Image stabilising lenses

[Markatw]

Hi - I'm looking at buying a secondhand 300mm lens for my Canon DSLR to start taking images. I've come across Canon lenses that have in built image stabilisation.

I don't have a tracking mount. Does anyone know if, or by how much, the image stabilisation system can extend exposure times before stars start to create trails across the image?

Many thanks.

[oldpink]

image stabilizing at fast FPS is easy
when doing long exposures I doubt it would be of any use as it has to see movement to correct it
I may be wrong  though

[Markatw]

Oldpink - thanks that's very helpful. Maybe I'll just buy a cheaper lens and an astrotrac and have done?

Thanks

[astrorabbit]

Image stabilisation for camera lenses should be switched off for static tripod work, otherwise you get odd results where the system goes a bit nuts and spins the image round creating terrible results... This is especially noticeable in longer exposures.

[oldpink]

unfortunately for Astro Photography there is no real easy  / cheap path by skimping on gear
at least thats my take on it so far last months months outlay is over £200 just to upgrade my imaging capability's on accessory's alone (USB focuser, wifi Xbox dongle & controller, cables, power supply) 
DSO = Deep pockets 

[Markatw]

Dear all - many thanks for your replies - it was worth a try!

I've seen in the threads that people recommend a fixed 300mm lens as opposed to a zoom to avoid instances where the zoom can creep on long exposures. I was keen to go for a zoom for its flexibility.

Has anyone had any problems using zoom lenses?

[Psychobilly]

Pentax use in body stabilisation and there was a unit developed that used it to track the stars - how well it worked - I don't know...

http://www.ephotozine.com/article/pentax-o-gps1-gps-unit-review-20956

In lens stabilisation should be off.. If the lens is likely to spend most of it's time for astro use then go for non IS lens... IS adds extra elements into the lens design that by their very nature are designed to move the image" around on the sensor....  

Primes are better than zooms - especially at the budget ones - Prime are less complicated optically and usually produce cleaner images....

There are some pretty good high end zooms out there but at prices that would probably make your eyes water...

If your main use them for terrestrial then they can be used for astro...

Peter...

[Kirscovitch]

Sorry to jack this thread, but I wanted to get a telephoto lens for my 1100D and was torn between the Canon EF 75-300 f/4-5.6 and a Canon 55-250 f/4-5.6. 

The 75-300 is 60 bucks less but does not have the IS feature that the 75-300 has.

Is the image stabilization worth that much if mounted piggyback on an EQ?

[Psychobilly]

Sorry to jack this thread, but I wanted to get a telephoto lens for my 1100D and was torn between the Canon EF 75-300 f/4-5.6 and a Canon 55-250 f/4-5.6. 

The 75-300 is 60 bucks less but does not have the IS feature that the 75-300 has.

Is the image stabilization worth that much if mounted piggyback on an EQ?

It's of no use at all for tracked astro but for day today shooting is really useful....even then you have to be aware of the "lock time" ... Some lenses can take a while to spin up the IS leading to blurred grabbed shots but if you have time on the subject it's well worth it...

Some of the higher end (usually longer FL) lenses have IS which still works properly when mounted on a tripod......

Peter...

[Kirscovitch]

Only reason I asked was a good friend of mine knows a lot more about photography than me and he hated the non IS lens. Suggested the more expensive one. But he does more normal day to day shooting and not that familiar with AP.

[Zakalwe]

Only reason I asked was a good friend of mine knows a lot more about photography than me and he hated the non IS lens. Suggested the more expensive one. But he does more normal day to day shooting and not that familiar with AP.

Personally I think that expert knowledge in daytime, terrestrial photography is more a hindrance than a help when it comes to AP. The two disciplines are completely different and the techniques used are very different. I've seen a fair few people saying stuff along the lines of "I'm a professional/expert/very good photographer, so AP should be easy for me to pick up". Man, do they ever learn quickly just how different it all is!

IS, as others have said, has to be switched off when shooting on a tripod. Therefore all it is doing is adding weight, cost and optical elements to the job.

I've seen a couple of shots taken with the Pentax system and I was very, very impressed with the results.

http://www.cloudynights.com/ubbthreads/showflat.php/Number/4793879