Faking and expensive tilt-shift lens

I have found that from russia you can have tilt and shift lenses:
http://www.rugift.com/index.html
which are not so expensive.


--
Juha Heinonen
FINLAND
Mobile: +358 405492347
E-mail:
URL: http://personal.inet.fi/koti/juha.heinonen

I have found that from russia you can have tilt and shift lenses:
http://www.rugift.com/index.html
which are not so expensive.


--
Juha Heinonen
FINLAND
Mobile: +358 405492347
E-mail:
URL: http://personal.inet.fi/koti/juha.heinonen

Mr.T wrote:
"John A." wrote in message
...
As for gaining information, perhaps if you moved the camera to the left
a half a pixel for the second shot. :-)
I wonder if any of the cameras with in-body image stabilization could
be firmware-hacked to do that.

No way could they move only half a pixel, including vibration, unless by
accident :-)

You have no idea what translation resolution is.


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"Chris Malcolm" wrote in message
...
| In rec.photo.digital.slr-systems Mr.T MrT@home wrote:
|
| "John A." wrote in message
| ...
| As for gaining information, perhaps if you moved the camera to the
left
| a half a pixel for the second shot. :-)
|
| I wonder if any of the cameras with in-body image stabilization could
| be firmware-hacked to do that.
|
| No way could they move only half a pixel, including vibration, unless by
| accident :-)
|
| I don't know whether any of the current in-body stabilisers can
| actually do it, but very similar technology has been employed for
| decades now to adjust the position of slides in automated microscopy,
| and that technology is certainly capable of well under half a pixel
| adjustments.


and moving half a pixel gives you..?


moving 2 might give something useful

"k" wrote in message
...
and moving half a pixel gives you..?

Theoretically some of the information you lost in between pixels.

moving 2 might give something useful

What, a few hundred extra pixels in image size? Far better to move a full
screens worth in that case!

MrT.

On Mon, 09 Feb 2009 01:32:10 -0500, John A. wrote:

and moving half a pixel gives you..?


moving 2 might give something useful

Moving a half pixel horizontally, then vertically, then back
horizontally for a total of four exposures would give full coverage
for each color in a Bayer pattern. (Double coverage for green,
actually.)

Moving 1/2 pixel isn't enough. Starting from a point centrally
located between 4 pixels, one way for a movable filter array to have
each filter color reach of the 4 pixels would be :

0. Move down 1/2 pixel and right 1/2 pixel

1. Click! Move up 1 full pixel

2. Click! Move left 1 full pixel

3. Click! Move down 1 full pixel

4. Click! Move right 1 full pixel

5. Go to #1 for each successive photo

The same four positions could also be reached by either shifting
or rotating the filter array along a circular path, where the
diameter of the circle would be equal to the distance between 2
non-adjacent pixels, presumably the distance between an Red/Blue
pair or a Green/Green pair.

On Mon, 09 Feb 2009 03:40:39 -0500, ASAAR wrote:

On Mon, 09 Feb 2009 01:32:10 -0500, John A. wrote:

and moving half a pixel gives you..?


moving 2 might give something useful

Moving a half pixel horizontally, then vertically, then back
horizontally for a total of four exposures would give full coverage
for each color in a Bayer pattern. (Double coverage for green,
actually.)

Moving 1/2 pixel isn't enough. Starting from a point centrally
located between 4 pixels, one way for a movable filter array to have
each filter color reach of the 4 pixels would be :

0. Move down 1/2 pixel and right 1/2 pixel

1. Click! Move up 1 full pixel

2. Click! Move left 1 full pixel

3. Click! Move down 1 full pixel

4. Click! Move right 1 full pixel

5. Go to #1 for each successive photo

The same four positions could also be reached by either shifting
or rotating the filter array along a circular path, where the
diameter of the circle would be equal to the distance between 2
non-adjacent pixels, presumably the distance between an Red/Blue
pair or a Green/Green pair.

On a Bayer-filtered sensor 1/2 pixel = 1 photosite. In your sequence
remove step "0" (which is pretty much meaningless) and replace "pixel"
with "photosite" and you've pretty much got what I've described.

In article , John A.
wrote:

On a Bayer-filtered sensor 1/2 pixel = 1 photosite.

that's incorrect.

On Mon, 09 Feb 2009 18:24:05 GMT, John A. wrote:

On a Bayer-filtered sensor 1/2 pixel = 1 photosite. In your sequence
remove step "0" (which is pretty much meaningless) and replace "pixel"
with "photosite" and you've pretty much got what I've described.

You still don't get it. First of all, the "0" step was only used
to identify the surrounding 4 pixels (sensels). Traversing from any
pixel to the next requires stepping the distance from one pixel to
another, which is *not* 1/2 the distance/size of a pixel. If it'll
help, place four hamburgers on a plate. How far is it from the
center of one hamburger to either of its adjacent neighbors (not the
diagonally opposite burger). If you say it's 1/2 of a hamburger's
diameter, you've bitten off more than you can chew.

On Mon, 09 Feb 2009 15:28:12 -0500, ASAAR wrote:

On Mon, 09 Feb 2009 18:24:05 GMT, John A. wrote:

On a Bayer-filtered sensor 1/2 pixel = 1 photosite. In your sequence
remove step "0" (which is pretty much meaningless) and replace "pixel"
with "photosite" and you've pretty much got what I've described.

You still don't get it. First of all, the "0" step was only used
to identify the surrounding 4 pixels (sensels). Traversing from any
pixel to the next requires stepping the distance from one pixel to
another, which is *not* 1/2 the distance/size of a pixel. If it'll
help, place four hamburgers on a plate. How far is it from the
center of one hamburger to either of its adjacent neighbors (not the
diagonally opposite burger). If you say it's 1/2 of a hamburger's
diameter, you've bitten off more than you can chew.

I get it. You don't.

If a sensor is going to be moving like this its initial position will
already be where your step "0" is intended to put it, so that step is
not necessary. We can safely assume the sensor will be designed to
start out exactly where it needs to be for its first exposure. It's
just good engineering. Otherwise it's just added motion that only
serves to wear the mechanism. Seriously, why would it have a "home"
position somewhere other than where it needs to be for one of the four
exposures?

And a pixel IS made of 2x2 photosensors on a Bayer-filtered sensor
array. The sensors are arranged something like this:

G R
B G

Together, those four photosensors make up one pixel.

Ahhh... But I think I see what you're talking about. That's in a
single-exposure Bayer system. In the theoretical four-exposure system
we are discussing we would get four three-color synthesized pixels
from each 2x2 Bayer array. (Minus a row and a column for the image, I
believe, assuming we'd only keep the overlapping portions of the four
exposures.) That was what you meant, right?

So maybe we both get it, and don't get it. =D