Paramount MX AG Optical 12.5 IDK Apogee Alta 16803 AstroDon Series 2 E LRGB AstroDon Ha 5nm SII 5nm OIII 3nm SBig Sti ACP observatory control, ACP Scheduler PixInsight, Maxim DL 5, My Images http://www.remarkableheavens.com/
Quote: Your shorter subs will show far less detail resolution and contrast no matter how many you take. That is the point of Jimmy's experiment. Even with far less total imaging time the amount of faint data he was able to obtain is clearly visible. Secondly, with narrowband, you are never going to reach the sky limit from what Don Goldman has told me. There are bright objects that will get blown out by longer subs such as M 42, but if you stick to short subs, you'll miss this wonderful detail that exists elsewhere. Adam Block has a great tutorial on how to combine short and long subs in CCDStack using missing value to combine. Tony Hallas demonstrates another great procedure in his newest addition to Photoshop processing in Vol 5 using the reveal all layer mask in CS5 and CS6. Jimmy used the Hallas method in his M42.
C14 EdgeHD, C11 EdgeHD Zhumell 8" f/6 Newt AP1200GTO, CGEM DX, CG5-ASGT Rob Miller Tri36M tripod Canon Rebel XS, Atik 314L+, DSI pro I,II, QHY5L-II SX 7 FW with Astrodon LRGB, Ha 5nm Hutech OAG5, Rainbow Optics Grating Scorpio Observatory
Terry Danks Photography: Birds, Scenery, a little astrophotography too. http://danks.netfirms.com/home.htm Equipment List: Too embarrassed to list it all. Roll-off-roof Observatory Constructed Fall, 2013
Quote:From John SmithI have found that prima-donnas, attention-seekers, know-it-alls and other personality types that vex the spirit are to be avoided. Rather than try to change or convert such individuals, an impossible mission in most cases, I will choose to disengage from these vexatious types as much as possible, whether individually or the venue in which they operate. They just aren't worth any of my remaining time.
6" Baby PowerNewt ES 152mm Achro iOptron iEQ30 QHY12 Lodestar & 50mm Borg guidescope Luck
http://www.astrobin.com/users/orion69/ TS 150 mm APO Triplet, Feather Touch 3.5" focuser, Micro Touch Focusing System CGEM on custom made platform Atik 383L+ mono, Atik filter wheel, Baader LRGBC + narrowband filters SX Lodestar + TSOAG9 Dew-Not heater
Quote: I have question that has been already addressed in this and other posts but to make things more clear (at least for me): suppose I shoot somewhat dim object and I'm using NB filters. After 10x30 min subs I've got my new stacked picture. Now I'm shooting same object, with same gear, same sky quality (completely same conditions as before) only now I'm shooting 5 min subs x times.
Question: is there some detail on first image that would not be visible on second image no matter how many 5 min subs I take?
Quote:1200 seconds at f/24 is mighty short! f/24 is about 4.5 f stops slower than a more typical imaging OTA used by folks here . . . say f/5.6 just for discussion.--edit--Why? Perhaps . . .1/ They are limited by the observing window of opportunity, i.e., the target is not available long enough per orbit to allow longer subs. Or . . .
AT10RCF, TMB SV105 F6.2, C11, Obs 15, DS solarmax 40 AP900GTO QSI 683 & 640wsg-8 12' X 15'6" BYO http://www.astrobin.com/users/jaddbd/
Check it out! I can form a full sentence! Scopes: Explore Scientific 152mm f/8 Carbon Fiber Triplet, Obsession 15" Classic Camera: SBIG ST-8300M, SBIG FW8 Filter Wheel, Astrodon LRGB and 3nm Narrowband Filters Mount: AP900 Hang out with us at Mount Lemmon Sky Center
Quote:The Hubble is a native f/24 system . . . VERY slow! Who of us here would even consider an f/24 OTA for doing AP?
The individual subs comprising the UDF used a typical exposure time of 1200 seconds according to this Wikipedia article.