Read this and weep - Pentax GPS + more

[Greg Beetham]

That info looks like it would come in handy Winston, especially the processing section, for me anyway. I guess you could do a dark frame Javelin, only thing is I wouldn't know how to subtract it myself, at the moment, I guess there is a way of doing it in E8 maybe. Besides wouldn't one need to do an equivalent 300sec dark frame? that would mean lots of noise I think, and how much would that subtraction affect the original stars and nebular, galaxies etc. that were in the photo before the subtraction, I wouldn't know myself it's all new ground to me, I've always been content to gaze through the eyepiece so far.
Greg

[UrsaMajor]

On the subject of astronomy photos - and related images - I encourage everyone to take a look at the "Astronomy Picture of the Day" at

http://apod.nasa.gov/apod/astropix.html

In addition to a new image each day, it is possible to click on the "Archive" link and go back through many years of daily images. Personally, for over twelve years I had have my browser set to go to APOD as its home page, so I automatically check what new image may be appearing each day. There have been some absolutely stunning images posted there over the years - and each image includes a brief discussion by a professional astronomer.

With best wishes,
- Tom -

[Javelin]

Actually your camera will do it itself automatically Sony calles it long exposure nise reduction and it does shoot a black frame of the same length exposure. it won't affect anything in the picture that is really there. it will just remove noise and hot pixels that would crop up when leaving the sensor on for a long time

That info looks like it would come in handy Winston, especially the processing section, for me anyway. I guess you could do a dark frame Javelin, only thing is I wouldn't know how to subtract it myself, at the moment, I guess there is a way of doing it in E8 maybe. Besides wouldn't one need to do an equivalent 300sec dark frame? that would mean lots of noise I think, and how much would that subtraction affect the original stars and nebular, galaxies etc. that were in the photo before the subtraction, I wouldn't know myself it's all new ground to me, I've always been content to gaze through the eyepiece so far.
Greg

[Greg Beetham]

Pretty wild image that one Tom, a 360 view, the same road (I think) both coming and going at the same time ha ha, and a spectacular sky as well.
I noticed Javelin the other night when I did some shots in the backyard at various experimental exposures, 20,15 and 10 seconds the camera would put up a sign on the rear screen after the shutter closed saying ‘processing’ and that was there for quite a while, so I’m assuming it was probably doing a dark frame at that time, possibly. The dark frame I was thinking of though was what that guy (with the stacking program) was talking about in his procedure; he takes dark frames himself with the lens cap on of equivalent time to the exposure and subtracts them himself, I’m not sure how he does that though, like I say there might be a facility in Photoshop or Elements for that but I don’t remember seeing it in my travels so far. He also takes what he called ‘flat frames’ and ‘bias frames’ and does something with those too. All told his procedure was a bit hard to follow, he had a ‘Master Dark’ a ‘Master Flat’ and a ‘Master Bias Offset’ and all apparently constructed just for each photo, if I understood it properly…I’m not sure I want to get ‘that’ involved myself, and besides after you do all that to an exposure do you end up with a photo that accurately represents what is actually there?
Greg

[bakubo]

I found the first article on this page interesting.

That pdf has fantastic info and also some really nice shots. I bookmarked it.

[Javelin]

Yes thats the dark frame. a lot of photographers learned to do it manually because their cameras didn;t do it automatically. doing it yourself has the advantage of not locking up the camera for a period equal to the exposure but letting the camera do it is more accurate because the conditions and as close to identical as when the exposure is taken.

Pretty wild image that one Tom, a 360 view, the same road (I think) both coming and going at the same time ha ha, and a spectacular sky as well.
I noticed Javelin the other night when I did some shots in the backyard at various experimental exposures, 20,15 and 10 seconds the camera would put up a sign on the rear screen after the shutter closed saying ‘processing’ and that was there for quite a while, so I’m assuming it was probably doing a dark frame at that time, possibly. The dark frame I was thinking of though was what that guy (with the stacking program) was talking about in his procedure; he takes dark frames himself with the lens cap on of equivalent time to the exposure and subtracts them himself, I’m not sure how he does that though, like I say there might be a facility in Photoshop or Elements for that but I don’t remember seeing it in my travels so far. He also takes what he called ‘flat frames’ and ‘bias frames’ and does something with those too. All told his procedure was a bit hard to follow, he had a ‘Master Dark’ a ‘Master Flat’ and a ‘Master Bias Offset’ and all apparently constructed just for each photo, if I understood it properly…I’m not sure I want to get ‘that’ involved myself, and besides after you do all that to an exposure do you end up with a photo that accurately represents what is actually there?
Greg

[Dr. Harout]

I found the first article on this page interesting.

That pdf has fantastic info and also some really nice shots. I bookmarked it.

me too.