North American Nebula: 9-7-2012 Pak Tam Chung

I went o Pak Tam Chung (北潭涌) this Monday and captured the North American Nebula. To me it is just a practice & I used two flatteners to image the North American Nebula, namely WO FLT (zero power) & the APM Riccardi Super ED reducer (0.75X). After finished the imaging with Riccardi reducer, clouds covered!!! I only got one frame of North American Nebula with the FLT flattener. So I just post the resized raw image.

For the combo of APM-TMB 105/650 & APM Riccardi Super ED 0.75X reducer

APM-TMB 105/650, APM Riccardi Super ED reducer, P2, HEQ5Pro, LVI II, 5DII (Astrodon Modified)

ISO 1600, 16 x @2mins, Dark Frame, Flat Field

DSS, PS

For the combo of APM-TMB 105/650, WO FLT flattener

APM-TMB 105/650, WO FLT flattener, P2, HEQ5Pro, LVI II, 5DII (Astrodon Modified)

Since I only got 1 frame, so just resized unprocessed photo

APM-TMB 105/650, Riccardi 0.75X

APM-TMB 105/650, FLT, resized unprocessed raw

6-6-2012 Venus Transit

After the disappointing annular eclipse in Hong Kong, finally we got a successful Venus transit in 6-6-2012! I led my students to the observation site, somewhere between Clear Water Bay (清水灣) and Po Toi O (布袋澳) at about 4:30am in the morning. We setup the equipment quick and waited the sunrise. As the transit would start short after the sunrise, we got limited time to get focusing and exposure setting ready.

As expected the angle of elevation was low, clouds ran around and the images on the notebook screen were very dim. We were anxious about couldn’t catch the important moment, the first contact. Luckily, we just made it before the transit! The imaging was successful, although some images were affected by the sky condition.

        In the past 3 weeks, I tried my best to rectify the images in terms of details, color tune and brightness. The most difficult part was the beginning of the Venus transit. It was because of the clouds. The alignment point of Registax just failed in tracking. I needed to reject those bad frames manually and tried to use different alignment points in order to get the best possible results. Anyway, I finally created this 150M pixels image! (10,000x15,000 = 150,000,000 pixels) See you 105 years later!

M45 Pleiades: A trial shot

This M45, Pleiades (七姊妹星團) was taken with an APM-TMB 105/650 with WO’s FLT flattener in 24-11-2011 at Pak Tam Chung, Hong Kong. I didn’t optimize the back focus for the flattener in present of P2 filter. The performance was good. I need to wait for clear skies to do the optimization, but the sky in HK is always disappointing. Maybe I need to use artificial star to do the optimization. Although the distance is not infinity, it gives an approximated back focus adjustment. This can save me some time during field test.

APM-TMB 105/650, FLT, P2, Canon 5DII, HEQ5Pro

ISO 1600, 5 mins x 10

DSS, PS4, cropped