Search the Community
Showing results for tags 'ritchey chretien'.
Found 4 results
Hi Guys, I thought I would share with you my first DSO taken with my new Orion 8" Ritchey Chretien F8 Telescope. The frame is made up of 12 x 4min shots, no light or dark frames, using my Sony A7Rii camera. The camera had the long exposure noise reduction switched on, which does help to reduce the total number of stars captured by the camera, as the Sony A7Rii does tend to overdo the number of stars captured. The telescope was mounted on my trusty skywatcher NEQ6 mount and the guiding was via PHD 'of course' via my skywatcher ED50 guide scope. The shots were taken from my back garden in Stowmarket, Suffolk where I believe I am a Bortie 4 location, so the skies are mostly dark, with just a little light pollution from the main town, no filters used. My normal telescope is a Skywatcher ED100 Pro Esprit F5.5, which is an incredibly sharp scope, but with a wide 550mm field of view, great for capturing the whole of Andromeda but a struggle with smaller images like the Iris Nebula. I will say the Orion RC scope did need to be collimated out of the box, which was a little disappointing, and it was not just a little out of collimation, it was a long way out, but with the use of a collimating tool, I soon had it dialled in. First impressions of the Orion Ritchey Chretien 8" Telescope are fair, not super impressed, as it is nowhere near as sharp as my ED100 Esprit, but then this is to be expected based on price and telescope type, however, the pictures it has produced are pretty good, if you downscale the full 42MP from the Sony A7Rii camera, as can be seen in this picture. I purchased this 8" Orion Ritchey Chretien OTA mainly for Planetary work, but as yet I have not had a chance to 'get onto' a planet, fingers crossed some clear nights will arrive soon, so I can try. I welcome comments, many thanks Jamie
I have encountered a unique problem last night while trying to image using my GSO RC6. The scope is well collimated using a long Cheshire as well as a Howie Glatter single beam laser for verification. CCD inspector also gives me good results when checking with an artificial star. However, when I check using a collimation cap the innermost shadow looks offcentered as well as when I pointed the scope on a real star yesterday (Alp Libra) as well as Spica, it showed a crescent shaped star. This I found to be really weird. Anyone have any idea whats happening here? I live in Bangalore, India, so there's virtually no cool down time required. The temperature gradient between outside and inside is very little if any.
Ordered my Altair Astro 6" RC and quickly arrived (I got it shipped as I was away for few days). I know this same design is created by GSO and sold rebranded my others, but I decided to go for Altair Astro one because they're just nearby and it seemed the best value for quality, arriving with double dovetail (fundamental to keep the optical axes linear), better focuser, and all the needed extension rings. The scope arrived perfectly packed. As I knew collimation could be a problem, I brought it to the shop to get it checked in case of big collimation problems and to get some advice. First light was on Moon and was great even if visually with some powerful eyepieces I had impression it was probably needing some tweak to collimation. First pics were of the sun with Kendrick solar filter, and they were quite good even if again I felt was probably going to need some more collimation. I don't use any focal reducer or field flattener with it, and I have a Nikon D750 full frame, so I know I'm testing it a lot in particular on the edges. Anyway first night out and some test shots and star test, I got quickly frustrated being not able to correctly collimate, most of all because on the internet I found tons of different procedures. I actually posted all process on SGL and you can check it all, including final victory arrived quickly following simple suggestions provided by AA: http://stargazerslounge.com/topic/249532-altair-astro-6-rc-collimation-help-needed/?p=2720144 Now that is collimated, and after a full session and a few days using it, I can say that the scope is very solid and well assembled. Surely it looks and feels much more expensive than what it is. With my D750 and the provided focuser there's basically no flex, the baffling looks excellent and there's no stray light entering. I have to be honest I'm really surprised by the quality of the scope, for the cost I'm absolutely satisfied, compared to even more expensive refractor(s) I had in the past from William Optics and Skywatcher. No plastic or cheap or loose parts, all metal and solid, seems and feels to be built to last forever. Like everyone I think that initially the collimation process can be daunting and discouraging for new comers (I never did it before), and it's indeed crucial to get perfectly sharp images. The scope is better built for non full frame DSLR or CCD, but even with my full frame I can use easily up to 70% of the central image, and that is a lot of resolution, details and light with my 24 megapixel full frame! Despite what many said I did not find the f/9 particularly problematic, even visually is absolutely stunning on DSO as well as on Moon or Sun. I use high quality Baader eyepieces (24,17,5), all on the 2" focuser with a 2" diagonal, and the views are great. Surely a more open aperture would be better visually (doesn't matter imaging with a noiseless camera like the D750), but I noticed it did not really made such a huge difference with my F/5 Startravel150. If anything everything looked much sharper and detailed, no aberrations whatsoever, fantastic. I also did not notice any difference in contrast despite the central obstruction of the secondary, if compared to my ST150 big refractor. All in all a fantastic instrument, it feels 'professional' and the process of collimating makes you feel it's more yours in the end. I have to say that once you go past the collimation, is by far the best quality you can buy for the money, without the aberrations you get on other configurations, and without problems of dew etc. (I have my dew strip on the guider but nothing on the RC, no need at all even after hours pointing directly up in a very humid night). Looking forward to spend many nights with this great little monster of quality!
Hi all, I finally got my hands on my new Altair Astro RC 6" and my new full frame Nikon D750! I updated all my software, tested all connections (BackyardNikon, EQMOD, Astrotortilla, CdC etc.), all working and nice So I got a first test image to check collimation...and what I feared happened, that is I need to collimate the scope! This first 30 secs image of M13 shows obvious stars problems: So I decided to do a star test (defocused star Arcturus as Vega was covered at first), and this was the result: And I said ok...not really collimated, I need to adjust the secondary, and using my camera's liveview maximum power (out and in focus were out the same), I started trying to guess/adjust things a bit, and after it seemed to be better (small movments and recentering the star every time), I took another pic of same M13: It looked definitely better down right, but worse elsewhere...overall an improvement, center at least is good, but not so much, so I went on tweaking more on the star test but moving on Vega (Arcturus was now too low and covered by some clouds). After some adjusting on secondary mirror, and with clouds now gathering, I took another example shot (all 30sec iso 6400 to have consistency): And it looked again that I'm 'moving around' the problem, but never getting it properly right...so I decided to take another pic of the star test on Vega. Overexposed as I forgot to reduce exposition, but in the 'reflections' the secondary is still visibly de-centered, maybe slightly less, maybe in a different direction...I'm not sure: So before clouds completely covered the sky, I tweaked it a bit more and took this final test shot: Now the question is....I have a feeling I'm shooting in the dark, center is pretty much ok but I cannot seem to get decent collimation results, considering I want a quite good one. All I have is a normal collimation laser (the red one I cannot afford the more expensive green one), that seems decently collimated, and I got it today to test it. And then when sky is clear I get a star test. I'm looking for some help for a down to earth approach working with these simple tools? I've read a lot but there are many different ways and opinions, too much talking about theories and useless stuff, while I wonder if someone with a similar scope have found a simple way to collimate, meaning I can spend all the time and patience but cannot afford too expensive tools at the moment. Anyone with experience can tell me what I'm doing wrong based on these pics and how to improve my procedure to collimate? Possibly also during the day considering that clear nights are rare so I'd rather do it during the day and just verify it later As I said I know there are various degrees of perfection, I'm not looking to get it perfect right away but at least to know how to achieve the best I can, how am I doing now, how to do it better etc. Thanks!!