[aliquis]

Panasonic engineer reveals workings of GH2 'dual exposure' sensor - Blogs - EOSHD.com

Sony:
"At the end of the talk Suzuki-san referred to two new future imaging functions being 3D imaging and curved image sensors.

Curved image sensors curve around the back of an aspherical lens element, producing huge gains in image quality and lens design. It's actually similar in design to the human retina."

Don't ask me how one do that of a silicon waffer or how it works but cool nonetheless

(Optical fibers of various lengths and cut at various angles?)

[Steinback]

I think Leica was using angled micro lenses on the edge of some sensors to help compensate for the shallow angles at which light was hitting due to a short flange-focal distance.

There were at least a few film cameras that used curved film planes to improve image quality with lenses that focused with a curved field.

[Digitalis]

"I think Leica was using angled micro lenses on the edge of some sensors to help compensate for the shallow angles at which light was hitting due to a short flange-focal distance. "

yep that is correct, though back illuminated sensor technologies will make this approach much more efficient, if not obsolete.

"There were at least a few film cameras that used curved film planes to improve image quality with lenses that focused with a curved field"

give me an example of a 35mm camera that has a curved pressure plate, and I'll believe you.

[lithos]

give me an example of a 35mm camera that has a curved pressure plate, and I'll believe you.

Horizon 202.

[Digitalis]

Horizon 202.

LOL I knew some smart ass would come up with that. okay I'll play, show me a commercially produced 36X24mm SLR camera with a curved pressure plate.

[Ben_Edict]

LOL I knew some smart ass would come up with that. okay I'll play, show me a commercially produced 36X24mm SLR camera with a curved pressure plate.

Wouldn't make much sense, wouldn't it? The field curvatore of any lens used should be the same to make a curved film plane useful. This and the mechanical problems involved (film transport being among them, if the curvatore is more pronounced) do not make this a sensible concept for cameras with interchangeable lenses.

A curved sensor or film plane, I think, is only useful with fixed lens cameras, where the curvatore of the sensor surface and the field curvatore of the lens can be optimzed to match each other.

The only cameras I know off (and have one in my possession) are Schmidt cameras and other scientific imaging systems (like x-raying cameras and some aeronautical cameras), which have curved film planes.

In 35mm system camerasa the efforts were always directed the other way round: to get as plane a film plane as possible through higher precision of the film rails and the pressure plate or viy vacuum backs (Contax RTS III) etc.

Ben

[Steinback]

I'm not aware of any SLRs with a curved film plane; as Ben mentioned the concept makes more sense matched to a single fixed lens.

8x11mm example:
Minox III - Camerapedia.org

35mm examples:
Sakar FF-8 on Flickr - Photo Sharing!
FT-2 - Camerapedia.org

Various medium format examples:
Clack - Camerapedia.org
Purma - Camerapedia.org
Ansco Pioneer - Camerapedia.org
Baby Minolta - Camerapedia.org

Nesster's camera was the one I was thinking of when I made the comment but I had read about medium format examples at one point or another as well.

[lithos]

LOL I knew some smart ass would come up with that.

It's what I'm here for.

[aliquis]

yep that is correct, though back illuminated sensor technologies will make this approach much more efficient, if not obsolete.

Any link with more information or should I just google / read wikipedia?

Wouldn't make much sense, wouldn't it? The field

I'm new and may not understand the problem but I thought it was that light come in at and angle (always) out on the sides of the sensor and that it was some issue with "hitting the gaps" or lenses of the sensor receptors which broke of the light in some way. But maybe that's not it? Is it because the various wave lengths of light is already somewhat moved against eachother after the glass? Or don't all the lenses spread the light at the same angle over the sensor?


Or why doesn't it work and what's the cause of CA to begin with?

[Ben_Edict]

I'm new and may not understand the problem but I thought it was that light come in at and angle (always) out on the sides of the sensor and that it was some issue with "hitting the gaps" or lenses of the sensor receptors which broke of the light in some way. But maybe that's not it? Is it because the various wave lengths of light is already somewhat moved against eachother after the glass? Or don't all the lenses spread the light at the same angle over the sensor?


Or why doesn't it work and what's the cause of CA to begin with?

The problem is, that a curved sensor will be a new variable in this game. Lenses (in fact most) already have a somewhat curved focal plane and the lens designers aim to reduce this curvatore and get a flat focal plane, which then coincides with the flat film/sensor. The inherent field curvatore is mainly dependend on the focal length: the shorter the fl, the higher the amount of field curvatore. This is one of the reasons, why well-corrected wide angle lenses are expensive and have often a very complicated lens design.

If you now introduce a curved sensor, all those lenses, which were corrected to have a flatter field will be unuseable. Some lenses, with a curvatore near that of the sensor will improve in performance - but that would be a tiny number. Also, you then have to unify the sensor curvatore for all cameras or the third party lens makers would be out of the game, if Pentax, Canon etc. would use differently curved sensors. That sure is a idea, which would appeal to some sales paople at the camera makers, but basically, it would be a big blow to the overall market.

On top, I think, that correcting for the micro löens-related problems is more esily done via in-camera post-processing - as some cameras already do - and/or by optimizing the geometry of the micro lenses.

Ofcourse I agree, that a curved sensor would be ideal, because it deals with a couple of optical problems, from field curvatore over vignetting right to distortion - but applying that to a camera system with interchangeable lenses is really a very big problem.

Ben

[aliquis]

Ah, ok.

Well, I guess like if for instance Panasonic want to make a camera even smaller than the NEX or of similar size they would have to redo all the lenses again and maybe then they don't care that much that the old ones aren't designed for it.

Or that they would only do it in non-interchangable lens cameras.

[er1kksen]

I would suspect that something like a curved-sensor would be more likely to make it into their non-interchangeable-lens products and probably on the small-sensor side of things. Smaller curved sensors would probably be cheaper to produce (to a certain point, of course... there's probably an optimal size) and they would make sense in helping to alleviate some of the optical problems encountered when designing super-short fl lenses to project a sharp image onto a tiny pixel-dense sensor.

[Digitalis]

The biggest issues affecting image quality on small cameras these days is the pixel density,trying to make a sensor curved so that the lens is able to provide better resolution isn't going to change much.

[er1kksen]

I disagree. The high pixel density leads to problems with DR, noise, and diffraction starts early, but those aren't the only limiting factors. A big factor is that most of those 10-14mp compacts are going around with lenses that can barely resolve 7mp worth of detail, so up close the images are very soft and display loads of CA. A curved sensor, while it wouldn't eliminate the DR, Noise, and diffraction issues, would at least allow better lenses to deliver more of the detail that the sensor is capable of (a small, high-density sensor coupled with a decent lens, like in the Canon G10, can deliver a surprising level of detail) and help to reduce the CA.

"Pixel Density" isn't really the issue. It's the effects of pixel density, and every year little innovations help to reduce those effects. It's possible that some day we'll reach a point where the sensors are adequate, and at such a time the lenses they put in compacts today would be a severe limiting factor. Curved sensors may be vital to the future of compact cameras, at that point.

[Digitalis]

"help to reduce the CA."

A curved sensor wouldn't affect CA in the slightest. Yes, the lenses in compact cameras are bad, compared to SLR designs..but because they are so small the tolerances have to be extremely high to produce a quality product...and that just isn't possible when P&S cameras are experiencing a reduction in market size due to the increase of EVIL cameras, and low priced entry level DSLR cameras.

But I still say the biggest limiting factor in image quality is and always will be the size of the sensor itself in comparison to how many pixels they are cramming on it....Why do you think people use digital medium format backs? because of the high image quality and the fact that a larger sensor enables manufacturers to have a high MP count but keep the size of each pixel large enough to be efficient. there is also the shallower DOF that can be obtained, but that really isn't a quality that has much to do with the sensor itself.