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First images last night, got lots of questions


fragmonkey

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Howdy. Bear with me as I'm horribly new at this business.

So after a ton of research about astrophotography and waiting for equipment, I got my Canon 1000D and Celestron Astromaster 114 EQ2 and went out for some imaging last night. I used BackyardEOS for the session.

Scope stats (I can't afford nice things):

Newtonian Reflector

114 mm aperture

1000 mm focal length

f/9

Finding things with the included 'starpointer' is awful, so I focused on mostly getting images of the brightest thing I could easily find: Vega.

After staying up pretty much the entire night, figuring things out, polar aligning, managing the cheap drive motor, focusing, etc, I settled on taking 20 shots of Vega for stacking purposes to learn some post processing (took some darks and bias shots too).

Loading the images into Deep Sky Stacker, it tells me my images suck and will only stack one photo out of 20. After some research, I determined this is probably because it cannot detect enough clear stars due to crappy focus, trailing, crappy tracking, crappy drive motor, and crappy balancing of the scope.

Here is a single image for reference: http://i.imgur.com/tqQ8cdt.jpg

Here is the same image with the levels enhanced more detail: http://i.imgur.com/Ove7YCP.jpg

13 second exposure with 800 iso.

With the best polar aligning I could manage (how to tell if I'm properly aligned?) and the right speed setting on the eq drive motor, I think I am basically limited to 15 second exposures. But even with that, stars appear blurry, faint, and almost always streak to some degree.

So. How to improve this tonight? I was expecting something closer to this with enough tinkering: http://www.astrobin.com/47473/

I am surprised at the total lack of other stars in my photos (and not just Vega, but aiming the camera anywhere leads to a whole lot of nothing except some specks here and there). I hope I'm not missing something glaring with regards to my scope setup (DSLR w/adapter goes directly where the eyepiece should go, yes?)

In the level enhanced image, you can see a faint blue circle with a cross through it above Vega that look suspiciously like the inside of my reflector. What is that? Is this a focusing issue?

Focusing is a huge pain, and I cant seem to get it right. Using the Focusing tool in BYE, I got the lowest number I could manage for Vega by playing with the scope's focusing knobs, and I suppose it looks alright, but it still feels horribly wrong. And another thing: How does one focus on a star/object that is too faint to appear on the live view in BYE?

On a related note, how does one actually find things that are too faint to see? Does it really just boil down to pointing the scope at where an object is supposed to be, taking a photo, and seeing if its there? How does that work with objects that take many many long exposures stacked to show up in a photo? Trying to find Vega, as bright as it is, took ages and very fine movements would cause it to leave my camera view.

My goal is to get a passable photo of M31/Andromeda after sorting out the issues. However, I am highly skeptical of ever seeing the thing. Using Stellarium and my eyes, I can definitely see things and where they are supposed to be with confidence. I live in a suburban zone and I can just barely make out what should be M31 with my eyes, but I have no confidence at managing to point the scope at it. I definitely tried last night, and even tried with some of the brighter stars near it, but resorting to the "take photo and see what's there" method isn't useful. I have no idea if what I am seeing in the output image after a 10-15 second exposure is actually what I am trying to find. I could very well have taken a photo of it, or it could have just been random stars.

I've seen photos taken with scopes using much smaller spertures and focal lengths, yet their ultimate result is very large and detailed photos of M31. My scope, being as cheap as it is, has a million issues and is probably not very suited for deep space photography. Though I've seen other photos using very similar scopes and they can manage very acceptable photos, but I am under the impression that whatever I happen to see will be tiny. Or maybe I just have no idea what I'm doing.

So what advice have you got for me for tonight's session? I don't really know what to do differently compared to last night. I imagine I will try to spend more time polar aligning (still unsure when I'm "aligned") and will balance the whole thing better (but I think I reached the mount's limit and need more counterweights). Also I suppose I should spend a lot more time getting the speed right on the motor drive to have as little movement as possible, though I was very very close to stillness yesterday.

TL:DR I will try imaging Vega again tonight. If I can end with a couple dozen frames that will ACTUALLY stack in DSS, then I will consider it a success. Advice?

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As a newbie myself I'm probably not in the position to give a lot of smart advice, but from my own limited experience, getting the newest version of DSS is helpful. Also, tinkering with DSS' stacking settings may help, even though that will probably take you only so far.

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For accurate polar alignment a polar scope is very useful. From a quick search I presume the EQ2 does not have one. I'm sure someone with more experience than myself can advise you on methods for PA without a polar scope.

Looking at pictures of the Astromaster 114 I would guess that the 1000mm focal length is a result of it being a Bird Jones design with a barlow inbuilt into the focuser. Again, I'm far from being any kind of telescope/imaging expert but this may be the cause of your focus woes?

As Oily says, a Bahtinov mask is very helpful with focusing but whether this will overcome the 'Bird Jones effect' (if this is indeed the case) I honestly can't tell you. Hopefully someone with more experience will be able to help.

The problems stacking in DSS may be due to the lack of other stars in the image. I think that a certain number of stars are required for it to be able to stack successfully.

If you want to be able to take decent images of DSOs then I would suggest that you get a copy of Making Every Photon Count (available through FLO) - it is not widely recommended on SGL for nothing! Hope this helps.

Gareth

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I'm a newcomer to this and you might do this already but once I've got a decent bright star e.g. Vega in the centre of my field of view I'll use the magnification setting on my DSLR's liveview screen and bump it up to x5. Focus it a bit more and use the slow motion controls to keep it centred. Then bump up magnification to x10 and focus a bit more. Admittedly focus does gets trickier at x10 magnification on the liveview camera screen as the image tends to move in and out of the screen as you nudge the scope slightly whilst focussing but using the slow motion controls (or a handset if you've got one) keeps it centred.

Another thought, have you checked the collimation of your scope at all? Might be out slightly which could cause focus issues.

When everything is properly lined up and collimated I can get reasonably sharp focus using the method described above e.g this image of Vega:

Vega - first astro pic

Sure more experienced people will be along to help you out soon but don't give up!

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My advice is practice on the Moon first, it will soon be with us! Once you are comfortable finding the Moon, polar aligning your mount and adjusting the tracking speed, so that the Moon does not drift away you can fine tune your focusing.Then practice on Polaris which is reasonably bright and doesn't move (much). You should be able to image quite a few stars that way in only a few seconds and then you have something to stack. Carry on with high declination targets that don't move much.

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With the best polar aligning I could manage (how to tell if I'm properly aligned?) and the right speed setting on the eq drive motor, I think I am basically limited to 15 second exposures

Sounds about right for an EQ2 at 1000mm FL I would have thought. And forget polar alignment errors - at that scale on that mount periodic error is going to be your number one problem. And the only way round that is to guide (or to image with larger pixels). I struggle to get 30sec exposures on an HEQ5 with a Canon 1000D at a similar focal length.

NigelM

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1. Your equipment is not ideal

2. Your equipment is not ideal

3. Since you can't guide with your mount, you'd need to either fork out more dough for a HEQ5 or do proper polar alignment (don't have a polar scope? Learn drift alignment)

4. Collimate your scope properly (astronomyshed videos invaluable on YouTube)

5. If you get startrails on longer exposures, u haven't polar aligned the scope properly or maybe it was just windy (a better mount would help with windy nights)

6. Rather than starting with long exposure AP - do the moon, then the planets (although, a webcam for that sort of thing is better than a DSLR)

7. Don't give up! It's one of the hardest hobbies to go for!!

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