help understanding ratios

asamuel

Can anybody help me understand these ratios, given to me in relation to the file/print size eligible to be submitted to a group.

35mm negative ratio is preferred. 1:1.5. ( I think height is 1 and width 1.5 neg/file)


35mm = 3:2 (they say this now because its round numbers?)
fat rectangle = 4:3 (what format makes this? they don't like this)
16:9 kicks ass (and this?)


ie: 4x6 not 3x4 (so 4x6 is 35mm equivelent to 1:1.5, i can figure this out its round numbers again BUT a) why not just say 3:2 is that because 4x6 is the ratio in inches b) WHAT MAKES A PHOTOGRAPH 3x4 is this a crop ratio?)

8x12 not 8x10 ( now I'm totally confused as to where these numbers come from)

thanks as ever sam potatoe shop guru.

ivar

Hello Sam

What is important to remember is that the ratio says nothing about the actual size. It gives you a relation between the length&width of an image.

The 'classic' 35mm ratio is 2:3 -- If the height is 2, the width is 3. (The images on the negatives are 24x36 mm. (2x12 by 3x12). This is also the ratio used on most DSLRs.

2:3 is exactly the same ratio as 1:1.5 or 4:6 or 8:12.
Divide the above numbers and you'll see that you'll always end up with 2/3

The 2:3 ratio is mostly used, as it uses the smallest whole numbers.

Looking at print-sizes, you'll be able to print 4x6, 8x12, 12x18, 16x24, 20x30, 24x36 for instance. Again, if you divide the length by the width, you'll always end up with 2/3. A 4x6 print is 2:3 ratio (2x2 and 3x2) as is a 20x30 print (2x10 by 3x10).

The 3:4 ratio is a format that is used by digital P&S cameras mainly (and the non-widescreen monitors). Print sizes there are 4x5.3, 5x6.7, 8x10.6, 9x12, and 18x24. Divide those numbers and you'll always end up with 3/4.

I hope this helps.

asamuel

that helps alot but I don't see anything in this that accounts for the 16:9?

or have I missed it.

thanks Ivar.

ivar

asamuel wrote:

that helps alot but I don't see anything in this that accounts for the 16:9?

or have I missed it.

thanks Ivar.

hi Sam,

Sorry, I forgot about the 16:9 ratio. You don't see it a lot in cameras at this time. It is the ratio used for High Definition TV. It is not very common on photography cameras (yet), but I believe that Panasonic has one that does that ratio.

We (SmugMug) and most other print-facilities, don't have prints specific for that ratio.

asamuel

ok. that sounds cool, I haven't heard of ti, but it sounds cool and I will look it up. but none of these ratios would account for medium format and large format cameras right?

I'll look that up now I've begun to understand.

thanks for your help.

pathfinder

The Panasonic Lumix DMC-LX1 ( and others) can be configured to shoot 4x3, 3x2, and... 16X9.

You can crop any image in Photoshop to whatever ratio floats your boat ( or works for your image), of course

sirsloop

I dont't know why panasonic has that feature to crop the sensor. Its ridiculous! By using something other than 4:3 with it you are just kicking yourself in the foot. Its throwing away the pixels straight out of the camera.

claudermilk

fat rectangle = 4:3 (what format makes this? they don't like this)

Going back to one unanswered question in the OP. This is from medium format (6x9)--one of many: 645 or 6cm x 4.5cm, 6cm x 7cm, 6cm x 9cm, 6cm x 17cm, etc.).

colourbox

To understand why some ratios exist, you might want to read this Wikipedia article about aspect ratios.