Color vs Mono

Hi Schmaks,
i live in a Bortle-7 region, too.
In my last home, i had a relatively dark garden, amid loads of bushes and trees. Low local stray light. From there i also captured RGB.
In my actual home, even if it is further toward the outskirts, i can only use RGB for comparably bright objects. It was a good place before they built the house. Now there are a lot of large windows with good vistas above me (i'm at grond level), and why would you shut your blinds if there is nobody looking in?
That's why i voted for mono. You can still complement your frames with DSLR frames if you want.

CS Horst

Same boat as you! I live a B7 zone and am shooting with a stock DSLR.
I have thought long enough about this choice, and I've finally decided to take the mono route.
Now I'm just waiting to have enough money
I guess I'll start "cheap" with just an L and 5nm Ha filter (Chroma).

I bought a DSLR in January this year.  At the end of the week I will be 4 months into the hobby.  I just got my ASI6200MM last week.  I'm in Bortle 6 with Bortle 7 light domes north and south of me.  I only got to use it a little bit (25 minutes RGB and 30 minutes L) on one night, but I have to say I was amazed at what I got.  There were also really bad clouds in every RGB sub that the filters more or less ignored (note that clouds would ruin L and some others, but RGB wasn't affected too badly, but I'm also not a purist and take what I can get for "clear" skies).  I already had the ZWO drivers and all the ASCOM platform/drivers because of my ASI120MM Mini guide camera.  After installing the filters in the wheel and some cable management literally the only two changes for me were: needing to use LiveView in APT to focus instead of the LiveView on my DSLR and clicking a button to "connect" the filter wheel to APT to change filters from my laptop between sets of subs.

Here's a comparison of the Leo Triplets using my DSLR on a good night vs. very little data with the mono camera on a bad night:

Leo Triplets First Light with ASI6200MM - 25 Minutes Each of LRGB Data



Leo Triplet Wide Field

I started this hobby 12 months ago (albeit from.a career in astronomy - mostly spectroscopy).  I started with a DSLR and moved to an ZWO OSC when I got frustrated with the lack of red response in my DSLR.  However I now have a mono camera, and I use that pretty much all the time now.  I am happy with my NB, LRGB attempts so far - not up to the level of many here, but only a month in, I am getting some reasonable images.  Most importantly, I don't find it that much different/most time consuming than processing OSC.  

For me the advantages are NB options, greater creativity/flexibility/fun with colour palettes and higher efficiency with RGB (plus L) imaging.  I found the learning curve from OSC to LRGB or NB imaging not too bad, and there are some great tutorials out there (I used Keller's and Bracken's book s- invaluable reference sources, no need to struggle with PI using them).  

Now, I live in Bortle 3 - and still find mono useful.  Living in Bortle 7, I would have gone for mono straight away.  Imaging will take longer, but I usually pick my objects so my scope can run all night unattended (I have an ASIAir, which even coordinates the meridian flip for me).    Just starting out, you will have plenty of objects to choose from.  For me, it also means I can observe in much brighter moon with NB.  The SNR is reduced compared to dark nights, but not swamped. 

My only frustration is that my ASI 1600MM is much smaller than my ASI 2400MC, and I wish I had simply gone for the ASI6200MM at the start (anyone want to swap an ASI6200MM for an ASI6200MC?).  

The only down side for mono imaging is the cost of the filter wheel and filters.  But it is a good investment.  

You don't say what refractor you have, but I would go for the biggest sensor that covers the corrected field.  The new APS-C sized ASI2400MM looks great.  I would advise against an ASI1600MM.  It is now quite old technology and has a weird "gravitational lens" halo around bright stars (particularly [OIII]).  As for filters, you very much get what you pay for.  I use ZWO filters, and might move to Optolong/Bayer.  But I cant afford/justify Astrodons.  

Hope this helps

Brian

Maybe check these threads :
https://www.astrobin.com/forum/post/35752/

Hi,
after reading some of the comments above, i want to mention one thing:
If you just started imaging with a DSLR, you might first want to improve your skills with that. Before buying a 6k$ camera with filter wheel and stuff. Otherwise you wont be able to benefit a lot from the new equipment. And if you can get the same camera in an updated version, but for less money one year later, you might regret your overhasty investment.

One suggestion:  get parfocal filters to avoid the pain to re-focus (so take flats) among each filter

of course! However, you'll have to re-focus anyway. At least in my experience. My rigs are not completely free of chromatic aberration (i'm ignoring that for my flats. Sometimes even use the same flat for different filters )

CS Hoschie

I have a 2600MCPro and a a 1600 MM will full filter set. The MC Pro is very very capable. But it cannot replace a mono camera with filters. The big difference is the ability to take true luminance with the mono - the MCPro cannot match this for detail. And of course, the ability to do true narrowband with 3 nm filters.

Edit : Would completely agree with Die Launische Diva's post below about the importance of dark skies for true broadband imaging. A DSLR  at a Bortle 2-4 site will outperform a mono camera at a Bortle 6 site for the same imaging time. I've seen this personally. I was able to get more detail on M42 with a simple 7D mark II DSLR and 400mm lens stopped down to f/7.1 in less time from a Bortle 2/3 site than with a mono+filters from a Bortle 6 site with an 80mm f/6 Stellarvue. The ability to drive to a dark sky site, regardless of equipment, will make an enormous difference - this point cannot be overstated.

Die Launische Diva:
The latter is very hard — so hard that people are willing to spend more and more money on new gear, instead of trying to be more honest to themselves.

I couldn't agree more. I have been in this hobby for over 20 years and I am still the weakest link. Spending more money on stuff isn't going to buy the needed skills. 

On the subject matter I moved from mono/LRGB on to OSC (dedicated, not DSLR) and I am very definitely NOT looking back. And I am most definitely NOT blessed with dark skies. Mostly Bortle 6, rarely if ever 5 and more time than I wish between 7 and 8. And I make my own Bortle 8 imaging run when I shot with the Full Moon. RGB, not NB. Well, with a decent LP filter but this is par for course.  And I expect being not the only one. DSLRs have a lot to go for them and more importantly even decent/good ones won't bust the bank.

I can see I might eventually buy a Mono camera with a smallish sensor  to use with my existing filters for high resolution stuff. And I mean really high resolution not just high image scale. Nights for this don't come very often in my neck in the woods.

Read this thread for a data driven comparison of OSC vs Mono. https://www.cloudynights.com/topic/682340-monochrome-vs-one-shot-color-%E2%80%93-by-the-numbers-please/
For both OSC & Mono  cooled cameras will get you more accurate darks that you only need to shot once per exposure time.

Also it depends on which OSC. I upgraded my DSLR to an ASI294MC_Pro, so colour & cooled with a decent size sensor and a Pixel size of 4.63  (which is a critical factor).  The improvements were huge. It is way more sensitive and of course does not need to be astro modified.  In bortle 5 skies or worse you need an LP filter. I use the Optolong L_Pro.  For targets with nebulosity use a triband filter like the Optolong LEnhance.

You need to match your pixel size with your scope, but 4.63 is a good balance for long & short focal lengths. If you are going to shoot mainly wide angle (less than 400 FL) then get a smaller pixels.
The difference (not advantage) between the OSC and Mono is not mainly about number of photons collected or about detail (see the link) .  If you want to more photons get a faster scope (or a longer FL + a reducer)

OSC are more time efficient, in that if you only get a few hours between clouds then you can use what you have. If you shot LRGB  you run the risk of abandoning a set and running out of time.  Plus you spend less on equipment and don't have to worry about refocusing between filters or collecting separate flats and darkflats.  But you can't do narrow band properly (although you can do pseudo NB).

Mono Can do everything an OSC can do but is more expensive and requires more time and planning. Plus you can do Narrowband and Hubble Palette and all that good stuff.

After 2 years with my OSC on an F7 refractor and a C8 in the cloud affected UK , my next step is an  F2 RASA. That will get me over 10 times more photons,  so I can get the equivalent of  4 hours integration time in 24 minutes and will not support a filter wheel, so ideal for my OSC.

When that route is exhausted I may go for mono + filter wheel. I may also trade in my automatic car for a stick shift and abandon my MP3 files for vinyl all of which are superior under particular conditions.

Max

After 13yrs of DSLR usage my upgrade to mono dedicated astro cam was obvious decision.

If you are implying that by decreasing the focal ratio you collect more photons you would be quite wrong. The only thing that changes is how you spread them around.  BTW, I didn't know that they made 25" RASAs. That must a view to behold...

I should have been clearer I was comparing an  F7 scope to an F2 scope both with the same focal length and therefore much different apertures. Of course in practise an 400mm FL refractor will be more like f5.8  so the practical multiple is likely to be around 8.5.  However although a  25" RASA is a trifle on the large side, an 11" RASA is on my radar at F2.2 , FL=620  and refractors with that Focal Length are around F7 (ED80 is F7.5) so we're back up there spending our money to get 10-12 x light gathering ability rather than 0.5 by spending it on a mono camera. But as I said earlier it depends on what you are trying to achieve.  I want to get the most RGB photons in my weather limited conditions.    
You would of course get a similar effect with a fast Newtonian, but they have their own issues.

If however you do know someone who has a 25" RASA for sale, I have a bridge I could swap it for.

Hi…
I live in a Bortal 4 area and have just moved on from using a 127MAK for planetary, with an OSC camera, to imaging DSOs…
I faced the same choice but went for mono (ASI1600mm Pro) in the end and have actually found the processing to be straightforward…
So, for me, mono is a no-brainier on all accounts and especially in high Bortal areas.