Using the full circle of the square - aspect ratios and the imaginary circle.

Started 4 months ago | Questions thread
TeddyD Senior Member • Posts: 1,108
Re: Using the full circle of the square - aspect ratios and the imaginary circle.

FrancoD wrote:

TeddyD wrote:

Ellis Vener wrote:

Toronto Photography wrote:

Ellis Vener wrote:

Toronto Photography wrote:

A general and specific question.

The general. Lenses are round, Sensors are square. Whenever you see a square image you are throwing data away - is there a way to get the full Circle of your photographs with any camera? And more specifically the Canon 3ti?

dont forget that

1) with a zoom lens the diameter of the circle changes with the focal length.

2) that with both fixed and variable focal length lenses, the diameter of the circle changes with the distance to the subject, Most obviously when you are focusing close enough that the ratio between the size of the object and the projected image is greater than 1:8.

3) a few lenses (tilt-shift lenses mainly but also fisheye zoom lenses ) project a much larger image circle than conventional design lenses of the same focal length


Which aspect ratio gets the most data ? Which removes the most? Does it differ from camera and to camera

off the top of my head this can be figured out by geometry. Compare the area of a circle with the area of different rectangular formats that could fit into that circle. Also off the top of my head, I think it is going to be rectangular 1:1.25 (4x5, 8x10, etc.) format.

Thanks for the info.

There is one more issue, and it has nothing to do with the image circle size of the lens but is also related to geometry at manufacturing costs.
As I understand how CMOS sensor arrays are made, those arrays are fabricated on circular disks and then cut out of that disk. If I am not mistaken, cutting out circular sensor arrays would not efficiently use the disk as harvesting rectangular arrays.
Ellis Vener
A working photographer since 1984.
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Which make agood point pro circular sensors, no need to cut the disc. Large format circular sensor, maybe GB file size...

A silicone wafer is usualy 8" wide.

This gives a godd idea of the cost differences as you go up in the final sensor size.

Cutting circles out of those wafers woul substantialy increase the wastage and therefore the cost of each single wafer.

Note that you can have 10 x more 1" sensors than FF from the same wafer.

You missed the point by a mile.. Round large format 8" sensor 0% waste. The most effective use of the wafer.

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