Very BASE question

[wrbjr]

Picture frames.... 5x7 8x10 11x14..... did I mention 8x10? Did I not mention 8.5x11? Why does photo paper come in this odd size? Why do we have to crop and cut all the time? Probably a very good answer for this.... but at the moment it really escapes me.

 

[Tysonic]

This company has 8x10 gloss and satin papers:
http://tinyurl.com/3tenu

The reason for 8 1/2 x 11? Never really found an answer beyond the manufacturing process (most paper mills are set for the standard sizes, whereas Kodak and their ilk have their own contracts for their special sizes). If customers started demanding 8x10, then they'ed switch.

I don't worry about it anymore though, I just buy the right sized frame when I print 8 1/2 x 11 or 13x19 (another non-standard size):
http://tinyurl.com/59y7d


Tyson

 

[Nifty]

I'm more into printing than photography, so excuse any errors:
Personally I don't understand why there isn't the same ratio for all these paper sizes. 3x5, 4x6, 5x7, 8x10

So, if I took the ration of 3x5 as my base, then I should have:
4 x 6.666...
5 x 8.333...
8 x 13.333...

Well, when I first started printing pictures I didn't notice that the ratio wasn't the same as you got bigger. I wondered why it was that when I cropped an image for a 4x6 it didn't fit right when shrunk and printed on a 3x5.

What am I missing? Please help me you photo experts!

 

[fotofreek]

Go back to film photography to find the ratios. To the best of my recollection, cut film packs were 2.25x3.25, 4x5, 8x10. 35 mm. film image area was 24x36 mm.(to create the most popular uncropped 4x6 format) Twin lens reflexes were 2.25 in. square (meant to be cropped to a rectangular format for most prints)and the 120 film based slr's were 2.25x2.75. My digital images are a different ratio from any of the popular frame or mat sizes, forcing me to shoot pictures slightly more wide angle (or step back a bit) to give me the freedom to crop to a fixed size for easy framing withs precut mats. The alternative is to crop and print to the most idel ratio for each picture and custom cut your own mat.

 

[wrbjr]

Sounds like what I've been doing without thinking about it. Backing off just a little, rather than shooting in real tight.

 

[fotofreek]

unfortunately, shooting less tightly to preserve cropping options runs counter to the advisability to "use" all the megapixels at your disposal. In the film world the viewfinder cameras automatically included slightly more of the scene on all sides to compensate for paralax and the possibility that part of the desired subject would be cut off. SLR's permitted excellent composition with a 'what you see is what you get" view of the subject. Using the viewfinder in most of the digital (non-slr or non-digital viewfinder) cameras probably includes a little more of the scene in the recorded image than you see in the viewfinder - again, to compensate for paralax with zoom lenses. More accurate framing can be done by using the digital viewing screen.

By the way, when I mentioned the cut film cameras (view cameras, speed graphics, etc) the earliest prints were contact printed and were, therefor, the same size as the film. Early Kodak bellows roll film camera prints were also contact printed. I think that the 35 mm and 2.25 in. square formats were what pushed photography more rapidly into the enlarger era.

 

[BlasterQ]

Shrinking a 4x6 picture to a 3x5 picture will not preserve it's width and length ratios. You don't shrink it by removing an inch in width and removing an inch in lenght unless your picture is a perfect square.
In this case, your picture is a rectangle. To reduce your width from 4 to 3, don't think of inches, think of percentage. In this case, to get the percentage, you divide 3 by 4, giving you a .75 percent target width or .25 percent less than 4 inches, or 3/4 of the actual width. With that information, you do the same on the length of your picture, reduce it to .75 percent. Therefore, the .75% of 6 inches is equal to 6 inches multiplied by .75 percent, giving you a 4.5 inches length.
Therefore, your new image will be 3x4.5 inches, not 3x5. with this, you preserve the ratio.

 

[Nifty]

BQ, unless my math skills have deteriorated greatly, I think I did as you suggested... proportionately increase each side of the rectangle. I'm so anal I did it in excel.

I divided 3.5 by 4 which gave me a hight to width ratio of .6. Using this relationship I calculated each subsequent width to a given height.

My point was simply that the proportional relationship between all the photo sizes is inconsistent. Making shrinking and increasing sizes between these standard image sizes impossible: For example, here are the ratios of width to height:

H W Ratio
3 5 0.6
4 6 0.666666667
5 7 0.714285714
8 10 0.8

Maybe my math is off? If so, please help me!

 

[wrbjr]

I guess I'm fortunate in that I have an SLR Digital camera. Its viewfinder is 95% accurate. I print mostly 8x10's, so I don't have so much of an issue in most regards except for framing. I suppose I will have to start custom matting inorder to preserve the 8 1/2 x 11 format with borderless printing. I do trim some down to the standard 8x10 for a standard frame, but some of these photos deserve every inch they can get. I used to have a darkroom back in the "dark ages" of the early 70's. My my, the song and dance we had to go through to get an 8x10 without the grain..... and that was black and white. Times they are a changing.

 

[BlasterQ]

yeah, nifty, you are exactly right on that one. the standard sizes of photo papers don't match when it comes to ratios. i dunno why, but i guess we'll just have to settle to cropping. that will be dissapointing if you want to print the whole picture without editing. the second solution is to print it on A4 and just cut the paper according to the size of the printed image.