Thanks for the explanation Darren. I'm thinking I'll go buy a lottery ticket and then shop around for a used observatory when I get ready to try my hand at this.
stan On Oct 15, 2013, at 10:12 PM, Darren Addy wrote: > You are technically correct, Stan. But I was out there for approx. 75 > minutes to get my 6 minutes of integrated exposure time. After doing > the precise calibration, a lot of my first shots were complete misses > (Andromeda not even in the frame). And then when I finally located it > and started taking images, I was trying to find the maximum amount of > time I could expose and not get star trails. For me, in this part of > the sky, with this lens, on this night, that max was about 45 seconds. > I then rejected over half of the images that I shot, only stacking the > very best (which ended up to be 11). > > So, if one could go out, locate the object immediately, and get 100% > "keepers", the sky would only be rolling for 10-20 minutes or so. But > the reality is that you need to shoot more than you keep, and you need > to get the object in the frame first. I'm looking into better ways to > do that, but mostly they involve mounting a Telrad (or other laser > projection "finder") beside the camera and looking in the exact same > place. Then that plate, with camera and Telrad mounted, would have to > be put on the ballhead and oriented around. > > On Tue, Oct 15, 2013 at 8:46 PM, Stan Halpin > <s...@stans-photography.info> wrote: >> Huh. I had imagined that you would locate the target or target region, set >> the camera, fire a series of shots, and then stack away. From your comments >> it seems that you need to re-target the target for each shot. I know the >> stars are "moving" relative to us, but I hadn't thought they would move that >> significantly in 6-8 minutes . . . >> >> stan >> >> On Oct 15, 2013, at 9:24 PM, Darren Addy wrote: >> >>> Thanks to all who have looked (and/or commented). The image is a crop >>> of what I got from doing an "overlap" stack in DSS. It is difficult to >>> frame each sub-exposure exactly the same (particularly when simply >>> using a ballhead), but with DSS that doesn't matter because it will >>> stack only the common parts of each image. From that result I cropped >>> in even closer resulting in the "centered" composition that Stan >>> didn't care for. I could have left more stars on the right and bottom, >>> but I guess my thinking was more like what Paul expressed earlier. >>> Also, the nature of astrophotography, particular with the lens near >>> wide open, is that the edges will drop in quality due to coma, CA, >>> etc. I didn't really have M31 centered well in any of the shots. It >>> was mostly left-of-center or lower left. So again, lots of room for >>> improvement with future images - even of the same subject. It is a >>> learning experience and I have a LOT left to learn. >>> >>> I don't see the banner either, but I'm also a paid account (if that >>> makes a difference). Rather annoying to hear about, though. : \ >>> >>> By the way, I had a couple of astro imagers suggest a free PhotoShop >>> plugin called HLVG (HastaLaVistaGreen) which I think I will >>> find/download and try on this image. I thought I got the green out, >>> but apparently not enough. >>> >>> To Larry's earlier question... not sure about stacking software for >>> the Mac. I believe Steve Sharpe mentioned one up-thread. >>> DeepSkyStacker and Registax are the two biggies (both free, I believe) >>> on Windows. If anyone is interested, I can share a good link that >>> helped me with the histogram/curve part of DSS. >>> >>> On Tue, Oct 15, 2013 at 8:07 PM, Larry Colen <l...@red4est.com> wrote: >>>> On Tue, Oct 15, 2013 at 08:38:04PM -0400, Paul Stenquist wrote: >>>>> As I said, a fabulous shot. But what's with Flickr putting a banner in >>>>> the corner of your frame, covering part of the image -- "Try our New >>>>> Photo Experience." And people complain about ads on photo.net?? Bizarre. >>>> >>>> I don't see that baner. But then, I have a paid account. >>>> >>>> -- >>>> Larry Colen l...@red4est.com >>>> http://red4est.com/lrc >>>> >>>> >>>> -- >>>> PDML Pentax-Discuss Mail List >>>> PDML@pdml.net >>>> http://pdml.net/mailman/listinfo/pdml_pdml.net >>>> to UNSUBSCRIBE from the PDML, please visit the link directly above and >>>> follow the directions. >>> >>> >>> >>> -- >>> Nothing is sure but death and Pentaxes. >>> >>> -- >>> PDML Pentax-Discuss Mail List >>> PDML@pdml.net >>> http://pdml.net/mailman/listinfo/pdml_pdml.net >>> to UNSUBSCRIBE from the PDML, please visit the link directly above and >>> follow the directions. >> >> >> -- >> PDML Pentax-Discuss Mail List >> PDML@pdml.net >> http://pdml.net/mailman/listinfo/pdml_pdml.net >> to UNSUBSCRIBE from the PDML, please visit the link directly above and >> follow the directions. > > > > -- > Nothing is sure but death and Pentaxes. > > -- > PDML Pentax-Discuss Mail List > PDML@pdml.net > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow > the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
