Stef C
Loc: Conshohocken (near philly) PA
I'm buying a new full frame wide angle lens and can't decide if the 2.8 is necessary. I will be doing a lot of night/astro photography and I want to capture as little star movement as possible, but I don't know if that's possible with anything less than 2.8 on a full frame..
Anyone have examples of still night shots (no trails) at F4 or higher?
It is not the lens that will prevent star trails. In order to capture the milky way arm, long exposure is required, and any shots over 90 seconds will produce star trails. So, you will need to have a guiding system. The other option is to take a number of short exposures and stack the images together. The picture I have attached is a one-shot 4.5 minute exposure, guided. No post-processing done.
Hi there. Please could you let me know what a guiding system is thanks in advance. Terry.
Stef C
Loc: Conshohocken (near philly) PA
Terrymac wrote:
Hi there. Please could you let me know what a guiding system is thanks in advance. Terry.
Yes, i would be very interested.
I've taken mikly way pictures at 25 second exposure f/3.5 but it clear isn't as good as yours haha!
Hi Terry and Stef. My camera (Canon 50D) with a Sigma 10-20 mm. was guided on a Kendicks astroguide.
a guiding system is an equatorial tracking mount used for telescopes or astrophotography. When properly aligned they track the movement of the stars across the sky so that you can take long exposures at lower ISO (less noise).
Fred is correct: You need the equatorial mount if you are hooking your camera directly to a telescope to take the pictures. The kendriks astroguide sits on a normal camera tripod, with your camera on top of that. It only weighs about 2 pounds, so you can easily take it anywhere you go. Hauling an equatorial mount is quite a bit more cumbersome. I use both methods for astrophotos.
Cottondog,
I actually have the camera mounted directly to the EQ mount. No telescope. You are right in that it is a heavier set-up than a typical tripod, but this weight also means a more stable platform, especially if there is any wind.
This is a common method for widefield images of the sky.
Stef,
What you need is not necessarily a faster lens, but a way to have your camera follow the movement of the sky (actually the spin of the earth), so that you can leave the shutter open longer so that the faint light from each star records onto the camera sensor. You also need dark skies for this. If I image from my house and I leave the shutter open for 2 minutes the image will be completely white, because of the light pollution, so it is impossible from my home. I have to travel to a dark site (in the middle of the Florida Everglades), to be able to image properly.
Cotondog wrote:
Hi Terry and Stef. My camera (Canon 50D) with a Sigma 10-20 mm. was guided on a Kendicks astroguide.
I am an amateur astronomer and have numerous scopes and goto telescope mounts yet I have never heard of the kendiks astro guide system. I tried to google it and found nothing other than the kendrick site relating to dew removal or astronomy sites showing the same. Do you have an image of your kendrik astroguide or know the site where it shows or sells it. I would appreciate it if you could post the site. Tim
Hi Tim: It is actually called an Astrotrac. I purchased the tt320x model about 2 years ago. The developer of this guiding system lives in Toronto, where he has continued to defvelop a large variety of astro photography accessories. They now have an updated model. I think it is called the tt320xs. A couple of web sites you can check:
www.astrotrac.comFor a PDF review of the original astrotrac in 2008 (the tt320):
www.skynews.ca/PDFs/Review_PDFs/sky-rev_Astro Tracso08.pdf
Sky and Telescope also did a positive review of the astro trac a couple of years ago. You may be able to fins it on their site.
I believe OPT in California sells them (just google opt telescopes), and they typically have decent write-ups of the equipment they sell.
Hope this helps.
Wabbit wrote:
Stef C wrote:
I'm buying a new full frame wide angle lens and can't decide if the 2.8 is necessary. I will be doing a lot of night/astro photography and I want to capture as little star movement as possible, but I don't know if that's possible with anything less than 2.8 on a full frame..
Anyone have examples of still night shots (no trails) at F4 or higher?
Hey Doc ..... sure
That was my first thought when I saw the topic. :thumbup:
Wabbit wrote:
Stef C wrote:
I'm buying a new full frame wide angle lens and can't decide if the 2.8 is necessary. I will be doing a lot of night/astro photography and I want to capture as little star movement as possible, but I don't know if that's possible with anything less than 2.8 on a full frame..
Anyone have examples of still night shots (no trails) at F4 or higher?
Hey Doc ..... sure
You know I would like to say, grow up, yet what good would that do? Oh I guess I did. Quazy wabbit. I'm hunting you.
tim57064 wrote:
Wabbit wrote:
Stef C wrote:
I'm buying a new full frame wide angle lens and can't decide if the 2.8 is necessary. I will be doing a lot of night/astro photography and I want to capture as little star movement as possible, but I don't know if that's possible with anything less than 2.8 on a full frame..
Anyone have examples of still night shots (no trails) at F4 or higher?
Hey Doc ..... sure
You know I would like to say, grow up, yet what good would that do? Oh I guess I did. Quazy wabbit. I'm hunting you.
quote=Wabbit quote=Stef C I'm buying a new full ... (
show quote)
Hey Doc ..... of course you know that this means war .....
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