|
Hi Mike,
I use my observatory mounted scope, a 16" F4.5 newt on a very heavy German Eq mount designed and built by me. The scope is highly modified. The primary mirror cell and secondary mirror mount are designed and built by me. The primary mirror cell is 27 point made from 25mm by 25mm squ tubing with 3mm wall, all fully welded. The cell is triangulated, very rigid allowing excellent air flow to the back of the primary. I have a cooling fan forcing air over the back of the mirror. This air flow makes a considerable difference to the quality of the live feed from the CCD at high magnifications.
The focuser is a JMI motofocus and the CCD is a DMK 21AU04.AS. I use an Orion 5 position manual filter wheel loaded with Astronomic LRGB filters.
The scope drive is dual axis by Peter Mellander from Anssen Technologies with remote drive corrector.
I am now up to about 150 avi's of the storms and really by trial and error have arrived at settings that work best on my system for the results that I an trying to deliver for Georg.
I use the DMK provided IC capture. If I am using monochrome I go with Brightness at 50 Gain at 600 Gama at 160, Exposure of 1/30, Frame rate 30/sec which gives me a Histogram at 200.
When I RGB for the R and G avi's I have the Brightness at 50, Gain at 760, Gama at 180, Exposure 1/23, Frame rate 30/sec which gives a Histogram of 150. For the B channel I use the same settings but change the exposure to 1/15 to bring the Histogram back up to a similar position to what it was for the R & G channels.
If I am imaging in monochrome I capture 1000 to 1200 frames if I am capturing RGB's I capture about 600 frames for each channel.
I initially stack and process in RegiStax 4 and generally stack half of the frames from each channel that normally results in about 95% quality of the tagged frame.
For the purpose of revealing any storm structure I use the wavelet processing in RegiStax much more heavily than I would to make a nice picture, typically slider1 set to 40, Slider 2 to 20, slider 3 to 10 and so on.
I then load my images into Astra Image 3.0 Pro. I have found that for grey scale images the maximum entropy deconvolution filter works well. It does nothing for the esthetic's of the image but if there is very small structure it does reveal it.
For my RGB avi's I use the LR deconvolution filter generally 4 iterations at a level of 1 for each individual channel before they are merged.
I love how accurately Astra Image 3.0 Pro allows me to merge the RGB channels.
This RGB imaging is all new to me, all of my deep sky imaging over the years has been on 35mm film hand guided. Over the last few years I have done a fair bit of imaging with a ToUcam. I would love to become more competent with my RGB imaging, the more of it I do the better the results I am getting, still not a patch on some of your work I have seen since being on Iceinspace. I am very isolated out here and there is no one else in my region doing this, it would be great to have someone else to bounce ideas off.
Regards
Trevor
|