MarsG76

Love it.. great color and detail... great work.

Great result.. I like the amount og detail within the "Dumbell".

That is very good for first images... I can imagine the pictures you'll be coming out with in 6 months...

More subs will result in less noise too....

Hi Astronomers,

Sharing another of my images taken using the new QHY268M astro camera... this time it's the NGC 6334, an emission nebula and star-forming region located in the constellation Scorpius, also known as the Cat's Paw Nebula, Bear Claw Nebula or Gum 64.
The nebula lies at an estimated distance of about 4,350 light-years from Earth.

This image was taken from my backyard in Bortle 4-5 skies through a 80mm refractor at F6.25 (500mm focal length) with the QHY268M camera through 7nm H-Alpha, SII and OIII narrowband filters.

Total exposure time was 18 hours and 15 minutes. Subs captured were HII: 15x600s OIII: 21x1200s and SII: 15x1800s @ HGC:62 on multiple nights between 31st May & 11 June 2021.

CS

MG

On 26/05/2021 at 17:11, SteveNickolls said:

Thanks MarsG76, I'll have a good read of your thread. 😃 I am aware of the cooled camera mod that Martin Pyott made available on You Tube. My Canon 700d was astro-modified when I purchased it years ago new and has done sterling work creating wide field nebulae shots in conjunction with an Astronomik 12nm Ha filter so you can understand my wishes not to buy an astro-camera with a smaller sensor unless that is the only affordable route to a cooled solution. Despite having a Bayer array the Canon 700D has collected some decent compositions in the past that way

Cheers,
Steve

I had a look at your pictures and they're great... with a upgrade to a cooled mono camera you'd basically increase resolution and capture the same amount of data in around 1/3rd of the time.... might have less noise too... but overall you wouldn't find a quantum leap in improvement as you're still limited by your sky.... ultimately It's a decision where you want spend the money not need to to enter the next level of astrophotography....  

My justification was to get it was for (hopefully near) future "F2  Fastar" imaging on my C8 that I wouldn't be able to do successfully with the DSLR (covering the whole objective)...

On 26/05/2021 at 17:11, SteveNickolls said:

Thanks MarsG76, I'll have a good read of your thread. 😃 I am aware of the cooled camera mod that Martin Pyott made available on You Tube. My Canon 700d was astro-modified when I purchased it years ago new and has done sterling work creating wide field nebulae shots in conjunction with an Astronomik 12nm Ha filter so you can understand my wishes not to buy an astro-camera with a smaller sensor unless that is the only affordable route to a cooled solution. Despite having a Bayer array the Canon 700D has collected some decent compositions in the past that way

Cheers,
Steve

I completely understand.. it's a expensive jump and if you're happy with the DSLR... which I know can deliver awesome images.... than there is no hurry to upgrade.... getting a smaller sensor is really a step back IMHO.

Great report.... I agree that Jupiter and Saturn are fantastic views during clarity.... along with Mars during clear opposition time...

I remember when I could view Jupiter  and Saturn at 406X during a clearest night and the view was staggering.. I couldn't take my eye off the eyepiece.... the planets were massive and the amount of detail in the planets was photographic.  This was through my C8... once through the 14" dob I had a view of Jupiter at 480X with the GRS that was sharp as a tack... the GRS was surrounded with fine detailed cloudband and had a darker speck visible within.. the moons were like little discs not just points.. awesome planets to view.

I'm hanging for such views again...

AWESOME images.. although my favourite is the HaRGB version.... superb.

If you get a 8" SCT on  CGEM mount and a f6.3 focal reducer, I can guarantee that you will not be looking to upgrade your scope for a long time.... The C8 is my first serious and still my favorite scope.... views are awesome and the images I take through it make me happy... an 8" SCT is the scope that is the "jack of all trades" and does those trades very well.... Its powerful, small and delivers great planetary & lunar details (weather permitting). as well as opens Deep space to the eye.

PS: I do not have shares in any 8" or other telescope manufacturer, I just love my C8-CGEM combo.

That is an awesome timelapse!

Hello Astronomers,

There was a (near) total lunar eclipse last week and I happened to be lucky enough to be on the right side of the planet to see it in it's entirety....

These images were taken with a stock Canon 7D DSLR attached to my 14" Skywatcher GOTO Dobsonian.... I had my 8" SCT setup to observe it along with the binoculars... what a fantastic night.

I'll tell you that the eclipsed moon viewed through the C8 with the TV 31mm Nagler Type 5 eyepiece is a amazing sight... the full disc of the rusty moon, some stars sprinkled around it and witnessing a star being occulted by the red moon was something else.

Clear Skies,

MG 

6 hours ago, SteveNickolls said:

Thanks again for creating this thread, I certainly endorse your reason for carrying out the experiment to show real world results particularly given the paucity of other similar work. I've shared your reluctance into not moving from a DSLR to purchasing a new astro-camera given the compromises,you clearly saw existed in the offerings laid out previously.

This thread certainly shows the value of cooling a DSLR too, the Canon 40D image would be quite sufficient an improvement from my perspective-can I ask did you modify your Canon 40D for cooling yourself?

Enjoy your imaging with the new camera. 👍

Cheers,
Steve

Hello Steve,

Thinking long and hard about such an upgrade is a normal thing since it's not cheap and can also create doubt and second thoughts of the expense if you're convinced of spending all that money for no, or very little improvement in images... but as you can see, there is improvement over even a very modded DSLR altered for the job.

I modded and cooled the 40D myself... if you're interested, I wrote of my experience in this thread: 

.

2 hours ago, Allinthehead said:

That looks great Mariusz, you must be pleased. Well worth the upgrade from your dslr.

Thank you... I'm very happy with the result.... the new camera is definitely a marked improvement.. than again we're talking about 15 years newer tech, newer sensor, higher resolution, more sensitive and mono...

This is a unscaled 1:1 pixel comparison between the same nebula imaged with the QHY268M and my Modded and Cooled Canon 40D. Unlike the last side to side comparison where I scaled down the QHY image, this image is a crop of the actual resolution and detail capture by both cameras.

Images were exposed for a similar duration, through same filters, through the same telescope and at the same focal length.

The result of the comparison and the detail increase really should be no surprise when thinking about the technical aspects of the two sensors. Using the H-Alpha or SII filters with the Canon 40D used only 2.5 megapixels and through the OIII filter used only 5 megapixels of the sensor. The QHY268M is a mono camera and utilises all 26 megapixels of it’s sensor through every filter. The smaller physical pixels of the QHY sensor is the reason for the larger image scale at 1:1 pixel crop.

I agree... DSLR imaging is great... and can definitely deliver beautiful images.

On 24/05/2021 at 07:02, SteveNickolls said:

Thanks  MarsG76 for all the effort you have put into this comparison I am very grateful for your time you have put into it.

Both images are very good and as you say its up to each one of us to decide if the upgrade is worthwhile. Whatever astro-camera I do go for it will be some time in the future as pennies have to be slowly saved up. Your work though has helped me on the trail.

May I wish you every enjoyment with your gear, oh and dark skies to image under.

Cheers,

Steve

Hi Steve,

You're welcome... I hope that this helps astroimagers with the decision of whether it's worth (for them) going to a dedicated astrocamera with a real world use comparison that simplifies the choice without mudding the facts with numbers and test bench specs. 

I couldn't find anything online that compared (real world or other use) any dedicated astrocams to DSLRs that were cooled as well as modded so this might be useful, and upgrading from stock to modded to cooled and modded than to the QHY allows me to share some of my experiences and real results over the years.

Bottom line I find is that a dedicated camera, such as my QHY268M, is an obvious improvement in resolution and overall image quality but the DSLR produced great images too so the upgrade might not be worth it for everyone, and modding and cooling a DSLR is a lot cheaper... especially if done yourself. I'll add to this that I dare say that the ZWO ASI2600MM, and the color camera versions, will delivrer the same kind of improvement.

So far I love my new camera and definitely do not regret upgrading... but at the same time I'm glad that I waited until now to get a astrocam since this camera has features that I was waiting for (e.g. APS-C mono sensor and dew heating) and problems (e.g. amp glow and coolant leakage) sorted out... anything before this generation of cameras would (to me) be a compromise.

Clear Skies,

MG 

Hi All,

This is my second image taken with the new QHY268M camera and I think that this is the most detailed, and quite possibly my best, DSO image to date.

The Carina Nebula (NGC 3372) also known as the Grand Nebula, Great Nebula in Carina, or Eta Carinae Nebula, is a large complex area of bright and dark nebulosity in the constellation Carina. The nebula lies at an estimated distance between 6,500 and 10,000 light-years from Earth.

This image was taken from my backyard in Bortle 4-5 skies through a 80mm refractor at F6.25 (500mm focal length) with a QHY268M camera through 7nm H-Alpha, SII and OIII filters.

Total exposure time was 5 hour and 50 minutes. Subs captured were HII: 12x600s OIII: 2x600s & 4x900s SII: 10x900s @ HGC:62 on 18th May 2021.

The most surprising thing is the relatively short exposure time spent on this nebula... never before was I able to complete a narrowband image in less than one night.

Clear Skies,

MG

Hi All,

I've competed the comparison image that I set out to do initially with the start of this post. Both images were taken using the same telescope and mount, and only 3 months apart, with almost the same exposure time spent for both images, so It's a close comparison.

Below are the full resolution image from the QHY camera...

...and the full resolution modded and Cooled Canon 40D image.

The scale of the two images are different due to the pixel size differences between the cameras so below is a crop and rescale of images taken with both cameras side by side...

The QHY image is definitely more detailed, but I'll leave it up to you to decide if it's worth the upgrade?

Pity that I can't change the title from "ZWO ASI2600MM-Pro vs Cooled and Modded DSLR image quality" to "QHY268M vs Cooled and Modded DSLR image quality" since I changed my order to the QHY camera from the ZWO due to ZWO not being able to deliver cameras before mid-July at the earliest... ABSOLUTELY no regrets!

CS,

MG 

On 18/05/2021 at 08:15, rsarwar said:

and that is solely due to DR, bit dept and increased relosution due to smaller pixel and lack of RGGB matix    

 

glad you finally came to the obvious conclusion that "brightness" means nothing but it is all about SNR. no apologies needed

You again... thanks for making me laugh... what are you talking about? Go else where, no answers needed.

Awesome image.....

Also have a read of my PEC experience... now this might be a coincidence but worth noting as it did happen...

https://stargazerslounge.com/topic/336050-my-cgem-mount-sudden-death/?tab=comments#comment-3657266

Hi John,

I played with PEC on my CGEM a couple of years ago and even though I got it working, I didn't find the difference to be substantial enough to be worth while when autoguiding through an OAG and PHD2. The slightly lower correction and RMS figure could easily have been better seeing... That said, perhaps unguided imaging would see a benefit?

MG

 Hello all...

O K... I had my first real comparison between the cameras and I was wrong... boy was I WRONG... after calibrating and stacking the subs, the QHY runs rings around the 40D...

I managed to get 10 x 900 second HAlpha subs at HGC gain 62, juggling between clouds, generated some flats, bias and darks and below is the (very quickly processed) result.

Below is a comparison of my HAlpha image taken with the 40D in February full res, next to a crop (and scaled down to 60%) of the image taken with the QHYCCD. Scaled down for comparison reasons because of the smaller pixels & higher res of the QHY generating a larger image.

Total exposure time for the 40D was 3 hours and 50 minutes and the QHY was 2 hours 30 minutes.

All I can say now is that suddenly I'm a believer.

Hopefully I'll have a clear sky tomorrow and capture SII and OIII to add to this image.

CS

MG

23 hours ago, The Admiral said:

Perhaps I'm being a bit dense here, but won't the output levels from either camera be influenced by their respective gains or ISO setting. How do you take that into consideration?

The CR2 raw can surely still be linear data, even if there has been a lot of gain applied from using a high ISO?

Ian

That is true, and I am comparing ISO1600 of the Canon 40D with ISO settings capability between 100 to 3200.... and the QHY raw at gain 56 on a scale that 1-100... both at half way in their gain settings... 

I'm aware of the different technologies applied.. a 14 year old camera vs the latest sensor with HGC capability and the more I play with it, the more I see the benefits.

But out of the camera the 40D shows nebulosity and structure where as the QHY raw seems to be more crushed and shows not much more than a few stars... raw without gain applied?

28 minutes ago, Stu said:

Grass lawns can bite too!

I had a C925 drop down in its dovetail, and only just caught it. So easy to get caught out. These dovetails can sometimes get caught at an angle and feel like they are fully tightened, but then just need to shift a small amount to be come completely loose. Best to keep checking them, particularly as the night chills down as temperature changes can prompt it too.

YOWZA!!! Thats one sad face!