Clear skies - Jim Crazy PNW imager !
A-P Mach1 on 12" concrete pier - ROR structure.
Tak FSQ85-EDX, Tak FS-128. Orion 8" f/3.9 w/MoonLite motorized - MPCC MkIII CCD:
SBIG 8300M/FW8, Astrodon 36mm LRGB, 5nm Ha, 3nm SII, OIII - Canon EOS 6D unmod SSI3, SSAG,
Skytools3pro, MaxImDLpro, PSCS5, PSPpro, TheSkyX, TheSky6, BYE, StarTools
Orion XX14g -for visual- diags, ep's, accy tubes, Binocs .
QSI 683ws-5 hole Astrodon Gen II LRGB, Astrodon 5nm HA, Astrodon 3nm OIII Rigel systems Auto focuser Cannon T3i(un-modded) Astronomik CLS EOS clip filter Orion ED80T CF Sirius EQ-G w/EQ-MOD Orion MMAG PHD2 Backyard EOS ImagesPlus 5.0 Pix-in-sight Sequence Generator Pro Spike-a Flat Fielder
Orion XT8 Classic, Self built EQ platform
AstroTech 72ED, AstroTech 6 Imaging Newt
Celestron Advanced VX EQ Mount
Celestron NexStar SE 4/5 Mount (for grab and go)
Canon T3i, Canon XT (Hap Griffin Baader Mod)
QHY5L-II Mono/Orion 50MM Mini
Fort Bend Astronomy Club
Quote:... but I now have the Astronomik. I've prepared it by using a custom white balance for my next outing.
Quote:Stelios, that's what my post is about essentially, because shooting wide angle guarantees you'll be dealing with several different gradients. With a little work in photoshop you can flatten your picture out nicely and remove almost all of the light pollution. Done correctly, you can even do it without removing your signal with it .
Quote:It always gets me when people starting talking about Unity Gain being the absolute ideal exposure then admit that they use a wide range of ISO values that aren’t at the point of Unity gain.
Quote:Quote:It always gets me when people starting talking about Unity Gain being the absolute ideal exposure then admit that they use a wide range of ISO values that aren’t at the point of Unity gain.
I was simply stating that the discussions around unity gain are a good starting point if you want to learn how the sensor stores data and how ISO affects that. I agree there are many factors and I won't pretend to know what they all are. Versus trial and error though, I try to read up on the physics of what is happening and make my choice as to what works for me. As an example, if I am inherently clipping data, I'd like to know that.
Regarding WB, the raw data is unaffected by your selection (custom or otherwise). It may help the post processing but there are other ways to get the balance calibration right. I find without the LP filter that 'daylight' is the closest selection to the coloring that looks right to my eye. Afterall, it's starlight.
Quote:However, unity gain is rarely the most important factor for beginner users. Tracking, Focus, and Sky Conditions usually are by far the biggest factors.
Quote:Think he was referring to seeing, transparency, light pollution, etc.If you take a short exposure at low ISO, you are clipping data on the low end or at least quantizing it. I would say better for ISO to be higher than lower up to a point. I was just suggesting that it is worthwhile to understand how a dslr sensor records data. It's a common question, "what ISO?" and I'd does matter in many scenarios. Here is a good link to get you started ....http://www.clarkvision.com/articles/digital.sensor.performance.summary/