PDA

View Full Version : Dinamic range on Epson V750?



ataim
9-Jan-2011, 16:26
Sorry for such a NOOB question, I've searched and looked at the archives trying to find a solution, but did not find one. Soooo here is a picture that I took last year. On the negative both the water and the bolder have plenty of details but I cannot get both to come out with a single scan. I've scanned it with three different brightness levels, which do bring out the details and then ran it through HDR, but I don't like the results. Also in Photoshop I've lightened the shadows, but still do not like it either. Below are the three scans. Any ideas? Oh and thanks in advance.

http://i301.photobucket.com/albums/nn70/ataim_1991/img104s.jpg
http://i301.photobucket.com/albums/nn70/ataim_1991/img105s-1.jpg
http://i301.photobucket.com/albums/nn70/ataim_1991/img103s.jpg

mdm
9-Jan-2011, 23:16
Vuescan will do multipass scanning. Try it instead of Epson Scan.

Joanna Carter
10-Jan-2011, 05:25
Here is a very similar image:

http://grandes-images.com/en/Landscape/Pages/Lancashire_files/Media/ViewFromHornbyBridge/ViewFromHornbyBridge.jpg

From spot exposure measurements of the water on the weir and the shadows under the trees, I found it necessary to take three transparencies (bracketed) and copy areas from the "highlight exposure" and the "shadow exposure" onto the main image.

Trying to compensate for wide range at the scanning stage is always going to be sub-optimal in my view.

pdmoylan
10-Jan-2011, 06:41
Quite the contrary, I have found that reducing contrast and maximizing DR with the initial scan is critical. Two simple methods: a) try multiscans using Silverfast. It does tend to lower contrast somewhat and slightly improve DR. The downside is slightly less acutence (edge sharpness) subject to the transparency being kept perfectly flat throughout the hour or more scanning process (when using 4 multiscan option and full ICE for instance, you can easily exceed an hour subject to your DPI choice. Next, I have found that choosing a different Profile setting may reduce contrast in an image - alternatively, setting the contrast levels in Silverfast manually. If you are shooting Velvia, sometimes using GND/SND and/or Polatizing filters are a must to capture wide DR scenes. Kodak E100G tends to work better in contrasty lighting.

Given

Sascha Welter
10-Jan-2011, 06:43
Seeing that this is a color negative, you should be able to get it all out with a single scan. (Note that Joanna refers to transparencies.)

You didn't mention your scan software. I would second mdm in the recommendation of VueScan, but no matter what software you use, you should read this:
http://www.kenleegallery.com/html/tech/scanning.html

Note how the default setting clips stuff and has the output restricted. What you want to do is to make sure in the scan software that nothing is clipped and you get all the output. The scanned image will appear too soft and flat after that, but then you get to decide how to adjust the image (e.g. using the "Curves" tool) to your liking. If you get "banding" after adjusting the image, make sure you scan in 16bit per channel.

ataim
10-Jan-2011, 07:34
Seeing that this is a color negative, you should be able to get it all out with a single scan. (Note that Joanna refers to transparencies.).

I'm sorry in my original post I did say negative, its actually transparency. But the method is sound for either negative or transparency.

Thanks to all on the comments, I'll get VueScan and visit Kenn Lee and give 'er another shot.

rdenney
10-Jan-2011, 12:38
I'm sorry in my original post I did say negative, its actually transparency. But the method is sound for either negative or transparency.

Thanks to all on the comments, I'll get VueScan and visit Kenn Lee and give 'er another shot.

With VueScan, there is a setting for the percentage of pixels that are allowed to reach maximum white and a percentage allowed to reach maximum black. If you set both of those to zero, the scan will come out quite flat, but it will give you everything the scanner is capable of. Multiscanning might also reduce noise and therefore improve the signal-to-noise ratio, but getting those clipping points out of harm's way is the bigger move.

You'll have to stretch it back out in Photoshop. I have had some difficulty with banding, despite being pretty careful to insist on 16-bit scanning, and am still experimenting. That only happened once and I just moved the 6x12 negative over to my Nikon scanner and stitched two scans together. I haven't had the problem on the 750 with other scans, but it bears trying to reproduce the problem so I can see what I did wrong.

Rick "noting that it has always been deadly difficult to print transparencies without losing one end of the scale or the other, no matter what the technology" Denney

mrladewig
10-Jan-2011, 13:35
Most likely, you need to adjust your workflow in EpsonScan. If there is detail in the negative (which there clearly is) you should be able to get it all in EpsonScan, it just might look a little flat. First off, you need to be in professional mode.

Starting in the levels function of Epsonscan, ensure that your output limits are set to 0 and 250-255 instead of 10-245 they are typically set at. I use 255 for my upper limit, but some like to keep the ceiling from clipping.
Next, you need to start out in levels input parameters by stretching the upper and lower endpoints until the highlights and shadows all fit into the scan. I also find that starting out with a gamma setting of 1.0 helps me to get everything balanced. The values will be very different from one sheet of film to another.
The previous step will probably result in an unpleasant shift in color across the frame. You need to go into each color and adjust the endpoints until everything comes back into balance. I'd recommend moving red, then blue and lastly green if needed. If you're having trouble getting everything to balance, then go into the image adjustments tab and increase the saturation to somewhere between 30 and 50. This helps to make the shift more clear, but remember to come back and set saturation at your normal level later. Use the densitomer to inspect highlight and shadow areas of the scan to ensure some detail exists.

Finally once the color is close in levels and you've toned down the saturation, use the curves tab to set the black primary curve to give the image the right contrast and mid tones and dial in the color with R, G and B curves.

That is my color negative scanning workflow with EpsonScan.

SMBooth
11-Jan-2011, 14:45
Set the levels in the Epson control panel independently of each other for much better control.
Much like this workflow.
http://cjeastwd.blogspot.com/2008/10/epson-3200-more-optimal-scans.html

Joe O'Hara
12-Jan-2011, 07:32
You can successfully scan this transparency with Epson Scan. After previewing the image, unselect Unsharp Mask and Auto Exposure (if on). Open the Levels window and set the output range to 0--255. Set the Input range such that the black and white markers are at the edges, or almost at the edges, of the histogram. The resulting scan will look dark and flat but will not be clipped in the highlights and shadows. You will be able to adjust it easily in PS.

This is basically the strategy that Ken Lee describes on his website. I find it works well for me.