Telescope Reviews: NexStar Imaging Showcase

Hi everyone,

This is my first post. I have a NexStar 8SE and a C5 Spotter Scope for travel use. I’ve used the 8SE to do a little AP with the Neximage webcam, but I’ve not been satisfied with the image quality that I’ve been able to achieve so far. Jerry Lodriguss’ recent EdgeHD 11 images of the Moon and Jupiter using a Canon EOS T2i in movie Crop 640x480 mode on his www.astropix.com site encouraged me to try my hand at using a DSLR in movie mode in place of the Neximage. I recently purchased a T2i and just started experimenting with it.

I used my C5 Spotter Scope mounted on the 8SE mount to capture several Moon video clips. I used a Hyperion Mark III 8-24mm Zoom with T2i attached to it with the Baader eyepiece-to-T-ring adapter for easy eyepiece projection imaging. I did this to gain some basic experience using the T2i with an SCT and a zoom eyepiece before moving up to the 8SE. I found the setup quite easy to use and the fact that a laptop was not necessary during imaging provided an extra degree of psychological freedom beyond that of my Neximage experience. I have a JMI MotoFocuser on the 8” OTA, but not on the C5, so focusing was a bit frustrating for my preliminary tests.

The T2i was set Auto movie mode so that ISO and shutter speed where selected by the camera. I varied the zoom over the 24 mm to 8 mm range to get a feel for the overall behavior of the scope-eyepiece-camera combination. The setup was mechanically smooth to work with. I put a Baader 2” SCT Click-Lock on C5 to provide secure attachment of the diagonal-eyepiece-camera train. I used my WO 2” Dielectric Diagonal to provide a comfortable view of the T2i Live View Screen without having to perform contortions to see the camera LCD screen. The SE tripod was in its shortest configuration allowing me to sit comfortably in my observer’s chair while performing the captures. The Moon was used as the alignment target under the SE Solar and Planetary alignment option on the SE mount HC unit. The setup was fast and easy to use.

The T2i’s MOV video clips were easily transformed into AVI format by the freeware program SUPER. Registax 5 was to align, optimize, stack, apply wavelets, and adjust the gamma (curves) to produce the final images.

I concentrated on two Lunar Craters, Plato and Copernicus to perform my preliminary experiments with the equipment. If my memory is correct, these are at a nominal f/20 zoom setting. I’ve included Flickr links to the final images here in case my attempts to attach them in two posts to that will follow fails due to my inexperience with posting here.

Plato image link:

http://www.flickr.com/photos/quadstar/6246539192/in/photostream/

Copernicus image link:

http://www.flickr.com/photos/quadstar/6245402112/in/photostream/

The preliminary results of using the T2i with the SE setup are encouraging. The Plato image shows at least three of the nominal 2 mile diameter cratelets on the floor of the crater. Perhaps a better Sun angle would make them stand out better? This image was taken 2 days after the First Quarter. I was surprised to be even see them in the image of the Plato since the seeing was just average and C5 is a rather small scope. The Plato video clip was about 75 seconds long at 60 fps.

The Copernicus image was about 40 seconds long at 60 fps. The SE HC was used to keep the crater from drifting too far during the making of the video clips.

The results of this experiment are encouraging. The video clips from the T2i produce more robust stacked images than the Neximage webcam and the logistics of image capturing are significantly less complicated than the working with the webcam and laptop. The weather is now clearing up and I will be able to start using the 8SE with this imaging setup.

Carl