Aspect ratio of 10x8 and 5x4?

[abruzzi]

typically people only reduce it to the smallest whole numbers, with a bit of rounding off if necessary, since that's the easiest to work with.

except in the cinema universe where aspect is always stated against 1, so the academy ratio is 1.375:1, widescreen flat is 1.85:1, cinemescope (anamorphic) is 2.35:1. By making all x:1, its easy to tell how they relate.

[Tin Can]

We also have old Electron Microscope sizes

I have a SS glass plate tank made for 10X10 and very old

[maltfalc]

except in the cinema universe where aspect is always stated against 1, so the academy ratio is 1.375:1, widescreen flat is 1.85:1, cinemescope (anamorphic) is 2.35:1. By making all x:1, its easy to tell how they relate.

we're discussing photography here, not cinema, and even in your "exception" people still commonly refer to video aspect ratios as 16:9, 4:3, etc..

[abruzzi]

we're discussing photography here, not cinema, and even in your "exception" people still commonly refer to video aspect ratios as 16:9, 4:3, etc..

Not in the cinema world in my experience, just in the TV world.

[r.e.]

we're discussing photography here, not cinema, and even in your "exception" people still commonly refer to video aspect ratios as 16:9, 4:3, etc..

As @abruzzi points out, 16:9 and 4:3 are shorthand ways of referring specifically to High Definition and Standard Definition Television. Those ratios are used for marketing televisions (and computer displays in the case of 16:9) to consumers in preference to 1.78:1 and 1.33:1. They're also used to describe Hi-Def/Standard-Def capture areas in the marketing of consumer/prosumer hybrid cameras.

I think that how someone approaches aspect ratio depends on what they're trying to accomplish, and that whether one is talking about one photograph or 24 photographs/second is beside the point. To my mind, aspect ratio doesn't even come up as an real issue if you're just deciding whether to print a 4x5 image on 8x10 or 16x20 paper.

On the other hand, for some purposes reducing aspect ratio to its base is useful. It's also common throughout the graphic arts. I don't think that I've ever seen the Golden Rectangle ratio expressed as anything other than 1:1.618 (short side first) or 1.618:1 (long side first). Manipulating that ratio is grade school arithmetic in an era when just about everybody has a calculator in their pocket.

I made the table below because I wanted to see what I have to do with 4x5 and 8x10 sheet film to conform to several aspect ratios. The table takes landscape orientation as a given and image height as the variable. The table makes it easy to compare the resulting heights. Note how 16:9 and 4:3 (rows 5 and 8) are expressed. There's info about this table and what I'm doing with it in the thread Masking a Ground Glass for Cinema Aspect Ratios.

[Alan Klein]

As @abruzzi points out, 16:9 and 4:3 are shorthand ways of referring specifically to High Definition and Standard Definition Television. Those ratios are used for marketing televisions (and computer displays in the case of 16:9) to consumers in preference to 1.78:1 and 1.33:1. They're also used to describe Hi-Def/Standard-Def capture areas in the marketing of consumer/prosumer hybrid cameras.

I think that how someone approaches aspect ratio depends on what they're trying to accomplish, and that whether one is talking about one photograph or 24 photographs/second is beside the point. To my mind, aspect ratio doesn't even come up as an real issue if you're just deciding whether to print a 4x5 image on 8x10 or 16x20 paper.

On the other hand, for some purposes reducing aspect ratio to its base is useful. It's also common throughout the graphic arts. I don't think that I've ever seen the Golden Rectangle ratio expressed as anything other than 1:1.618 (short side first) or 1.618:1 (long side first). Manipulating that ratio is grade school arithmetic in an era when just about everybody has a calculator in their pocket.

I made the table below because I wanted to see what I have to do with 4x5 and 8x10 sheet film to conform to several aspect ratios. The table takes landscape orientation as a given and image height as the variable. The table makes it easy to compare the resulting heights. Note how 16:9 and 4:3 (rows 5 and 8) are expressed. There's info about this table and what I'm doing with it in the thread Masking a Ground Glass for Cinema Aspect Ratios.

It's not only printing that you have to be aware of these ratios. When I started shooting video clips which record at 16:9 for showing on monitors and TVs, I noticed that my still pictures created black bars on each side of the pictures. That was because still format was 4:3 in my camera or 3:2 if you shoot DSLRs. When I combine video clips and stills into a video "slide show", the switching between the 4:3 stills and the 16:9 video clips annoyed me. So I started to shoot all my stills in 16:9 so stills as well as video clips fill up the TV or monitor screens completely.

You can see how that works with this short video I downloaded to Youtube.
https://www.youtube.com/watch?v=mcmwLSiS-as&t=42s

[r.e.]

It's not only printing that you have to be aware of these ratios. When I started shooting video clips which record at 16:9 for showing on monitors and TVs, I noticed that my still pictures created black bars on each side of the pictures. That was because still format was 4:3 in my camera or 3:2 if you shoot DSLRs. When I combine video clips and stills into a video "slide show", the switching between the 4:3 stills and the 16:9 video clips annoyed me. So I started to shoot all my stills in 16:9 so stills as well as video clips fill up the TV or monitor screens completely.

You can see how that works with this short video I downloaded to Youtube.
https://www.youtube.com/watch?v=mcmwLSiS-as&t=42s

Exactly. The following post explains that one of my objectives is to make photographs that can be incorporated seamlessly into a film, i.e. without letterboxing or cropping the photos. I'm also interested in Chris Marker's technique in La Jetée, which Marker calls a "photo-novel": https://www.largeformatphotography.i...=1#post1624080

I also want to try 2:1, which is an aspect ratio for both still photography and some modern films, such as Green Book, the film that won the 2018 Academy Award for Best Picture. A 2:1 mask of a 5x4 sheet gives you the same size image that you get from a roll of 120 film loaded in a 612 camera or 612 roll film back. A 2:1 mask of an 10x8 sheet gives you an image that is an inch (25%) taller than a 4x10 image. The latter is actually narrower than an anamorphic widescreen image. I haven't looked into the history of 4x10, but a possible reason for its existence is that you can get two 4x10 images out of one 8x10 sheet.

[Oren Grad]

I haven't looked into the history of 4x10, but a possible reason for its existence is that you can get two 4x10 images out of one 8x10 sheet.

So far as I know, 4x10 as a commercially-offered format is a relatively recent development, and the easy cutting from a readily available format is a very plausible justification. Many of us are familiar with the classic panoramic and banquet cameras offered in 5x12, 7x17, 8x20 and 12x20 formats by Korona and/or Folmer and Schwing. But I don't know of any 4x10's from that era.

[Tin Can]

I am looking back to before photography

https://fibonacci.com/art-architecture/

https://www.compulsivecontents.com/d...quence-in-art/

https://www.npg.org.uk/research/prog...standard-sizes