Thursday, October 24, 2013

Levenhuk 8" carbon fiber RC astrograph

The weather here in Arkansas isn't always cooperative with my astrophotography hobby. Even when it's clear the Summer months have not been conducive for imaging, especially for my un-cooled DSLR. However, I have owned this scope a couple months now and have had several opportunities to try it out. I would like to share my opinion of it here.





First of all, the carbon fiber tube simply looks outstanding. Aside from its good looks, the carbon fiber tube also serves a very important function. I can image with it over multiple nights and not have to adjust focus. This is something I simply cannot do with my steel tube newtonian and refractor astrographs. The focuser itself is very smooth and seems to be more than adequate using my Canon 1100D. I dont know how it would do with the added weight of a CCD camera, filter wheel, etc., but it has done its job so far. I am now perhaps spoiled after installing a Moonlite on my newtonian and will probably upgrade the focuser sometime but its not something that is needed at the moment.





The second thing I would like to mention is that I am very happy with how the stars appear in my images. Most of you that have imaged with newtonians and refractors know that a coma corrector or field flattener is needed. The stars in the corners of my images look very good. They are not perfect but I would say they are better than what my f/4 newt with Baader Mark III MPCC combo produces. This is also with a full size DSLR sensor. If you are using a camera with a smaller sensor then you probably will not see anything wrong with your images. Also worth noting is that the scope was slightly out of collimation when I received it. I have only adjusted the secondary screws to get a nice looking diffraction pattern on an out of focus star. Further tweeking with the primary adjustment screws could make my corner stars look even better.

Imaging at f/8 with a DSLR was pretty tough for me after being use to the fast optics in my f/4 newtonian. For this I purchased the Astro Physics CCDT67 Telecompressor. The reducer screwed into a 23mm long Baader 2"/T2 nosepiece has dropped the focal ratio from f/8 down to f/5.68 and has proven to be a very good combo. I also own the AT8IN and AT65EDQ astrograph offerings from Astro Tech. I like both of these scopes a lot but the Levenhuk Ra 200RC is an excellent telescope and is my weapon of choice for long focal length astrophotography. I also own an 8" and 10" Schmidt Cassegrain scope and this RC is many times over the better imaging scope. I would recommend this telescope to anyone looking for a long focal length astrograph.

I have managed a few test images using my Baader UV/IR modified (by Gary Honis) Canon camera. The image of the Wizard nebula is the only one I have spent a good amount of time on (4.5 hrs). The Elephants Trunk is just 21 subs and the Swan is just 14. All subs were five minutes and ISO 1600 was used. The Swan was shot at f/8 and the other two were done using the Telecompressor. The full resolution images and any future improvements to them may been found here: http://www.astrobin.com/users/rflinn68/









There will be more work from this scope in the future so be sure to check back with Little Piney Observatory for updates. I have received a new scope from Levenhuk. They have sent me a nice 80mm triplet for a test and review. After a few nights of using this scope I decided that I would be keeping it and have sold my AT65EDQ. The Astro Tech was a very fine scope but the Levenhuk 80mm will be a more versatile telescope to have in my arsenal. Test results and a thorough review coming soon!

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