Key Code On Wrong Side

Neil Davis · July 5, 2005

Hello All:

Perhaps a senior member can answer this question?

Recently I helped out on a small 35mm film shoot, we used short ends from a short end supplier. On one of the rolls the key code was on the wrong side, we where told this by the lab.

Now we are editing this our selves in FCP so we don't really care about the key code, and the lab tech told us we would still be able to use the image. I thought ok, phew that's good.

Then I told a DP friend of mine about this and he said that roll will be thrashed, no good. He said it happened to him once using a short end with the key code on the wrong side and the image from that roll was a disaster, all kinds of nasty stuff all over it he said.

So now I'm confused which is right? To my way of thinking we still exposed the emulsion side (of course) so what difference does it make what side the key code is on with regard to the actual image?

Thanks

Neil

Laurent Andrieux · July 5, 2005

Just my 2 cents : if the lab figured out the Kcode was on the wrong side, that means they processed it, right ? From that point, they can figure out what is possible and what is not. When they say it's not a problem, we can get the image from it, that means they can telecine and print it. I would trust the lab but as to make sure, ask them to do a test. Are you going on TC or printing on film the traditionnal way ?

John Hall · July 6, 2005

Perhaps they gave you the short ends tail out, which means the keycode will run in the wrong direction, not be on the wrong side of the film.

I did this once when winding down film from a larger roll down to 200ft for use on an Oxberry. I didn't have any problems though.

You may run into some complications later down the post production road (neg cutting... perhaps someone else here could explain better), but it will not affect the image or the processing. You should just give the lab a heads up that the keycode is backwards, but everything should be fine.

If you shot through the backing though, thats another story, see http://www.cinematography.com/forum2004/in...?showtopic=5624

Stephen Williams · July 6, 2005

Perhaps they gave you the short ends tail out, which means the keycode will run in the wrong direction, not be on the wrong side of the film.
I did this once when winding down film from a larger roll down to 200ft for use on an Oxberry. I didn't have any problems though.

You may run into some complications later down the post production road (neg cutting... perhaps someone else here could explain better), but it will not affect the image or the processing. You should just give the lab a heads up that the keycode is backwards, but everything should be fine.

If you shot through the backing though, thats another story, see http://www.cinematography.com/forum2004/in...?showtopic=5624

<{POST_SNAPBACK}>

Hi,

Any film shot with an Oxberry will have the keycode on the wrong side! The Magazine is on the bottom and the film runs backwards!

As neg cutting is done by hand its not a problem, if you had a print. However your telecine copy won't have the keycode dada. You will have to calculate the neg cut from timecode.

Stephen Williams DP once operated an Oxberry!

www.stephenw.com

Adam Frisch FSF · July 6, 2005

There is only one explanation:

Since the image is OK, that means you didn't shoot through the base. That would have been painfully visible.

That means that someone re-spooled the film back on tail end out, i.e. like a reel to reel spooling. If you spool from one reel to another, emulsion side in, then when you load that spooled reel you have to flip it, i.e. making the Key Code end up on the other side. Not only that, the Key Codes will decrease as you advance it, not increase as it otherwise does.

No big deal unless you need to neg cut the film later. Even so, with a DI you don't even need Key Codes anyway so if by some chance you need to neg cut that part, either do it manually and "backwards" or do it as a full frame scan tied to timecode set by the whole punch at the beginning of that roll/reel.

There is nothing wrong with the emulsion and nothing "terrible" will happen to the images at all, as your friend suggested. He got that wrong - emulsion is emulsion.

Edited July 6, 2005 by AdamFrisch

Dominic Case · July 7, 2005

I think the answer has emerged from all the other replies, but . . . .

Without a doubt, you had some re-wound short ends, which would therefore have been "tail out" rawstock. You have exposed the stock absolutely correctly - on the emulsion side. But the keykodes are not only on the "wrong" side, but also they run downwards not upwards. In other words, the KK at the tail of a shot will be a lower number than at the head of the shot.

This is something that caused great confusion in the early days of Keykodes and non-linear editing. While the dedicated neg matching programs like Excalibur and OSC/R dealt with this little anomaly quite well (it's not a new issue for neg matchers) none of the keykode add-ons to editing systems like Avid and FCP managed the numbers correctly. It's better now, but not always simple.

If you need Keykodes for neg matching, you will have two issues: the "downhill" numbering, and the fact that the numbers may not be read on the telecine if they aren't on the edge that the Keykode scanner is on.

The problems arise when you have to convert an EDL with timecode into a cutting list with Keykodes. The software needs to understand that the shot is real, that because it computes the length as (say) -46 frames it is still + 46 frames long (nor is it a reverse action effect), and it needs to manage the frame offset properly.

If you are neg cutting, talk to your neg cutter, early on. It won't be a problem, but they should know about it.

The advice you were given that the reel would have unuseable images is really dumb. Your DP friend probably had a roll of stock loaded back to front (there's been a thread on this elsewhere recently). That would also put the edge numbers on the wrong side - but put the image on the wrong side too. That would be so much of a bigger problem that it's silly to confuse the two errors.