After struggling with the image scale of Jupiter, the double transit and the ordinary seeing, I decided to hunt down a few doubles listed in Hartung’s 2nd Edition. This time, I plugged in the Vixen x2 Barlow and crossed my fingers.
The stack sizes varied from 8 to 26 frames from AVI’s of 1200 frames, an indication of the poor seeing. The colours have been pumped a little, by increasing the saturation in Photoshop. Where the magnitude variation between the companions made the fainter companion(s) almost invisible in the raw image, I used "Curves" in PS to brighten the fainter star(s), altering their brightness relationship.
The post processing in Registax and PS CS3 has really turned a sow’s ear into (almost) a silk purse.
I haven’t done a side by side comparison between the DMK and the DBK, so I’m going on memory and impressions here.
In terms of sensitivity, I reckon the DMK is more sensitive than the DBK and this does make sense if the each DBK pixel is only receiving either x1 Red, x1 Blue or x2 Green photons, whereas each DMK pixel collects everything that falls on it. I presume the pixels only record the energy that falls on them, and are ignorant of the wavelength, so the RGB filters of the DBK would block some of the signal?
I also seem to recollect that RobT wrote that the DMK + Filters was closer to performance to the ToUcam 9000 than the 840K? The DBK, like the DMK, does not have a built in IR blocking filter, whereas the DFK does.
That’s about the extent of my knowledge so far, but I’ll try to run some tests to see if I can compare the two.
The DBK was purchased purely to give me a “ToUcam on steroids” for targets such as colourful double stars and colour images that do not require the full resolution and better sensitivity of the DMK.
I’m also learning Photoshop CS3 and boy, is there a lot to learn but gee, isn’t it a fabulous application. I’m trying to learn how to make templates so I can slide images in behind them as Layers without having to manually construct the same things every time. Never a dull moment in our lives eh?
Cheers
Dennis
EDIT:
I just read your post correctly re DBK and DFK. The difference is the DFK has a built in IR filter which is optimised for terrestrial stuff, so the DBK without a built in IR filter is the preferred model as the user can fit one more suited to astronomy.
Last edited by Dennis; 18-06-2007 at 09:42 PM.
Reason: Just read the post correctly and answered the right question!!!
Thanks Dennis. The DBK looks like a good option for quick and easy colour imaging with teh extra sensitivity of the chip, lower noise and faster framerate.
As you pointed out you're losing some resolution and sensitivity over the DMK, but for what you're using it for I think it's great!
