Difference Between Fidelity 5x7 vs 13x18 holders

[mark_baylin]

Hello,

 

I just aquired a few (what I thought were) 5x7 inch holders made by Fidelity. While they are marked 5x7 in

very small printing at the very top of the holders, further down below, under the name "Fidelity Deluxe", it

is clearly marked 13x18 cm.

 

I've already noticed that, although the outer dimensions of the holders seem to match my other 5x7

holders, the inner dimensions are bigger. I've loaded some old processed sheets into these holders and

there is more play side to side than in my normal holders.

 

I was wondering if someone could shed some history on this type of holder and let me know if they can or

can't be used as normal holders for the 5x7 inch film/camera format. If they can be used, what

disadvantages might there be in using them. If they can't be used for precision work, I will be returning

them ASAP.

 

Thanks very much for any help!

 

Take care

 

Mark Baylin

[michael_briggs2]

5x7 inch and 13x18 cm holders have the same external dimensions, but the two formats

have different dimensions, so the film sizes don't interchange reliably between the holders.

See "5x7 vs 13x18 cm is it the same format?" at

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00Dre7

[ilkka]

I try my luck with a brief history lesson. There are two systems of measurement that have been widely used throughout history. One is metric system and the other is often called Imperial system. Basically, continental Europe is metric while the English speaking world is Imperial. This happens to affect sheet films as well and common sizes used in continental Europe are 9x12cm, 13x18cm and 18x24cm. In the imperial world these translate to 4x5" (for some strange reason called 5x4 in the UK), 5x7" and 8x10". The cameras for these formats are the same. The film holders have the same external dimensions, so that they can be used in the same cameras, but the actual sheets of film are slightly different in size. The film holders for 4x5 and 5x7 for example, have slightly different film pocket dimesions than the corresponding 9x12 and 13x18 holders. The 4x5 is a bit bigger than 9x12 while the 13x18 is a bit bigger than the 5x7, as you have noticed. If you go to Germany, for example, you can buy 13x18cm sheet film. For reference, one inch is equivalent to exactly 2.54 cm, but the actual dimensions of these sheet films do not always follow the nominal measurements. Just like 6x6cm film is not exactly 6x6 cm but something like 5.6x5.6 cm. In imperial world this is called 2 1/4" square which is actually a bit closer to the true size.