BlueAstra

I have an imaging setup driven by a NUC computer. It's located on the pillar and controls the camera (SXV-H16), guider (OAG+Lodestar), filter wheel, focuser, sky sensor, and mount (MX) through TSkyX. I want to add a second scope as a piggy back on the main scope with an SX-M25C camera. This camera is fairly large format, and downloads very slowly. To avoid any potential USB issues if both cameras start to download at the same time I thought of using a mini stick PC mounted on the scope just to control the SX-M25C camera. Can anyone suggest a suitable 'stick' mini-pc, or an alternative?

I got one of these holders for the hand controller. I’ve not found it from any UK supplier. It clips to the handle on the upper mount and rotates with it, so no cord wrap issues. There are some dedicated forums elsewhere that have a good discussion of the Evo and especially Wi-Fi control. I generally control my Evo 9.25 (an original version from FLO) from my iPad, but I have to use a Celestron SkyPortal adapter to avoid Wi-Fi issues (I think a lot of these are due to conflicts with home wi-fi, I get few problems at remote sites). I believe the Wi-Fi is improved in later versions. I use 21 and

SOLD

The Revelation RD003 0.75x Focal Reducer effectively reduces Revelation and Altair Ritchey-Chretien Telescopes from f/8 systems to f/6, increasing the apparent field and reducing exposure times accordingly. The 0.75x reducer also assures flat field and round stars edge to edge. The Reducer has a practical spacing distance of 80mm (+/-5mm) from the rear element to imaging chip, with an M42 thread if you want to use a spacer. Brand new, never used. Price £45 including postage to UK.

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I have the Evolution 9.25 with the Starsense camera. The OTA is large, but with the handle, manageable. I agree the tripod is sturdy but quite heavy and a bit awkward when you are lifting it into the car. I use primarily for visual or planetary/lunar imaging. You do have to check that the diagonal doesn’t clash at high elevations, especially if you are using Starsense auto-align. I sometimes unbalance it slightly forward to give clearance, the mount doesn’t seem to complain. I use a astrozap dew shield, I’ve never needed a dew heater strap. If you don’t use Starsense then you want a decent red

Sorry I didn’t get back to you earlier, I missed the post. The bracket was made up from some pieces of Dexion (I think it’s called) screwed together, the sack trolly was from Costco. I drilled two holes in the trolly to mount the bracket. It was important to have some form of clip to hold the pillar mount in the bracket Otherwise it would slip out when moving. I don’t use this setup any more so I still have a spare trolly and pillar mount (but not the eq6) available for sale, although they are a bit scruffy now. I took part of the bracket off and would have to look for it now. PM me if you are

I'm looking to change my camera mounted on an Esprit 150 to improve the pixel resolution (limit 0.77 arcsec) while trying to maintain FOV. I currently have an SXV-H16 which gives me a FOV of 0.83 deg and pixel resolution of 1.45 arcsec. I believe both the cameras quoted use the same chip and would give me FOV 0.68 deg and resolution 0.89 arcsec. Does anyone have any experience of these cameras, any preference between them, or maybe an alternative?

Here's the table for your scope:

The following table may help (values calculated for your scope): The Max A"*50 is the theoretical maximum magnification, the Max Dawes is a practical magnification limit. The exit pupil essentially tell you how bright the image will be, with a larger pupil letting more light into the eye. Note as you get older the ability to increase your eye's pupil size decreases.

For interest, this is two separate combined daytime images taken some years ago with my Canon 1000d and a lodestar guide camera, showing the relative field of view size and position. The OAG location is not perfect, ideally it wouldn't interfere with the main camera FOV. The OAG prism shouldn't 'block' any information from the main FOV, just reduce its brightness slightly.

I think I read somewhere that smaller apertures look through a smaller ‘plug’ of atmosphere, so are less susceptible to seeing effects. This could explain why the C5 looks better than the C9.25 if you have poor to moderate seeing. Conversely, the larger apertures would look better if seeing was excellent.

Another thing to note is that the SCT is a mirror system so doesn’t suffer from chromatic aberration. You probably need a triplet refractor to get minimal CA. Another difference is that SCT can need collimation, whereas refractors rarely need it.

Well, Takahashi have an enviable reputation for build quality and optical performance. Just check the camera is well matched in terms of pixel resolution and field of view. Its not very heavy so shouldn't need a particularly large mount. I would say with the right camera ideal for deep sky wide field photography with a portable rig.

For Sale - SOLD 10” Ritchey-Chretien Telescope Altair RC250-TT Truss Telescope with: Focuser tilt adjuster Primary & Secondary dew heater strap Mini dovetail clamp (for red dot finder) Starlight Instruments Feathertouch FTF-3015-B-A R&P focuser + custom adapter Baader Steeldrive focus motor Cloth light shield Mirror Covers Primary Mirror Fans Focus Spacer Tubes Dual Losmandy Rails Stock Focuser (replaced by Feathertouch) I got the RC250-TT from Altair Astro. Its been installed in my roll-off observatory