Settings for Scanning

[maverick911]

What dpi should I use to scan in old photos? And which file format should I save them in using PS3?

Using an Epson Perfection 1240U.

[mistermonday]

Choose your scan resolution so as to generate 300ppi at the ultimate OUTPUT size. So for example if the largest size that you ever intend to print will be 8 x 12 inches, you would ideally need 2400 x 3600 pixels. If the photo that you are scanning is 4 x 6 inches, then you will need a scan resolution of 600ppi or greater. If your output will be 12 x 18" from a 4x6 photo, you need 3600 x 5400 or 900ppi. Since 900 ppi is not a standard scan res, you would need to go to 1200ppi.
Save the scan output to a file format that uses lossless compression - like TIFF or PSD but preferably not jpeg or if jpeg use the highest quality setting. TIFF is probably preferable because it has a Lossless compression setting and you can set PS to open them automatically in Adobe Camera RAW.
Regards, Murray

[maverick911]

Thank you very much Murray, most helpful.

[Dak Paule]

Good info Murray. I have been meaning to ask that same question.

Dak

[maverick911]

Murray, another question please. Should I scan as a Gray Scale image or Color? Reason I ask is that I am following a tutorial on levels, the tutorial is showing RGB Channels on a B&W image but I only get Gray Scale Channel?

[mistermonday]

Definitely scan in color, even if the photo is in B&W. For example if you have some yellowing discoloration or stains or colored mold spots, they can be filtered out much more easily. Certain reflections or textures in the paper will be recorded differently by the R,G,B channels resulting in contrast that can be more easily isolated when post processing the image.
One other thing that is important when scanning. Turn OFF all of the automatic settings that the scanner s/w want to apply to "help" you. Turn OFF:
- DeScreen
- Auto Levels
- Auto Contrast
- Auto Color
- Auto Brightness
- All Sharpening
- All pretty much anything
The scanner s/w will almost always do more damage to a scan than it will do good. Wrong guesses produce damage & loss which is difficult or impossible to recover from. You would be much better to take a raw unmodified scan and then open & process it in Camera RAW or PS or both.
Regards, Murray

[maverick911]

Thats great info thank you. However, you now have me wondering if my scanner is good enough, it seems the only thing I can overide is the DPI?

[Florin]

Good info, Murray

[mistermonday]

Maverick, you can control all that stuff on your 1240U. You need to switch from auto to manual mode. Please check your user manual or dowoad one from Epson.
Regards, Murray

[maverick911]

Thank you once again.

[unimatrix001]

I found this link on another forum.
http://photodoctor911.com/scantips.html

[maverick911]

Originally Posted by unimatrix001

I found this link on another forum.
http://photodoctor911.com/scantips.html

Thats really useful thank you.

[Carol Heath]

I generally suggest the following formula for calculating a suitable scan resolution. Of course, you should always take into consideration the output size.

scan resolution = (desired width / actual width) * desired resolution
If the original image is 2.5" wide and a 6" print @ 300 ppi is required
scan resolution = (6 / 2.5) * 300 = 720ppi.

I scan all images in RGB, regardless of whether they are black and white, sepia or colour. Information potentially useful for restoring monochrome images can be extracted from the individual RGB (red, green and blue) colour channels.

I also avoid using any auto correction functions on my scanner. I would much prefer to make corrections in Photoshop where I have full control. I do use the descreen function on occasion however. HTH

[maverick911]

Thanks Carol

[JoReam]

Thanks for posting this question its one that I have been struggling with. Thanks for the advice on sizing (MisterMonday and for the calculators Unimatrix001 and Carol). I have scanned photos at 300, 600, 1200, 2000 dpi - the higher resolutions only because of needing to enlarge a really small old photo. Where the photo is of good quality this has been useful if I have been looking to resize it. However one problem I have discovered is this introduces unwanted textures or enlarges those age defects - so I would be interested to know what people do... particularly where your printer outputs higher than 300dpi. Is it better to scan at the printer resolution or scan at a lower resolution and let the printer resample to size (I have an Epsom that prints at 1440 dpi ). Or is it better to scan at the lower resolution and resize in photoshop?

[mistermonday]

JoReam, I wish printer manufacturers would not mislead people with marketing numbers. That 1440 dpi is not the same as 1440 ppi.That's because each inkjet printer rating dpi is something entirely different, referring to inkjet printer ink dots instead of image pixels. The inkjet printer tries to simulate the color of one image pixel by making several ink dots of four CMYK ink colors, which are located perhaps on 1200 or 1440 dpi spacing. The printer is trying the best it possibly can to reproduce the pixels (pixels is all there is), but inkjets cannot reproduce colored pixels directly. Image pixels and inkjet printer ink dots are NOT the same thing at all.
A 300 pixels per inch image is considered print quality and is the highest you should ever need for a high quality print.
Regards, Murray

[Carol Heath]

JoReam, Scanning small images at a very high resolution can, as you mentioned introduce new challenges, especially with textured papers. I sometimes find re-photographing these very small images a better option. Of course, this also means you need a good, sharp macro lens.
As Mistermonday has explained, your printer does not really output at 1440ppi. I would aim for 300ppi as your output resolution.

[4personnen]

Just another stuff that comes to my mind...When you scan an image on paper (I mean not a film) Try to scan the same image at different angles (I mean parallel to upper borders, parallel to the side borders and 45 degrees) sometimes it helps to get rid of moiré and/or rays of lights created by creases and folds. Sometime you will be able to use 2 images and combinate them afterwards eg. in case of silvering stains (because the scanner light doesn't come on the same angle each time)

[JoReam]

This is really helpful - thanks very much Murray, Carol and 4personnen it has made me go and look at my printer output a little more carefully. My printer maxiumum print settings are 1440 dpi in one direction and 2880 dpi in the other which I mistakedly thought was 1440 dpi and I now realise it is not. Thank you also for the suggestions about scanning in different directions, I didn't know about offsetting at 45 degrees.
Last year I tried restoring a small photo for a friend who wanted it enlarged. I then struggled to get rid of the texture. I didn't know at that time how to calculate the scanning resolution from the output size and I didn't have a good enough light setup to photograph it. The good thing is I found this wonderful site as a result of a google search trying to solve these problems!
Jo