Scanning B&W negs

colyn

colyn

ישו משיח
Local time
6:28 PM
Joined
May 31, 2006
Messages
4,532
I have been scanning my B&W negs in high res which creates an image too large for posting and would now like to scan for posting both here and on my website and was wondering what scan settings should I use to get both a decent image and one small enough for posting...

I prefer to scan my negs instead of darkroom prints.
 
In Photoshop/Elements there's a "Save for Web" feature, where you can specify a smaller size easily, or you can resize to 1000 or so pixels across.

If no editing software, scan at 800 ppi, that'll look fine.
 
Scan with 3200 dpi and TIFF , select the full histogram not to lose the dynamic of film , the resize to 800 pixel and save for the web. Always keep the tiff from the scanner if you want to rework on your pictures ;)
 
Scan at a high resolution for possible printing and then resize for posting to RFF or other web sites. Most of my gallery images are 640 pixels on the long side (horizontal or vertical) with a JPG quality of 90%.

I use Picasa (free at: http://[SIZE=-1]picasa.google.com[/SIZE][SIZE=-1]) to "export" high resolution scans at the desired size and JPG quality setting. Works like a charm. iPhoto, Photoshop and every other image editing package I can think of will also resize and adjust your JPG quality for reaonsable output with just a few clicks.

Hope this helps.
[/SIZE]
 
not really sure

Je sais pas trop comment dire ca mais en gros si tu impose à la fois taille et dpi, tu ne laisse aucun paramètre de libre-> photoshop risque de devoir interpoler et donc te faire perdre en qualité.


sorry for not saying it in english , I miss a few word
 
When Photoshop/Imageready "export for web" and Picasa "Export"s the output is a 72dpi JPG.
 
Hmm, I'll check again <pause>

I get 72dpi from Photoshop CS (not CS3) when I "Save for Web"

Picasa (version 2) outputs a 96dpi JPG.

Guess I never checked the Picasa output.

According to this site (http://www.scantips.com/no72dpi.html) it doesn't really matter for screen viewing, printing is another story... The second page has good info too.
 
The specific dpi for web is somewhat irrelevant. Your image has X * Y pixels and whoever is viewing it is on a monitor with a fixed pitch. Pixels divided by the monitors pitch is going to give you the viewed size irrespective of how many inches worth of dpi you originally gave it. The 72 ~ 96 number merely represents the typical pitch of common monitors.
 
^ IOW, an image saved at 2" across at 72dpi is 144 pixels across. The monitor resolution of the person viewing dictates the size of the image on their screen. You could save the image at 1" across and 144 dpi or 14.4 inches and 10 dpi andthe image would look the same on a monitor.

As a result, I ignore any dimensions but pixels. 640 pixels on the long side is a decent size for gallery viewing, but can be a bit small for some images with lots of detail.

If I understand "le vrai rdu" properly (not sure I do), a real concern is the loss of image quality as it is resized. I find that a bit of trial and error is necessary, but in general, resizing by 1/2 or 1/4 in steps until the desired size is approximated works best. I experiment with "sharper" or "smoother" bicubic settings, but the difference is often subtle. Any time you resize a scan you lose detail, and then when you convert to jpg you lose color and tonal accuracy, so it's an art itself rather than something with a single perfect anser for each image. And one must accept some loss somewhere, or never share images.
 
40oz said:
^ IOW, an image saved at 2" across at 72dpi is 144 pixels across. The monitor resolution of the person viewing dictates the size of the image on their screen. You could save the image at 1" across and 144 dpi or 14.4 inches and 10 dpi andthe image would look the same on a monitor.

As a result, I ignore any dimensions but pixels. 640 pixels on the long side is a decent size for gallery viewing, but can be a bit small for some images with lots of detail.

If I understand "le vrai rdu" properly (not sure I do), a real concern is the loss of image quality as it is resized. I find that a bit of trial and error is necessary, but in general, resizing by 1/2 or 1/4 in steps until the desired size is approximated works best. I experiment with "sharper" or "smoother" bicubic settings, but the difference is often subtle. Any time you resize a scan you lose detail, and then when you convert to jpg you lose color and tonal accuracy, so it's an art itself rather than something with a single perfect anser for each image. And one must accept some loss somewhere, or never share images.
Click to expand...
As I said in another thread I will make a small tutorial during the holidays, cause I was told how to scan in another french forum and I Have to say that the difference between "default" settings and personnal setting can be dramatic.

The only thing to remember is to keep the whole histogramme so as not to lose higthlight and shadows and to resize only when the picture is treated (durst and scratches removed etc etc ) I'am quite sorry not to explain it right now, it is not so complicated but I not sure I would make myself understand for english is not my native langage. So to sum up I will quickly make a tutorial with screenshot to make me more clear ;). I have already posted a comparaison on a thread about HP5+ concerning default/personnal setting on your personnal scanner ;)
 
You must log in or register to reply here.
Back
Top Bottom