> Milky Way in different filters
This is a comparison of my not modified Pentax k5 DSLR and the same, but modified one without IR-cut filter.
Removing the IR-cut filter not only increase sensitivity by 1-2 stops, but also slightly increase the resolution as the IR light (despite not being that much detailed) pass trough the byer RGB mask without filtering.
Below we can see a shot with UHC-s filter as well, witch give us best contrast and brightness of the H-alpha objects as Lagoon nebula (M8). Thus it needs the longest exposure 120s against 60-90s for the other filters. You can see the beautiful Galactic horse dark nebula on the shots :)
While cleaning up my PC I found sequences of shots of Virgo galaxy cluster taken during springs of the last 2 years. Those were attempts to shot this object, but I was not satisfied with the result and left them.
I recently bought a pocket spectroscope for laboratory use. You can find it at Ali for 5$. It is with glass prism and well build. So I did some test to use with a telescope but did not
http://www.deepskywatch.com/deep-sky-hunter-atlas.html This is an amazing resource. Detailed atlas of all the sky with NGC and IC objects.
Reading a new product that claims to be 100x time more powerful then conventional telescope, I realise that this is just an astrograph with a digital camera that is doing stacked images and show them trought eyepiece or App.
I am so impressed with the K5 ability to quickly gather signal from nebulas (Quantum efficiency) and galaxies, so I decide to take one more K5 and to remove the IR-cut Filter of the old one.
