Woke up to chilly, clear skies & had a go with Saturn and the DBK, this time employing a new 2.5x barlow from GSO that I picked up recently to try and push things to f/30-ish. To my amazement the new barlow is producing *only* f/22 as measured using the following formula:

F = 206.265 x Object size in pixels x CCD pixel size in microns
                        Object size in arc-seconds

So it turns out that with the DBK + 2.5xGSO barlow I get Saturn to appear approximately 80 pixels in diameter, which combined with the DBK's 5.6 micron sensor and Saturn's 17.7" diameter gives out: 5220mm. Dividing 235mm of primary mirror into that, I get f/22.2. Comparing this data with my January 14th images of Saturn which were done using the 2x Ultima + DBK, I get as-near-as-makes-no-difference, 79 pixels width for Saturn & 17.5" which gives f/22.1!

I guess the fact that my focuser has about 20mm of travel does play a role on just how big the targets will appear on the chip and maybe, the 2.5x isn't exactly 2.5x but a little less. I have to measure exactly what the effective f/ of the 9,25 is at 0 extra travel all the way to 20 and take measurements with both barlows to come to a conclusion on what is the exact f/ I'm using.

As for Saturn, here's a view under good but not great seeing. There's more coming.

Had another chance to test the DBK camera. Conditions started out unfavorable but a small window of slightly improved appeared just before cirrus clouds blocked the planet! I experimented with a variety of exposure settings as well as capture codecs. This is a rough shot from a 4800 frame stack taken at 30fps and very high gain. Saturn is unpleasantly dim at f/24 for my telescope and I worry that f/30 might just be undoable!

With Saturn, it's a whole new game! Not to mention the hardware/software changes!
There's potential, which is always a good thing!

Well, the skies finally cleared and I was able to test my new DBK21 camera! Got up at 02:00 UT and opened up the C9,25 which was cooling outside at 7c. The difference from the SPC900 is tremendous in terms of noise, sensitivity, versatility and speed! Here are the first results!

- First try on Saturn with the tail end of the storm visible. The seeing was horrific but I just had to try out the DBK & catch this phenomenal storm!

- Mercury added! Very low and with a lot of atmospheric dispersion! Stacked the best 500 out of 3000 frames.