Bleach Bypass

Glenn Hanns · February 6, 2005

Well I've just done a test roll of 7274 200ASA and bleach bypassed the neg. Hoping for a high con low saturated look I was suprised to see the telecine transfer was LOW con and blue! Having shot under tungstan lights in a controlled environment Im left scratching my head. Anyone know where I went wrong? Does the telecine chain need to have a different setup for bleach bypass or was my requested "one light" a mistake.?

Cheers G.

:(

David Mullen ASC · February 7, 2005

Well I've just done a test roll of 7274 200ASA and bleach bypassed the neg. Hoping for a high con low saturated look I was suprised to see the telecine transfer was LOW con and blue! Having shot under tungstan lights in a controlled environment Im left scratching my head. Anyone know where I went wrong? Does the telecine chain need to have a different setup for bleach bypass or was my requested "one light" a mistake.?
Cheers G.

:(

<{POST_SNAPBACK}>

Maybe the lab didn't do the skip-bleach? Did you underexpose to compensate for the increase in density?

As for why it is blue, I have no idea. Did you put a gray scale at the head of the roll?

Dominic Case · February 7, 2005

Maybe the lab didn't do the skip-bleach?

Wash your mouth out, Mr Mullen <_<

My guess is the telecine guy tried to make the neg look "normal" in the absence of any other instructions.

And there is a slight change in the colour balance of a bleach bypassed neg - normally removed in the print by the grader (or at telecine). So the colour is anyone's guess. A one-light transfer probably means he did the usual trick of grading by waveform - get the blacks and whites at the top and bottom, and centre the vectorscope. With a contrasty neg, that would certainly give you a reduced contrast in the final image.

Glenn - did we process this at Atlab? Give me a call or PM if so, we can at least check on the process.

John Pytlak RIP · February 7, 2005

Since silver absorbs infrared energy, and dyes absorb relatively little infrared, you can determine if silver has been left in the image by comparing the image densities on an IR densitometer (800 nanometer peak sensitivity), often used by labs for controlling the density of analog soundtracks.

Glenn Hanns · February 7, 2005

Wash your mouth out, Mr Mullen <_<

My guess is the telecine guy tried to make the neg look "normal" in the absence of any other instructions.

And there is a slight change in the colour balance of a bleach bypassed neg - normally removed in the print by the grader (or at telecine). So the colour is anyone's guess. A one-light transfer probably means he did the usual trick of grading by waveform - get the blacks and whites at the top and bottom, and centre the vectorscope. With a contrasty neg, that would certainly give you a reduced contrast in the final image.

Glenn - did we process this at Atlab? Give me a call or PM if so, we can at least check on the process.

<{POST_SNAPBACK}>

Hi Dominic,

No it was neglab that did the process. I did underexpose a stop when shooting. On a slightly

different note- what I thought was strange though was when looking at the setup scene files on the panasonic AJ-SXD900 website I noticed that the SkipBleach setup is exactly what my transfer looks like. I didnt run a colour or gray scale chart on the head nor was I there for the transfer. I did make it clear to all though that I was doing a skipbleach test and I spoke to the lab prior to processing, Werner was very clear on what I wanted Dom.

hhhmmmmm.

Is this the normal look of skipbleach? or am I missing something?

Glenn Hanns · February 7, 2005

That reminds me, I havent paid my lab bill !. LOL

Brent J. Craig · February 7, 2005

Looks like a lazy one-light to me. They probably just loaded up the normal setup for the stock number they saw on the edgecodes.

Here is what 30 seconds in Photoshop did, I can only suspect a multi-million dollar telecine suite could do better :-)

Glenn Hanns · February 7, 2005

I should of gotten you to do my transfer Brent!!!! LOL

Dominic Case · February 7, 2005

Is this the normal look of skipbleach?

Hmm.

Visually I'd say you definintely got your skip bleach processing done correctly. Full marks to Neglab. John's note about detecting silver in the neg would confirm that beyond all doubt.

So the problem has arisen with your telecine transfer.

As Brent suggests, I think you are seeing a bad transfer. They've set the blacks to black, the highlights - well - they've brought the level down so it's not crushing, but not touched the colour, (and as said before, bleach bypass doesn't affect all layers equally, but that usually is corrected), and then hit the "go" button.

At least the colours are quite desaturated.