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Showing posts from 2016

Venus - Again

Facebook reminded me that almost three years ago I posted a crescent Venus. Coincidentally (or may be not so much, given the climate and periodicity of Venus as evening star), I had another shot of Venus compiled last week. And here we go: Venus - NexStar 4SE, Canon 550D in 640x320 crop mode and Celestron 2x barlow. While going through my shots, I realised that I have an interesting ensemble of Venus photos over 3 years: 6 Dec 2013 26 Jan 2014 25th Nov 2015 6th Dec 2016 Obviously the images aren't to scale. The 2014 image is a 2x enlargement after 2x barlow and 640x320 crop while the 2015 one is very likely to be shot without a barlow. Regardless, I am quite happy to stumble across these as it shows a clear phase change of Venus around the same time of the year. In 2013, it starts off with a crescent phase with 205 moving in to a half full. In 2016, it is in a waxing gibbous state. In 1610s, Galileo was the first in recorded history to observe that Venus...

Orion Nebula - A second go

Owing to somewhat kinder weather, managed to have a small window two days ago for some astrophotography.Luckily for me, Orion becomes a good target straight from my balcony. M42, or the Orion Nebula is the first nebula that I tried to shoot. My first attempt was very unsuccessful and all I managed to get was a light patch that showed where the nebula was. This time I was determined to get something better. However, instead of using the 4SE for imaging, this time I decided to use the 100-400mm Canon lens while using the 4SE as a tracking mount. The results I should say are better than I expected. But I still have a long way to go. 22 light frames x 2-5sec + 10 dark; Canon 550D on 400mm telephoto lens   So far I have identified several problems with my astrophotography: 1. Unpreparedness Most of my astrophotography sessions are spontaneous. I am never prepared for those and don't have everything set up and calibrated. 2. Not the best equipment and  not using th...

What's in a stacking?

My last attempt at photographing Saturn was posted on an FB group and one of the members quickly pointed out that me shooting at a high ISO shouldn't necessarily give that bad of an image. After experimenting with a few different stackings, I got some interesting results. 100 frames In my previous attempt (pictured above), I stacked only 100 frames of a total of nearly 5000 frames. The reason that I didn't stack more is because I was worried that it'd average out too much that the finer details such as the Cassini Divide will not appear. It seems like what happened was exactly that; if you stacked a higher number of frames, the stacking process will cause the grains to somewhat be smoothed out. Today evening I spent experimenting with different stacking sizes to see what the results would turn out to be. 10 frames 50 frames 100 frames 200 frames 1000 frames 2000 frames 4500 frames As the number of frames stacked increase, the graininess ...

Saturn - a few days after the opposition

The Saturn opposition took place on 3rd June 2016 and was incidentally having a close approach with Earth. Tried my luck a few days after and it didn't turn up too bad. Saturn - 6th June 2016. 4SE and Canon 550D with 2x Barlow (Samyang). A stack of 150 frames on 640x480 crop mode. An opposition does not always mean that the planet is closest to Earth. However in this case it seems to have been so. I probably need to touch up that image a lot more and probably would end up with a clear demarcation of the Cassini Divide. But for now, this'd have to do :)

Mars - few days after the closest approach

On 30th May 2016, Mars had a close approach to Earth (being only 46.8million miles from Earth). The photo below was taken few days after. Mars - 04th June 2016. Nexstar 4SE, Canon 550D with 2x barlow (Samyang mirror lens accessory) The photo is a result of stacking 25 frames of a avi made in 640x480 60fps movie crop mode. Since the image was a little small, I enlarged it 2x via Registax. The image was further enhanced with wavelet processing and for brightness and saturation. One of the questions I had when I heard about this close approach to Earth, was that whether it really makes a difference. In short, it does. Here's a comparison of a shot I took in 2014 Jan 26 with the same set of equipment. Mars - 26th Jan 2014 Mars - 04th June 2016 NASA has a page http://mars.nasa.gov/allaboutmars/nightsky/mars-close-approach/ that outlines some facts about the closest approach. One of the most interesting facts I found there was the change in the apparent size of Mars....