Crushing defeat

[Buldric]

Allright, so I went out and tried this astrophotography thing, and needless to say, it didn't go so hot in the end. My telescope got a PERFECT lock onto my target, the scope wasnt the problem. So heres the details of how the night went.

1.)Tried a few pictures of the night sky with the cameras stock lense, to get a feel of its exposure's and ISO's. Every thing is going dandy.

2.)Attach camera to scope. Good good, no problems.

3.) Attempt to take picture with camera after having focused the eyepiece in the camera adapter....This is where it went wrong.

At this point, for some time, all I was taking was black pictures, and for the life of me, I could not understand why. It doesn't show me live image, so I cant check the focus that way, and the viewfinder is so dim I might as well be wearing a blindfold.

I finally decided that the problem must be the focus, that the camera simply does not focus at the same level as the eye. So, after turning the focus nob bit by bit, with 10 second exposures, 100 pictures later, I finally get the camera into focus...kind of. 30 pictures later again, I get the focus fine tuned, and I have myself a lot of blurry pictures of some very bright stars.

4.) After attaining focus, Photograph M31 as planned!
Using 30 second exposures, I took a total of 30 photo's, totaling 15min of exposure. I know thats not very long, but, hey, when you have to keep pushing that button 30 times, it seems like a long time =p.

5.)After taking my photographs of M31, time to move on to M57, and M27, just for fun.

At this time, I start leaning towards doing bodily harm to the chipmunk who's home is currently blocking these objects. But I decide to chill instead, and call it a night, leaving M57, and M27 for tomorrow night.


6.)So I get inside, hook up the camera and download the images. Only at the point where I start stacking them, do I notice I was being a very smart boy earlier, and had decided to use ISO 1600.

So I now have 15 min of exposure of a noisy M31. I did make a dark frame, however I don't know how to subtract it from the others, adding to the difficulty. However, what is there of M31, I can make out the core(phew) and some dust. Tomorrow night is a whole new night to try this again!



Another oddity(to me, being a newb at this), I found that the camera could not see in 30 seconds, what my eye could see immediately. I tried M57 before M31, but it wouldn't show up in a picture, and I'm hoping that it was just the focus, something i will attempt to verify tomorrow night. One would think, that at 1600 ISO, and 30 seconds of exposure, the camera would pick up more than what my eye can see immediately. If anyone knows anything about this, a word of it would be great!


Thank you.

Buldric

[Buldric]

Its odd, I have been looking at the image gallery, and I'm seeing pictures taken with much less exposure time, however are near infinitely brighter than my stacked image came out >.< Ill upload what registax gave me to show you guys what I mean.

[dmill1220]

Hi Buldric,

There are a couple of statements in your post that has me confused as to your method of imaging.

here is the first one;

Attempt to take picture with camera after having focused the eyepiece in the camera adapter....This is where it went wrong.

Are you attaching your camera afocally? this is where an eyepiece is used and the camera is placed just above the eyepiece, this only works for Bright Stars , the Planets, and the Moon.
For deep sky work you must use the prime focus method or the piggy back method with another scope or telephoto lens.

The second statement you posted;

After attaining focus, Photograph M31 as planned!
Using 30 second exposures, I took a total of 30 photo's, totaling 15min of exposure. I know thats not very long, but, hey, when you have to keep pushing that button 30 times, it seems like a long time =p.

You should never make physical contact with your camera, or scope, or mount, when initiating an exposure, it should be done by means of a remote system that eliminates the need for you to have contact with your equipment,
any contact will result in images that are blurred, no matter how fine a touch you have!

Get back to us with more specifics like the make and model of the camera and the method of attachment you are using.


To accomplish focusing at the prime focus of your Scope efficiently, you need to make a Hartman Mask, and install it over the Scope's objective.
IF you dont know what a Hartman mask is get back to us!

You first use your lowest power eyepiece and center and focus a bright star while the tracking is engaged, then remove your eyepiece and attach your camera, place the Hartman Mask over the objective of your scope and focus until you see the different holes in the hartman mask come together as one point in your camera's view screen, then remove your camera and without refocusing the scope re-install your eyepiece with a adjustable slip ring over the eyepiece barrel.

to achieve focus in the eyepiece, move the eyepiece in and out of the holder, and slide the slip ring down onto the holder and tighten it when the view comes into focus. now you have an eyepiece that is matched to your camera's focal length, you may have to try different eyepiece focal lengths to enable the use of the adjustable slip ring.
this will speed up the focusing issue.

Now you just use the matched eyepiece to focus your target before installing the camera, the camera when installed, should then be very close to a focused image, but usually a hartman mask is used again on a bright star and not your target image for precise focusing, when you are happy with the focused star image proceed to your target.
At prime Focus, a 30 second exposure for a total of 30 subs, should be much brighter than the image you posted.

If you attempted to image M-31 by placing the camera above the eyepiece, you will not achieve satisfactory results! stray light can ruin your image and your image will be very faint.

You're not defeated my friend! You just need to use the right method and technique.

Dennis

[Buldric]

Are you attaching your camera afocally? this is where an eyepiece is used and the camera is placed just above the eyepiece, this only works for Bright Stars , the Planets, and the Moon.

I bought 2 things to attach the Camera to me scope, a T ring of course, and a nifty little tube that goes from the visual back(or diagonal) to the T ring. Inside this tube is a ledge, and a thumb screw to enable you to slide eyepieces into the tube. I'm uploading a panoramic of my viewing site later on,(to show you guys just how horrible it is) I'll upload some pictures of the tools I use for attaching the camera.

I can't say for certain, but I "believe", that when I took this M31 picture, I did not have an eyepiece in the hole, just Visual Back->Tube->T ring->Camera.

(so no, no it's not afocally)


You should never make physical contact with your camera, or scope, or mount, when initiating an exposure, it should be done by means of a remote system that eliminates the need for you to have contact with your equipment,
any contact will result in images that are blurred, no matter how fine a touch you have!

This is true, and I understand it, however I'm a little short on cash right now, so the remote is coming along in a while. Instead I've made a compromise, I use the Self timer mode, in which I hit the button, then step away, and it takes the picture after a 10 second countdown(normally used to run into the picture with your friends)

Get back to us with more specifics like the make and model of the camera and the method of attachment you are using.

Canon EOS Rebel XTi 400D (DSLR) -Unmodified
Using a T ring, and a...forget what the tube is called, but I'll upload pics of it like I said.

To accomplish focusing at the prime focus of your Scope efficiently, you need to make a Hartman Mask, and install it over the Scope's objective.
IF you dont know what a Hartman mask is get back to us!
I'm getting back to you =p I guess I could Google it if it takes a while to explain, thats no problem.


"come together as one point in your camera's view screen"

Unfortunately, my camera does not have a live updated screen for some unknown reason. I have looked through the menus, but have yet to find anything as such. All I have is the Viewfinder, and as I said before, its very....very dim.



"...and slide the slip ring down onto the holder..."

Hmm, a good idea, however, thats another item on my yet to buy list >.< Maybe some precisely placed tape can pull off the same trick... or I can canabalize my old $100 telescope and make a slip ring from it....



30 second exposure for a total of 30 subs, should be much brighter than the image you posted.

I thought so too, but as to why?....no clue, through a near 10" light bucket, it should be decently bright. I have uploaded another version of it, modified.

To tell the truth, for all I know, I screwed up big time, had high magnification, and was photographing M32 the whole time...sounds like something I'd do... All I know is I had it aligned, I told it to go to M31, it brought me straight to this one, and kept on it perfectly, so I went with it, heh......Might explain my inability to see the companions around it...


I have now updated my user Pictures with Pictures of the adapter + T ring.

[Buldric]

Allright, i found out about, a Hartman Mask, makes good sense to me, and this guy came up with the perfect idea to make one on the go.

http://www.mapug-astronomy.net/ccdastro/hartmann.htm

Just thought I'd post that, I could have never thought of that...

[dmill1220]

PLease check out this site it covers using your camera for Astrophotography!
http://www.covingtoninnovations.com/...300Dastro.html

When You get the Cash I strongly reccomend a Flip mirror system, this way you can find and frame your target with the Eyepiece and step ring adjusted to your camera's focus.

I hope this helps!

Dennis

[dmill1220]

With your set up I would just get a bright star in your Finder scope, place the Hartman Mask over the objective and take a short exposure, and view the image in your view finder after the image is taken, you want to merge all of the openings into one point. thats when you know you have achieved perfect focus.
By the Way, A step ring wont work with that tube, the set screw would be covered by the tube walls. I would skip that idea with your current set up.
BUt the Hartman mask will never fail you.

Dennis

[Buldric]

Well, just got in from another night of astrophotography. The Hartman Mask worked BEAUTIFULLY. Instead of taking 130 pictures to attain an "iffy" focus, I got a really good focus with only 14 pictures! Thank you SO much for that tip.

I tried again at M57, yet still to no avail, I know I took a 30 sec 1600 ISO pic of where it was supposed to be, it was there, but the camera still didn't pick it up. only some stars, odd that it would pick up the stars, yet not the nebula that was brighter than them... However, faced with my failure, I went to my old pal M31, and decided to have some fun with him.


Now, at my place, M31 doesn't come up over the tree line until about 1:00, so the camera had been running for some time, and the battery nearly depleated. I took some more 30 second exposures, hoping something was going to be different from last night, alas, if anything they were only darker. So I decided to go against everything everyone had told me, and attempted a bulb exposure.....without a remote. First off, I went for a 5 min. manual bulb exposure, but it was too much for me, and I ended up with a bunch of little worms. So i decided to cut it down to a 2 min manual bulb exposure. The first one went pretty well. The second one was PERFECT, wouldn't have been any better if I had used a remote, the third one was decent, and on the fourth one...the camera died.

So now im back inside, however, what I saw on the camera (before it died) from my 2 min exposures was VERY promising. It's now charging, so I cant stack the few I got, but I think they shouldn't turn out too bad at all. On the next good night I will have to try a manual bulb exposure on a nebula, see if THAT cant pick it up.


Also, we have already determined that I have fairly steady hands, I found that to check the camera's targeting, I can detach the camera from the T ring, then just hold a 25mm eyepiece at the proper distance (unfortunately, its not anywhere near inside the tube) and I can focus, and see what its looking at. Works fairly well, and don't need to buy any extra parts!


I'll upload the pictures from tonight as soon as I get a chance, I'll be asleep long before that battery will be charged enough.

Also, I'm taking down the pictures of my T ring and tube, to clear up the gallery. If for some reason you wish to see them again, just leave me a post and I'll e-mail them to you, or temporarily re-upload them.

Thank you for your tips, especially the Hartman Mask,

-Eric