• Posted on: 14 February 2019
  • By: tihomiry

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:


This is a comparison of my not modified Pentax k5 DSLR and the same, but modified one without IR-cut filter.

Astrotracer is a great way to take advantage of the Pentax DSLR camera in-body shake reduction mechanism. It is available since Pentax k5 and track celestial bodies by moving the sensor. Here is what is it ablout:

Staying at my home inspires me to make some documentation of my experience. I got a dedicated drive for my astrophotos and start reorganize them by objects. Here is an article of the most recent process I use on my photos. Enjoy: )

For a few months from now Betelgeuse (Alpha Orion) dim so much, that it looks as bright as the stars in the Orion belt. This is not so disturbing and does not mean that cataclysmic events are happening with it.

For my last trip to the Rodopa mountain I decided to cross the limits and to target an object that is hard to believe that a non-professional equipment could catch.