I have been imaging now for a while with a 120mm Orion EON ED refractor. I had an old Orion 6" F5 reflector sitting in the corner of the garage. Knowing that many reflectors won't come to focus with DSLR cameras I had not tried it.Just out of curiosity though, I decided to give it a try one night. I noticed that the upper part of the focuser could be removed and a T-Ring could be screwed directly on to the adapter on the silver part of the focuser tube. This is it with the upper part of the focuser removed.

This is another view of the whole rig. This is the mount I used for imaging here on this thread and is also my quick grab and go mount. I used an EQ 5 clone. I will modify it later in this thread.

The night I tested the rig to see if it would come to focus the Moon was out and a little past half. I decided to use it as a target. Low and behold the thing actually came to focus with room to spare. It makes a great wide field imaging scope at F 5. The Moon image came out sharp and well focused with no chromatic abbe ration. I also shot the Dumb Bell nebula with it but can't see to find the image any more. Here is the Moon shot though. It has been cropped as I could probably get 3 Moons in the field of view.

I picked this scope up used for $150 for a grab and go. It does do a fine job for what it is. The only draw back is with the upper part of the focuser removed, you can't use a barlow to up the magnification. In this configuration it can only be used at F5. I don't think there is enough in travel left on the focuser to use a reducer. Those on a tight imaging budget might consider looking for one of these used.

JJ

johnjohnson:

Low and behold the thing actually came to focus with room to spare.

Newts, at least properly configured newts, make great imaging scopes. I've been using a newt (originally an 8", followed by a 10") for galaxy imaging. The 10" newt focus point is 5-6" out of the tube, no problem for the mono ccd plus filter wheel (with the Baader coma corrector inside the focuser.

A primary mirror move (and upsize of the secondary) would easily allow for a Wynn reducer/corrector to be used in place of the simple coma corrector (the approach used on the expensive ASA and Orion Optics f/2.8 to f/3.8 newt astrographs). Don't discount the newt, it can work well for photography.

Robert

tkerr,

Yes the upper inch and a half of the focuser draw tube simply unscrews and the T-ring can be threaded directly to whats left. I also noticed that the secondary is quite large. It's to bad the focuser is only a 1.25 inch model but that is common for apertures less than 8". 

JJ

I got a chance to try out the 6" reflector on a DSO. This was taken at 4:00 am so dawn was coming and beginning to wash out the sky.This was 16 images of 10 seconds each at ISO 1600. Canon EOS XSi at prime focus. EQ 4 ( Sky View Pro clone) mount unguided. I used the 10 second self timer to eliminate the shakes. I just wanted to see if the reflector would focus easily and take faily good images. There was some vignetting so I croped it off. Processed with DSS, then GIMP, then PS elements.

This is what the images looked like before processing. I was surprized how the main images came out.

JJ

I found the image of the Dumb Bell M 27 nebula that I took with this scope. It was on the EQ 5 clone mount unguided. I don't recall the spec's for ISO or number of images stacked as it was a while back. The stars are a little elongated but a perfect image was not my goal that night. I did not do a very good polar alignment either so the stars a probably elongated in Declination. I just wanted to see how well it would wide field image.

JJ

Last night 6/ 27/09 I had another excellent chance to try out this rig. I imaged M56. This is 256 images of 20 seconds each. This was done from down town Sioux Falls SD. Images stacked using DSS, and processed with Gimp and PS elements. I am real pleased with it as I modified my Apogee EQ 5 clone mount with dual axis drives to have an ST4 input  and guided it with an Orion SSAG. Not to bad for one of the crummiest mounts in history! The mount cost $150 brand new!

JJ

Modifying an Orion dual axis hand controller for an ST4 guide port. This is a real easy mod to do and guides very well at short focal lengths. The hand control has to be used in the 2X sidereal mode for guiding. The mod was described on the Shoe String Astronomy web site. This mod can apply for the EQ 5 mounts. using dual axis controllers. The clone mounts can be found on Ebay by typing in the following search description.

CG-5 type Dual Motor Equatorial Telescope EQ Mount  

[url]http://www.store.shoestringastronomy.com/eq_mod.pdf[/url

This is the modified hand control and all parts were bought at Ace hardware. A six line phone line and coupler. Make sure to use the end that gives the straight through connections to keep the color coding correct. This works perfect with the Orion Star Shoot Auto guider and it's cable.

JJ

Got another chance to test out this rig. Shot from backyard in town. 60 images of 45 seconds each. Canon XSi at prime focus, ISO 800. Guided with SSAG and PHD through a 60mm Celestron refractor. 6" Orion short tube reflector. No flats, No darks. processing was DSS, Gimp. PS.

JJ

Back in June I took an image of the Sun and spot group 1019. Single shot With XSi. Image cropped to show group. processed with PS elements 6. False color added to enhance spots.

JJ

 pretty cool shots JJ. I've always wanted to use one of my reflectors with my DSLR, but focusing remains a problem. I even purchased a zero profile adapter, which didn't help.  I thought about maybe adding a low profile focuser, but didn't want to spend the money when there's a chance it won't help either. So I just keep using the refractors for imaging. With the skies the way they've been this year, there hasn't been much imaging going on anyway!

Kevin

Have you tried Barlowing your reflector? When imaging with my refractor, which has graduations on the draw tube, I all ways right down the settings for the different optics. I found that at prime focus and barlowed, there was a difference of 3 cm of out travel provided by the barlow. This could quite make the difference you need to focus.

I have done FOV indicators in The Sky 6 and my Canon XSi has a very equivalent FOV to a 27mm Panoptic. I therefore use the Pan to center and adjust my field. That is the equivalent to a low power EP. We know that Barlows extend the eye relief of low power EPs, so it should do the same for the camera. I have not tested this on a reflector but it could be true.

JJ  

 JJ,

You didn't need the Shoestring interface box with the Orion SSAG, right? The SSAG can conect directly to the RG cable from the hand controler and to the computer USB?

I want to do that to a Vixen DD1 and Shoestring shows a picture of the solder points for that controller.

 Johnm

That's correct. The SSAG cable hooks Directly up to the new port just as if you were connecting it to the guide port on any other mount. You will have to set your sidereal tracking to it's lowest value. I found it to be a very easy mod. You will have to work on your mount to get as much backlash out of it as you can.The motors themselves have plenty of built in backlash! I would not want to image with this mount at much over F5 due to the backlash.

Good luck on you mod.

JJ

 That's what I thought. One of the reasons I got the SSAG was because of the opto-electronic circuit. My split ring uses a Losmandy G11 controller and they need the SBIG relay or an isolated circuit in the guide camera. I'm using Vixen MT1 motors on a CG-5 mount because it has a little more capacity than my old Vixen GP, be nice to hook up an auto guider to it.

Here I really put the scope and mount to the test. I wanted to see if I could image a very faint object from town with moderate light pollution. I did not use any filters. I chose NGC 6960 or the West side of the Veil nebula. Would a 6" reflector do any thing from town? Would the clone mount guide good enough to get any resolution? Well it sure surprised me. This is a cropped image to cut out the vignetting. 120 images of 30 seconds each. Canon XSi ISO 800. Guided with SSAG through 60mm Celestron refractor and PHD. Processed with DSS, Gimp, and PS6.

JJ 

Latest upgrade to this system was to replace the tripod with a steadier mount. This kinda happened by accident. One of our club members built a portable pier for his CG5 GT and didn't need the tripod anymore. It has the 2" diameter stainless steel legs and a leg spreader. My old tripod had no spreader and was shaky especially in the torsional axis. This was a direct bolt on exchange to my clone mount. I traded him and old gateway laptop for it. It is solid as a rock now and I expect to be able to guide even better now. Cost = $0.0 as the gateway laptop had been moth balled anyway.

Old tripod in front of new one.

The rig now.

JJ 

I took the wide field image of M56 and zoomed way in to check the old mount and tripod's rigidity. The SSAG did a good job of guiding as the stars are not trailed but they are not quite perfectly round. I lay blame on that to the old tripod and a bit of a breeze on the night I imaged M56. I will have to do another zoom on a star field with the new tripod and see if it helps or if it is that the SSAG just can't guide this chepo mount as good as could be.

Wide field full frame.

 Zoom and cropped.

Still not too bad for a chepo mount on flimsy legs and guiding at 2X sidereal rate!

JJ