but then the Moon started to effect the subs and it was quite close to the trees by this time, so I swapped to M42.

M42 or anything close to Orion is only visible for a couple of hours for me, due to tall trees to my South. I have a gap between the trees in which I can image Orion, but not for long. On Thursday, M42 was getting a bit too close to the trees by time I started imaging it and I only managed 16 x 60s exposures before I could see branches in the subs. When it came to processing, I ended up with 12 usable frames but I went ahead and stacked them in DSS using Darks, Flats & Dark-Flats.

Post-processing was done in PI with a final "enhancement" to the starless image in Topaz AI (I may have gone a bit OTT with the Sharpen AI but I was only playing ). The ASI294MC settings were: Gain 120, Offset 8, exposure 60s and fixed point cooling set to -10°C. The scope was a Skywatcher Evostar ED80 DS Pro with the 0.85 FR/FF and UV/IR cup filter only. I'm blessed with Bortle 2, so no LP filters needed. 

I know M42 is a bright object but, for a 12 minute exposure, I think the ASI294MC Pro has done quite well.

Maybe I'll get some more subs to add to these when I get my clear night for March! 🤣

[Adam J]

6 minutes ago, Budgie1 said:

The ZWO ASI294MC Pro camera has been getting a bit of a bashing of late in various threads, mainly about the difficulties getting decent Flats, which I know can be a pain and more so if you're using one of the duo-band filters.

Great image,

As you say the issues are more with the duo-band filters though.

Adam

[PadrePeace]

I thought I’d chime in just to say firstly, that’s a great image Budgie1 that shows that the 294MC is a capable camera for OSC. Secondly, as AdamJ rightly says, the issues are with Dual band filters which specifically expose the non linear response of the sensor between 117-190 gain settings. I personally tried many different exposure, ADU, temperature Flats combinations at my preferred gain of 120 and just could not find flats that worked. That all changed once I read the SharpCap article on the 294MC sensor here: https://forums.sharpcap.co.uk/viewtopic.php?t=3855

I now avoid the 117-190 gain window when using my dual band filter (I shoot at 200 gain 30 offset) and have immediately found that my matched flats now work perfectly. The loss in stops due to shooting at 200 gain vice 120 gain is not that significant so I’d commend this fix to anyone struggling with their Flats for a 294MC /Dual band filter combo. Note that it seems that each sensor/dual band filter combination seems to offer a different looking Flat image, in the way that fingerprints are different. 

Finally, here is my latest image shot with this combo (L-extreme Dual) which used the flats shown very successfully as you can see. 

Hope this helps, clear skies

 

[Budgie1]

Thanks @PadrePeace, I'd been keeping my eye on the thread that @scotty38 started about using the L-eXtreme with the ASI294MC back in January, but confirmation from yourself about the gain settings you're using and the link to the SharpCap thread is useful. 👍

I use the 1,25" L-eXtreme and have just got the 2" version of the Askar Duo-Band filter so I can use a filter draw with the 294MC, rather then having to remove the camera when I want to change filter. The Askar is a 7nm fitler, the same as the L-eXtreme, and with the little use I've had with it to date, seems to produce good results.

It looks like I've got another week or so of clouds & storms to come, so I'll use your settings and create a Darks library and give it a go on the next clear night.

Did you find you could reduce the exposure times with the added gain setting, or did you stick to what you would normally use?

[SimonHutch]

Really nice image! 👍🏼

[PadrePeace]

59 minutes ago, Budgie1 said:

Thanks @PadrePeace, I'd been keeping my eye on the thread that @scotty38 started about using the L-eXtreme with the ASI294MC back in January, but confirmation from yourself about the gain settings you're using and the link to the SharpCap thread is useful. 👍

I use the 1,25" L-eXtreme and have just got the 2" version of the Askar Duo-Band filter so I can use a filter draw with the 294MC, rather then having to remove the camera when I want to change filter. The Askar is a 7nm fitler, the same as the L-eXtreme, and with the little use I've had with it to date, seems to produce good results.

It looks like I've got another week or so of clouds & storms to come, so I'll use your settings and create a Darks library and give it a go on the next clear night.

Did you find you could reduce the exposure times with the added gain setting, or did you stick to what you would normally use?

I did reduce exposure time with increased gain. 

[Budgie1]

That's my new Darks library created this evening.

Cooled to -10°C, Gain 200, Offset 30 and exposures of 45, 60, 90, 120, 180, 240, 300 & 360 seconds.

All set for the next clear night, when ever that may be.

[IDM]

On 13/02/2022 at 10:49, PadrePeace said:

I thought I’d chime in just to say firstly, that’s a great image Budgie1 that shows that the 294MC is a capable camera for OSC. Secondly, as AdamJ rightly says, the issues are with Dual band filters which specifically expose the non linear response of the sensor between 117-190 gain settings. I personally tried many different exposure, ADU, temperature Flats combinations at my preferred gain of 120 and just could not find flats that worked. That all changed once I read the SharpCap article on the 294MC sensor here: https://forums.sharpcap.co.uk/viewtopic.php?t=3855

I now avoid the 117-190 gain window when using my dual band filter (I shoot at 200 gain 30 offset) and have immediately found that my matched flats now work perfectly. The loss in stops due to shooting at 200 gain vice 120 gain is not that significant so I’d commend this fix to anyone struggling with their Flats for a 294MC /Dual band filter combo. Note that it seems that each sensor/dual band filter combination seems to offer a different looking Flat image, in the way that fingerprints are different. 

Finally, here is my latest image shot with this combo (L-extreme Dual) which used the flats shown very successfully as you can see. 

My heart sank when I first started reading bout issues with the Zwo ASI294 MC pro when used with Optolong L extreme as i own the 294 and was waiting delivery of the L extreme filter. However, I have to report that using Adam's recommended 200 gain setting has produced excellent results for me. The attached image is 91 60 second exposures (I used 60 seconds as it was so windy I was concerned that the scope might move). Calibration flats were taken using a tablet PC as a source of even light. All images were stacked in DSS, the stretched using Siril histogram auto-stretch and then just a few very minor tweaks. It may not be brilliant but it is by far my best effort so far, particularly as I regard myself as an L-plate learner!!

[Budgie1]

I still haven't had a clear night to try the settings, I was looking last night and I've had 5 days in 2022 when it hasn't rained up here!

I think you've done alright with the Rosette, there's a little movement in the stars but the nebula is good.
I took the liberty of putting your image through Topaz AI DeNoise & Sharpen, nothing major with the setting, see what you think.

[IDM]

2 hours ago, Budgie1 said:

I think you've done alright with the Rosette, there's a little movement in the stars but the nebula is good.
I took the liberty of putting your image through Topaz AI DeNoise & Sharpen, nothing major with the setting, see what you think.

Hi Martin,

The star movement might be the wind, plus a polar aligned by eye and didn't bother setting up guiding (still a learner with PHD2 as well). I think your reprocessing gives a subtle but worthwhile improvement, so many thanks for that. I will have to do some more research on the best software for cleaning up images. I have only just started to play with Siril and have certainly been very impressed with the histogram auto-stretch function, it gives better results than my manual attempts using GIMP.

With regard to the rain and general rubbish weather, it is so frustrating, I know I have a lot to learn but tend to not take risks or try new things as clear nights are so precious, and I know if I get nothing due to conducting experiments I will be frustrated. I know at some point I will have to take some more risks.

Your feedback on my image is highly appreciated.

Cheers

Ian   

[Budgie1]

29 minutes ago, IDM said:

Hi Martin,

The star movement might be the wind, plus a polar aligned by eye and didn't bother setting up guiding (still a learner with PHD2 as well). I think your reprocessing gives a subtle but worthwhile improvement, so many thanks for that. I will have to do some more research on the best software for cleaning up images. I have only just started to play with Siril and have certainly been very impressed with the histogram auto-stretch function, it gives better results than my manual attempts using GIMP.

With regard to the rain and general rubbish weather, it is so frustrating, I know I have a lot to learn but tend to not take risks or try new things as clear nights are so precious, and I know if I get nothing due to conducting experiments I will be frustrated. I know at some point I will have to take some more risks.

Your feedback on my image is highly appreciated.

Cheers

Ian   

Guiding is worth the effort and, once you get it setup & get used to PHD2, it's not that difficult. For Polar alignment, I use the Pro version of SharpCap which has a PA tool and is only £10 a year.

Post-processing software is more of an individual thing. You'll get lot of views about which one does the best job or is easiest to use, but I'd advise using what you're comfortable with and what gives the results you're happy with. If you've started with Siril then I would stick with that and see what it can do. I'm sure there's plenty of tutorials and help out there for it.

Every day's a learning day with this hobby.

[edarter]

Just come across this thread while researching whether the 294MC Pro is the camera for me. I had long got it on my shopping list but recently saw all the negative comments surfacing about using it with a dual or tri band filter.... something I would be interested in medium term as it seems the only clear nights in the south UK are full moon 😒
So am I right to assume from this that there should be no issue with the 294 and dual or tri band filters if the gain is upped to 200 in order to get on the linear part of its response? (for subs and calibration files)

Thanks
Ed 

[Budgie1]

4 hours ago, edarter said:

So am I right to assume from this that there should be no issue with the 294 and dual or tri band filters if the gain is upped to 200 in order to get on the linear part of its response? (for subs and calibration files)

That's my findings with the ASI294MC Pro that I have. Since switching to 200 gain & 30 offset when using the Askar Duo-Band filter my flats have been fine and calibrate as they should. I haven't had chance to use the L-eXtreme yet but I don't expect it to be any different.

It's worth noting that not every ASI294MC seems to have the issue and some work fine at 120 gain settings.

This is that last image I took with the 200 gain 30 offset using the Askar filter. This was 3h32m of 4 minute subs of the Heart Nebula, taken on the 26th March with an Evostar 100ED DS Pro.

Edited June 9, 2022 by Budgie1

[PadrePeace]

5 hours ago, edarter said:

Just come across this thread while researching whether the 294MC Pro is the camera for me. I had long got it on my shopping list but recently saw all the negative comments surfacing about using it with a dual or tri band filter.... something I would be interested in medium term as it seems the only clear nights in the south UK are full moon 😒
So am I right to assume from this that there should be no issue with the 294 and dual or tri band filters if the gain is upped to 200 in order to get on the linear part of its response? (for subs and calibration files)

Thanks
Ed 

That’s my experience as catalogued in this thread. Others are finding the same. 
 

Anyone else had success using 200 gain with a Dual NB filter wish to chime in to add to our findings?

Edited June 9, 2022 by PadrePeace

[edarter]

That's good to hear, thanks. Would be good to bottom this one out for good as I'm really struggling to choose an alternative which gives as good for, sensitivity etc without spending at least £500 more!

[Budgie1]

Your main choices, as I'm sure you know by now, are the ASI533MC, ASI294MC and ASI2600MC.

If I had the money then it would be 2600, but I don't and it wasn't available when I got my camera anyway.  

The 533 seems a good alternative to the 294, slightly cheaper and with a newer sensor which doesn't produce amp-glow. It does have the square sensor, so you loose some FOV with it over the 294, but those who have this camera don't seem to notice this after a while. 

I haven't had any issues with my 294MC, which I got second hand from a fellow SGL member. Before @PadrePeace suggested changing the gain settings, I just dealt with the gradients when using the NB filters. When you get enough integration time on the images the 294MC produces very clean stacked images and sometime I don't even need to bother with noise reduction. 

Overall, I happy I got the 294MC and it's worth looking at the second hand market because it can safe you a few hundred quid.  

[ONIKKINEN]

19 hours ago, edarter said:

Just come across this thread while researching whether the 294MC Pro is the camera for me. I had long got it on my shopping list but recently saw all the negative comments surfacing about using it with a dual or tri band filter.... something I would be interested in medium term as it seems the only clear nights in the south UK are full moon 😒
So am I right to assume from this that there should be no issue with the 294 and dual or tri band filters if the gain is upped to 200 in order to get on the linear part of its response? (for subs and calibration files)

Thanks
Ed 

If you dont mind going for less popular brands you can have an equivalent camera to the 2600MC for a much more palatable price, have a look at these:

https://www.teleskop-express.de/shop/product_info.php/info/p13286_Omegon-Camera-veTEC-571-C-Color-cooled--Sensor-D-28-3-mm.html

https://www.astroart-store.com/product/976/deepskypro2600-c26mp-imx571-back-illuminated-aps-c-cooled-astrocamera

https://www.aliexpress.com/item/4001359313736.html?spm=a2g0o.productlist.0.0.6f047164JGhOx6&algo_pvid=88c7fc7f-59b2-4b58-9bdc-a75b08237944&algo_exp_id=88c7fc7f-59b2-4b58-9bdc-a75b08237944-0

https://www.teleskop-express.de/shop/product_info.php/info/p14967_TS-Optics-Color-Astro-Camera-2600MC-Sony-IMX571-Sensor-D-28-3-mm.html

All are basically the same camera, but be aware that none of these will work with an ASIAIR (if you have one).

Right now it looks like the Omegon 571 is the best deal with the Rising Cam from aliexpress pretty close. The 2 others are more expensive but i just linked them anyway, since they are the same camera and still cheaper than ZWO.