i have a 10" f4 newtonian (GSO). i have tried to take pictures of Jupiter, Mars and Saturn in the past with my canon 600D as well as a logitech webcam i bought specifically for planetary work. However, each time i try to get video or shots it looks like a uniform blob. i have tried a 3x GSO and 5x teleview barlow but it still looks like a blob, a rather large blob. with Saturn i was able to make out the rings , barely. i can't imagine that this is a focus issue because as i modify the focus it passes through its optimal focus and it is no better, i have also checked the collimation. i would have thought this is an artifact of my equipment but i have seen others getting much better images with the same gear. i am getting a QHY5l-ii soon and i hope i don't have the same issue. does anyone know what is going on here?
When you are taking images even in quite good conditions the images will not appear perfect until you have stacked and processed your videos.
Go through a process of letting the scope cool down first, even as far as blasting the mirror with a domestic fan to help it; then collimate the scope; once you plug in your webcan try and achieve perfect focus; then evaluate the seeing and make sure you choose a night where there is very little wind - check sites like skippy astronomy weather for seeing forecasts; then once you have taken your video process is in Auto Staker 2 and other software.
Attached is a raw shot from one of my best Saturn's this year - this is what is looked like on the screen - it's does not look great on it's own - but when I stacked 1000 of these x 3 in Red, Green and Blue you can then see the result.
Only with something like the moon does what you see on the screen look more like the post processing result.
hope this helps - it takes time - so take your time and enjoy your imaging!
a) Have you taken any daytime terrestrial photos with your set-up? (E.g. take some shots of something on a distant hilltop or building.) It's a whole lot easier to tinker with equipment configuration and settings (focus, exposure, ISO, etc) in daylight than in the dark.
Some equipment choices may simply "not work" on your telescope - e.g. on my telescope, I can't get my webcam to focus unless it is fitted in the 2x Barlow mounted in the diagonal, as the focuser won't extend far enough for direct use of the webcam alone, but my DSLR needs a tele-extender tube but no Barlow or diagonal to reach focus.
Make a note of the focus and exposure settings required to get a reasonable daytime shot, and compare that with what you would get with a conventional camera and lens set-up, so that you basically understand the field of view, exposure and focus characteristics of your telescope rig compared to a conventional camera equipped with a telephoto lens.
b) Is it possible that you are in-focus, but you are massively over-exposing the images? This will give you shots that just look like fuzzy white balls, with no discernible detail.
The Moon is very bright, so needs exposures comparable to day-time terrestrial photography.
If you are using auto-exposure metering, and it is giving exposures of 1 second or so, it will be hugely over-exposed. Try something like 1/30" with "normal" ISO of around 200 for starters. Similarly for the major planets - auto-exposure meters will see 99% black sky / 1% light spot, and will tend to over-expose the bright spot (which is actually the only image you are trying to capture) in an attempt to get a reasonable overall exposure. Again, start with something like 1/30" or 1/15", and experiment with different ISOs (or "Gain" on a webcam) to get an understanding of what exposure is "about right" for the planets. (Save the high ISOs for deep sky objects, until you have got reasonable images of the brighter targets.)
As an experiment, set up your camera with your longest telephoto lens, point it at the Moon, and take a few shots using automatic metering, and again with varying manual exposures. Unless you have a VERY long telephoto, the Moon will only take up a small part of the shot, floating in a lot of black sky, but chances are your best shots will be with "normal" ISO ratings, lens pretty much wide open (f/4 or so), and around 1/30" exposure. That can be used as a guide for shooting the Moon with your telescope - a small adjustment for the focal ratio of your telescope vs your lens (but that's probably only 1 f-stop difference or thereabouts) is all that should be required.
Once you have captured some recognisable images of some key targets, and made a note of the ISO and shutter settings, you can experiment with these as a starting point to get better images.
What length of image are you taking. I haven't tried imaging the planets yet but I think you should be using a very fast shutter speed, eg. something like 1/4000. If you go too long it will saturate and you wont get any detail.
seems logical that it is an exposure issue, i will try a few settings out if i get some clear skies tonight. it definitely was not a matter of stacking up images that were not perfect. there was absolutely no detail visible. jupiter looked like a pulsating blob, like a massive star. i would have thought that the web cam wouldn't have had exposure issues, i guess that is the thing that has thrown me, i also cant figure out how to change the settings of the logitech web cam, e.g. frame rate, output file type etc, they just have this simple wizard which lets you set one of 3 preconfigured settings (small, medium or high res). Finally, the set up of the rig, it did take me a while to get a configuration that worked, i too had to take the diagonal out (of my refractor) when connecting my camera up but i am confident that the set up is okay. like i said, i am able to pass from out of focus to in focus to out of focus again, it just doesn't resolve very well. from all of the suggestions, i think that overexposure is the issue. i will let you know if i still have issues
i would have thought that the web cam wouldn't have had exposure issues, i guess that is the thing that has thrown me, i also cant figure out how to change the settings of the logitech web cam, e.g. frame rate, output file type etc, they just have this simple wizard which lets you set one of 3 preconfigured settings (small, medium or high res).
If the app that came with your webcam doesn't allow full manual over-ride, try a generic freeware webcam app such as "Amcap" (should be pretty easy to find with a Google search).
In Amcap, you go to the "Video Capture Filter" settings, choose manual mode, select the highest resolution, a frame rate of something like 5 to 30 frames per second, and manually adjust the shutter speed and gain to something like 1/30". You should be able to see a reasonable exposure on-screen on your PC, and then you can work on focus etc, and go for your first video capture.
Like I said, it's a LOT easier to tweak the basic settings on a daylight terrestrial target, and then target the Moon or a bright planet, initially using similar exposure settings; full automatic exposure is likely to hugely over-expose planets against a dark background.
You will also need a stacking program, once you have "mastered" the art of capturing reasonable quality video. RegiStax is the most common one, so will be the easiest to find for downloading, and also for getting community support.
You might want to take a look at the Celestron NexImage manual, even if you aren't using a NexImage, because the procedures are the same on pretty well any webcam, and the applications are freeware and can be downloaded easily even if you don't have the Celestron CD-ROM: http://www.celestron.com/c3/images/f...structions.pdf
Most Logitech webcams, even dirt cheap models, when in action have a strip down the right hand side of the screen containing icons. The top one from memory is the now discontinued Logitech sort of conferencing doodad. The next one down is adjustments such as contrast, brightness,etc.
The next one is ,I think, sound adjustment. The next one is the gain, which is the most important adjustment. I just wondered if you were aware of it's existence.
raymo
Most Logitech webcams, even dirt cheap models, when in action have a strip down the right hand side of the screen containing icons. The top one from memory is the now discontinued Logitech sort of conferencing doodad. The next one down is adjustments such as contrast, brightness,etc.
The next one is ,I think, sound adjustment. The next one is the gain, which is the most important adjustment. I just wondered if you were aware of it's existence.
raymo
