20Da worse than 20D for astronomic photography?

[Tomsk]

I was just thinking about the 20Da having the live preview available on it's LCD and being aimed at astronomic photography.

Surely keeping the CMOS sensor powered means that it will generate more heat and thus more noise - the last thing you would want on a photo that will mostly be black.

IMO

[pierrot]

Yeah, sure, they released it specially for that:
making bad pictures of something that no one can see anyway. ;)

[who me?]

If you use the live preview for just alignment purposes on the brightest of stars in your desired frame, it may not be too bad as long as the alignment period is short. BUT, depending on your lens, you may be able to see the stars in the viewfinder anyway. Thus, negating the need to use the preview. For me, I would not use the live preview. Anything that needed decent magnification would be done through a telescope with a T adapter or at prime focus. And for any wide field shots, I would just use the viewfinder and piggyback the camera on a guide scope unless I wanted star trails.

[Tom W]

I think that the preview might be designed more for focusing than aligning. Granted, its not as "real-time" as using the viewfinder, but you've got the advantage of time and the ability to zoom into your image. And if the 20D viewfinder is anything like that of the 10D, it's nearly impossible to focus manually (well at least for me, anyway).

[ron chappel]

it's a brilliant idea-ever tried to focus on stars (auto or manual!)?

The noise issue will likely be well thought out

[Tom W]

it's a brilliant idea-ever tried to focus on stars (auto or manual!)?

The noise issue will likely be well thought out

I tried with my 10D a couple of times. Finally had to achieve autofocus on an earthly object, then switch to MF and mount the camera & lens on the back of my friend's telescope. Its very difficult to see the stars in smaller viewfinders.

[Khai]

I couldn't actually get the live preview to work when I handled a 20Da on Monday. Admittedly I didn't try for very long as my attention was on the Digital Kiss N (350D). You can try both at the Canon S Tower in Shinagawa (Tokyo).

[Tom W]

I couldn't actually get the live preview to work when I handled a 20Da on Monday. Admittedly I didn't try for very long as my attention was on the Digital Kiss N (350D). You can try both at the Canon S Tower in Shinagawa (Tokyo).

Unfortunately, that is a very long drive from Tennessee! :)

j/k - My friend in Ohio would be very interested in this camera, as he is very interested in astrophotography. He has my old 10D, plus a couple of manual Nikons that he uses quite a bit.

[RoB_m]

i've done a lot of night/astro shooting with my 10D and looking through the viewfinder to find focus is almost worthless in a lot of cases. i'd have to take short test shots and look at them to see if the focus was right, then manually adjust acordingly, all hit and miss. i'd like to have this preview feature for that purpose.

[Tom W]

i've done a lot of night/astro shooting with my 10D and looking through the viewfinder to find focus is almost worthless in a lot of cases. i'd have to take short test shots and look at them to see if the focus was right, then manually adjust acordingly, all hit and miss. i'd like to have this preview feature for that purpose.

The other alternative is to connect the 10D to your computer and use your computer to fire the camera. The downside of that is that the computer monitor's bright display is bound to ruin your night vision for several minutes.

[pcasciola]

Another benefit of the preview will come in software, which can then use the preview data through the USB to control an autofocuser. I've seen software that does this by taking multiple shots and adjusting focus automatically, but having the preview data will make it much more efficient. It's very hard to obtain perfect focus manually when the dSLR is hooked up to a telescope.

[Nic]

You will never be able to take descent photographs of 'stars' with the 20Da alone, not even with the 600mm prime. It must be attached to an astronomical telescope which must be able to track the object(s) you want to shoot.

[karusel]

Absolutely. I've tryed this only once, and all I got was real nice star spaghetti. Without a tracking system there is no astrophoto.

[pcasciola]

Who said the 20Da was intended for astrophotography without a telescope or tracking system?

I think it was designed to be used on a t-mount adapter through the telescope, for doing deep space objects. I have seen some pretty impressive shots though, with 200mm lenses or less piggybacked on top of a nice tracking scope, like this one. The first shot on this thread was taken with the 20d + 200mm, and the 2nd pic shows the 20d mounted on top of the telescope just for tracking.

http://www.fredmiranda.com/forum/topic2/150642/0#1218443

[kawter2]

it's a brilliant idea-ever tried to focus on stars (auto or manual!)?



umm.. just put the ring at infinity 00

[pcasciola]

umm.. just put the ring at infinity 00Tried that last night. Didn't work. I had to back it off slightly.