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01-18-2008, 06:10 PM   #1
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Next Next Pentax. Now

If an image circle really is circle, then only a square would be the optimal shape of the sensor. A square covers the maximum area that you can cover inside of a circle with a rectangle because no other rectilinear shape can cover as much area inside of a circle as a square.

Can someone confirm this for me mathematically? I'm not really good at math.

....and this keyboard sucks so bad that my fingers hurts so im not explaining this anymore.


Last edited by MJB DIGITAL; 01-18-2008 at 08:24 PM. Reason: grammar: hmm i thought i was good at that....dang
01-18-2008, 07:44 PM   #2
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im also wondering if anyone knows where i can look at lens diagrams online.

thanks
01-18-2008, 07:53 PM   #3
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A circle would be optimal!

But since rectangular images usually are more pleasing to the eye than square or circular, that's what our cameras produce!
01-18-2008, 07:56 PM   #4
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QuoteOriginally posted by MJB DIGITAL Quote
im also wondering if anyone knows where i can look at lens diagrams online.

thanks
Bojidar's page has the optical diagrams of all Pentax lenses:

Welcome to Bojidar Dimitrov's Pentax K-Mount Page

01-18-2008, 08:32 PM   #5
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QuoteOriginally posted by MJB DIGITAL Quote
If an image circle really is circle, then only a square would be the optimal shape of the sensor. A square covers the maximum area that you can cover inside of a circle with a rectangle because no other rectilinear shape can cover as much area inside of a circle as a square.
A square is the largest -- here's the proof if you're interested: WikiAnswers - Find the dimensions of the rectangle of largest area ...


But, if you *want* a rectangular shape in the end, going with a square means you're either wasting a lot of valuable space on the sides, or else you have a square so big that it goes out of the image circle on the corners. A compromise might be to make the sensor shaped like a + or, as I said in another thread, like a + with a larger square in the middle (so stair-stepped). This would be a little more practical than a circle, and you could choose in-camera if you wanted landscape, portrait, or square. Not sure how the viewfinder would work, though.

The best compromise is to match your typical output format as closely as possible.
01-18-2008, 10:17 PM   #6
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I vote for a square++

regular hexagon and I know people at Pentax already work on it.
Do not believe it? take look into a viewfinder ;-)
01-19-2008, 10:05 AM   #7
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QuoteOriginally posted by Ole Quote
A circle would be optimal!

But since rectangular images usually are more pleasing to the eye than square or circular, that's what our cameras produce!
oh yeah, duh.
hmmmm
worlds first circle format camera? ha

I want a square format anyway. 8P

01-19-2008, 10:19 AM   #8
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If 2:3 is set standard ratio for rectangular recptors in cameras (film or sensors) why do we have circular lenses?
01-19-2008, 10:43 AM   #9
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we seem to have a number of points raised here, so lets hit them one at a time.

although a circle would be the optimum shape for a receptor , in terms of pixles per square cm. a circle is NOT the most efficient thing to cut a receptor from. film came in strips, putting a bunch of curcular images on film would waste an incredible amount of film surface. While you only make a lens once, and may use it for thousands of shots, you need a newpeice of film and paper for each image. A circle only fills 78% of a square therefore 22% of all film and paper would be wasted. Therefore square or rectangular was better and more economical in the past..

Televisions began as circular, and went to a 4/3 format because it was easier to produce than a wide screne, this has changed in the last few years as production techniques have permitted wide screnes

In the present, the same issue comes from the economical manufacture of sensors. they are cut as slices from a very large crystal. again it is more economical to cut and process squares or rectangles.

So now the only issue is, what is the aspect ratio?

While square is the most efficient for lens use, (cant argue physics) it is not necessairly the best for pictures.
- People , for example are not square. (for the most part any way, please don"t add any bad jokes here, I am working very hard not to myself)
- We don't see equally horizontal and vertical, we see much more horizontally,
- many objects we look at are either quite wide or quite high, but rarely square.

Aside from all of this, as someone pointed out, rectangular images seem to be more pleasing to the eye
01-19-2008, 11:15 AM   #10
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A square format sensor would be best. You can crop rectangles from your square image or not, your choice.

ROT viewfinder would work very well too for compositioning. Or, a viewfinder with standard crops shown to aid in composition.

The average Joe consumer might see the square format as a hassle but us photo-geeks would love it.
01-19-2008, 12:29 PM   #11
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QuoteOriginally posted by Tom M Quote
A square format sensor would be best. You can crop rectangles from your square image or not, your choice.

ROT viewfinder would work very well too for compositioning. Or, a viewfinder with standard crops shown to aid in composition.

The average Joe consumer might see the square format as a hassle but us photo-geeks would love it.
tom, maybe, but what size square, one to fit the image circle of current lenses, or something smaller.

also a square would cost us width within the same sized image circle, and to get a taller image would do the same compared to turning the camera.

If it is agreed the most pleasing format is rectangular, why give up this for a square which would be optimum for only a small percentage of shots

Last edited by Lowell Goudge; 01-19-2008 at 12:36 PM.
01-19-2008, 01:08 PM   #12
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I think the confusion lies in the fact you're assuming I want a square format in APS-C, which I don't. It is my thinking that if I had a Full Frame square format sensor I could get images just as wide as current APS-C is now but ones that are also as tall as they are wide.

Essentially, I'm OK with the 1.5x cropped image circle the APS-C provides, just give me a larger format so I can get an APS-C-squared image.

And for the folks that want normal FF rectangular crop, it's just a menu button choice away.

here's a quick diagram of what I mean.. This way you get the best of both worlds - standard FF as well as APS-C square format. They do it now with that 4.3/16.9 in P&S cameras etc.. Hmm, the diagrammight not be the best but I think you get the idea. If they switched to a FF sensor we'd be able to choose our prefered crops, FF, APS-C 4.3/16.9/Square

Last edited by Tom M; 02-05-2008 at 05:06 PM.
01-19-2008, 01:27 PM   #13
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OK I see what you want, now, this will, of course change the shutter dimensions. going taller on a vertically moving shutter will possibly change the size and shape of the mirror box also. I/m not sure geometrically that you could fit the same mirror in all cases unless you go back to the size of a 35mm shutter and mirror box.
01-19-2008, 05:20 PM   #14
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thats interesting about changing the distance for the shutterby changing to a square.

but you still get maximum rectilinear coverage, then you can crop your 5x7 or 16x9 or 12x36 or whatever.
01-20-2008, 07:25 AM   #15
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Wouldn't it also be nice if computer monitors, camera lcds, and lcd projectors were all square? Then horizontal & vertical shots would show the same size with the format we have now. I miss slides because of this.
thanks
barondla
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