DSLR or Dedicated Astrophotography Camera?

[Bluemoonjim]

I started my AP journey at the end of summer 2020, so still very much a newbie, but at the stage of beginning to make some sense of how to capture images and getting familiar with various bits of kit.
I have so far been using an unmodified Canon EOS 500d as my main imaging camera a ZWO 120mm for guiding and am now getting some reasonably trouble free sessions with some pleasing (to me) results (after some of the sessions ANY sort of result was pleasing!). When I look at more experienced people's images I can see that I have some way to go to achieve something similar. I have been considering buying a dedicated astro' camera but I am also starting to realise that this is a pastime that can quickly consume large amounts of money and sometimes give little return, either because the newly purchased bit of kit is not quite the right 'bit of kit' or because to get the best out of the new kit you need to upgrade other parts of your setup ... and so it snowballs. The whole process of astrophotography has so many variables and nuances and even experienced practitioners seem to find much to debate regarding methods and equipment so it quite easy for people like myself, new to the field, to go off on all sorts of tangents, often expensive tangents! I have to remind myself from time to time why I was drawn to AP in the first place, remember the wonder I felt at my first view of space through a telescope. It was a late summer evening, about 50 years ago using one of the old telescopes that used to be on the seafront in most seaside towns. There was a very bright star out above the sea and with no knowledge, just out of curiosity, pointed the 'scope at it. The 'star' became a small bright disc with four small stars (moons) in a diagonal line across it, it was Jupiter. I couldn't believe that I could actually see another world, it was bloody amazing! 
I know that to progress with AP one does have wrestle with issues of pixel scales and focal lengths, cabling issues, tracking, guiding, exposure times, calibration frames, processing etc but I'm wondering at what point does the whole thing become an unwinnable pursuit of perfection? As I said I have been excited by results so far, in much the same way I was with my first view of Jupiter, so should I stick with what I have and just work on getting better?
OR will £1000+ worth of dedicated astro camera make THAT much difference, I don't know, will it?
 

[Lee_P]

Ha, tricky question! I believe the short answer is that £1000+ of dedicated astro camera kit certainly can make a big difference and help take your imaging to the next level. You could think of it this way: do you currently think you're being held back by the camera you have? If it's limiting you then that's a point in favour of getting a dedicated astrocam. Or, if you think there's still room for your skills to develop with your Canon, maybe stick with that a bit longer?

I've written about upgrades, and some may give you more bang for your buck than a dedicated astrocam.  

Edit: an additional thought is that FLO currently have a Summer sale on ZWO cameras...

Edited July 31, 2021 by Lee_P

[Bluemoonjim]

Hi Lee

Thank you for response. Just read your web pages about upgrades. Think I'm there on most of it bar the OSC camera, the pier and the electronic focuser
The OSC route is what I'm considering, apart from the more whimsical issue about pursuit of perfection, one of the things I was hesitant about was whether my current usb cable setup could handle the data from one of these cameras. My trusty Canon downloads images using BYEOS quite reliably but when I experimented using a small sensor Altair Astro GPCAM I had all sorts of usb traffic issues ie. drop outs, freezes. I think it may be voltage power issues rather than data but I am running cables out about 10+ metres, from nice warm garden studio, and wonder if long usb2 can truly support these larger sensored OSC cameras.

I had been considering a 183c but from what I think I now understand, that may not be best for my scope which is 102mm F/7 (714mm).
So now I think it's between a 269c or the 294c or maybe you would recommend something other?

I'll take a look at the FLO sale, thanks for the heads up on that.

[Lee_P]

I tend to recommend kit that's similar to what I use, so you should definitely gather more opinions than just mine -- but with that caveat in mind...

* A ZWO ASI 533MC-PRO seems to be within your price range and is currently on sale. It should be a good match for your telescope according to CCD suitability.

* I'd also get an ASIAIR PRO to control both the 533MC and your ZWO-branded guidecam. Then you've got remote automation sorted, plus no issues with USB traffic.
* I'm a huge fan of the Optolong L-eXtreme filter for OSC cameras, as you'll have gathered if you've perused my site 😛

You're right in your original post that things snowball quickly. You may need new power sources, cables etc. to run the kit I've suggested, so budget accordingly. It's easy spending other people's money 😂 

It would be good to hear more opinions on this, maybe someone with broader experience than I have will suggest something even better!

Edited July 31, 2021 by Lee_P

[happy-kat]

Hi

Do you have any other images you have produced to share? How many light and calibration frames taken. 

It feels like early stages and the biggest gain now might be investing time in learning more into your processing steps with what ever tools you are using. 

Maximising what you achieve now with what you already have may help indicate in which direction to make updates.

[Bluemoonjim]

Hi

I've attached a couple more images. 
These were around 25- 30 lights 10 Darks 10 BIAS 10 Dark FLATS 
iso 800   240sec for Sunflower Galaxy
iso 800 150 sec for Whirlpool Galaxy

Be merciful

I have other images, but these are most recent. So far, managed no more than about a dozen sessions some of them were completely fruitless in terms of images, so I do appreciate it is early days.

[Lee_P]

Very respectable pictures! How dark are your skies?

[happy-kat]

Thank you for sharing.

I'd look into calibrations frames and whether with your DSLR do darks improve or hinder and also the overall amount of calibration frames 10 isn't very many though great to see you have used dark flats.

What's processing approach are you using?

[Bluemoonjim]

Skies are officially bortle 4. Quite rural, can see milky-way. 

I use dss and then photoshop for processing, haven't tried any photoshop plug-ins yet. 

Once dss has finished I import into ps and play with levels and stretches. Not really worked out a proper work flow yet

[Clarkey]

In terms of DSLR or Astro camera, for me the main advantage of the dedicated camera is the ability to create a darks library and the reduction in noise. I use a modified 600D which is OK but it does give a lot more noise and is pretty bad for banding. You could start by getting your camera modified for the autumn winter nebulae.

At the end of the day I think it boils down to cost. Yes, a cooled camera with generally get better results, but it is a slippery slope (that I have been sliding down for too long already). How much better is really down to expectations and what you feel is acceptable. Would I go back to a DSLR - no, but I am always trying to improve my images and am a perfectionist. (Not that my images are perfect - but that is the unachievable goal).

[Bluemoonjim]

You nailed it - ' the unachievable goal'. 

More like art than science.

[happy-kat]

The book Dark Art Magic Bullet could be a good start for processing and there's a StarGaZine on it by Steve who wrote it and a great imager. The book mainly covers PS which you are using

 

[happy-kat]

https://stargazerslounge.com/topic/361860-ep18-youtube-dark-art-or-magic-bullet-by-steve-richards/

[Bluemoonjim]

Thank you all for the feedback, I'll be checking out 'Dark Art or Magic Bullet' and thanks for various suggestions.

Lee, I looked at the 533 but on the Altair Astro version they warn that it may have problems running on usb2 their 269c has similar pixel size (3.3) and supposedly good to go usb2.

Anyway, we'll see. Plenty to be getting on with without spending a load more cash. 

 

[happy-kat]

More time is good as the number of frames could definitely be increased, more data better result

[Richard_]

These are great pictures @Bluemoonjim. DSLR's work just fine for galaxies and such since they can collect a lot of data, as is shown in your images. For emission nebula and other H-alpha regions, unmodded DSLR's are at a disadvantage to astro-cameras since only a fraction of H-alpha is collected. 

You've seen & commented on my images in my "welcome" post, so I will refer you to my rosette nebula images as a case example. I shot the same target with my unmodded Canon 600D (~4hrs total integration time) and my ASI533 (~2.5hrs total integration time) and the difference in H-alpha data between the two is night and day (if you'll pardon the pun)! There is so much more H-alpha data with the ASI533 in a shorter time which is exactly the reason I bought it (along with very low dark current, and the ability to keep it cooled at a set temperature). 

To your original post "should I buy one or not?", I would say it depends on what you want to capture. If you are going to focus on galaxies, the DSLR will continue to serve you well as per the results  you've already posted. If you want to shoot emission nebula, then you are going to struggle to pick out H-alpha data unless you sink a number of hours into collecting more data, so a dedicated astro-camera would be a good improvement over your existing setup. 

[Bluemoonjim]

Hi Richard

Thanks for the encouraging words. I can certainly understand what you are saying regarding intergration time and tha abilty to see H-alpha compared to my current setup. I did attempt the Witches Broom in the Veil nebula a while ago and (apart from focussing problems!) soon realised that it would requier many hours to get anything like a decent amount of detail using my dslr. Now I have seen some of the images captured by yourself and Lee (check out his website) I know it's  just a matter of time before the itch to buy a dedicated camera will  have to be scratched!