Keyboard Shortcuts
Likes
- C14EdgeHD
- Messages
Search
|
Re: Remote Focuser for C14
开云体育Thanks Donald,I’ve heard of ASCOM and FocusMax. ?Are they PC/Windows only or do they also run on Linux? Rick
|
||||||||||||||||||||
|
Re: Digest Number 3526
开云体育I’m debating whether I should look at one star, using FWHM or Half Flux Diameter or a similar measure, or whether there is a way to have the software look at a larger subset of the whole image. ?If I use a Raspberry Pi I don’t have a whole lot of processor power. ?It will be a good software challenge for me. ?Wavelet analysis might be faster than FFT and give good results. ?Wolfram and Mathematica are installed on the Pi. ?Jpeg file size is another possibility, as it might measure how much entropy is in the image.Rick
|
||||||||||||||||||||
|
Re: Digest Number 3526
开云体育Rick,? ?Maybe you could look for spatial frequencies, e.g. do a spatial Fourier transform and find a spatial frequency peak that corresponds to stars. That would be pretty processor intensive. JPEG files are already encoded as Discrete Cosine Transform. You may be able to get spatial frequencies by examining the file. (Possibly helpful article here: <>) The JPEG will only give you spatial frequencies over 8x8 pixel blocks but that may be sufficient. -Charlie Lasnier On Sep 7, 2015, at 2:16 AM, C14_EdgeHD@... wrote:
|
||||||||||||||||||||
|
Re: Digest Number 3526
开云体育I’ve started a page on my website at?Not very complete yet, but keep checking back. ?I’ll put the mechanical, electrical, and software there over time. Thanks for your interest! Rick
|
||||||||||||||||||||
|
Remote Focuser for C14
开云体育A while ago I got a HyperStar for my C14, which converts it to f/2 using the primary mirror and some optics. ?It replaces the secondary mirror. ?I use it with my Nikon D600 SLR with great results.I needed a way to focus while looking at the camera, but all the motorized focusers I could find were way out of my budget, so I decided to design my own. ?It uses an Arduino to control everything, running software I wrote. ?A stepper motor drives the focus knob, and I have a hand controller with a rotary knob and display. ?The Arduino is in its own box attached to the pier, so that motion of the telescope doesn’t drag the hand controller around. ?I designed the plastic parts and had them 3D printed, the rest of the parts came from Adafruit. If anyone is interested, I’d be happy to share the design. Now the question is, how to determine when the focus is optimal. ?I can drive the Nikon using gphoto on a raspberry pi (I’d rather not take a laptop out to the telescope but if I have to, I will use a MacBook). ?With that software I can capture jpg or nef files onto the raspberry pi. ?Can anyone suggest software that can read a jpg and either do fwhm or some other measure of sharpness? ?I’d really like it to report sharpness of the whole photo as a single number. Rick |
||||||||||||||||||||
|
Re: NGC 6188 Nebula
开云体育Wonderful detail Dale!
?
Clear
skies,
Kevin Dixon ? From: mailto:C14_EdgeHD@...
Sent: Saturday, September 5, 2015 4:34 AM
To: C14_EdgeHD@...
Subject: [C14_EdgeHD] NGC 6188 Nebula ?
?
Despite not thinking it worth processing after stacking, it surprised me with the detail.
Dale |
||||||||||||||||||||
|
Re: M16 with C-14
Very impressive. I visited the website
This looks like more than just a C14 and a CCD camera. It looks like the image also put an image intensifying camera in the imaging train in front of the CCD camera. The system?relies on?very short exposures and long focal length or narrowband imaging where you can get a photo flux low enough to fit within a range where the image intensifying camera works in an individual photon counting domain. One strong benefit to this approach is that the individual exposures are short like we do for planetary imaging. Therefore, you can capture at the resolution of the telescope with minimal atmospheric blurring by selecting good frames. 5.5 hours of imaging adds up to high SNR and high resolution. I have a few questions. 1. What focal length did you use for the image of M16? 2. How can you register individual frames with an SNR like the single frame shown for M57? The edges don't look?adequately defined. 3. How would a series of 5 second CCD?exposures (selected and?averaged for 5.5 hours) look compared with the intensified system at exposures of 200 ms. I ask because the SNR of a CCD looks as good as the intensified system when using exposures about?10 times longer than the photon counting exposure length. 4. I sense a possible product here.?Are you planning to produce systems for sale? Andrew? |
||||||||||||||||||||
|
Re: M16 with C-14
maybe the best M16 I have seen. -- benoit On Sun, Aug 30, 2015 at 5:53 PM, Thomas Ashcraft ashcraft@... [C14_EdgeHD] <C14_EdgeHD@...> wrote:
|
||||||||||||||||||||
|
Re: M16 with C-14
toggle quoted message
Show quoted text
|
||||||||||||||||||||
|
Re: focus inside tube
Not sure if the C14_Edge is the same as the old C14 that used a sliding tube moving mirror focuser with a single lead screw on one lobe of a three lobed bracket for focus position. It appears that the Edge uses the same sliding tube ?moving mirror focuser with the addition of mirror locks on the two other lobes that have to be locked each time focused to prevent mirror flop. ?I believe this makes it impossible to have autofocus without mirror flop using the moving mirror focuser. Not good in Hyperstar mode which is only focused using the moving mirror focuser. The original C10 used a three lead screw arrangement for focusing. ?I have a Max Bray Mak-Cass that used the left over C10 10" primaries which were blanchard ground down to 9.5" after production stopped on the C10.
---In C14_EdgeHD@..., <garyjarrette@...> wrote : I hate to show my ignorance but I am not sure what you are referring to when you say "come to focus inside the tube". As far as the two knobs goes though if it is an Edge then the two knobs are mirror locks.? You would loosen them,? focus,? then snuggle them up again.? This must be done every time you focus if you are using g the stock screw focuser. Gary Carpe Noctem Sent From My Spaceship via Nexus 5 |
||||||||||||||||||||
|
Re: M16 with C-14
开云体育Thanks for the feed back.
Very interesting :-) Christian Le 16/08/2015 16:37, stan_ccd@... [C14_EdgeHD] a écrit?:
|
||||||||||||||||||||
|
Re: M16 with C-14
开云体育Wonderful resolution Stan !
I was wondering if you had tries the new ASI224 camera ? It is doing wonder for Uranus and Neptune imaging. The read noise of the IMX224 sensor is only 1 e-, which is equivalent to EMCCD camera. Best regards Christian Le 15/08/2015 21:28, stan_ccd@... [C14_EdgeHD] a écrit?:
|
||||||||||||||||||||
|
Re: Images of the moon taken on August 7 with the C14 (part 1)
开云体育Thanks Stan,
Usually, I cool down the optical tube with the two attached fans : This time that was not necessary, there was no difference between the mirror temperature and the ambient temperature. I used an ADC (Atmospheric Dispersion Corrector) because at the beginning of the session the moon was rather low (about 35°). So even the red filter, I had to correct for atmospheric dispersion. Of course, I tested and tuned a little bit the collimation. Best regards Christian Le 15/08/2015 21:54, stan_ccd@... [C14_EdgeHD] a écrit?:
|
||||||||||||||||||||
|
Re: Images of the moon taken on August 7 with the C14 (part 1)
toggle quoted message
Show quoted text
|
||||||||||||||||||||
