Sanity check before pulling the trigger.

[Auspecial]

Hi all,


I am planning on purchasing my first dedicated astro-photography setup. My primary intention is to photograph galaxies. Not especially interested in nebula or planetary imaging. I have dabbled in astrophotography before with a Canon 5dmkii and 200mm lens stacking hundreds of short exposures but have since sold that camera. Some photos here. https://imgur.com/a/5lKCxmN


My current plan is to get a



NEQ6 mount
Skywatcher 200mm f5 newtonian
QHY163M
LRGB filters and wheel.


What is everyone's thoughts on this to start with?
I went with the mono as I really enjoyed the post processing previously.


What would be a good single eyepiece to buy with the scope and mount as I will likely space out the purchase?


Thanks!

[astro744]

You don’t need an eyepiece to photograph as you use prime focus. For visual there’s no such thing as one eyepiece. Long focal length for low power, short focal length for high power, another less short for slightly less high power and one or two mid focal lengths in between.

For visual at f5 coma corrector is optional not mandatory especially at 1000mm focal length. For photography you will need one if you want you star field pinpoint toward the edge of frame but as you are photographing galaxies which are going to be small on the image plane you can probably get away without one although one is highly recommended especially for groups of galaxies.

As for eyepieces if you buy highly corrected ones then eyepiece aberrations will be well controlled. How dark is your sky? If dark then something around 30mm (6mm exit pupil). If not then around 20mm (4mm exit pupil). Apparent field of view your choice depending on how much true field you want and how much you want to spend.

I am a little puzzled as you wanted a dedicated astro-photography setup so all the money should go toward that. Probably need a guide scope and guide scope camera too and all mounting hardware, power supply.

[Auspecial]

Ah sorry I should have been more clear, my plan was to get a (cheap) eyepiece to use while I wait to purchase a camera so that I get to play with the new toy, potentially waiting for a camera to come up on the classifieds.


Similarly with the guiding equipment it would be an addition later down the track once I have got the polar alignment and general workflow more dialed in.


Also I live in class 4/5 bortle skies according to the light pollution map

[astro744]

Ok. Get a low power eyepiece around 30mm around 65-70 apparent field. This will serve as a finder eyepiece for you. Perhaps others can help you choose something here. Maybe 30mm/80 deg.

[Auspecial]

great thanks for the tips, what do you think of the rest of the items?

[Harpage]

Don't forget a coma corrector and good collimation tools!

[multiweb]

If you want to do galaxies exclusively get a GSO RC 10" or larger.

[Auspecial]

While I would love an rc10 that's a significant jump in cost

[Auspecial]

Maybe I should consider a c6/c8 for more focal length?

[Retrograde]

You can always get a Barlow to double the focal length if you want to go after smaller galaxies. I personally think the Newt is a good choice & can do pretty much anything.

Remember that the scope and camera together give the image scale. The 8" f5 paired with a CMOS camera with a smaller sensor and smaller pixels should give you the image scale to capture quite a number of galaxies.

[gregbradley]

I agree with Retrograde.

I would consider the QHY294M over the QHY163M which is an older model and the 294 is generally considered the upgrade from the 163.

A good Newt is able to image plenty as seen on this site.

1000mm is not that long for galaxies but with a 294 or 163 being relatively small sensors that will magnify the view.

On the other hand the ASI1600 or QHY163m are being sold off 2nd hand for a considerable saving. There are plenty of excellent images from the ASI1600 (QHY163M).

I find the best way to evaluate gear is to go on Astrobin and type in the search engine the gear you want to use and then see what others have managed to do with that gear.

Greg.

[Auspecial]

Thanks for all the advice everyone, definitely still struggling with decision paralysis at the moment. Will take all this on board and have a think and a peruse of astrobin. Cheers!

[multiweb]

Not necessarily. You don't gave to go to 10" if you don't want to. I saw 8" RCs going for $800.00 even cheaper. The f ratio is ideal for galaxies. You don't need to barlow. Less glass in the light path. More flux, less light scattering and aberrations. Still light enough to take on the field. Check the classifieds here.

Sure you can get a F/5 newt but you'll need to barlow unless you like wide fields galaxy shot but it looks like a fly on a wall TBH. Personal taste. It also introduces other issues. Tube flexure around the focuser due to the added weight unless you brace it.

The RC design is compact, lighter and stiff.

[Splurk]

Auspecial, I am in a similar position, looking for my first Galaxy rig. I was advised on CN to look at the EdgeHD 9.25, 2000mm+ FL. I have the ASI294mm version and its a good camera.

[Startrek]

I use an 8” f5 GSO newt ( 1000mm fl ) on an EQ6-R mount to image everything in the night sky
My camera is a ZWOASI2600MC and use a Baader MPCC Mk3 coma corrector which eliminates coma at the corners
Have a look at some of my images in Deep Space section ( including a couple of galaxies recently and also back in April / May too

Cheers

[strongmanmike]

Yes and also check out Lee Borsboom's gallery (https://www.astrobin.com/users/leemr/collections/2102/) he used an 8" F4.5 Newt, the camera you use is part of the equation too, small pixels are common in cameras now and make imaging small objects, at shorter FL's, very viable. Good luck with your journey :thumbsup:

Mike

[Startrek]

Mike
I checked Lee’s rig out
8” f4.5 Scope is carbon fibre with high end optics $2,500
Mesh 200 friction drive mount $12,000
Plus he’s using a great Mono camera with smaller sensor and small pixels ZWOASI183MM 2.4uM pixels
His equipment is on the higher end side and camera is better suited to galaxy imaging, his resulting galaxy images are top of the shelf stuff for sure, incredible !!!

My 8” rigs a bit of an all rounder with big APS C sensor and bigger pixels plus colour , so I struggle with some of the dimmer galaxies , but you do your best with what equipment you have
Maybe an alternative mono camera for galaxy imaging is in order for next year ??

Cheers
Martin

[strongmanmike]

Your results are great mate, I was just adding to this discussion to show that big, long focal length telescopes are not in fact required, at all, to get great galaxy shots :thumbsup: Given the option of course, bigger and better would be welcomed :D...it can be an endless argument but in the end, as far as revealing details in small objects goes, it is the site that makes more of a difference IMO because image scale is image scale and anything under about 1"/pix as a image scale, will generally return pretty good results on galaxies, provided the seeing allows :)



Yeah, I agree and the art of good processing is an ongoing learning curve :thumbsup:

Mike