what can i photograph @ 300mm

[robatman (Robert)]

I've spent lots of time researching and seeing all these amazing photos, but not sure how much I want to dive in yet...
So what can i photograph with a 50D and 75-300mm, (or a modified 300D)

I've seen some great links for spotting with binoculars, esp glenc see http://www.iceinspace.com.au/forum/s...ad.php?t=18551 but not short exposure images at 300mm. These images are awesome but not sure of the imaging details http://picasaweb.google.com.au/dunlo...thernObservers#

I'd like to know how big the object size will appear. The limiting factor in this is that I dont have a tracking mount, though i can almost get good exposure for 1 minute with a barn door tracker! still getting the hang of it.

The only parameters in addition to the above is it would be best in the south part of the sky as my backyard has trees covering the northern sky.

Thanks for any suggestions and/or links to images taken with a 300mm.

Robert

[Zuts]

Hi,

If you download this program it will show you the apparent size of objects with various focal lengths and chip sizes.

http://www.newastro.com/book_new/camera_app.php

it's called CCDCalc and is very good.

Cheers
Paul

[AlexN]

Theres heaps you can image at 300mm... At the moment, Orion/running man, Horsehead/flame, LMC, SMC, Eta Carinae... You might (depending on your location) get a shot at M31 before next year.. M31 is a real stunner at 300mm...

[robatman (Robert)]

Thanks Paul, that ccdcalc was exactly what i was looking for- i also added the extra images mentioned on that site. In conjunction with Stellarium i am keen to see what happens!

Thanks for the ideas alex- i think i wont be able to get m31 but will def look for the others.

Are most of these photos we see long exposures or are they short 30 secs stacked?

Robert

[xelasnave]

I surprise myself what 30 secs can do ... dark site is very helpful... but just get out there and try it...I like 30 secs set the camera on continuous shooting have a cuppa and see how many, a couple of dark frames, deep sky stacker and another cuppa... I would back off the 300 just a little ...and work on focus
alex

[AlexN]

i did a lot of images at 30sec to 1 minute.... I found out very quickly that you really want 5 minute exposures at least to get good signal to noise ratios..

I found that stacking 30sec subs generally gave noisy results...

[xelasnave]

true but if you are starting out and you find getting a decent polar align not easy the 30 sec shot approach is very encouraging
alex

[Octane (Humayun)]

You can do wonders with 30 second sub-exposures.

Here's one of my very first efforts from Lostock in 2006, using a 50mm lens.

The Pointers in Centaurus and the Southern Cross (Crux)

Noisy -- yes. Acceptable -- I think so.

Once my equipment is all set up, I hope to do this region wonders.

Regards,
Humayun

[xelasnave]

Here you go ..this was taken with the $200 70.300 l3ns on a canon 450d that I am still learning about...and done while I was doing other things, the mount was playing up, no darks two long exposures that still did not show up the mount problem...it was so out you could not stack images taken 2 hours apart... wild distrotions I should post them so strange...but to give you an idea of a effort you should better first couple of goes
alex

[xelasnave]

Hang on I will have to put in Deep Sky as it wont blow up here I think.
alex

[xelasnave]

Anyways I was not really trying in so far as I was setting up to take this object the next night (which did not happen) and tweaking the gear for the next night as I wanted to get horse head ... with that lens..you may see it ..but the next night as I said didnt happen so I played with some test shots

alex

[Wavytone]

Over the next week I hope to have a chance at a shot of the night sky using a very small compact with a fast lens - a Panasonic LX3 - with a 2.5X converter that gives the equivalent of 150mm at f/2.8. Big glass on a small compact. It's able to expose for a minute and the noise looks tolerable from such a small camera. While I don't expect much it is conceivable that it will record the brighter stars.

If I was more serious I'd acquire the gear but I don't see much point in imaging since so many others are, with more spare time and skies far better than I have.

[xelasnave]

I am dying to get a go... new camera most things sortted but the weather just beats me every dark.
alex