Galileo's Camera

I've been using a Celestron NexStar4SE for about five years now and have tried photographing various types of sky objects. The best photos I have so far have been of planets. My rig for these have been the following: Celestron NexStar 4SE Canon 550D unmodded Celestron 93635-A T-Adapter for NexStar 4GT Celestron T-ring for Canon EOS camera Samyang 2x teleconverter Along with these and shooting on 640x480 movie crop mode on the camera, you can get pretty decently sized photos of the plantes such as the following. Saturn through Nexstar 4SE, Canon 550D via Samyang 2x converter and 640x480 movie crop mode shooting. However I always had doubts about the optics of the Samyang 2x converter. It was built to go with the Samyang 500mm mirror lens and wasn't exactly built for the purpose of astrophotography. My choice of replacement was the Celestron 2x Barlow. The Celestron 2x Barlow however comes with its own set of new requirements. While the Samyang 2x converter could ...

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 :)

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....

About a month or so back I realised that there is another problem with the 4SE, it wouldn't power up. Firstly I thought this was due to a battery drain, and that's the first thing I tried. While it worked once, after about half an hour of sky watching it stopped working again. It is quite improbable for a new set of batteries to drain that fast. After hooking up with a 12V 2A power supply, it still did not power up. This could mean two things: the power doesn't get to the circuitry or the circuitry it self is busted. After playing around a bit with a multimeter, the fault turns out to be... again on the switch . I think it is fair to assume that the part that has most physical/mechanical movement will be the first to fail. It is true that the electronics could fail, but I guess it is better to start from the switches. For the moment, I have bypassed the switch, and all is well (well except for the weather...)

Few days back, when I was trying to do some random stellar observations, I realised that the 4SE wasn't aligning properly and the goto function was off a little more than you'd expect. Given that weather wasn't on my side, I decided to let it go for the moment. I finally made a one star alignment and was trying to get the Sync function to work (the Sync function, when activated, would track the current position it is pointed to by auto adjusting to compensate for the stellar movement). The first worrying point when the controller returned an error that said "Offset too large, Sync failed". Yesterday, while I was trying the same, I was trying to align the telescope using the Two Star Alignment mode. After trying to align using two reasonably nearby stars (Alpha Centuri and Hadar and repeating with Alpha Centuri and Acrux), the controller was returning an error that said "Align failed". This was even more worrying. It is only slightly later that I rea...

During a failed attempt to observe and photograph the Camelopardalids meteor shower, I found out that the finderscope of the 4SE was not working. If you have not done this, try doing it, it is ridiculously hard to successfully aim the telescope at anything if your finderscope is not working. After testing with multiple batteries, my immediate worry was that the LED in the finderscope may have burnt out. If this was the case it would be quite hard to fix it. That's when I decided to dismantle the finderscope to pinpoint what exactly went wrong. Removing the finderscope from the telescope is quite easy. You need to unscrew the two bolts on the side of the finderscope, just under the switch and the calibration screws. Once done, you need to remove the unscrew the calibration screws themselves. You need to hold the calibration screw with one hand and unscrew the bolt. The calibration screw will otherwise turn along with the bolt. And this is what the inside look...

About a week back, the NexStar 4SE that I ordered arrived. I've been quite eager to test it out in the field but however so far been unsuccessful due to bad weather. But the first impressions so far have been good. Here's a short review on the 4SE compared to the 114EQ. Out of the box: Everything was neatly packed in one single box. Assembling the telescope was very easy, the entire set was only four pieces or so. There is no way you could get it wrong. The batteries for the controller of the telescope are not included (8 AA batteries). The battery for the spotting scope (CR2032) was included, but had already drained. Tripod Assembly: The tripod mount of the 4SE is made out of steel. This is not a major change from the tripod of the 114EQ, but does differ in one aspect. The feet/base of the tripod of the 4SE consists of rubber bushes instead of the plastic base of 114EQ. This somewhat absorbs vibrations and would allow a better photographic experience. The plastic moun...