Noise in dark areas of scans

  • Thread starter Thread starter Chris Birkett
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Chris Birkett

I've been scanning a lot of my black and white negatives with my Minolta
Scan Dual III and VueScan. However, I've been noticing that a lot of the
time, the black (clear) areas have absolutely dreadful amounts of grain.
It's like golf balls sometimes, it's so gigantic. When it transitions to
black, it will go white, grey, golf balls black. I know a lot of my
negatives aren't exactly exposed particularly well (I do a lot of push
processing), but I've seen lots of scans of pushed negatives that look
great. It even happens in normally exposed negatives wherever there's a
dark area.

My normal method of scanning is to set VueScan to B&W and use the TMax 100
settings, with neutral colour. I then use the black and white point
settings to manipulate the histogram and capture a full range of tones.
This means I end up with flat scans which are (supposedly) better for later
adjustment. I've tried scanning my negatives as slides, but all I end up
with that way is more contrast. I am scanning in 16 bit.

Here's a couple of examples (HP5 Plus, EI 400 in D-76 1:1):

http://www.noctilust.com/images/example1.jpg
The transition from grey to black is very abrupt, like it's being clipped or
something, it just goes straight to nasty grain. There's a magnified view
of a different photo below.

http://www.noctilust.com/images/example2.jpg
General grain all over the place.

http://www.noctilust.com/images/example3.jpg
Here's a somewhat magnified view. I can see there is grain everwhere in the
scan, but the transition to black is disgusting, and very distracting in all
my scanned shots. I've heard similar-looking stuff described as "pepper
grain" before.

I don't have a lot of experience with black and white film (well, I have
shot about 30 rolls, but I've never printed it), so I'm really not sure
whether to expect large amounts of grain in thin areas of the negative. Is
this the scanner, the way I'm scanning, or a fact of life? I haven't
adjusted these scans yet, this is how they look when I scan them. Could
anyone recommend a better method?

As a side note, I've also noticed that a lot of my scans are not aligned
correctly. They can be off by as much as 0.2 degrees both ways, which is
very annoying, because I have to rotate them (which isn't ideal for some
scenes), or crop off even more than the negative carrier does.

- Chris
 
I've been scanning a lot of my black and white negatives with my Minolta
Scan Dual III and VueScan. However, I've been noticing that a lot of the
time, the black (clear) areas have absolutely dreadful amounts of grain.
Click to expand...

I don't do B&W myself, but I've seen similar things in my scans of
high-speed color negative film shot in dim light so that there are large
weakly-exposed areas. I think it's just the combination of large dark
areas, and VueScan attempting (by default) to capture most everything on
the film, including the grain, and letting you decide what to discard or
de-emphasize in postprocessing. Try raising the black point a bit in an
image editor, to "submerge" the grain, or apply a curve that tails off at
the low end. In your first picture, for instance, it looks like much of
the background should be black anyway.
 
Jon Bell said:
the low end. In your first picture, for instance, it looks like much of
the background should be black anyway.
Click to expand...
I agree. Trying lowering the picture's gamma in photoshop. The background
will go to black and the grain will disappear.
Sorry but due to spam I shall not provide a valid e-mail address.
Please reply to group with questions or comments.
 
I've been scanning a lot of my black and white negatives with my Minolta
Scan Dual III and VueScan. However, I've been noticing that a lot of the
time, the black (clear) areas have absolutely dreadful amounts of grain.
It's like golf balls sometimes, it's so gigantic. When it transitions to
black, it will go white, grey, golf balls black. I know a lot of my
negatives aren't exactly exposed particularly well (I do a lot of push
processing), but I've seen lots of scans of pushed negatives that look
great. It even happens in normally exposed negatives wherever there's a
dark area.

My normal method of scanning is to set VueScan to B&W and use the TMax 100
settings, with neutral colour. I then use the black and white point
settings to manipulate the histogram and capture a full range of tones.
This means I end up with flat scans which are (supposedly) better for later
adjustment. I've tried scanning my negatives as slides, but all I end up
with that way is more contrast. I am scanning in 16 bit.

Here's a couple of examples (HP5 Plus, EI 400 in D-76 1:1):

http://www.noctilust.com/images/example1.jpg
The transition from grey to black is very abrupt, like it's being clipped or
something, it just goes straight to nasty grain. There's a magnified view
of a different photo below.

http://www.noctilust.com/images/example2.jpg
General grain all over the place.

http://www.noctilust.com/images/example3.jpg
Here's a somewhat magnified view. I can see there is grain everwhere in the
scan, but the transition to black is disgusting, and very distracting in all
my scanned shots. I've heard similar-looking stuff described as "pepper
grain" before.

I don't have a lot of experience with black and white film (well, I have
shot about 30 rolls, but I've never printed it), so I'm really not sure
whether to expect large amounts of grain in thin areas of the negative. Is
this the scanner, the way I'm scanning, or a fact of life? I haven't
adjusted these scans yet, this is how they look when I scan them. Could
anyone recommend a better method?

As a side note, I've also noticed that a lot of my scans are not aligned
correctly. They can be off by as much as 0.2 degrees both ways, which is
very annoying, because I have to rotate them (which isn't ideal for some
scenes), or crop off even more than the negative carrier does.

- Chris
Click to expand...
You can minimize the visual appearance of the grain by selecting the
dark areas in your image editor after scanning. Then do a gaussian blur
of just the selection. You'll have to experiment with the radius setting
but, usually 1 or 2 pixels in enough. Since there isn't much detail in
the shadows anyway you won't loose much apparent overall sharpness.
This trick also works well on images with lots of (grainy) sky and
clouds.
 
Chris said:
I've been scanning a lot of my black and white negatives with my Minolta
Scan Dual III and VueScan. However, I've been noticing that a lot of the
time, the black (clear) areas have absolutely dreadful amounts of grain.
Click to expand...

http://www.neatimage.com/
Get the demo and play with the program.
(Be sure to put the program in 'YCrCb Symmetric' colorspace. The
default, RGB, is not going to be the best for B/W.)
http://www.noctilust.com/images/example1.jpg
The transition from grey to black is very abrupt, like it's being clipped or
something, it just goes straight to nasty grain. There's a magnified view
of a different photo below.
Click to expand...

I'm not sure, but your push development might be partially responsible
for the abrupt drop off. You might try a lightly fogging pre-exposure,
then push the blacks back down with software.
I don't have a lot of experience with black and white film (well, I have
shot about 30 rolls, but I've never printed it), so I'm really not sure
whether to expect large amounts of grain in thin areas of the negative. Is
this the scanner, the way I'm scanning, or a fact of life? I haven't
adjusted these scans yet, this is how they look when I scan them. Could
anyone recommend a better method?
Click to expand...

I think any 400 speed film is gonna be chunky. Pushing a slower film is
probably even worse. Get some 50~100 ASA or try alternate developers.

-Greg
 
Chris Birkett said:
I've been scanning a lot of my black and white negatives with my Minolta
Scan Dual III and VueScan. However, I've been noticing that a lot of the
time, the black (clear) areas have absolutely dreadful amounts of grain.
It's like golf balls sometimes, it's so gigantic. When it transitions to
black, it will go white, grey, golf balls black.
Click to expand...

Try using the Advanced Workflow Suggestions in the VueScan User's Guide.
This will set the mask color properly. There's a good possibility that
the problem you're seeing is that mask value being too high.

Regards,
Ed Hamrick
 
Ed Hamrick said:
Try using the Advanced Workflow Suggestions in the VueScan User's Guide.
This will set the mask color properly. There's a good possibility that
the problem you're seeing is that mask value being too high.

Regards,
Ed Hamrick
Click to expand...

Thanks Ed, I'll give that a try and see how it works out.

- Chris
 
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