V700 issue: preview much better than output image

wolfpeterson

wolfpeterson

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I call upon the collective knowledge of RFF to help me out!

I just noticed this starting yesterday. I'm scanning TMY2 in my v700 and the preview image is much more contrasty than the resulting scan. The issue is present in both Epson Scan and silverfast.

For example, I marquee an image, zoom in, adjust the black, white and midtone in the histogram adjustment pane to my liking and scan. The resulting scan has way less contrast than the preview image...

Film type is set as b&w neg, image type is set as 8bit grayscale. There is some improvement if I scan it as 24bit color and convert to grayscale in photoshop but it is still a little bit off.

I know that I can adjust this stuff in post, but I would like to have a more representative preview.


Here is an example of scanning directly to greyscale, on the left is the image resulting from the scan, and on the right is the preview image. This example is not as dramatic as others, but it shows.

example.jpg
 
I think it may be a fact of life for many scanners, and it may depend on the software. Previews from Vuescan, for example, are not the same as the scan from my V500 or Nikon.
 
wolfpeterson said:
I call upon the collective knowledge of RFF to help me out!

I just noticed this starting yesterday. I'm scanning TMY2 in my v700 and the preview image is much more contrasty than the resulting scan. The issue is present in both Epson Scan and silverfast.

For example, I marquee an image, zoom in, adjust the black, white and midtone in the histogram adjustment pane to my liking and scan. The resulting scan has way less contrast than the preview image...

Film type is set as b&w neg, image type is set as 8bit grayscale. There is some improvement if I scan it as 24bit color and convert to grayscale in photoshop but it is still a little bit off.

I know that I can adjust this stuff in post, but I would like to have a more representative preview.


Here is an example of scanning directly to greyscale, on the left is the image resulting from the scan, and on the right is the preview image. This example is not as dramatic as others, but it shows.
Click to expand...

I've noticed this too with my scanners. With the same type of difference that your images exhibit (lighter on scan). I've always chalked it up to my uncalibrated workflow and the different scan resolutions used for preview and scan modes. My biggest difference is in the print stage.



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Looks like the preview is crunching the blacks... there is more shadow detail in the scan. You can always add contrast but impossible to regain shadow detail once it's lost.
 
It's fine if the scanned image is less punchy. In a scanned image you don't want punch, you want detail. You can always add punch in postprocessing.

Also I'd recommend scanning negatives with more than 8 bits.
 
You could lower the output black level, lower left box...Don't know if that's a part of your routine or not...
 
This is just a guess because I can't see what your settings are or exactly the order you are doing things in. But, you made your preview and the scanner has scanned the surrounding area (black) and you are making your adjustments based on the exposure the scanner needed to scan both the image and border. So you go to the full scan but the border is no longer there because you cropped it, so whatever base level exposure settings the scanner is working on have changed significantly.

So, make a first preview, crop the background, then make another preview of just the image and adjust that, not the one with the border. Then try a full scan and see if the image comes out closer to what you want.

As I say, just a guess.

Steve
 
Why not choose 16bit greyscale? Curious if there is a specific reason not to do. As others have said. Detail over contrast in images that have not gone to final PP is optimal. I use Epson scan for b&w. Just fill up the histogram to right before clipping points. When doing final Post, black point adjustments can be made to add some pop if desired.
 
250swb said:
This is just a guess because I can't see what your settings are or exactly the order you are doing things in. But, you made your preview and the scanner has scanned the surrounding area (black) and you are making your adjustments based on the exposure the scanner needed to scan both the image and border. So you go to the full scan but the border is no longer there because you cropped it, so whatever base level exposure settings the scanner is working on have changed significantly.

So, make a first preview, crop the background, then make another preview of just the image and adjust that, not the one with the border. Then try a full scan and see if the image comes out closer to what you want.

As I say, just a guess.

Steve
Click to expand...

Hey steve,

as you can see in the provided image, the marquee does not include the black border so it did not affect the adjustment. I also hardly ever use the auto-exposure, always adjust the histogram by hand to my liking.

For the others, I am well aware of good scanning practices :D, and I am aware that the preview image is clipped.

However, my question is directed to the accuracy of the preview image. Regardless of whether the black is clipped or not, the scanner should obey my command and give me the image I want.

Maybe I'm expecting too much precision on the part of this flatbed. When you think about it, it does a preview scan at a given exposure, never a d. Then THAT image is modified via histogram adjusments to try to give you an accurate representation of the resulting scan. You are dumping a ton of data in that preview image, and so it might be silly to believe the resulting scan will look identical...

Maybe I just answered my own question. But then why is the issue aggravated by having it set to greyscale rather that color.

Also, for those who suggested 16bit, the issue stays the same, and I am using these scans for the web, so there's no advantage to the larger file size.
 
Out of curiosity I just tried replicating your Preview problem and all my contrast adjustments in the Preview are mirrored in the final scan using either Vuescan, Silverfast, or Epson scan. So all I can assume is that you are doing something fundamentally wrong. Try approaching it from that standpoint instead of thinking the scanner or software is doing it wrong, its often a good way to solve technical problems.

Steve
 
Steve, I'm not sure what you mean by "fundamentally wrong". The only thing I changed in my workflow is that I switched to Tmax Dev. instead of my usual D76.

I'm pretty certain that changing the developer would not create this issue.

I even reset all settings to default and started from scratch. I cleaned the calibration area properly. The top light source is unlocked, plugged in and working. Emulsion side up. My negatives are contrasty...

Are there any other human variables I'm not thinking of? Could it be a ICC profile thing?

I guess I will continue to scan in RGB and convert to grayscale as that seems to be the acceptable alternative.
 
I've always experienced this when scanning on my V500. I assumed the "preview" was a highly contrasted image to make the frame selection process a little easier when seen on the small thumbnail.

I've never thought there was a link between the preview and the final scan.

I've always dealt with my BW images (also colour) after the scan by using the levels correction function to set the black, gray and white points. I disregard the preview for anything other than framing/cropping the selected part of the scan for the final pass.

Now I'll wait to see what other RFF'ers do in this situation.
 
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Have you calibrated your screen properly? Have you selected the proper color profile within Epson's scanning software? Are you assigning the proper color profiles to scanned images when you import to PS?

If you don't know much about proper calibration / color profile management, I'd recommend you take the time to learn. There are lots of good resources on the net to help you get started. There are also some great books out there, too - it's a little daunting for someone not familiar with the terminology / process -- but without it you'll continue to struggle with attaining the results you'd like - and should expect.
 
My screen is calibrated by eye using the apple calibration tool. If it was just my monitor that was miscalibrated, both images would be equally off.

I will read up on profiles and make sure that it's all in order, because I know that I've never checked to make sure my setup was proper.

I don't print, so I haven't taken the plunge into hardware calibration tools and such, but I know a few things about profiling from when I printed digitally during my BFA.

Thanks to everyone for the help and suggestions, I will chime in when I've exhausted every avenue (hopefully one will be the right one!).
 
Well that was a total flub on my part. I had just changed my screen's gamma to 2.2, I did no realize what effect this would have on the greyscale color space. I just adjusted the color space and grayscale scans are back to normal and looking good. So it was a technical problem, although aggravated by a man. :D

Steve, I'm sorry you I made you pull out your dictionary, I already knew the definition of the word. :) What I meant to say was I was looking for a few suggestions.

Thanks for all the help!
 
In my experience the Apple self-calibration tool is bogus. I use a Spyder and it's much more accurate. My iMac tends to drift too bright over time, so this will lead to photo output that is too dark.
 
jan normandale said:
<snip>
I've never thought there was a link between the preview and the final scan.

I've always dealt with my BW images (also colour) after the scan by using the levels correction function to set the black, gray and white points. I disregard the preview for anything other than framing/cropping the selected part of the scan for the final pass.

Now I'll wait to see what other RFF'ers do in this situation.
Click to expand...

I think Jan got it right.

Also, do not worry and don't adjust the contrast of the final scan file. Just make sure the endpoints of the histogram are not clipped and ignore everything else.

Adjusting the contrast in the scanner software is a bit crude and irreversible. Do all those adjustments in your image editor (Photoshop) so you can see what you are doing and only do them one time. Remember the actual data captured in the scan is what it is and cannot be adjusted. So you do not want to begin adjusting that data in the scanner software.

Lastly, remember that a flat looking ugly scan will usually result in the best final image. Make no attempt to get a good looking file direct from the scanner.

Step back and realize: 1) what the scanner itself actually does, 2) what the scanner software does, and 3) what you do in your image editor. 1) is a function of the scanner's optics, mechanics, and electronics. You cannot adjust it. 2) is crude, done blindly, and irreversible. You want to minimize it. 3) is where you want to do all adjustments.
 
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