I've been trying to see Ison before it passed by the sun.
I spent some of my time going out to locations down near the Detroit river.
I wanted to take some wide field photos of the comet and other targets. I thought about setting up my four inch f4 telescope on my nexstar 4se mount, but had some issues with that setup. I found a way to quickly mount the scope on the mount, but Ison wasn't something I could easily find because of problems connecting to the mount.
I then decided to get a different setup. I was thinking about a Hyperstar setup, but a full blown hyperstar setup for wide field photography, if I'm using a canon dslr as the camera would be a huge setup and huge expense. I'd need to get a large telescope because a hyperstar setup requires the camera to be mounted in front of the front corrector plate, where the secondary mirror is. It essentially turns the telescope into a Schmidt camera. A Schmidt camera was a setup where a corrector plate holds a film camera in front and center of the telescope mirror. They were created in the old days for film cameras. Celestron invented the fast star setup which allowed cameras and lenses to be used in the front of sct telescopes turning them into Schmidt cameras. This system is now known as hyperstar setups, because a second company makes what are known as hyperstar corrective lenses that your camera would attach to.
In any event the entire setup, for a canon EOS owner requires a c11 which is rather large, and a hyperstar or fast star setup. A nice c11 hd with a cgem dx mount costs a little over $4100, closer to $4400 when it's not on sale, then the hyperstar lens has to be purchased. It costs about $800. Se we are talking about $5000 to photograph wide field stuff and really faint stuff, very quickly. I think a c11 records images at something like 18x, it's been a while since I did the calculations, but it's in that power range.
The photos can be taken much quicker, which would be good for comets of something where you'd like to take quick wide field photos.
Without $5000 in extra cash laying around, I decided to check the other wide field options. The cheap one using my f4 four inch telescope doesn't work very well because I have a lot of coma, elongated stars at the edge of the image. There is a cheaper option of getting a short tube portable refractor. Something like the Meade APO f6 telescope we have at HJRO. That costs about $1000. Or you can get an Ed glass Williams optics 60 or 70mm telescope that is fairly good for imaging and wide field stuff, the Williams optics telescope will cost about $500. Getting a telescope means I'd have to have a nice telescope mount for tracking as well.
A nice mount like a Losmandy gm8 costs $2000 or so. Maybe $2500 with all the goto options. A lesser mount can cost perhaps $500 to $700, that being a cg5, or Celestron VX mount.
A $500 mount and $500 telescope is still $1000 just to take a nice wide field shot in a portable location. It's kind of pricey. I could get a stripped down c8 nexstar for that price. But the nexstar c8 with mount is a different telescope, it's not wide field but narrow field, and f11 telescope with a long focal length. It won't take wide field shots of the sky and a long comet tale. You can get a hyperstar c8 which is only in the $2000 range, but you'd need to buy a nice small ccd camera that would fit on the smaller setup. A small decent ccd astronomy camera would have a lot of advantages and I could use it at HJRO as well. But those cameras typically cost $2500 to $3500 which brings the price of a c8 with wide field capability up to the $5000 price range.
So to get a wide low field of view of a comet would be cheaper with a small refractor telescope and a smaller mount.
But I did not want to risk and spend $1000 on a hyped up comet photo shoot that might not turn out. I knew I could spend money on an expensive rig and do other things, but I just could not pull the trigger on spending a grand or more on this comet Ison frenzy that I wanted to take photos of.
I already have a basic goto mount in the nexstar 4se. This mount can do basic goto and track in an EQ mode using the built in wedge bar. It's a cheap setup for imaging and lacks many features that an imaging system might have, especially for high powered imaging.
What if I could take wide field shots with a telescope that was just a Canon EOS lens. Some great comet shots have been taken with 300 or 400 mm lenses. There are limits to what a camera lens can do compared to a telescope, but these lenses are not bad and as a positive they are light weight.
I know at times my nexstar 4se will not work or lose tracking if it's not balanced well with a dslr mounted on it.
The DLSR and nexstar 4se weigh in at over 7.5 lbs, maybe a pound more, I'll have to reweigh and confirm the weights. But if I mount a dslr and a telephoto lens on the mount I'll end up with a lot lighter load. Just take off the telescope and mount the camera and telephoto lens on the little 4se mount.
I needed a vixen dovetail, but was in a hurry and didn't want to steal and jury rig the one on the telescope for the camera. So I found a block of wood and a camera clamp and a clap. With these three items I was able to mount the canon EOS on the telescope mount.
I did an impulse buy and went to Walmart and picked up a Canon EOS 55-250mm lens. I mounted these on the telescope and tried to get a nice tracking photo of comet Ison closer to the horizon. I wasn't able to find that comet, but I was able to test that combination on other objects in the sky.
Here's a test photo of the Orion nebula and it's surroundings taken with a 80 second exposure using the lens on my little telescope mount. This shot was taken at 8x. I processed this single shot a bit using nebulosity, photoshop, neat image pro noise reduction and even iPad apps. Here is the result.
(Not bad for a quick test photo.)
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