New Kit Alert!!!
31 October 2022An Ebay bargain as a little treat! I thought I’d take a chance on this is GoTo Altazimuth (AZ) Mount designed primarily for telescopes to see if it would improve on results I get from my little Nano Tracker, which I’ve been pushing way beyond its limits! Plus, my little telescope has been just collecting dust.
This mount is computer controlled (via its own handset), so once it’s set up and aligned with a couple of bright stars, it can automatically find whatever object you want, slew round till it finds it, and it tracks its movement too.
It’s not specifically a photo mount as it doesn’t rotate like Equatorial Mounts. The tracking adjusts vertically and horizontally, so it will track objects across the sky accurately, but won’t adjust for their change in angle.
Anyway, I tried it for the first time last night with camera only, aimed at Orion. That was after a bit of bodging work to mount it on my windowsill rather than using the very decent, heavy duty tripod (no pic of the windowsill mount I’m afraid, but it worked!)
After a few practice shots at 200mm, I found I was able to get decent sharp 60sec exposures with little or no star trailing – that’s an immediate improvement on the Nano, which I can’t really push beyond 15secs at 200m. I tried at 2mins, but got some trails.
So I decided to play safe and set it for 45secs with the lens at 140mm to get a ‘wide’ but portrait shot of the Orion and its Nebulae.
At these settings, the rotation wasn’t an issue – the first and last frame were slightly differently composed, but the stacking software, Deep Sky Tracker rotates images to align the stars anyway.
I ended up with 140x45secs (105mins) and set DSS to work overnight.
The resulting stacked image looked really sharp with nice round stars, but unfortunately once I started processing, the bright stars had massive blue haloes – I checked through the frames in Lightroom and there had been some really cloudy periods. So, I did a bit of whittling down and ended up with about 50 reasonably cloudless images that I stacked.
I’m fairly pleased with the result with so few frames – the Orion Nebula (bottom right) was really clear, as was the Running Man just above it. The Fire Nebula came through OK, but I had to do more processing than usual to bring out the Horsehead, so the final image is a bit over-processed.
So all in all, the mount is a success. I’m able to set exposure at three (or even four) times what I could achieve with the Nano and it’s a really heavy duty bit of kit that doesn’t have a problem with a big old lens on my DSLR. It’s also great fun watching it slew round to your target!!
Next test is to do a shoot with the camera on the telescope.
With a low-in-the-sky object like Orion there is no problem with ‘rotation trails’ at 45 – 60secs. However, it might be more of a problem with objects higher in the sky (such as Andromeda currently) as the ‘circle’ of their rotation is much smaller. I’ll just have to give it a go to see.
This isn’t the ultimate mount – ideally I’d like a GoTo Equatorial (rotating) mount that can handle plenty of weight, but for now that’s out of my budget. I think it will do nicely for now though.
The Nano was a great little introduction and can certainly be pushed beyond its recommended limits. I’ll probably sell it on in due course, but I haven’t tried a panning timelapse yet (not Astro) so will wait until I have. I’m not sure if the AZ mount would be OK for that. It doesn’t have a high tracking speed like the Nano, which can go to 50x normal.
