Equipment Advice for Beginner Deep Space Photography

[Nath2099]

Hi there, wondering if I can get some advice for equipment purchase for deep space photography. Budget is about $6K.

I already own a Cannon 5D MKIII, will that be suitable?

I am located about 40 minutes east of Hobart, and am right on the ocean, although it's quite sheltered, so no salt spray or anything. There's also little light pollution.

I was thinking something like this:
http://www.ozscopes.com.au/celestron-11-inch-cpc-schmidt-cassegrain-telescope.html


Wondering what peoples thoughts are on this, and What else would be required in addition?

Thanks,
Nathan.

[Merlin66]

Nathan,
Do you have a current telescope/ mount?
This is probably more critical than the choice of camera.
I have the C11, but don't think it is the optimum scope for DSO photography.
IMHO something like a good ED80 and an NEQ6 mount (for future growth) combined with your DSLR would get you started....
Then comes the guiding scope/ guide camera and all the rest.
Just my 2c

[Somnium]

Do not get the C11 for astrophotography, you will need something that has an equatorial mount otherwise you will get star trails in your image as the object rotates in your field of view over time. as for what scope to buy, it really depends on what you want to image. this question gets asked a lot, so i posted this video on youtube to go through all the details. it is by no means fully comprehensive but gives you an idea of what to look at.

https://www.youtube.com/watch?v=r4wFehe-hik

[casstony]

Welcome to IIS Nathan. You'll need an equatorial mount for long exposure deep space imaging; Skywatcher HEQ5 or EQ6, Celestron Advanced VX or CGEM are commonly used. The EQ6 and CGEM are quite heavy but also more capable than the other two.

The Skywatcher Esprit Apo triplets are a good choice for DSO imaging. They come with a range of accessories including a flattener and adapter ready to fit your Canon straight onto. https://binocularandtelescope.com.au/product/swesprit100-triplet-refractor/

I've recently started imaging and I've particularly sought out an easy to use setup, even if it's not the most capable. My gear:
Celestron Advanced VX mount
Skywatcher Esprit 80
Lacerta stand alone autoguider
The mount has an all star polar alignment routine which makes polar alignment easy and the guider corrects for imperfections in the mount drive gears.

The most common setup is probably an EQ6 mount with a guide camera both being controlled from a laptop.

[casstony]

Here's a pic of my scope. The guide camera (with adapter) fits onto a 9x50 straight through skywatcher finderscope which is easier than mounting a separate guidescope. I chose the Lacerta stand alone autoguider because I didn't want to use a laptop; the Lacerta hand control is also used to control my Canon 600D.

On the back of the Esprit 80 focuser you can see the flattener and bayonet fitting for a Canon DSLR (both included with the scope).
NOTE: The Esprit 80 is not suitable for full frame dslr as the image circle isn't big enough to cover the chip - Esprit 100 covers full frame.

[ChrisV]

Tony

Sorry to butt in, but does the guide camera a t-thread ? And how does the guide camera fit onto the finderscope ?

Chris

[Somnium]

Guide cameras usually have a 1.25" nose that can go straight into the guide scope, you may need some more length though to achieve focus on some guide scopes . Most finder scopes don't have the ability to take a guide scope though

[Nath2099]

Thanks for your thoughts everyone.

So I'm thinking:

SkyWatcher Esprit 100 ED Super APO Triplet
Skywatcher NEQ6 Pro GoTo Mount
Orion StarShoot Autoguider
Finder scope of some description.


Does the guide camera plug into the mount?
With the finder scope, is it worthwhile to spend more cash on one, or does it not really matter? And how does this attach?
Also, are the any considerations for being right on the ocean?

[Merlin66]

http://www.modernastronomy.com/product-category/accessories/finder-guider-adapters/

These adapters allow you to fit a guide camera to a standard finder.

[Merlin66]

Nathan,
Yes,
The guide camera has a guide cable which connects to the ST-4 guide port on the mount.
You'll need a guider software (and computer) PHD2 works very well.

[casstony]

Hi Chris, the camera has a t thread and is connected to the finderscope using this adapter: http://www.teleskop-express.de/shop/product_info.php/info/p4520_T2-Parfocal-Adapter-for-autoguiders-to-Skywatcher-9x50-finder-scopes.html

Other adapters are available to connect cameras to different finderscopes.
I have a vague idea that not all guiders are suited to use with a finderscope, some needing a bigger guide scope to compensate for lower sensitivity.

[Merlin66]

http://www.bintel.com.au/Telescopes/Professional-Refractor/SkyWatcher-Esprit-100ED-Super-APO-Triplet/2046/productview.aspx

The SW Esprit appears to come with a 9 x 50mm finder - that's all you need.

[pluto]

That Esprit 100 looks awesome, wish I'd had that as a first scope!

As for guiding it depends on how you do it. If you're going to guide you'll need a laptop (or desktop if you're in an obs). This can either completely control your mount, through eqmod, and you connect your guide camera/software through that. Or you can directly connect your guide camera to the mount - though the guide commands are still processed through your guide software (probably PHD2).

I would recommend controlling your mount through eqmod and guiding through that. The reason is that with the mount completely controlled though eqmod you can use other software to make your life easier - software like Stellarium Scope (to control your mount through Stellarium), and AstroTortilla (to do plate solving).

Having said all that I would recommend starting out without guiding. With a 5DmkIII on that scope, a 550mm, on an EQ6 you should be able to get good 60 second exposures just with good polar alignment, without guiding. When I started I could get up to 60 second exposures with a 5DmkII on an ED80 (600mm) on a crappy EQ5 so it will be way easier on an EQ6.

[Nath2099]

Awesome, thanks all!

Last question, what is an OBS?

Cheers!

[casstony]

The adapter I have is designed only for a straight through finder. There may be other adapters that will work with the right angle (which has a different body length and different eyepiece thread).

[casstony]

As Hugh suggested, it's a good idea to get used to the scope and mount first without a laptop or guider - just take 30 sec images with the dslr, work on polar alignment, get a handle on the new gear then go to guiding.
OBS = observatory

[casstony]

One other important point Nathan, if you buy a new Skywatcher Esprit ask the shop if it's a recently produced model, preferably made in 2015-16. Some of the early Esprits had problems with the mounting of the lens elements giving very uneven star halos in images.

On the other hand, if you did get a bad one it shows up easily in a 30 second image of a bright star and the dealer or Tasco (skywatcher distributor for Australia) will replace it.

[pluto]

Something that is incompatible with my 10 minute commute :(

[Somnium]

one of these :)

[ZeroID]

They're giving you the run around Nathan. :P :lol:

An 'OBS' is an Observatory, a permanent setup in the backyard or even remotely. Mine is a basic tin shed with sliding roof but others can be quite palatial by comparison.

The big advantage is you can leave your gear setup ready to go minimising setup, alignment times and just generally allowing you to get far more use of your expensive investment. I can be imaging within 20 minutes or can just shut down when the clouds appear. Also minimises damage through repeated setups and lugging heavy gear about. If you get serious long term it is definitely the way to go. I use my setup at least 10 x more than I would if I had to set it up every time.

[Nath2099]

Thanks all.

So I'm close to making what will no doubt be the first of many a purchase by the sounds of it...

So I'm thinking either the 100mm f5.5 or the 120mm f7 Esprit triplet. Is it worth the extra primary diameter at the cost of a bit of speed?

Initially I'll be using my existing 5D MKIII and am wanting to photograph nebula, galaxies and the like.

[Merlin66]

Nathan,
Which 100mm f5.5?
With such a fast system you may need to add a field flattener to get reason images (near the edges) of your DSLR....

[Nath2099]

Sorry, should have been clearer, also the 100mm f5.5 Espirit Triplet. I'll have a look into what a field flattener is and does!

EDIT: Both those scopes come with a "2-element field flattener".

What would be the trade off to add a .8x reducer to either of those?

[Nath2099]

So I just ordered the Espirit 120ED and the NEQ6-R and a few other bits n bobs. Looking forward to the weekend... no doubt it'll be overcast!

[Somnium]

that will be a really nice rig !!

[Nath2099]

Wow, I just saw a video of your setup on YouTube! :eyepop:

This looks like a crazy expensive hobby if one gets serious!

[Somnium]

Life is too short for compromise:)

[RobF]

Probably too late, but QHY5IIL rather than SSAG for autoguiding would be preferable.

[Nath2099]

I actually ordered the ZWO ASI 120MM Monochrome Camera for guiding. Is that one suitable?

It's not too late to change it.

[pluto]

Yep, that's fine.

[Nath2099]

I'm wondering if it's worth me buying a motorised focus controller? There seems to be a couple of main makers, Moonlite and Featherlite. If you think it's worthwhile, any thought on which one? This is for the Esprit 120 APO Triplet mentioned previously in this thread.

[Nath2099]

On the subject of focusing, how does one do that with a DSLR if your shooting a long exposure of something you can't actually see? If your imaging something a thousand light years away, I'm guessing you can focus on any star that you can see, over that sort of distance it won't matter?

[pluto]

Focus on a bright star using live-view on the camera - get a bahatinov mask and it's easy (something like this (http://www.bintel.com.au/Astrophotography/Focusing-Aids/Farpoint-Bahtinov-Mask-3-5--6-5-/643/productview.aspx))

As for a motorised focuser, I would wait until you've got your head around everything else. With a refractor like that Esprit you shouldn't have to refocus too many times in a night so it won't be a big deal.

[Somnium]

there is no difference to focusing on a star that is 4 light years away or on a galaxy that is a billion light years away, you are focusing to infinity. the only thing to keep in mind is changes in focus due to temperature changes. though in this scope you are unlikely to see much of a change