Given the proliferation of small drones for observation, has any
progress been made on reflective optics for cameras? Mirrors weigh
less than lenses, usually, and drone mounted cameras seem a very
attractive application for them. Reflecting optics work in the IR,
which would seem to be an added benefit for certain applications.
Thanks for reading, and any insights!
bob prohaska
Nikon had some mirror lenses, most notably the 500mm f/8. The bokeh is
very ugly and the aperture isn't variable, which is why they don't get
used.
Given the proliferation of small drones for observation, has any
progress been made on reflective optics for cameras? Mirrors weigh
less than lenses, usually, and drone mounted cameras seem a very
attractive application for them. Reflecting optics work in the IR,
which would seem to be an added benefit for certain applications.
On 2023-02-22 21:44, bob prohaska wrote:
Given the proliferation of small drones for observation, has anyMost drones are quite small and so are their cameras - to the point
progress been made on reflective optics for cameras? Mirrors weigh
less than lenses, usually, and drone mounted cameras seem a very
attractive application for them. Reflecting optics work in the IR,
which would seem to be an added benefit for certain applications.
where any "gain" in weight savings is too small v. the limitations that
a cat lens would bring.
One point of using drones is you can get much closer to what you're observing, most often undetected, so the need for a longer lens is less.
It's germane to note that the dominant small drone maker is DJI, a
Chinese company. They purchased a majority stake in Hasselblad in large
part to get access to their sensor and lens design expertise. This has
not yielded a cat to date that I know of.
To date the trend on such drones has been ever smaller drones and
cameras (at least for the lower end of the market).
For larger (small) drones that carry larger cameras for professional
use, (film making, defense, security, inspection etc.), including IR
sensors, they tend to go with the optics systems provided by the camera maker. I haven't seen a cat to date (not that I've been looking very
hard at such...)
On Thursday, 23 February 2023 at 15:34:41 UTC, Alan Browne wrote:
On 2023-02-22 21:44, bob prohaska wrote:
Given the proliferation of small drones for observation, has anyMost drones are quite small and so are their cameras - to the point
progress been made on reflective optics for cameras? Mirrors weigh
less than lenses, usually, and drone mounted cameras seem a very
attractive application for them. Reflecting optics work in the IR,
which would seem to be an added benefit for certain applications.
where any "gain" in weight savings is too small v. the limitations that
a cat lens would bring.
One point of using drones is you can get much closer to what you're
observing, most often undetected, so the need for a longer lens is less.
It's germane to note that the dominant small drone maker is DJI, a
Chinese company. They purchased a majority stake in Hasselblad in large
part to get access to their sensor and lens design expertise. This has
not yielded a cat to date that I know of.
To date the trend on such drones has been ever smaller drones and
cameras (at least for the lower end of the market).
For larger (small) drones that carry larger cameras for professional
use, (film making, defense, security, inspection etc.), including IR
sensors, they tend to go with the optics systems provided by the camera
maker. I haven't seen a cat to date (not that I've been looking very
hard at such...)
I'd say the biggest drone with a camera that uses mirrors is the James Webb telescope.
But maybe that is pushing the definition of what a drone and a cat lens is :-)
For larger (small) drones that carry larger cameras for professional
use, (film making, defense, security, inspection etc.), including IR
sensors, they tend to go with the optics systems provided by the camera
maker. I haven't seen a cat to date (not that I've been looking very
hard at such...)
I'd say the biggest drone with a camera that uses mirrors is the James Webb telescope.
But maybe that is pushing the definition of what a drone and a cat lens is :-)
Given the proliferation of small drones for observation, has any
progress been made on reflective optics for cameras? Mirrors weigh
less than lenses, usually, and drone mounted cameras seem a very
attractive application for them. Reflecting optics work in the IR,
which would seem to be an added benefit for certain applications.
Thanks for reading, and any insights!
bob prohaska
On Thursday, 23 February 2023 at 15:34:41 UTC, Alan Browne wrote:
On 2023-02-22 21:44, bob prohaska wrote:
Given the proliferation of small drones for observation, has any progress been made on reflective optics for cameras? Mirrors weighMost drones are quite small and so are their cameras - to the point
less than lenses, usually, and drone mounted cameras seem a very attractive application for them. Reflecting optics work in the IR,
which would seem to be an added benefit for certain applications.
where any "gain" in weight savings is too small v. the limitations that
a cat lens would bring.
One point of using drones is you can get much closer to what you're observing, most often undetected, so the need for a longer lens is less.
It's germane to note that the dominant small drone maker is DJI, a
Chinese company. They purchased a majority stake in Hasselblad in large part to get access to their sensor and lens design expertise. This has
not yielded a cat to date that I know of.
To date the trend on such drones has been ever smaller drones and
cameras (at least for the lower end of the market).
For larger (small) drones that carry larger cameras for professional
use, (film making, defense, security, inspection etc.), including IR sensors, they tend to go with the optics systems provided by the camera maker. I haven't seen a cat to date (not that I've been looking very
hard at such...)
I'd say the biggest drone with a camera that uses mirrors is the James Webb telescope.
But maybe that is pushing the definition of what a drone and a cat lens is :-)
On Thursday, February 23, 2023 at 10:47:37 AM UTC-5, Whisky-dave wrote:
On Thursday, 23 February 2023 at 15:34:41 UTC, Alan Browne wrote:
On 2023-02-22 21:44, bob prohaska wrote:
Given the proliferation of small drones for observation, has anyMost drones are quite small and so are their cameras - to the point
progress been made on reflective optics for cameras? Mirrors weigh
less than lenses, usually, and drone mounted cameras seem a very
attractive application for them. Reflecting optics work in the IR,
which would seem to be an added benefit for certain applications.
where any "gain" in weight savings is too small v. the limitations that
a cat lens would bring.
One point of using drones is you can get much closer to what you're
observing, most often undetected, so the need for a longer lens is less. >>>
It's germane to note that the dominant small drone maker is DJI, a
Chinese company. They purchased a majority stake in Hasselblad in large
part to get access to their sensor and lens design expertise. This has
not yielded a cat to date that I know of.
To date the trend on such drones has been ever smaller drones and
cameras (at least for the lower end of the market).
For larger (small) drones that carry larger cameras for professional
use, (film making, defense, security, inspection etc.), including IR
sensors, they tend to go with the optics systems provided by the camera
maker. I haven't seen a cat to date (not that I've been looking very
hard at such...)
I'd say the biggest drone with a camera that uses mirrors is the James Webb telescope.
But maybe that is pushing the definition of what a drone and a cat lens is :-)
It also did what drones do, which was to “zoom with your feet”, rather than a longer lens,
which in this case was to move just far enough away to get out of the atmosphere and
also into a slower moving orbit than what Hubble has.
Most of them are pure garbage, optically. Forget the donut caused by the central obstruction, the optics themselves are almost uniformly awful.
Excepts are Tamron 350mm f/5.6, Olympus 500mm f/8, Questar 700. But those lenses cost what good lenses do. I got a no-name mirror to play with at a recent camera show for $10 and I wouldn't wish
it on any camera, even if it only had one pixel.
[regarding reflective objectives for cameras]
Most of them are pure garbage, optically. Forget the donut caused by the central obstruction, the optics themselves are almost uniformly awful.
Excepts are Tamron 350mm f/5.6, Olympus 500mm f/8, Questar 700. But those lenses cost what good lenses do. I got a no-name mirror to play with at a recent camera show for $10 and I wouldn't wish
it on any camera, even if it only had one pixel.
8-)
But, reflective optics in the form of a three mirror anastigmat appear
to offer the best of all worlds: no distortions and wide spectral limits.
In principle they can be lightweight as well, which really matters on a drone. True, they don't zoom, but drones are free to move.
Admittedly the tooling costs for aspheric optics are high, but production
is cheap(ish) and the ability to image from near UV to IR limited only
by the detector and maybe diffraction would seem seem to offer vast advantage, exemplified by seeking/tracking imagers for weapons.
Way back when, the only usable materials for refractive IR optics were
things like germanium, or binary compounds like zinc selenide, only a
few of which would even transmit shorter wavelengths. Has that limitation been overcome?
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