Posts Made By: John Miele

Hello All,

Here is my first try ever at digital imaging. I just got a new Sony Digital camera and had to try it out. I don't think I focused very well and I only had 5 frames to stack. But it's a start...
6" f7 homebuilt dob on homebuilt eq. platform
Sony DSC-85 attached with Orion's Steadipix camera mount
32mm Meade SP, 2x Celestron barlow
3x optical zoom on full
Stacked best 5 of 10 images with Astrostack
Did a little unsharp masking within Astrostack (had no idea what i was doing with that!)

Any tips pointers and commetns (especially on how to focus) will be greatly appreciated. Thanks.

John

I made another attempt on Saturday night (brrrr it was a cold one here in Madison, Al). It's a little better than my first one. Still have the focusing problems but I'm getting a 5" monitor to use for focusing using the camera's video output. I hope that will help. This picture was made from about 20 stacked images in Astrostack. Only about 5 of the images were good, the rest I rated average to poor.

6" F7.2 dob
18mm Radian, 2x Celestron shorty barlow
Sony DSC-S85 3x optical zoom on full
A little unsharp masking

John

Hello,

One thing I have noticed, is that the moons of Saturn do not show up in my pictures. They are clearly visible when looking into the eyepiece only. How do I get them to show up without over exposing the image. Do you take a picture way over exposed to get the Moons to show up and then digitally combine it with the final stacked image?

Thanks in advance for any help.

John

My Digital camera (a Sony Cybershot DSC-S85) can take MPEG movies that are about 30 seconds long. Does anyone know if such movies could be used to do planetary imaging? I know it's done with video cameras but I was not sure the MPEG file format is useful. Can individual frames be grabbed from the MPEG movie and then stacked? Anyone know what software will grab the frames? I assume astrostack will do the stacking. Thanks very much for any advice and clear skies to all!

John

I'm building an equatorial platform to use with my homebuilt 16" truss dob (built pretty closely per the B&K book). Currently, the mirror is in a sling. On a platform, the whole scope will tilt up to 7.5 degrees in either direction. Right now there are two bolts in the mirror cell that will keep the mirror from shifting laterally as the scope tilts over. But this means a force will be applied at a point to the mirror. Could this distort the mirror enough to produce problems? I have seen where some builders have used a double sling design with each sling angled in a different direction. This looks like a lot of retro-work to the mirror mount and I'm wondering if it's really needed. Thanks for any comments.

I'm still pretty new to all this, but I have been noticing a trend (I think). It seems that the most detailed images of planets that I see are the ones taken using video methods like the Toucams and such. Is it correct to say that if one is looking to produce the most detailed image possible, that the video methods using web cams are the way to go? Or can a digital still camera also produce images as detailed as from video? Are video images intrinsicly better resolution, or are they better simply because of the sheer number of frames captured you have higher chance of getting some that beat the seeing? My digital still images, even the ones I stack 20 pictures to obtain, are nowhere near as detailed as the webcam ones I have seen. And my telescope has at least diffraction limited optics or better. Thanks for any replies.

Help! I can't resist the siren song of the webcam any longer. The webcam planet shots being posted are simply incredible. I have done some planetary imaging with a still digital camera but I think I'm going to switch to the webcam. I have decided on the Toucam Pro camera. I can get one with an adapter from Scopetronixs. It looks like it also comes with a USB cable to connect to the laptop. I know I'll need a laptop, and I already have registax2 and PSP7 loaded on my PC. My question is what else (if anything) do I need to start imaging? Any other software or hardware? Thanks.

John

Hi All,

Last Friday I took about 80 pics of Saturn through a sony cybershot digital camera connected to my 16" f4.5 dob telescope driven by a DDII system. Used a 9mm Nagler and 3x zoom no the camera. The shots spanned over about 15-18 minutes in time. I can't take 'em any faster due to blazingly slow download time to memory stick. Anyway, I later noticed while progressing thru the stack of images that field rotation had noticably rotated the images! When I stacked them in Registax, this rotation apparently ruined the result. Sigh and bummer. I guess I had forgotton this would occur in alt-az type of tracking system. Does anyone have a formula or tool to calculate how long of a time span one can image over (using still cams or webcams) before field rotation will become a problem? I guess I can trial and error this if I need to.

Thanks.

John

Does Registax have a limit to the number of frames it will accept for stacking? I have seen several folks mention they stack over a 1000 frames. Whenever I open my AVI files with Registax, I get an error if there are more than about 920 or so frames. Does anyone else have this problem?

If it matters, my AVI files are generated as follows: Astrovid Color planetcam input to Sony MiniDV camcorder. Then, using firewire, download the digital video to the PC with Ulead DVD Movie Factory. Then create an uncompressed AVI file using Ulead and read this into Registax.

Thanks.

John

Hi All,

A friend and I were talking the other day about all the fantastic planetary images getting posted here and that many of them are taken with SCT optical designs. I have always been under the impression that the SCT optical design is not that great for high resolution work because of the large central obstruction. That a SCT is a good all-purpose type scope but is not what one wants to use as a "planet killer". So what gives? The details on the webcam shots of Jupiter thru some of the SCT used by group members here are stunning! No contrast or resolution problems there. Any ideas as to why the large central obstruction appears to have no detrimental effect on the video images? Is it just a visual effect? What do you guys see visually with your SCTs when you look at Jupiter and Saturn? Just wondering what the thoughts are.

Thanks for any replies.

John Miele