rosette_ap155edf_f7_pl39km_fli_rsrch_hao3_50x15min_xga

Comment

Comment by Derek Baker on June 21, 2011 at 10:11pm

Hi Richard.

Many thanks for your reply and clear explanation! Of course, your superb images are "proof in the pudding" ....with 20+ hours of exposure time you have gotten some spectacular images!

BTW, have you heard of anyone trying the new "true-sense" detectors like the 8050 mono and the big 40000 colour chip, or kodak's recent 31600 colour and monster 50100 chips? I am really curious re: the results the early adopters are getting with them.

regards

Derek

Comment by Richard Crisp on June 21, 2011 at 2:22pm

The QE for the mono is about 20%. all that ends up meaning is that you need to spend more time taking exposures to reach a particular SNR

As for dark signal; it is no worse than the KAF3200.

Read noise is similar as well. Keep in mind that this is a dual readout chip: has two output amplifiers and two completely seperate A/D conversion systems in the camera. Each is running at 7MHz so this is a real screamer compared to the average astrocam that runs the a/d system at 100KHz to 500KHz.... The combined rate is 14MHz so it can readout and download the image in less than 5 seconds if your computer is fast enough

running things like FocusMax is interesting: it takes it a very long time to figure out which star in that HUGE FOV is a good one for focusing....

Comment by Derek Baker on June 21, 2011 at 12:34pm

Richard. I would love to hear your review of the 39000 chip as an astro-imaging detector. From what I recall, the QE and full-well capacities are not super-impressive, versus the 31600 or Kodak True-sense 40000 (although they are OSC's only, I believe) How does is perform in terms of thermal noise and read noise?

Comment by Richard Crisp on May 10, 2011 at 10:24am

well there was a photo of the three mounts etc in action....

Comment by Charles Dunlop on May 10, 2011 at 9:57am

That's a cool powerpoint. Makes the case for your filter combinations.

Comment by Richard Crisp on May 10, 2011 at 9:42am

yes, last summer I was able to run all three on a given evening. I was using a very old (rev 1.0) CCDAP but I am now switching to ACP

All I did with CCDAP was have it dither and then park when complete. I did not focus or change filters, only dither and park.


here's a link to an invited talk I gave in March at "Image Sensors Europe" in London. That is an annual conference of imaging professionals, primarily from the sensor supply business. Kodak, E2V, Omnivision etc all attend. I'm an IC guy, been in the semiconductor biz as a design engineer/technologist for nearly 35 years.

http://www.narrowbandimaging.com/incoming/Image_sensors_europe2011_...

Comment by Charles Dunlop on May 10, 2011 at 9:32am

Impressive. You run all three mounts on a given evening? You using CCDautopilot to run your setups?

Comment by Richard Crisp on May 10, 2011 at 9:24am

Yes I use an ST7E as my guider. I have three of them and three AP1200GTO mounts in my arsenal..... Have the PL39000M and the PL3200ME and the ML8300 and ML4022 for imaging....

Use the AP155EDF f/7 and AP180EDT f/9 as well as an FSQ106 and my 18" f/12.6 home built classical cassegrain. I also have a wide assortment of Pentax 6x7 lenses I use for widefield such as that Rho Oh and NGC7K

i've been at this for more than 10 years so it has taken time to accumulate all this gear.

Comment by Charles Dunlop on May 10, 2011 at 9:06am

oh wow, clicked to your site. You use an ST7 as a guider? Man you got some awesome toys! That's a crazy primary CCD, so much data.

Comment by Richard Crisp on May 10, 2011 at 9:04am

thanks Charles

that's a single aiming of a HUGE sensor: 39 million pixels, 36.8 x 49mm 6.8 micron pixels.... used at 1085mm focal length....

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