Is this amount of grain and noise normal?!

All the problems with Plustek film scanners

mcswampy
Visitor
Posts: 3
Joined: Mon Jan 31, 2011 9:46 pm
Scanner: plustek opticfilm 7600i
SilverFast Product: SE Plus
SilverFast Version: 6.6

Is this amount of grain and noise normal?!

Postby mcswampy » Mon Jan 31, 2011 10:01 pm

Hi,

I have recently purchased a Plustek Opticfilm 7600i with Silverfast SE plus,

I have been scanning 35mm negatives, but am experiencing a lot of gain and noise on my scans.
Either im doing something wrong, or the hardware is faulty, or this is just the amount of noise I should expect..?

I have tried almost every combination of every setting: image control, negfix, hdr/non hdr, and dpi etc, and this example image is the best i can get.. (this is a screenshot of the pre-scan but the final looks exactly the same..)

http://www.johnstuckey.co.uk/dump/plust ... _noise.png

The actual shot is well exposed, and I have a large, professional print of this photo and it is perfect.

Is this just the quality I should expect from this scanner??

Thanks in advance,

John

User avatar
LSI_Ketelhohn
LSI Staff
LSI Staff
Posts: 4283
Joined: Wed May 28, 2008 11:19 am
Scanner: all
Location: Kiel, Germany
Contact:

Re: Is this amount of grain and noise normal?!

Postby LSI_Ketelhohn » Tue Feb 01, 2011 5:45 pm

Dear John,

I do not see any unusual noise in that image.
(Noise can be reduced using MultiExposure or MultiSampling)

The grain is normal at that resolution what you see is the actual structure of the film emulsion.
(This can be reduces using the GANE filter)


kind regards,
Arne Ketelhohn.

mcswampy
Visitor
Posts: 3
Joined: Mon Jan 31, 2011 9:46 pm
Scanner: plustek opticfilm 7600i
SilverFast Product: SE Plus
SilverFast Version: 6.6

Re: Is this amount of grain and noise normal?!

Postby mcswampy » Tue Feb 01, 2011 6:04 pm

Hi,

Thanks for gettin back to me.

So the colour artifacts you can see on the red brick houses for example, that is within the actual negative and not the scan?

And the other noise/grain for example bottom left on the snow, it just looked digital to me as it's kinda areas of square pixels different shades of white. That's the best was to explane it. Like if there's a slightly over exposed area, like too much light on an area of a face, it will be white as expected, but will blend into the colours around with noticeable square pixels, stepping from one colour to the next. This is expected with digital photos, but not with film. Does this make sense? :S

Is the multisampling where it scans it up to 16 times?

Thanks again,

John

degrub
SilverFast Master
SilverFast Master
Posts: 597
Joined: Fri Dec 21, 2001 1:00 am
Location: Texas

Re: Is this amount of grain and noise normal?!

Postby degrub » Wed Feb 02, 2011 12:30 am

At 2400 PPI, i doubt you are seeing the dye clouds. i am seeing some chroma noise, that may or may not be helped by multisampling. That scanner may have an optical resolving capability of around 3200 ppi from what i read.

some examples here:
http://www.imaging-resource.com/SCAN/PLTK7600/7600.HTM

but these are at 100%.

Perhaps the software/hardware may be interpolating. Try scans at 7200ppi and then down sample in photoshop or similar with a bicubic algorithm to whatever resolution you need. There are some good articles here on how -

http://www.digitalphotopro.com/techniqu ... oshop.html

A little more idea on a scanning approach -
"
Film scans are a bit different in this respect because we are talking about a second generation capture (analog camera on film, analog film on discrete sampling sensor) and the layered grain filaments (or clouds of dye) is the image. Noise or grain in the presence of signal hampers the successful restoration of only the signal component. For filmscans the best approach is to avoid grain-aliasing by oversampling (scanning at 6000-8000 PPI, or at least at the maximum native scanner resolution). Then, after pre-blurring (=convolution) and adaptive noise reduction, downsampling can take place, followed by final output sharpening. It's there where I see the most use for deconvolution, after a number of preprocessing steps." extracted quote from Bart Van der Wolf on LuLa forums

http://www.luminous-landscape.com/forum ... #msg386847

reply #190

although it may be more work than you want.

Frank

mcswampy
Visitor
Posts: 3
Joined: Mon Jan 31, 2011 9:46 pm
Scanner: plustek opticfilm 7600i
SilverFast Product: SE Plus
SilverFast Version: 6.6

Re: Is this amount of grain and noise normal?!

Postby mcswampy » Tue Feb 08, 2011 6:08 pm

Thank you for all that information!

I think I will scan at the native resolution (7600 or 7200 I think) even though it is about a 120mb file, then do any colour/noise adjustments and save down to a more acceptable file size using photoshop. I'll aim for about 25mb to match the RAW files straight out of my digital camera. Then, hopefully this will get the most out of the scanner, and side affects of noise reduction and colour adjustments will be minimised.

Cheers,

John


Return to “Plustek”

Who is online

Users browsing this forum: No registered users and 1 guest