Hello all.

My wife and I are interested in astrophotography and a google search brought us to your web site.

We use a Meade LX200 10” – first scope (only scope) for the past 3 years or so....love it.

Camera is a digital rebel XTI
Lens 70-200MM F/2.8 IS & 17-55MM F/2.8

I started my online research about a month ago and found I needed a T-ring and a T-adaptor. I have these both. In my readings many people suggested that a piggyback mounted camera is a good place to start – so I figured for the $35 why not, so I picked up a piggyback mount for my XTI (I already own a remote switch)

So that’s where I am and what I own.

My wife and I do internet searches and see incredible pictures of utter beauty – things I can not see with my scope, if I view M31 it’s a fuzzy little mess – yet I see pictures of stunning beauty captured with lesser equipment than I own. With that in mind, I am hear to learn. I have two young children that I Would love to show these things too.

I am not where the best place to start is? I think I am going to mount my camera piggy back – and attempt Saturn. I am not at all sure what setting to use on the camera – any advice here would be great ! I think I should put it to manual and set it to bulb (not sure how to do that, but I read it online) and I will shoot Raw. We need some baby step advice if anyone is willing to help.

Saturn is something you need to capture through a telescope, there's no point in trying to shoot it piggybacked when you have the scope right there. Saturn doesn't require a slow shutter speed at all if you want to get detail.

I use a Digital Rebel XT. What you need for long exposures is a cable release. Set the camera to manual and scroll through slower and slower shutter speeds to get the "bulb" function. You may want to also set the ISO speed to a faster or slower speed, depending on length of exposure.

Stacking multiple exposures instead of using a single exposure will yield better results.

Orion (http://www.telescope.com/) sells plenty of accessories to mount your camera to your telescope. You certainly have a fine scope for imaging.

I am just a beginner so I cannot offer so much help, but there are many other members here with plenty of experience.

For piggy back shots just open the lens as far as you can and still get nice round stars at the edges (may have to stop down one or two stops), set the zoom to fit the field you want to image and if you are well polar aligned (needs a wedge) you should get nice star fields in 5 to 10 minutes. Stacking several will reduce noise. Set the camera in RAW mode so no data is lost. Set the ISO as high as you can without noise getting into the image. Ditto the exposure time. At least with a digital camera you don't waste film and can keep trying until you get the results you want. Not having a DSLR I don't know what's optimum for your camera.

Without a wedge you might get by with lots of shorter exposures if taking near the meridian. The problem is the field rotates as an alt-azimuth mount tracks the sky so each image will need to be rotated slightly to keep the stars from turning into arcs. With an equatorial mount that isn't a problem.

For best results you'll want to have the camera's IR cut off filter replaced with one that doesn't block Hydrogen Alpha light as the factory one does. Replacing it does void the warranty however. Hutech offers this service.
http://www.sciencecenter.net/hutech/canon/index.htm

For planets you will remove the lens and replace it with a T adaptor. Use a barlow lens or two stacked to enlarge the image to about f/30 or so. At f/10 you'll want a 3x barlow minimum to get the image scale needed for planets. For the moon you'll want none for the whole moon then add one for higher powers. For this the alt azimuth mount is fine. Exposure time is short so you don't have to worry about field rotation as you do with deep sky shots.

Later as you gain experience you can add an off axis guider and take long prime focus deep sky shots. Though to get that shot of M31 you'll want a small, high quality refractor such as a ED80 type mounted on your LX200. Use the LX200 to guide with another CCD. You'll only be able to fit a small part of M31 into the field of your LX200 even with a telecompressor. Something you will want when you are ready for that type of photography.

Find a club in your area. Most have experienced astrophotographers and can give you a lot of hands on help that will greatly reduce the learning curve which can get very steep.

http://www.astronomyclubs.com/
http://www.skyandtelescope.com/community/organizations

There are a few books on the use of DSLRs but not using one I'm no up on these. Maybe someone will give you a lead there. Still the fellows in a local club are the best way to go if at all possible.

Rick

yes the piggy pack option is a great way to shoot widefields but for planets you are best to get a webcam-say a toUcam -even a used one

Mike Salway has a nice tutorial on planetary imaging

http://www.iceinspace.com.au/index.p...63,306,0,0,1,0

HI,
What exactly does a wedge do and do i need one for my newly purchased (used) LX200 GPS 8" for astrophotography ? I have the camera (canon 40D) attached to the scope and thats as far as i have gotten so far. I am trying to figure out how the scope tracks the objects if i do not use the goto computer. Do i need to do this manually ?

The wedge will allow you to align the axis of your scope to the north celestial pole (NCP). This will negate field rotation, if properly NCP aligned. Without the wedge, on a Alt/Az mount, objects in your camera frame will be smeared.

You will also need to acquaint yourself with the concept of guiding, and the equipment required to guide, preferrably autoguide.

Pick-up copies of Mike Covington's "Astrophotography for the Amateur" and Robert Reeves' "Wide-Field Astrophotography" as fast as you can locate them.

Robert

You might want to look at programs like Astrostack, you take lots of images of an object (maybe 100-200, digital images cost nothing but time!) the program then combines the images and produces a final image with more detail than any single image.

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The meek will inherit the earth ... the rest of us will go to the stars.

Thanks is that like the program registax.

Yes, same idea!

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The meek will inherit the earth ... the rest of us will go to the stars.

Welcome Aboard Crimsom Ghost!

I believe your mount is an alt/az type. Very stable and versitile howevever for tracking objects for any longer than a few minutes, (for astrophotography), you need to tilt the axis of your mount to the angle of your latitude so that it aligns with the celestial pole in your hemisphere. Otherwise, your scope will not be able to compensate for the apparent rotation of the stars around the pole. The wedge sits between your mount and tripod, (or permanent support), and allows for setting your latitude.

With 'go to' we are dealing with two separate alignments. The physical alignment of your scope to the celestial pole, and the computer alignment which allows Autostar to find things.

Autostar prompts you to 'align' your telescope to anywhere between one and three stars. This compensates for errors in the initial polar alignment as far as Autstar is concerned and so allows for easy object location. This alignment allows the 'go to' to find the object you choose.

Once you chose and find your object, the tracking motors which are now independant of the go to take over and track according to sidereal or 'celestial' time. At this stage, Autostar has no control over alignment. It is the physical alignment of your telescope to your celestial pole, (among several other factors which I won't go into here), which determines the tracking accuracy.

There are many references to methods of polar alignment on the net and there are probably some specific to your telescope. Others in the forum may know of a specific reference for your LX200.

There are many more experienced people on the forum who will no doubt be able to explain this more clearly but I hope this may clear up some of your confusion about what 'go to' does and does not control. I should probably mention here that there are several other settings in the utilities section of Autostar which are independent of the 'go to' and which certainly affect tracking speed and accuracy as they change the physical tracking speed for your motors but for now it would probably be inadvisable to alter these until you are more familiar with thier purpose.

Kind regards
Matt