bdk Loc: Sanibel Fl.

How clear of a pic of Mars should I get using a 600 mm lens.
I tried anything from 5 to 25 second exposure
F5.6 , iso from 64 to 400.
I've only looked at images in the camera, ill load them into the computer. The images in the camera do not look good.
So, what settings are you using and can I see some pix?

Architect1776 Loc: In my mind

Not sure but is that long enough and take into account atmospheric haze/distortion?
I believe that the astronomy section might help better.

Retired CPO Loc: Travel full time in an RV

A red dot, and not a sharp pinprick either! I have some, but it would take a while to find them. @ 45second exposure if I remember correctly.

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A photographic telephoto type of lens is NOT an astro telescope, even tho some may have numerically similar FLs.

If youre hoping to see a bit of Martian surface detail using a photographic lens youre gonna hafta get much closer .... huuuuuuuuuugely much closer.

DirtFarmer Loc: Escaped from the NYC area, back to MA

For anything longer than a couple seconds you will need a tracking mount. Here is a shot of some stars using a 10 second exposure. No tracking. The earth's rotation is clearly affecting the image. This was taken with a 70mm focal length. A 600mm focal length will make the trails longer.



If you want to take a planetary image, Jupiter might be a better choice since it is larger. However, you need to pick the best time of year, when it is close to earth and visible in the night sky. Jupiter has visible moons as well so you might get some of them in a shot. Saturn is also fairly large and has a shape that differentiates it from other objects in the night sky.

PS: Don't be afraid to use high ISO (giving shorter exposures). Digital photos are almost free so you can take a lot of them with different settings. One thing to consider is focus. Don't depend on the stop marked infinity on your lens. You might have to experiment to find the actual infinity setting. Or use smaller apertures. However, apertures smaller than f/8 could increase diffraction which will introduce blur to your image.

agillot

Anything over 20 seconds will elongate the circle , due to earth rotation .Set the iso to 1000 , wide open , and go from 1/20 sec , down to 5 , 10 sec . Mars is just a small red dot .The moon is much more interesting .

alberio Loc: Casa Grande AZ

Here is a comparison shot of the Moon and Mars at 600mm if I remember correctly.

(Download)

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The moon looks sharp, but Mars is very soft. Maybe there were too many gravity waves in the way ;-)

DirtFarmer Loc: Escaped from the NYC area, back to MA

EXIF data give focal length 600mm and shutter 1/400

Longshadow Loc: Audubon, PA, United States

Unless one has an equatorial mount the 25 seconds will be blurry.
Maybe longer that 5 seconds? The longer the exposure the blurrier the image.

gordone Loc: Red Deer AB Canada

With a 600 mm lens the max exposure time before you get star trails will be in the 0.6 to 0.8 s area, depending on the camera and lens aperture.
The PhotoPills app will give you camera specific info. Many also use the 500 rule where the max exposure time would be 500/600 mm = 5/6 s. This tends to be a bit optimistic with current cameras and cropped sensors would be closer to 300/600= 0.5s

alberio Loc: Casa Grande AZ

Yeah, that was a compromise on focus distance and exposure and lousy atmospheric conditions.

dlmorris Loc: Loma Linda, Ca

I think you will need a MUCH longer focal length to see any details at all on Mars. It is a small planet. 600mm will just get you a brighter spot..... Planetary photography is a specialty in it's own right, and requires somewhat specialized equipment and software to process the images.
I've never tried Mars, but do have some pretty reasonable shots of Jupiter, but I was using a 1200 mm 5" telescope, and a somewhat specialized camera taking videos, then stacked and processed the hundreds of images into a single picture.
But you gotta start somewhere! Good luck!

DirtFarmer Loc: Escaped from the NYC area, back to MA

I had occasion to use a telescope once. It wasn't something I could attach my camera to but we aimed it at Jupiter and got some nice images. It was a 48" Cassagrain telescope with an effective focal length of 1.2KM.

dlmorris Loc: Loma Linda, Ca

That works!