Pleaides with 300mm lens - further tips required

That's a good effort Seanie, at 300mm, with no tracking, you would proably get star trailing after 5 seconds. I would beg to differ about the neblosity, without tracking, I really doubt that you will see any neblosity after even 5 seconds at this focal length and stacking, I have tried this before with no result.

Now if you could track, there would be a different result. At f5.6, you are at the maximum light gathering power of the lens at 300mm.

Keep up the good Work Seanie

Keith..

at 300mm, with no tracking, you would proably get star trailing after 5 seconds.
Keith..

I did some tests with that kind of lens and found trailing begins at 3 sec .

Keep snappin Seanie,
Registax is the tool of choice for this kinda stuff.

Longer exposures.
Requires tracking.
Take plenty of images.
Stack them up.

Thanks for the kind words and tips guys, it's all appreciated.

Seanie, I'm finding with the 350D that nebulosity in M45 is only starting to be seen at 30sec exposures, and even then only after stacking 12 or more (Use DSS for this as it can take in the RAW CR2 files directly and is much faster than Registax)- even at that, you'll only get a hint of the Nebulosity, its not extensive. Mind you I am using ISO200, but that is mostly because of light pollution, and orange skies if I run much longer.

Fact is - without long tracked exposures, you'll only drive yourself bananas trying to achieve the impossible. You might get some success with M42 on shorter exposures, but then its a much brighter nebula.

Seanie, I'm finding with the 350D that nebulosity in M45 is only starting to be seen at 30sec exposures

When I was taking these shots on Sunday night, I was thinking that with M45 on long exposures (even after 5 seconds) that I was seeing nebulosity. Now, I also considered the fact that I KNOW they have nebulosity, so was I either seeing what I wanted to see, seeing what was there, or (worst case, by coincidence) seeing 'nebulosity' due to an artefact of refraction of the light from the brightest stars? Hence why I ask about how long with my set up would it take to see the nebulosity. Other factors are air quality, transparency, and so on.

I shall continue to experiment.

Seanie.