> STACKED IMAGE VS. LONG EXPOSURE
Witch is better. Stack or long exposure? It depends…
Long exposure will reveal more details but stack will improve the contrast and faint details by decreasing the background noise. It also decrees the atmosphere turbulence winch as the noise has a random distribution (of course this is more obvious for short exposures)
Long exposure is also hard to shoot as you need guider setup. Also at my place there is a lot of wind, so this is a hard thing to do. Best is to estimate the limited exposure of the sky background and do a stack with that exposure. To estimate it look at the histogram the peak should be 1/3 away from the left.
Below is a comparison of Galaxy M33 between long shot – 80 seconds at ISO 51200 and stack of 20 frames by 30 sec. at ISO 12800.
The single frame is easier to process but stacked frame give us more signal to noise ratio. We can always add more and more signal by taking extra frames. You can use higher ISO and reduce the noise that way.
SKY is the limit :)
One shot:
Stack:
To check the polar alignment of your telescope look trough the polar scope. When turning the Ra axis the polar star should move in the exact circle in the eyepiece without any deviation.
Removing the DSLR build in IR-cut filter will give you at least 50% more sensitivity for hydrogen alpha emissions of the nebulas. Also the camera will be more light sensitive at dark allowing you to shoot more faint objects.
We can check what is like to process day shot with similar to astrophotography techniques. It is cloudy in Bulgaria for the next week or so and I took shots of the nearby mountain trough the fog with 200mm lens.
Most of the modern LED backlight screens including Laptops, TV and smart phones use PAM technique for Pulse-amplitude modulation. This means that they switch on and off state very rapidly.
Having a video background gives you a lot of expression and dynamics to your site.
There a few ways to put your video as a background of your page layout.