# 28 Dec, 2018 11:49
Hope you are all well.
I'm very new to Astrophotography and started with a Cannon 800D DSLR camera , now making the jump to a CMOS sensor, I have been looking at the ZWO ASI1600MM complete with 36mm filter wheel and LRBG / Narrowband filters.
I have always been looking at monochrome for high sensitivity, however many people are using coloured CMOS cameras , any advise on this before I make final purchase.
# 28 Dec, 2018 13:11
|Excellent choice, grab this camera and enjoy!|
# 28 Dec, 2018 13:24
|Thanks Adel for your reply , would you also agree with going with monochrome version|
# 28 Dec, 2018 17:32
Going monochrome is a more work when doing LRGB. More work especially when processing and I find it slower when imaging (even if the subs are shorter) because each filter needs to be focused and there is more down time for dithers as there are more frames. You also need more space on your computer hard drive as the the subs are more numerous. You also have to do more flats (one set for each filter), that can be a big factor at 3h in the morning and it is cold out there.|
Monochrome does however yield a lot more details in your images as the camera is more sensitive. I have gained about 20% in details over using a DSLR for RGB images.
There is no question that monochrome is better when doing narrowband imaging. Less noise, shorter exposure times.
One caveat, the imaging train is heavier than color CMOS, hence new challenge in balancing the mount and gear.
If you go down that road, make sure to get a COOLED camera ;-)
The only place I will keep using my DSLR is with comets.
# 28 Dec, 2018 17:53
Thank you for your reply.
Your advise is very helpful, my big concern with going mono is my lack of experience and as you say a lot of work , more work considering my experience.
The colour CMOS camera I have been looking at is the ZWO ASI1600MC Cooled camera , which is also available in Mono.
Would you recommend using a Colour CMOS camera at my level will be more beneficial short time while I gain experience in deep sky imaging.
I have recently invested in an EQ6R - Pro mount , which has made my life a lot easier, after purchasing a new CMOS my next target is ESPRIT 100 skywatcher telescope which is within my price range.
# 28 Dec, 2018 20:42
I have the cooled 1600MM. It is a great camera. Have a look at my pictures. I started doing narrowband with it before going LRGB. It allowed me to better learn processing as I added the OIII filter and eventually the SII filter. You can do a lot of imaging just with the Ha filter. I don't know what your skills are like when processing but going LRGB from.the get go would be a huge undertaking.
The skills you learned with your DSLR will be useful.
The milestones for me were : guide the mount well, narrowband, control everything with the computer (no more hand controlled on the mount), autofocusing and plate solving (huge time savings here!!). I then joined the LRGB dark side lol
If you have any other questions, let me know.
# 28 Dec, 2018 21:09
Thanks for this , your pictures are amazing , a lot of detail , especially your Ha detail.
I think I will go down the route of mono :-) If ok I may contact you privately for some further advise regards narrowband imaging.
I use photoshop CC 2019 for processing , I'm getting there slowly and have obtained many skills over the past few months with the help on YouTube , however I have not done much research on progressing mono LRGB / Narrowband.
I have just recently purchased a few photoshop astro action tools that I'm yet to try out, which I'm hoping will improve my knowledge of processing.
One of my biggest success with my new mount is guiding. I spend a lot of time setting up my mount and polar alignment to ensure great guiding so I shouldn't have any issues in this area.
I do now control everything from a PC , I purchased a powerful intel 5 core processor 64bit PC stick which mounts to my telescope then team view via access point (LAN Connection) , this helps with cable management and being able to stay warm inside on those cold nights.
Really appreciate your advise on this subject.
# 28 Dec, 2018 21:19
My pleasure Michael.|
I am also a photoshop user. I don't use pixinsight.
Let me know if you need any further help.
# 30 Dec, 2018 19:58
|You're doing the right thing to get mono, especially if you have light pollution.|
# 30 Dec, 2018 21:48
My vote goes to the ASI1600mm too. I bought one recently as an alternative to my large CCD cameras and it is easy and fun to use. If you're serious about imaging I don't think it's worth getting an OSC camera. You'll want to go mono in a few months anyway |
Here's an example image taken with the ASI1600mm under light polluted skies: https://www.astrobin.com/383279/?nc=user
# 30 Dec, 2018 22:05
Very Serious about imaging , therefore willing to spend the money and work harder on the correct equipment.
Your Tarantula Nebula image is amazing , I noticed your frames are very short on RGB , but many of them, I'm assuming thats down to high sensitivity CMOS sensor being more effective with shorter exposures but more of them.
# 31 Dec, 2018 00:20
Another vote for Mono here. I have a both and find the processing much more difficult with OSC because I still have to debayer the images and process same as mono anyway. And you lose 50+ of the light so you end up needing more exposure time too.|
Can’t think of a decent competitor to the 1600 Mono cooled right now. Wish I owned one. Go for it!
Do think about the image scale. This is a small pixel camera so it best with shorter focal length scopes.
# 31 Dec, 2018 01:44
|Kevin, what about the 071MM Pro, at 4.78microns compared to 3.8microns and diagonal of 29mm versus 21mm for the 1600 ? Would it suit a Meade 12in ACF better? Or are even larger pixels better?|
# 31 Dec, 2018 04:01
Isn't that one color only? As far as I know, the largest mono CMOS sensor is the 1600 until you get to the vastly more expensive 4040, etc, large pixel cameras.
Rough math on the right focal length for a given pixel size is to have an image scale that is 1/3 of the average seeing you will experience. So if you expect 2.5" on average, look for an image scale of .83 arc seconds. With the ASI 1600 that would be 950mm FL, or so. Don't get pedantic about it, but that would be the goal.
Go here for an easy calculator: https://astronomy.tools/calculators/ccd
# 31 Dec, 2018 14:38
I want to join your discussion.
i’m also planing to buy the exact camera,
asi 1600 mm cool.
What I read now was hard to believe.
narrowband seems to be little bit easier to process and also data collecting not so time consuming ? I mean easier than lrgb ?
that would mean I’d have to consider to start out that way, not to buy lrgb but some sort of halpha oiii or sii Filter instead.
I’m torn between the “newest” set of Zwo filters 31 mm or Baader Filter 2”
do I really have to focus between each new filter ? Or does it stay in focus between all the Filter of one brand ?
same question is for flats.
Do you have to do that ?
# 31 Dec, 2018 16:46
Crash-dkYou will want to to have LRGB and SHO filters so plan for all 7 when you purchase the filter wheel. I have not used the ZWO filters, but my Astrodon filters do not require refocusing between filter changes. Why spend so much money on filters? Because very narrow filters like 3nm or 5nm allow you to shoot from the city and with the moon up and still get good contrast. THEY ARE WORTH THe MONEY!
# 01 Jan, 2019 02:14
|I asked a user whether the ZWO filters were parfocal. The reply was that they were pretty close. Thats not good enough. Maybe they will adjust but what a chore that would be.|
# 01 Jan, 2019 06:31
Thanks, Michael. The subs need to be long enough that shot noise from the sky signal swamps the read noise from the camera. This is called a "sky limited" sub as opposed to a "read noise limited" sub. I have been running the ASI1600mm at a gain of 200 which gives very low read noise and the FSQ85 with reducer is quite fast optically (about f/3.8.) I also have very bright skies. When you combine all those things it means that only short subs are needed. As you might have noticed, I'm doing longer subs for narrow band (120 seconds.) With one of my CCD cameras with much worse read noise I'd need to do subs more like 15 to 30 minutes.
# 01 Jan, 2019 06:44
Parfocal is a pretty meaningless term. Filters that give adequate results without refocusing at f/8 may not do so at f/4 where the critical focus zone is much narrower. I've used very expensive parfocal filters and generally found that it's always best to refocus or use filter offsets with any set of filters.
# 01 Jan, 2019 12:25
You are doing the right thing asking the experts. I am glad you have chosen the Mono route as speaking to you over the last couple of months, I know you are serious about imaging and I feel this is the right choice for you
You can always do mono images while you are finding your feet and add the colour afterwards though see comment at **
Yes it is more work and a bigger learning curve, but just think of the benefits.
Regarding re-focussing. I must admit that with my Baader filters I check focus with all the filters beforehand and mostly find they are parfocal. If I occasionally find one is slightly different I do a sequence with those that are par focal and come back to that filter afterwards. I don't really understand why it should vary from one imaging session to another.
I can help you with processing and combining the data once you have captured it.
Since like me you live in a LP location and have limited time at our dark location, I have taken to binning the RGB, Oiii and Sii which means you can capture data in half the time, but ** you will need registration software such as Registar or Pixinsight, I think APP also does it to re-size and/or rotate the images so they match. You will also need this sort of software if you image the same data on different occasions from a re-set up as getting the camera orientated exactly the same each time is pretty difficult.
# 01 Jan, 2019 14:03
|I had to erase my comment because it is already answered here.|
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