Beginners question about 5x7

[haris]

Hello,

When reading about 5x7" cameras, I saw people talking of 5x7 and 13x18cm film sizes as different sizes. I know 5x7" is 12,7x17,8, but as I know 13x18cm is common term for actuall size 12,7x17,8cm, atleast papers which are commonly called 13x18 have acutal size 12,7x17,8cm.

So, my questions are: Is film size 5x7" same as 13x18cm, if not, are different film holders are needed for 5x7" and 13x18cm films and does every 5x7" camera can work with both sizes of films/holders.

Or, are there 13x18cm cameras which can work with 5x7" if these are different sizes?

I know for example 8x10" is 20x25cm, and 20x25cm has actual size of 20,5x25,4cm, and 8x10" camera can work with 18x24cm films, but film holders are different for 8x10" (20x25cm, that is actually 20,5x25,4cm) film and 18x24cm film.

Thank you.

 

[snallan]

Hi haris,

The two films are different sizes, so different holders are required for each. The external dimensions of the film holders are identical (except perhaps for the oldest of vintage holders), so if you have holders for each size of film, you can use both on a 5x7/13x18 camera.

It is also possible to get "5x7" holders to take half plate (4¾ x 6½ in) film.

Cheers

 

[Jerevan]

There is also 12x16.5 cm film holders which has the same outer dimensions as the 13x18/5x7 holders. Be careful when you buy holders to get the right sort for the right film size. I have all three varieties. For the 12x16.5 size, I know Fuji Acros is available from Japan.

 

[haris]

Steve, Jerevan, thank you.

 

[Ole]

Also, if you measure a 13x18cm film you will find that it is almost exactly 12,7x17,8cm. 5x7" film is a few millimeters smaller!

That's the old "film adapter sheath in plate holder" adjustment again - same as all sheet films are a little bit smaller than the "nominal" size. In the case of 13x18/5x7" the tolerances even seem to be overlapping! So some 5x7" holders can take some 13x18cm films, and some 5x7" films will stay put in some 13x18cm holders. But it is far more likely that 13x18cm film wil bow out in a 5x7" holder and make it impossible to get the dark slide back in, and a 5x7" film will drop out of a 13x18cm holder to land inside the bellows...

You don't have to ask how I know this, do you?

 

[haris]

Thank you Ole.

I won't ask how you learned that. You must have read it somewhere...

Regards

 

[snallan]

You don't have to ask how I know this, do you?

Have you been watching me. Ole?

 

[ragc]

"... and a 5x7" film will drop out of a 13x18cm holder to land inside the bellows..."

Ah! that explains it... been there, done that!