hello, looking to get started in dslr astrophoto, need advice

[Stevemg13]

Hi there, I'm a new member to this site. I found you guys on the net when I was researching my new hobbie. Here is my story: My wife and I are looking into buying a new camera, one we both can share. She loves to scrape book and I like to stargaze. We asked around and decided to go with the Canon Rebal Xti. Good price range and (as I'm told) good for astrophoto. I currently use a Celestron NS SE 8" scope for observing. (SCT)
I've been digging around the web the past few days and here is a list of other items I came across needed for prime focusing astrophoto w/ this type of scope.
1 Feild Flattener
2 focal reducer (2 types 6.3/3.3)
3 (2") female adapter slide to SCT
4 Male SCT to 2" slide adapter
5 XTi adapter to 2" slide
6 Hartman mask
7 Flipe switch w/ some mm eyepiece for focusing
8 processing software of some kind

That is it so far, please help to fill in the list as needed. I'm new and in need of the pros. on the rest. thank you.

[Blue Fire]

Welcome to Extreme Astronomy, Stevemg13! I personally can't be of much help to you since I only use binoculars, but there are several folks here that know their stuff very well. I hope you get some good answers. And, that you hang around in the forum for a while.

[Buldric]

Originally Posted by Stevemg13

Hi there, I'm a new member to this site. I found you guys on the net when I was researching my new hobbie. Here is my story: My wife and I are looking into buying a new camera, one we both can share. She loves to scrape book and I like to stargaze. We asked around and decided to go with the Canon Rebal Xti. Good price range and (as I'm told) good for astrophoto. I currently use a Celestron NS SE 8" scope for observing. (SCT)
I've been digging around the web the past few days and here is a list of other items I came across needed for prime focusing astrophoto w/ this type of scope.

Glad to hear it. The more of us out there, the more of us that can compete creating better and better images. However, dont expect to be a main competitor on the first night out. It isnt as easy as you may think, even if you think its hard, its probably even harder than that.

1 Feild Flattener

All focal reducers for SCT's (as far as I am aware) Already do this. No need to but a seperate field flatening filter.

2 focal reducer (2 types 6.3/3.3)

Use 6.3 (Use a 6.3 Full Aperture Focal Reducer. about $155, not "neccissary" for many objects, but good in the long run. IS neccissary for a few things. It will decrease your magnification, give a wider FoV, and decrease your exposure time by a factor of 3)

3 (2" female adapter slide to SCT

Do you mean a 2" Visual back? I couldnt find if this scope can do 2". I could only find that it came with 1.25". Make sure you can even upgrade to a 2" Visual back first)

4 Male SCT to 2"; slide adapter

Im not sure what your doing here... I would use a 2" direct adapter to go from the Visual back/diagonal to the T-Ring. See http://www.meridiantelescopes.com/im...nical/dp2b.htm

5 XTi adapter to 2" slide

Rebel Xti T-Ring?

6 Hartman mask

See my own gallery for one design. Look at A.S.I.G.N observatories site for another design. Both use the same face design. In fact I modeled my "face" after his =p My mask goes over the entire end of the telescope, where as his slides in against the corrector plate lip. Though it doesnt touch the correcter plate, it gets too close for my comfort, so thats why i designed mine the way it is.

7 Flipe switch w/ some mm eyepiece for focusing

Now you lost me. Don't know what you mean by "Flip Switch" and eyepiece for focusing. 1.) You focus with the heartman's mask, 2.) You dont use eyepieces for "most" astrophotography, as it reduces contrast, and brightness.

8 processing software of some kind

I reccomend Adobe Photoshop CS 3 if you can, or the smaller Photoshop if not. For stacking I use Deep Sky Stacker.

That is it so far, please help to fill in the list as needed. I'm new and in need of the pros. on the rest. thank you.

Some other things you will need is if you'll notice, you have the same camera as me for astrophotography =) and you will need to order the remote for it. As you have to use the "bulb" setting to do the long exposure, which without the remote requires you to hold down the shutter button for the entire exposure, which, as you can imagine...hehehe. Press the remote button once to open the shutter, and again when your ready to close the shutter. This is NOT optional.

You will also need some way to guide the scope. Computerized guiding is only so good. Any real drift is bad for a picture, so it requires you to be at the helm. There are two main ways to do this. One is called an "Off-Axis Guider" Which sticks a little T-Bar into your assembly to steal off some light, so you can watch what your taking a picture of as its taking the picture. You need an "Illuminated reticle eyepiece" to do this, so you can keep adjusting your scope to keep the illuminated crosshairs over your designated "guide star".
The second way is to buy a high power "guide scope" This scope installs in place of your old guide scope, and you can either use the "illuminated reticle" method to manually track your object, or you can but another type of DSI camera which is called an "Auto-Guider" which takes pictures of the stars through the guide scope, and sends signals to the scope to change position to compensate for any change.

Another thing is that you will need a Wedge. If you don't have a wedge the stars in your F.O.V. will spin in the picture over time, even if its keeping track perfectly. I'm not going to explain this in this post, but its what happens=p Because of this effect, if you don't have a wedge, your exposures tend to be maxed out at around 3-6 min, depending on proximity to polaris. Clear Skies, and Good luck on your Astro-Photography mission!

[Buldric]

Oh yes, and of course, Welcome to Extreme Astronomy Steve =)

[dpab]

Lookin to take some pictures.

Well if its a single arm GOTO you have , good luck...you are going to need it.
Im not telling you this to bum you out.
You need to get control of the tracking , and with experience with a single arm GOTO ...Exposures for doing Comets, galaxies and nebulae are very, very challenging .
The Best way to take quality shots with a single arm GOTO is to get a wedge and polar align .
This way you are basically using one servo motor...more stable and less streaking of stars. You will notice the stability right away.
Most of the better quality guiding programs are for GEMS(german equatorial mounts) and tie in to a computer and hub and feed back to the auxillary input of the scope for tracking....programs like this a example being ..(maxim DL)
And lets not forget about the cash....ching ching.
You can take your OTA and put it on a good GEM, a good GEM is about 3 000 to 5000 dollars .
I have a CPC 1100 fork mount, its very good for viewing and it does okay for shots , but still no comparison to my buddies GEMS .
IF YOU WANT TAKE SERIOUS PHOTOS GEMS are the WAY...period ... otherwise be happy and settle for what you get.

For imaging using my single arm GOTO I use a program called guidedog ...
It produces a set of cross hairs with a hollow middle and you can click and drag the crosshairs onto a star in a CCD image and manually track and keep the star centered for the duration of the photo...this program is very helpful. and only 20 bucks not 600.
I have and use... 2 different webcams for planetary imaging , a CCD deep sky imager , the Meade deep sky imager is flexible enough to do multiple stuff with , but its monochrome so will require filters, and I also have a Canon Rebel XT , I take the family cam and do use it for Galaxies and nebulae this very good but its a ***** peeking thru the little focuser.
I also have a focal reducer and barlows.
Dave

[Dragon Star]

Just wanted to welcome Steve to the forum. Stick around man, you might learn a thing or two, and teach us a thing or two as well.

[dpab]

Well hello again , I have a few photos that a fellow Edmonton RASCal took.
He has the experience and equipment and the quality of the photos show it.
His name is Wayne Malkin and has a few photos on line .


It's been a busy month or so, collecting lots of data during that last nice run of clear weather, and digging into Photoshop some more when conditions weren't so great. Here are a few shots, both recent acquisitions and a bit of reprocessing of previous data.

M31: http://www.pbase.com/wmalkin/image/89877674/original
I think this will always be my favourite subject. This latest shot was the start of a planning lengthy LRGB sequence, but I only ever got the first 90 minutes or so of data. Nevertheless, the conditions were so good that night that I think it is my best attempt so far.

M44: http://www.pbase.com/wmalkin/image/90511591
This is a simple RGB shot with 20 minutes in each colour, shot between midnight and 2AM yesterday.

IC405-410: http://www.pbase.com/wmalkin/image/90283283/
A very wide field shot that includes the Flaming Star Nebula (IC405) at bottom-right, and IC410 at top-centre. The Flaming Star shows a very interesting blue reflection nebula in long RGB shots. I didn't pick that up really in this shot, where almost all of the data is narrow band Ha.

Heart & Soul (HaR)GB: http://www.pbase.com/wmalkin/image/88866030
I shared the Ha version of this a while ago. Shortly afterwards I collected 90 minutes of RGB data for each panel (this is a two panel mosaic). Then I spent the last two or three months trying to figure out how to combine the RGB and Ha. I'm really happy with this one.

IC1396: http://www.pbase.com/wmalkin/image/90427376
The Elephant Trunk Nebula. The framing is a little off and the elephant trunk is near the bottom of the frame. This is a bicolour narrow band image, just Ha and OIII data combined to generate colours pleasing to my eye, if not exactly scientific.

Thanks for looking!

thanks Wayne.


merry christmas and enjoy ...Dave