First light with GSO 8 inch F4 and ZWO ASI 183MC

[ahmed_haider (Ahmed)]

Hi,
This is my first try with the equipment so please be gentle
I have lots to learn.

Setting up the mount in my backyard, balancing in RA and DEC, collimating the OTA, focusing on a bright star, polar alignment (thank heavens for Sharpcap), 3-star alignment
I didn't realize it would be such an involved process
Anyway I finally got everything setup and was so tired I ignored the calibration frames completely and decided to go for an EEA approach. I would just pick a target in the east 30 degrees above horizon and let Sharpcap do its 'live stacking' magic for half an hour for each target.
The results weren't very good so I ended up doing some post processing in GIMP anyway (but only played around with stretching color channels).
I'm not using any coma corrector or light pollution filter of any sort (apart from the IR block on the camera)
Please have a look:

M42 the Orion nebula:


Flame and horsehead:


Tarantula nebula:


Moon:


All the pictures above were taken on the same night with 83% moon illumination.
All suggestions are welcome. I am going to get a coma corrector and some sort of light pollution filter eventually. And I'm watching youtube videos on calibration frames so will eventually try to start using them.
Suggestions please.

Cheers Ahmed

[Saturnine (Jeff)]

Hi Ahmed

You're off to a good start and have some idea of what's involved now with imaging. A coma corrector and an UHC, LPro, L-eNhance type filter of which there are several brands available, will make a world of difference to imaging from light polluted areas. You probably know that already and calibration frames too , really help. Also, is the ZWO183 a cooled camera.

[etill (Elliot)]

Hi Ahmed,

I have a 200mm F4 also, and found it great to learn with (and still use).

For the coma corrector you can't go wrong with a Baader MPCC, I used one with an APS-C sized sensor on two cameras and it was an easy setup. I've also have a paracorr now, which seems to be a bit of a step up from the MPCC, but also has a 15% Barlow effect so its F4.6 and ~920mm focal length with it. The paracorr is also quite expensive, and when I was learning I doubt I would have noticed the difference (or set it up properly to begin with).

The 183 will have a different pixel scale to the QHY10 I use now as it has much smaller pixels, there are calculators and tools you can use to visualise different focal lengths and sensor sizes as well as calculate the pixel scale and get an idea if its over or under-sampled. Bintel has one on their site in the tools section. You can see the difference between the MPCC (1.0x) and Paracorr (1.15x) with various sample DSO images.

I have used the L-Pro for a while and its also very good, but I haven't compared to the enhance or extreme.

elliot

[ahmed_haider (Ahmed)]

Originally Posted by Saturnine

Hi Ahmed

You're off to a good start and have some idea of what's involved now with imaging. A coma corrector and an UHC, LPro, L-eNhance type filter of which there are several brands available, will make a world of difference to imaging from light polluted areas. You probably know that already and calibration frames too , really help. Also, is the ZWO183 a cooled camera.

Thanks Jeff!
I'm saving up for a coma corrector and LP filter now. The camera isn't cooled. Reason being that I watched a YouTube video with Dr Robin glover (sharpcap creator) and he was of the opinion that cooling is not as important as stacking because lp is a greater issue than thermal noise. I took that a blessing to buy a cheaper un cooled camera because I was strapped for cash at the time and couldn't wait to get started

https://youtu.be/3RH93UvP358

In any case the pixels in my ASI 183 mc are too small and I'm probably over sampling. One thing I forgot to mention is that I'm binning 2*2 in all the images (except for the moon one)
I will eventually move up to a camera more suited to the 800mm focal length I have

[ahmed_haider (Ahmed)]

Originally Posted by etill

Hi Ahmed,

I have a 200mm F4 also, and found it great to learn with (and still use).

For the coma corrector you can't go wrong with a Baader MPCC, I used one with an APS-C sized sensor on two cameras and it was an easy setup. I've also have a paracorr now, which seems to be a bit of a step up from the MPCC, but also has a 15% Barlow effect so its F4.6 and ~920mm focal length with it. The paracorr is also quite expensive, and when I was learning I doubt I would have noticed the difference (or set it up properly to begin with).

The 183 will have a different pixel scale to the QHY10 I use now as it has much smaller pixels, there are calculators and tools you can use to visualise different focal lengths and sensor sizes as well as calculate the pixel scale and get an idea if its over or under-sampled. Bintel has one on their site in the tools section. You can see the difference between the MPCC (1.0x) and Paracorr (1.15x) with various sample DSO images.

I have used the L-Pro for a while and its also very good, but I haven't compared to the enhance or extreme.

elliot

Thanks for the input Elliot!
The baader and parracor are too expensive for a cheap sob like me
I'm saving up for a skywatcher aplanatic cc for F4 scopes. Have you used it? I've seen some great reviews on it. I'll check on astrobin if there are sample images with that.

[PaulSthcoast (Paul)]

Hey Ahmed ...


Beren has an aplanatic cc for sale in the classifieds.

Might be worth a look ?

Paul.

[ahmed_haider (Ahmed)]

Originally Posted by PaulSthcoast

Hey Ahmed ...


Beren has an aplanatic cc for sale in the classifieds.

Might be worth a look ?

Paul.

Thanks Paul!
I reached out to him. Looks like a good deal.
One thing that put me off in the beginning was the price difference between the scopes themselves and accessories. I got the 8" F4 GSO newt for 600$ but the cc (at least the ones that most people use and recommend, baader MPCC and parracor) are even more than that
Even the skywatcher 'budget' one is 450$ for a new one
I know optics are expensive but isnt the mirror in the scope expensive too? (and its a really good one in my GSO as far as I can tell)
Anyway, I was told this was going to be an expensive hobby when I was starting out so I shouldn't complain as much
Cheers

[etill (Elliot)]

I thought the aplanatic cc was more than the baader. If you get a good deal then I have read they are good, I don't have one to compare.

[ahmed_haider (Ahmed)]

Originally Posted by etill

I thought the aplanatic cc was more than the baader. If you get a good deal then I have read they are good, I don't have one to compare.

Thanks for the correction....Baader MPCC is cheaper at 340$ at bintel.

[AdamJL]

Originally Posted by ahmed_haider

Thanks Jeff!
The camera isn't cooled. Reason being that I watched a YouTube video with Dr Robin glover (sharpcap creator) and he was of the opinion that cooling is not as important as stacking because lp is a greater issue than thermal noise. I took that a blessing to buy a cheaper un cooled camera because I was strapped for cash at the time and couldn't wait to get started

He’s not wrong! But also only half right in the sense that light pollution is the true enemy in polluted skies but that doesn’t take away the problem of thermal noise either (stacking helps with noise but it’s not a perfect solution).
If you ever drive an hour out of the city to shoot, we’ll then now you’ll want a cooled cam

That said, I think you’re on the right track, focusing on the things that make sense for your situation right now and also keeping an eye on future options.

Great start, mate. You seemed clued up on what’s required which means you have a good future in the hobby!

[ahmed_haider (Ahmed)]

Originally Posted by AdamJL

He’s not wrong! But also only half right in the sense that light pollution is the true enemy in polluted skies but that doesn’t take away the problem of thermal noise either (stacking helps with noise but it’s not a perfect solution).
If you ever drive an hour out of the city to shoot, we’ll then now you’ll want a cooled cam

That said, I think you’re on the right track, focusing on the things that make sense for your situation right now and also keeping an eye on future options.

Great start, mate. You seemed clued up on what’s required which means you have a good future in the hobby!

Thanks Adam!
Also, taking darks will be more of a hassle with an un-cooled camera. I learned that after I got my camera

[AdamJL]

Originally Posted by ahmed_haider

Thanks Adam!
Also, taking darks will be more of a hassle with an un-cooled camera. I learned that after I got my camera

that's right. I started with my 5D IV. The only way to get reliable darks was to do the darks at the same time as the actual shooting. So I'd drive up to the Blue Mountains, shoot for a few hours, but have to spend an hour or more whilst the camera took darks.

Now, I can pack up, come home, and take darks either when I'm sleeping or during the day.

Or the newer generation cooled cameras arguably don't even need darks because of their performance when cooled!