Quote:
Originally Posted by alistairsam
Hi Rodney,
All one shot colour cameras including the Meade DSI, Canon, Nikon, even webcams, colour autoguiders, planetary cams etc have a bayer matrix and will not benefit from LRGB filters.
That's how they produce colour images. by exposing 3 filters at the same time and combining them in the camera's hardware/software (generally speaking).
enabling mono mode in the canon or any colour camera will not help as the mono is a "pseudo mono" built from the RGB data that the camera has captured.
reason is that you cannot force blue light through the Bayer's R filter so blue will still fall only on blue pixels.
you can create a synthetic luminance by combining your RGB data and using that as "L", but doesn't make too much of a difference.
your best bet, get your coma corrector spacing correct, use the LP filter at the end of the coma corrector and you'll be fine. you've got all the other bits.
you have a good FOV, so don't waste that by cropping it without a coma corrector.
the choices are - Baader MPCC mark3, Baader RCC1, Televue Paracorr apart from others. all have different spacing requirements so remember the 45mm for your camera, then add the depth of all the bits you add in front of it.
As suggested, save the money on the filter wheel and filters till you get a mono ccd. you can easily drift align with the dsi as is without filters.
The 10inch F4 is a powerful scope and you should get very good results with the dslr if you capture darks, keep exposure below 6 to 8 mins (depending on ambient temperate), iso 800, capture flats even sky flats.
Cheers
Alistair
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Thanks Again Alistair,
I am a bit concerned you mentioned to keep the exposure below 8 minutes as my main interest is Galaxies and I found with the Meade DSI, which seems to be more sensitive than the Canon but lower resolution, I achieved excellent results at 10 minute exposure and with the a Light pollution Filter I generally used a 15 minute exposure with no problems????
Does the canon have problems at longer exposures, I did do one test at 10 minutes ISO 100, even thought the histogram was pushed further to the right it was comparable to what my Meade achieved and looks like it was a reasonable setting but I have not had any clear skies to fully test it out with a 10 minute exposure???
I have been creating a large dark library with Maxim DL for use and noticed with one exposure that I did have a dark for it shifted the histogram quite a bit to the left after subtraction.
Cheers
Rod