loading sheet film into holder

[Jeff Canes]

When loading sheet film into the holder, the notches go on LOWER right side?

I Google it

 

[Hertz van Rental]

I think you'll find that the notches go top right (or bottom left) to get the emulsion side out when loading sheet film.
That was always the convention with Kodak, Agfa and Ilford.
If you want to check then pull a sheet out and have a look at it in the light - blowing one sheet is cheaper than shooting a whole load with it loaded the wrong way round.

To the initiated the notch pattern (on Kodak film at least) identifies the film type as well

:mrgreen:

 

[ksmattfish]

I think you'll find that the notches go top right (or bottom left) to get the emulsion side out when loading sheet film.

Yeah, if the notches are top right or bottom left the emulsion side is facing you.

 

[mysteryscribe]

here's a good question, what exactly happens if you do shoot it backwards. (I can't believe I haven't done that yet.)

 

[ksmattfish]

It would depend a lot on the anti-halation layer. Almost all roll film has it; I'm not sure about sheet film, but I assume so. It's there to keep light from reflecting back through the film, so it should definately affect how much light would get to the emulsion if loaded backwards.

Besides anti-halation issues, the image would be a mirror image. It might be a little softer, some film base has a subtle texture, but you might not even notice that with 4x5. I'd be worried about scratches to the emulsion when it was loaded and unloaded.

 

[Hertz van Rental]

Sheet film does have anti-halation dyes. The support base is also considerably thicker than that of 35/120 films.
Shooting with the film around the wrong way normally results in no image recording - mainly because the amount of light needed to punch through the back is far in excess of 'normal' exposure. Anti-halation dyes are designed to absorb light - they stop light bouncing back onto the emulsion from behind (causes halos around lights particularly at night [looks like they've been shot in fog], hence the name). Remember, of course, that the film is usually put in back to front by accident so you are not expecting it.
If you are going to try it I would start by increasing the indicated exposure by a factor of 6 to 8 (3 - 4 stops). This may still not be enough though - although on some films it might be a little too much. Depends on the film.
You might have to experiment a little - would that be a problem for you?

 

[JoeVanCleave]

Just jumping on this thread late, so Jeff has most likely already figured this out, but the rule of thumb for the emulsion facing you when the notches are in the upper right/lower left corner ONLY applies if the film is oriented in PORTRAIT mode.

Were you to orient the film in landscape mode and the notches were in the upper right or lower left corner, the emulsion would be facing away from you.

As always, the devil is in the details.

 

[mysteryscribe]

This made me crazy till I figured out you and I had opposite top and bottom references for the holder. I always considered the opening you put the film in as the top not the bottom. So I was orienting the film backwards from what you were saying but correctly in the holder.

I knew I had the emulsion side toward the lens just couldn't quite figure out what was different.