Astrophotography for begginers
Posted 05 March 2013 - 03:03 PM
Im based in Brazil and my equipment is:
Celestron Nexstar 6se (powermate 5x, 25 and 5 mm lens and a Philips SPC900 webcam)
OBS: Expecting delivery of SLR cam adaptor, 18mm, 7mm and 12mm lens and a 3x barlow.
My question are:
1 - Im able to align it 3 or 2 stars. But the object is never aimed perfectly with the scope. I mean, once I have it in the center, I just cant make it be "frozen" for more than a minute. It always goes up, down, one side or the other. Am I doing something wrong you can tell me?
2- is 6se able to get more stable/fixed exposure with a better mount?
3 - Cant connect to the pc. I plug the serial/usb adaptor but the pc never reconignizes it. Plug first the adaptor into usb (with no scope plug) but "unknown device"
Can somebody help?
Will post some pics Ive been taking from moon, saturn and Jupiter...some good ones (for my very basic skills)
thank you all
Posted 05 March 2013 - 03:58 PM
Welcome to cloudy nights. You will learn a lot here. There are other people here more experienced to comment on your question, but basically most long duration astrophotography (AP), is done with equatorial mounts such as the German Equatorial mounts. Most exposures over a minute are done with auto-guiding. Which is basically another camera like your webcam that locks in on a star using PC software and the PC sends minor adjustments to the mount to keep it on track. I am not familiar with your scope, so I will let others comment on what can and cannot be done with it. Your setup should lend itself well to webcam AP. I look forward to seeing your pictures.
Posted 05 March 2013 - 04:32 PM
To understand field rotation, look at Orion tonight as soon as dusk approaches, then look at him about 3 hours later. His orientation with respect to the horizon changed. The same thing happens in your camera's view when it is on an altitude/azimuth mount like the Nexstar SE. This results in ruined exposures.
A webcam lends itself to planetary photography and especially with the equipment you have now. Jupiter is up still and you can aim at it. Ask about planetary photography technique in the Beginner imaging section for more info about that.
To directly answer your issues:
1. While the Nexstar SE mount is very good at getting targets in the field of view of your eyepiece it is by no means super accurate in that it can place the star dead center every time. Even my Celestron CGEM DX isn't capable of that accuracy. Thankfully it is something you can live with since it gets "close". By close I mean the thing you want to shoot ends up in the camera's field of view.
2. The Optical tube of the 6 SE detaches from the mount to be used in any German equatorial with a Vixen style dovetail mount. This includes Celestron's CG-4 and CG-5, Meade's LXD 75 and LX 80 mounts, Orion's Skyview and Synta's EQ5 mounts. Mounts equipped with a Losmandy D size dovetail can be used with an adapter plate to convert them to the Vixen style dovetail. These include the Celestron CGEM, CGEM DX, CGE-Pro, Orion's Atlas mount, and the larger mount sizes.
3. I can't really help you with connecting your webcam to your PC. There are things to watch out for though. Some older webcams are incompatible with Windows 7 and newer operating systems. This especially goes for 64 bit operating systems (basically you can't find a 32 bit laptop anymore). Check with your webcam's manufacturer website to see if they have a driver for your operating system.
Posted 05 March 2013 - 08:15 PM
Posted 05 March 2013 - 08:24 PM
thank you so much for all help and quick repply. Very helpfull and for sure Ill get a better mount in the future.
I live in Sao Paulo so I get always cloudy skies but was able to take some pics. They are very very basic and are from the first night of a 2 weeks old scope. Ground zero skills from my side. Find those attached pls.
Again thanks a lot for all info and will let you know how it goes.
all the best and clear skies,
Posted 05 March 2013 - 08:42 PM
Posted 05 March 2013 - 08:56 PM
Posted 05 March 2013 - 09:44 PM
There are two other fora here that I would suggest you visit - the Celestron NexStar Forum and the Beginning and Intermediate Imaging Forum - both a little farther down the Main Index page.
Posted 06 March 2013 - 04:51 PM
Posted 06 March 2013 - 05:01 PM