how come they don't make circular sensors?

[ThrillaMozilla]

Why don't they make circular sensors? The reason is that the current technology mainly focuses on rectangular sensors, which are easier to mass-produce. The accepted standard is the rectangle, which is commonly used in photography and filmmaking. Of course, the idea of circular sensors is interesting, but their production could be more complex and costly. That's why rectangular sensors still dominate.

On the bright side, no one could tell you to level the horizon. Or maybe it would be easier to rotate any picture.

 

[FrancoD]

Why don't they make circular sensors? The reason is that the current technology mainly focuses on rectangular sensors, which are easier to mass-produce. The accepted standard is the rectangle, which is commonly used in photography and filmmaking. Of course, the idea of circular sensors is interesting, but their production could be more complex and costly. That's why rectangular sensors still dominate.

On the bright side, no one could tell you to level the horizon. Or maybe it would be easier to rotate any picture.

both of those were the reasons for Kodak to have their first cameras taking round photos but as we know that changed soon after.

 

[Sittatunga]

We also talk about such things as carbon footprint, but it's almost never elemental carbon that is at issue.

I suppose logically it should be called the CO2 footprint. The fact that the fuel composition is nonspecific (coal, natural gas, petroleum, etc.) offers a fig leaf.

My phone won't let me write COsubscript2 either, and spelling & grammar are even more important with chemical formulae than in prose. CO2 is annoying but not as bad as CO squared (CO²). But mixing up fluorite and fluoride, silicon and silicone, discrete and discreet all give the impression that someone either doesn't know or doesn't care what they're saying. And, yes, the active ingredient in swimming pool water is chlorine, but adding sodium chloride just turns it into dilute brine while adding sodium hypochlorite is what gets the chlorine gas into the water.

We also add chlorine to swimming pools right? But it's really chloride. Same thing.

More specifically, it's usually hypochlorite.

Yeah, I was too lazy to look it up and the word wasn't coming to mind. My point was that in the vernacular, it's common to say chlorine. If it works for chlorine, it seems like it should work for fluorine.

With water chlorination the chemical agent is nonspecific, so "chlorine" may be as specific as you can get. It could be chlorine gas or a chlorine compound. Sodium or calcium hypochlorite solution is usually chlorine gas dissolved in an alkali solution.

They're actually kissing cousins. (why do I feel like I'll get backlash from that now?)
Back to the post this discussion started with, I don't think I've ever seen it mentioned that lenses are coated in fluorine, other than in this thread.

It's all over. Marketing departments don't know the difference.

 

[J A C S]

Canon has been making fluoride crystals since 1968 so I think they do know a bit about it yet are happy to use ,at times, the word fluorine to describe what they use in their glass.

BTW, the company that does make it is called Canon Optron.

BTW, in the old days they used the word fluorite.

They still do. Unfortunately, the same page also refers to "fluorite and other optical glass". Fluorite is not glass.

It exists as a crystal (synthetically grown in this case) which is what glass is as well. Besides, we can take “fluorite” as an adjective in that sentence.

That is another likely source of confusion, because fluorides are possible additives to optical glass.

Canon Inc. produces synthetic fluorite crystals that are used in their better telephoto lenses.

wikipedia

 

[Joseph S Wisniewski]

You do realize that a circular sensor implied either a 'circualr viewfinder or a a circle image in a square viewfinder, same for LCD

Or a viewfinder that doesn't show 100% of the image that's captured, which is actually pretty typical. You can tell it's typical by the fact that camera reviews typically mention the percentage of coverage of the viewfinder.

Only for DSLRs.

All the mirrorless cameras I have used give 100% coverage.

Also analog SLRs.

I've not owned many FSLRs that had 100% viewfinder coverage. Generally, that was a "flagship" model feature seen on cameras in the $6,000 range (adjusted for inflation).

• 100% Nikon F5 ($3,200 at launch in 1996. That's $6,499 today)
• 100% Nikon F3 (but it was fairly common for that to only partially overlap the film plane image)
• 96% Nikon F100 ($1,430 at launch in 1999. That's $2,730 today)
• 93% Nikon FA ($636 at launch in 1983. That's $2,071 today, and its without a motor drive)
• 93% Nikon FM2
• 92% Nikon N8008/F801

EVIL (aka "mirrorless") cameras have 100% coverage across the line. The Z7 II has it at $2,300. ZF at $2,000. Z6 II at $1,600. Z5 at $1,000. Even a $760 Z50 has it.

 

[ThrillaMozilla]

Canon has been making fluoride crystals since 1968 so I think they do know a bit about it yet are happy to use ,at times, the word fluorine to describe what they use in their glass.

BTW, the company that does make it is called Canon Optron.

BTW, in the old days they used the word fluorite.

They still do. Unfortunately, the same page also refers to "fluorite and other optical glass". Fluorite is not glass.

It exists as a crystal (synthetically grown in this case) which is what glass is as well. Besides, we can take “fluorite” as an adjective in that sentence.

Glass is NOT a crystal!

That is another likely source of confusion, because fluorides are possible additives to optical glass.

Canon Inc. produces synthetic fluorite crystals that are used in their better telephoto lenses.

wikipedia

Yes, as this link, which is quoted above, makes clear: They still do.

 

[GeoffRG]

Canon has been making fluoride crystals since 1968 so I think they do know a bit about it yet are happy to use ,at times, the word fluorine to describe what they use in their glass.

BTW, the company that does make it is called Canon Optron.

BTW, in the old days they used the word fluorite.

They still do. Unfortunately, the same page also refers to "fluorite and other optical glass". Fluorite is not glass.

It exists as a crystal (synthetically grown in this case) which is what glass is as well. Besides, we can take “fluorite” as an adjective in that sentence.

Glass is NOT a crystal!

You beat me to it.

That is another likely source of confusion, because fluorides are possible additives to optical glass.

Canon Inc. produces synthetic fluorite crystals that are used in their better telephoto lenses.

wikipedia

Yes, as this link, which is quoted above, makes clear: They still do.

 

[Victor Engel]

You do realize that a circular sensor implied either a 'circualr viewfinder or a a circle image in a square viewfinder, same for LCD

Or a viewfinder that doesn't show 100% of the image that's captured, which is actually pretty typical. You can tell it's typical by the fact that camera reviews typically mention the percentage of coverage of the viewfinder.

Only for DSLRs.

All the mirrorless cameras I have used give 100% coverage.

Also analog SLRs.

I've not owned many FSLRs that had 100% viewfinder coverage. Generally, that was a "flagship" model feature seen on cameras in the $6,000 range (adjusted for inflation).

• 100% Nikon F5 ($3,200 at launch in 1996. That's $6,499 today)
• 100% Nikon F3 (but it was fairly common for that to only partially overlap the film plane image)
• 96% Nikon F100 ($1,430 at launch in 1999. That's $2,730 today)
• 93% Nikon FA ($636 at launch in 1983. That's $2,071 today, and its without a motor drive)
• 93% Nikon FM2
• 92% Nikon N8008/F801

EVIL (aka "mirrorless") cameras have 100% coverage across the line. The Z7 II has it at $2,300. ZF at $2,000. Z6 II at $1,600. Z5 at $1,000. Even a $760 Z50 has it.

There's a good reason the EVIL ones do but the SLR ones don't. The EVIL ones are not restricted by the light path like SLRs are.

 

[Sittatunga]

You do realize that a circular sensor implied either a 'circualr viewfinder or a a circle image in a square viewfinder, same for LCD

Or a viewfinder that doesn't show 100% of the image that's captured, which is actually pretty typical. You can tell it's typical by the fact that camera reviews typically mention the percentage of coverage of the viewfinder.

Only for DSLRs.

All the mirrorless cameras I have used give 100% coverage.

Also analog SLRs.

I've not owned many FSLRs that had 100% viewfinder coverage. Generally, that was a "flagship" model feature seen on cameras in the $6,000 range (adjusted for inflation).

• 100% Nikon F5 ($3,200 at launch in 1996. That's $6,499 today)
• 100% Nikon F3 (but it was fairly common for that to only partially overlap the film plane image)
• 96% Nikon F100 ($1,430 at launch in 1999. That's $2,730 today)
• 93% Nikon FA ($636 at launch in 1983. That's $2,071 today, and its without a motor drive)
• 93% Nikon FM2
• 92% Nikon N8008/F801

EVIL (aka "mirrorless") cameras have 100% coverage across the line. The Z7 II has it at $2,300. ZF at $2,000. Z6 II at $1,600. Z5 at $1,000. Even a $760 Z50 has it.

There's a good reason the EVIL ones do but the SLR ones don't. The EVIL ones are not restricted by the light path like SLRs are.

 

[Victor Engel]

You do realize that a circular sensor implied either a 'circualr viewfinder or a a circle image in a square viewfinder, same for LCD

Or a viewfinder that doesn't show 100% of the image that's captured, which is actually pretty typical. You can tell it's typical by the fact that camera reviews typically mention the percentage of coverage of the viewfinder.

Only for DSLRs.

All the mirrorless cameras I have used give 100% coverage.

Also analog SLRs.

I've not owned many FSLRs that had 100% viewfinder coverage. Generally, that was a "flagship" model feature seen on cameras in the $6,000 range (adjusted for inflation).

• 100% Nikon F5 ($3,200 at launch in 1996. That's $6,499 today)
• 100% Nikon F3 (but it was fairly common for that to only partially overlap the film plane image)
• 96% Nikon F100 ($1,430 at launch in 1999. That's $2,730 today)
• 93% Nikon FA ($636 at launch in 1983. That's $2,071 today, and its without a motor drive)
• 93% Nikon FM2
• 92% Nikon N8008/F801

EVIL (aka "mirrorless") cameras have 100% coverage across the line. The Z7 II has it at $2,300. ZF at $2,000. Z6 II at $1,600. Z5 at $1,000. Even a $760 Z50 has it.

There's a good reason the EVIL ones do but the SLR ones don't. The EVIL ones are not restricted by the light path like SLRs are.

The other good reason from film days is that slide mounts were generally slightly smaller than the format in order to give a good clean straight edge to the borders. And machine printers generally had slightly undersized negative masks for similar reasons and to allow for all sorts of tolerances.

Speaking of slides, going in the opposite direction, along similar lines to this circular sensor topic was superslides. With superslides, a 4cm square image was made on typically 127 film, larger than 35mm film but smaller than 120 film. The slides were mounted in frames of the same outside dimension as 35mm slides, about 2" square. They could be displayed in standard 35mm slide projectors but had a larger format, covering more of the image circle of the projector. One side of this format was just barely smaller than the diagonal of 35mm slides. I suppose there was some risk of vignetting at the corners, but I never noticed that. I guess projectors typically had an image circle that covered more than required for 35mm slides, perhaps to accommodate a variety of focus distances or zoom ratios. That would depend on the lens, of course. I'm not up on slide projector lens details.

 

[Enginel]

There's a good reason the EVIL ones do but the SLR ones don't. The EVIL ones are not restricted by the light path like SLRs are.

Only FF ones are *somewhat* restricted, and in vertical direction only. APS-C and m43 DSLRs have disproportionately large flange distances and could have easily allowed > 100% OVF coverage, which mirrorless camera can't do. This could have been a DSLR advantage over mirrorless, extending OVF coverage without expensive silicon.

 

[Enginel]

Plus, modern cameras are pretty cramped with electronics, etc. More space would be needed. The IBIS mechanism would have to be completely redone and enlarged, etc.

Manufacturers aren't making small cameras anyway, Sony A7 series grew in size and bulk a lot.

IBIS is needed less and less as sensors improve.

And category of users who would benefit from circular sensor the most, probably has least need of IBIS now. Just several years ago, when Sony FE was only FF mirrorless, CaNikon users were saying "Who needs IBIS? All the lenses that need stabilization, already have it"

 

[J A C S]

Plus, modern cameras are pretty cramped with electronics, etc. More space would be needed. The IBIS mechanism would have to be completely redone and enlarged, etc.

Manufacturers aren't making small cameras anyway, Sony A7 series grew in size and bulk a lot.

The initial small size and weight were a part of the marketing strategy to gain costumers.

And category of users who would benefit from circular sensor the most, [...]

They are welcome to buy MF cameras having a native 4:3 ratio.

 

[chrisfisheye]

Hello,

Here are the potential gains by using a multi ratio sensor compared to the native ratio (3:2)

• ratio 16/9

Resolution : +9.7%

Total Light; +0.14 stops.

• ratio 4/3

Resolution: +17%

Total light: +0.23 stops

• ratio 1:1

Resolution: +62%

Total light; +0.7 stops.

Just a remark, a multi ratio sensor does not need to be circular, and covering 16/9 to4/3 would require a sensor just slightly bigger..

The resolution is in term of surface (or pixel), I assume the same pixel density.

We have the advantage of a bigger sensor, it would add some value to all the lenses.

 

[golddc]

IMO the essential reason is that our two eyes are positioned horizontally and each eye has a horizontal opening, resulting in a view angle of about 180 degrees horizontal and 120 degrees vertical. (Numbers vary but the idea is the same.)

And then we can deduce that:

1) if you are looking at a picture or a movie close enough, you see a landscape portion of it more naturally, and you will have to move your eyes or head up and down to see the parts on the top and on the bottom. In other words, the parts on the top and on the bottom are less looked at.

And 2) if you are looking at a picture from a distance so you can see the top and bottom of the picture better, then the left and right part of your view area are less used, and the things which fill those parts may become distractions.

Saving money by manufacturing a rectangular sensor (which is placed in the landscape position in the camera) is a result of the reason above - why spend money on parts less used?