philpem.me.uk misc :: negative to positive  

Negative to Positive


If, like me, you have a lot of 35mm (or otherwise) photographic negatives, but you want to use them on your computer, then this tutorial might just save you a bit of money. Instead of going out and buying a so-called "transparent media adapter" for your scanner, go to a photo store (no, not your local film processor, a proper photo store, like Jessops) and get a "light box". I've got a 4x5" Jessops light box. It's a good low-cost replacement for a TMA. Anyway, on with the show!
Note: I've got an Epson 2400 Photo scanner now, which does negative scanning directly. This page is here in the hope that it may be useful, but it will not be updated.

Screenshot 1 Screenshot 2 Scan the image into Photoshop. Make sure you get some of the "header" and "footer" of the negative - you'll need the text to sort out the rotation of the image and the brown area to remove the colour cast. You should have an image that looks similar to the one on the left.
Screenshot 3 Rotate the image if necessary. Hopefully you should now have a good-quality negative that is the right way up. If you can read the text on the top of the scan then you have the rotation correct. If you took a photo with the camera at a 90° angle then rotate the scan by 90° to correct the alignment. Easy.
Screenshot 4 Make a selection containing the brown area between the two negatives. Now you see why I told you to get some overlap when you scanned the negative strip in! When you've got a good selection, select Edit -> Copy. Then create a new image, accepting the settings that Photoshop grabbed off the clipboard. Select Edit -> Paste and then Filter -> Blur -> Blur More. Blur the image about five times.
Screenshot 5 Select the Eyedropper tool. In the Options window, select "Point Sample". Pick somewhere in your new image (the brown one) and click. Close the window.
Screenshot 6 Now, go to Select -> Deselect to remove the selection. Go to Layer -> New Layer. Adjust the settings so they match the settings in the image on the left. Select the new colour layer.
Screenshot 7 Fill the colour layer with the brown you selected earlier. Go to Image -> Adjust -> Invert. You should now have a good quality negative scan without the colour cast. Go to Layer -> Merge Visible. You should now have a single layer image. Go to Image -> Adjust -> Invert again. You should have an image similar to the one on the left.
Screenshot 8 Right. Now to remove the excess brightness. Go into Image -> Adjust -> Levels. Ignore any residual colour cast, I'll show you how to correct that later. All you need to do is get the image visible. The settings used will vary from image to image, but a good starting point for experimenting is shown on the left.
Screenshot 9 Now, we've got a good quality image, except for one thing. It's got a colour cast! Go to Image -> Adjust -> Auto Levels. Photoshop will remove the colour cast for you. And, just to finish it off, go to Image -> Adjust -> Auto Contrast to finish off. The image is nice, but there's a lot of noise. Go to Filters -> Noise -> Despeckle. You'll lose a bit of detail, but it's hardly noticeable on most images. Remember I told you to set the scanner's resolution right up to 400? That's to help remove some more noise. Go to Image -> Image Size. Reduce one of the settings by half and the other should follow. Click OK.
Screenshot 10 Well. We now have a good quality positive image, but we still need to do one thing to make it usable. Remove the border. Select the area of the image you want and go to Edit -> Copy. Go to File -> New. Accept the settings Photoshop got off the clipboard. Select Edit -> Paste. You should now have a good quality image that's perfect for using on a webpage or, if you've got a good scanner (like one of the new Epson or Microtek scanners) with a high optical resolution, then you can get good quality high-resolution images suitable for using in a newsletter or other printed document. The image quality is good enough to rival a film scanner if you've got a good enough scanner.
Screenshot 11 The finished image is shown on the left. Clipped out and ready for printing or publishing on the Internet.

If you play around enough, you can get some really good quality scans. If you want better quality, the only real alternative is a film scanner.