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Showing results for tags 'tair3s'.
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Yesterday evening was clear and I just bought a Canon 300 F4 L sh a week ago. Didn't want to take out all the heavy mount, power supplies, camera, etc. and it would even have been impossible perhaps to set it up in time. So I took the EQ5 with RA tracking (powered from an USB power bank), the lens and the Canon 550D. Went somewhere outside, the galaxy was just visible, but much, much better than city lights. Had a look before at Venus and at Orion's nebula with the 100 F5 achro then I put the camera. I also recently bought a polar scope for the EQ5 and it was the first time when I aligned a/the mount using the polar scope. The circles were much darker than I would have expected. I tested then the tracking with 30s exposures and it seemed to track without trailings, but I was a little afraid so I set the exposures to 20s. I don't have an intervalometer so I couldn't even try longer than 30s with just the camera. I made a manual trigger though so I could fire it up with the camera set on continuous shooting. During the night tracking seemed to stay on spot, I had to refocus once. It was pretty cold, about 5C maybe and I stayed inside the car. So I took more than 200 exposures of 20s at ISO1600 and aperture wide open at F/4. I used about 220 of them. I also took about 60 5s exposures to use for the stars. I'm pretty impressed by the lens' resolution, though I suspect that stopping it down it could help even more. For comparison, I'll attach another try from early October, but taken with 2 Tair 3s lenses stopped down at F/5.6, put on a Canon 550D and a Canon 450D. If I remember well, I exposed then almost half an hour before the batteries went flat. So the total light acquired yesterday was more than double. But the sky was not as good. I also added about 2 hours of noisy Ha to the image, taken from the city with the ASI 1600 MMC also with the Tair 3s and Optolong 7nm Ha filter. I don't think I can make it look much better. Enough writing so here are the images. The colour ones with many spikes are the old ones taken with the Tair lenses. Clear skies, Alex
While waiting and calibrating the setup for the Heart and Soul, I decided to shoot ~15 minutes each RGB in 30s subs for the double cluster. I managed less on the B, but I still stacked and processed them. 15 min on R and G, 7.5 on B. ASI 1600, Tair 3s wide open. Unity gain, ~ -15C. Clear skies!