(meteorobs) Fisheye lens misunderstanding and photography update

[Leo S]

Hi Thomas,

In general, lenses for still photography are much better corrected for 
aberrations than lenses made for video cameras, since moving pictures 
hide many of the flaws that are easily seen in stills. That means 
extreme wide angles are very hard and expensive to make to a standard 
that will be good enough for still photography.

The upshot is that you won't find anywhere near as many super-wide 
lenses for still photography, and when you do find them, they are 
usually super expensive.

Here is a good example, the Nikkor 8mm/2.8 :
http://www.naturfotograf.com/lens_fish.html

If you can find one, it'll cost you many thousands of dollars!

Don't forget, if you are using Canon EOS, you can get adapters to mount 
most other makes of lens, including Nikkors, although in general I think 
Canon's lens line up is better for fast-wide lenses.

I'm afraid if you want to cover the whole sky, you will need multiple 
still cameras. I'd recommend using Canon 20Ds since they are fairly 
cheap and easy to come by now, and the sensor offers excellent 
performance, even compared to the current generation of DSLRs.

Could you post an example of one of the meteors you shot that has a 
"spiral look"? It sounds more like a lens artifact (coma perhaps?) than 
aliasing, which would be due to the sensor.

Leo







Thomas Ashcraft wrote:
> A month ago I asked about fisheye lenses for meteor photography and got 
> some excellent advice here. Thank you.
>
> Here is a brief update;
>
> For the Leonid peak I rented a 15 mm Canon fisheye lens to mount onto a 
> Canon T1i DSLR camera. I did not understand what I was getting at the 
> time as I thought a "fisheye lens" would give *all-sky* coverage from 
> horizon to horizon. In fact, the 15 mm lens was merely a wider field 
> lens.  Apparently, you need a 2 mm or 3 mm fisheye lens to get all-sky 
> coverage.  I am still researching this subject.
>
> Also, the 15 mm Canon fisheye lens tended to cause the meteors I 
> captured to have a spiral look rather than be straight line. I think 
> this is called aliasing.
>
> Since the Leonids I have been operating my camera in continuous 15 
> second shooting mode in the evenings from around dusk to 10:30 PM. The 
> 18-55 mm kit lens that came with the camera seems to be a pretty good 
> lens all in all. It shows the meteors with good detail so far although I 
> have only captured five or so meteors the past month.
>
> Thomas Ashcraft
> New Mexico
>
>
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