[Elphel-support] Reasonable motorized lenses for 50-60 meters zooming for Elphel camera

[Roman Golomidov]

> That's not that difficult. With that data and knowing that the pixel size is
> 0.0022mm you can calculate focal length of an ideal lens:
> http://www.google.com/search?hl=en&q=60m%2F((200mm%2F150)%2F0.0022mm)+in+mm
> - that would be ~100mm.

So, if I still with motorized zoom then am I right with H10Z1218MS
12-120mm? Or others? Under $1k it is ok to such lenses for me.
I didn't find any fixed length above 100mm for 1/2" Format at computar
pricelist.

> With the 120mm lens you will get less than 3 degrees horizontal
> If you need 150 pixels on 200 mm than 5 MPix sensor will give you 2.5m x 3.5
> m field of view (100mm lens). With 120mm - it will be even less. Zoom/no
> zoom lens, but without rotation platform you will not be able to see
> anything with full resolution (1.33mm/pixel) outside of that area. to be
> able to see 30 degrees with resolution of 1.3mm at 60 meters without
> mechanical rotation you'll need to have 0.5gigapixel sensor. Or about
> hundred 5 megapixel sensors with individual lenses (still probably cheaper)

Yesterday have experiments with your camera with standard lenses.
Tryed to focus on faces when they would 200 pixels height. In camera's
center and by sides. For my purposes side faces is still recognizeable
:) So if it will be the same quality (center/side) on zooming it
better for me without any additional mechanic.


>
> Andrey
>

Roman Golomidov