Sharpening 4x5 Black and White

[bbuszard]

This will be a frequently asked question, I know, but I've reviewed the answers already up and tried without success to follow the recommendations. I also asked on photo.net and got a couple of helpful responses, but wanted to post here for further opinions.

The problem: I've been trying to submit 4x5 negatives scanned on my Epson V700 to Alamy but have been rejected three times now for image softness. Their insistence on *absolutely no sharpening* is inconsistent with the process of digitizing film, as others have pointed out before, so I've been trying to guess how much will be accepted without being spotted by the reviewers. Here's a sample image, greatly reduced:

http://www.flickr.com/photos/brad_buszard/3898444700/sizes/o/

And here is a crop at 100%:

http://www.flickr.com/photos/brad_buszard/3898445294/sizes/o/

I've sharpened the image about as much as I can before it looks objectionable to me at high resolutions, but the results are not easily observable at the lower resolutions.

A helpful photo.net reader noted that my image looked sharp (i.e. lens and focus, I think) but that the grain was not, and that my scanner was the likely culprit. I had previously scanned my negs with the Epson holder, so I purchased a new holder from betterscanning. My first scan with the new holder is here (still dry mounting):

http://www.flickr.com/photos/brad_buszard/3898708872/sizes/o/

And here's the 100% crop:

http://www.flickr.com/photos/brad_buszard/3897927643/sizes/o/

I'd appreciate any advice or opinions. I don't really care too much whether Alamy likes my images; I'm not a pro and don't expect my hobby to generate much income. But I am an amateur in the sense that I want to improve my craft. I'd also like to avoid regular drum-scans at better than $60 a pop.

Many thanks for your comments

 

[Ray Heath]

g'day Brad

what's an Alamy?

are they trying to restrict film users?

 

[bbuszard]

Alamy

g'day Brad

what's an Alamy?

are they trying to restrict film users?

Alamy's a stock photo service. I've tried submitting images to them to see whether my quality if up to snuff.

I don't know that they're consciously trying to restrict film. I can't imagine why they would. They're a relatively new outfit, though, so I'm sure the vast majority of their images are digital.

 

[pellicle]

Hi

screen

The problem: I've been trying to submit 4x5 negatives scanned on my Epson V700 to Alamy but have been rejected three times now for image softness.

the images looked good to me, what size are you scanning and sending to them? (pixel dimensions please not "8x10"). If you are sending less than 6000pixels wide then perhaps the sharpening you are doing is not required.

Have you tried simply "downsampling sharper" and then perhaps doing some contrast type sharpening (say 60 pixels radius)

just a first thought

 

[bbuszard]

pellicle: I've been scanning at 1200 ppi. I received a new suggestion to scan at very high resolution (3200), then slightly sharpen. A new 100% crop is online here:

http://www.flickr.com/photos/brad_buszard/3901817905/sizes/o/

Does it look sharper than the previous attempts?

 

[pschwart]

http://www.flickr.com/photos/brad_bu...17905/sizes/o/

This looks fuzzy to me. How are you sharpening the image? Also, I think scanning at 3200 ppi is not gaining you anything as this is probably above the true resolution of the Epson.

 

[bbuszard]

pschwart: The suggested new formula that I followed is first to scan at 3200 ppi, then sharpen at around 130/1.3/0, then bilinear resample down to 1200 ppi, then add a final touch of edge sharpening.

There's a lot more information in the newer crop, but I agree that it's impression is blurry. And a small full frame image, say 1280x1024, looks far less sharp than my previous attempts, though they look far worse at the 100% crop.

 

[pellicle]

Hi

pellicle: I've been scanning at 1200 ppi. I received a

too low ...

new suggestion to scan at very high resolution (3200), then slightly sharpen. A new 100% crop is online here:

http://www.flickr.com/photos/brad_buszard/3901817905/sizes/o/

Does it look sharper than the previous attempts?

I agree more with this strategy, its heading where I was thinking in my quick post. However if you keep scanning different negatives then I'll have totally no idea what is happening as there is no basis for compairson

please pick one negative and keep working with it

 

[bbuszard]

This the same negative as my first scan. The crop to compare is the second URL in my first post.

 

[pellicle]

This the same negative as my first scan. The crop to compare is the second URL in my first post.

Ok ... understand better ... would be nicer / easier for me at least if you'd kept them same, but I understand now.

you seem to have quite different scan curves applied and different sizing ... Try not using automated scanning in the Epson, set your levels your self, scan neg as if it was pos and invert later, you'll get far far better control that way. Scan your negative linear with set black and white points and then apply curves to taste in photoshop, save the curve and then reapply on subsequent scans. This way you will get a consistent look each time

makes it much easier to see what's going on if there are not bundles of variables happening.

 

[Eckart]

Have you tried to check the sharpness in the individual channels ? I always use 50% of the blue and 50% of the green channel. The red channel appears less sharp from my V700.
Eckart

 

[pellicle]

hi

Have you tried to check the sharpness in the individual channels ? I always use 50% of the blue and 50% of the green channel. The red channel appears less sharp from my V700.
Eckart

ahh ... good point. I used to use the green channel, but found that when scanning in monochrome it defaults to using that.