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Issues with a a Spirit 2K scan


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#1 Phil Thompson

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Posted 14 December 2014 - 01:29 PM

Hi all,

 

I have a question. I've had a couple of scans done by a company that has a Spirit 2K scanner. The DPX files when viewed in Nuke (or any other viewer) displays these faint lines in the background. (see attached). When the footage is moving it's not *so* visible but I assume this isn't normal as footage from a  different post house never displayed this effect.

 

Can ANYONE shed any light on to this?

 

https://images.creat...21967/test3.jpg

https://images.creat...21967/test2.jpg

 

Yours sincerely

 

Phil


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#2 David Cunningham

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Posted 14 December 2014 - 03:38 PM

I can't see it in your test 3 image but your test 2 image looks like a scratch to me.
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#3 Dirk DeJonghe

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Posted 14 December 2014 - 04:08 PM

I don't think the Spirit has anything to do with this scratch. Could be camera loop or processing.
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#4 Dan Finlayson

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Posted 14 December 2014 - 04:31 PM

Are you talking about the faint horizontal striping?


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#5 Phil Thompson

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Posted 14 December 2014 - 04:51 PM

Yes sorry, to Clarify I'm not talking about the scratch. I'm talking about the horizontal striping. Any idea of the cause of this? I'm pretty sure it can't be the neg as this has happened to two batches now.


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#6 Phil Rhodes

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Posted 14 December 2014 - 05:40 PM

Hm. I see what you mean. It's subtle but it's there. Fixed pattern noise, more than anything else.

 

I hesitate to offer any sort of of opinion based on no information, but it really does shriek scanner fault. Does it change in parts of the scan that show (for instance) near-black or near-white stuff, stop flashes and roll ends etc?

 

P


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#7 Phil Thompson

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Posted 14 December 2014 - 05:55 PM

yes it looks like Fixed pattern noise. What would you do in my situation? I've emailed back the Scanning company with Stills.

Where do you reckon I Stand? I think they have a North light scanner too. I guess I could ask them to try on that. (though  they say it will cost a lot more). This is so annoying. Do you know anywhere with a 2K Spirit that don't charge 50p a frame. These guys were doing 1500ft for 200 quid which seemed 'ok'..


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#8 Kenny N Suleimanagich

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Posted 14 December 2014 - 06:37 PM

If it's fixed-pattern noise it is entirely their fault. There could be electrical interference in their scanner's imager. They should offer to re-scan for free. 


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#9 Phil Thompson

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Posted 14 December 2014 - 06:56 PM

Cheers kenny

I dug out the manual and it appears the spirit has some fpn buttons, do you reckon it's something as simple as that?

http://www.hawtreecr..._operations.pdf

?
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#10 Phil Rhodes

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Posted 14 December 2014 - 08:27 PM

It's not really your problem to figure out why. First ask (nicely and calmly) about the problem.

 

What I'd do is scan just a few frames of the material on another scanner, which would isolate the problem to the scanner, as opposed to it being some obscure camera or processing issue. Many digital imaging devices have the facility (not to say requirement) to do calibration on the sensor, but I suspect that's not what's going on here. If this is 16mm, and if (say) the per-pixel black level calibration was off on a any line-array telecine, you'd expect to see vertical streaks, not horizontal. 

 

I can't claim to be an expert on the low-level workings of the Spirit, however, and there are many associated issues that might arise. The thought occurs that any form of vibration or chatter in the transport could create this sort of mess, by affecting the speed of the film as it passed over the sensor. I'm speculating, of course.

 

I notice that if these are 1:1 pixel representations of the scan, the noise pattern seems to have a period of about 16 pixels, but really that's just idle speculation. Call the people who did it and (nicely) ask.

 

P


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#11 David Cunningham

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Posted 14 December 2014 - 08:30 PM

Sorry. I really thought you meant the scratch. I see what you mean. Very subtle but evely likely the scanner.
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#12 Dirk DeJonghe

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Posted 15 December 2014 - 02:54 AM

The FPN function will filter out the lamp and lens shading not horizontal noise. If the noise pattern is horizontal, check if it is within one color only (RGB). If so there might be a problem with the sensor since that is a line-array; If it is on all three color channels, it might be power supply or something common to the three channels. 

A rescan is definitely required.


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#13 Eugene Lehnert

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Posted 17 January 2015 - 11:58 PM

I see this when a telecine light is pushed too far from dark material.  I'm seeing it more and more though.  I'm wondering if it's a sign of aging telecines. 


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#14 Robert Houllahan

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Posted 18 January 2015 - 02:53 AM

Sometimes when line scan telecine or scanners get dirt or dead pixels on the line (because it's a line this becomes a streak through the picture) you get this it is something that probably requires a professional cleaning of the optical block.


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#15 Andres Pardo aka Gral Treegan

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Posted 28 January 2015 - 09:05 PM

I see that kind of lines in footage that comes out of a telecine, but never from a scanner.

First. Are you sure that your films runs a scanner and not a telecine?


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#16 Robert Houllahan

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Posted 28 January 2015 - 10:04 PM

I have seen this problem with a customer's 16mm film that Cinelab developed that was 2K scanned on a Golden-Eye scanner, it is a problem that can occur in ANY Line scan machine.


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