My Account  |  Login   |  Register  | Tell a friend


Film conversion
How to convert a 35mm negative into a usable digital image


Photosolve Xtend-a-Slide Plus film conversion system


More articles in the Photosolve Resource Center

Do you have 35mm negatives that you want to use digitally? If you have a digital camera, image-editing software and photosolve’s Xtend-a-Slide Plus, this can be done fairly easily. The techniques described here can also be applied to any digital image you have of a negative, so let’s dive right in.

Original Negative

Getting the negative image in the first place
If you have color or black-and-white 35mm film negatives that you'd like to convert to digital pictures, you've got a few choices:

• Take them to the local photo store and have them do it (generally expensive)

• Buy or borrow a good quality film scanner and do the job yourself (even with the cost reductions in negative scanners, this can be expensive, both in money and in time)

• Use your digital camera, some close-up lenses, an Xtend-a-Slide Plus and Photoshop (or equivalent)

Final Picture

A word of caution: The image you get from an expensive drum or film scanner will typically be much better (higher resolution, better quality) than what you should expect from your digital camera, although with the improvement in resolution, most digital cameras can do a very credible job and you'll be able to easily print 4x6, 8x10 and even 11x14 with good results. The major savings in time and money for many will be the key factors.
The tools
Converting a 35mm negative to a usable digital photo is certainly a bit more complicated than simply shooting a 35mm slide, but once you understand the process, it moves fairly rapidly. When you add the film carrier to the Xtend-a-Slide Plus, you get a convenient way to frame whatever segment of the filmstrip you’re trying to capture.

Xtend-a-Slide Plus Film Carrier with empty slide carrier

Xtend-a-Slide Plus shown attached to a Kodak 4800 Digital Camera, with Xtend-a-Lens 4800, step ring (43-49mm) and three close-up lenses (+4,+2,+1)
Method 1: Shoot the negative and use commercial software to convert the negative to a positive.
Approach A:

This approach is pretty straightforward and uses a highly recommended, commercially available program called VueScan from Hamrick Software ( Ed Hamrick was kind enough to broaden VueScan’s capability to include the ability to “scan” JPEG files as well as the standard TIFF. Once you’ve shot the JPEG of your negative, you can simply use the software to convert the negative to a positive image. You can even set up a batch of negatives to convert and go get some coffee. You should definitely check this out as it does make life pretty simple. But it may not be a perfect solution for everyone. The correction curves built into the software may NOT include your particular film, so you might end up having to do some correction work anyway.

Approach B:

If you have access to Photoshop, then this may be the method for you. Kodak has developed a plug-in for Photoshop called Digital ROC. It comes in two versions (Standard and Pro) and is available here. There are downloadable trial versions that you can try out. You can shoot the digital negative, invert it, and then apply Digital ROC. You'll be amazed how quickly and correctly it eliminates the blue cast.

A simple invert of the negative
(note: larger version is 2.2 MBytes)

Method 2: More manual, more control (and more variation in method, too)
The second method described here is the result of extensive experimentation as well as reading and web searching for other people's ideas. There are a number of different methods that you can use. This particular one does seem to work reasonably well, and if you've already got Photoshop or a similar program, it's certainly doable, but it does require some work on your part. Modify it to your own tastes. Also, each of the pictures, including the negatives, swatches, and final photos have full size, 72 dpi photos behind them which you're welcome to download and experiment with yourself. Your results will vary depending upon light, camera, etc.

If you simply take a picture of the negative film using the Xtend-a-Slide Plus with your digital camera, and then invert the image in Photoshop for example, you'll end up with something looking like the image here, with a serious blue cast...

Not pretty...but understandable, if you notice that the original negative has a strange orange colored cast to it. Knowing that and that the inverse of orange is this strange shade of blue, you may slap your forhead and exclaim, "Of course!" or you may not... This discussion will not go into all the why's and wherefores of the orange cast. Suffice it to say that virtually all color negative films have it, and that it was and continues to be a part of the regular printing/enlargement process. If you'd like to learn more about the "orange mask", here is a good explanation by Donl Mathis.

It's important to note that we have to get rid of the orange mask in order for all of this to work

To do that, we're going to have to essentially erase the orange cast by adjusting the color curves associated with the picture. We can do that by taking a picture of the clear film leader (which is generally returned with your 35mm film).

Film leader sample (note: larger version is 1.7 MBytes)

Fully blurred orange

... and black samples
Take a picture of the film leader as is shown on the left (above) and then in Photoshop or other editor, open up this picture, select a square section of the orange section, create a new file and paste in the orange. Then do the same with the black. It doesn't really matter a great deal how big they are. Using a Gaussian blur, heavily blur the content of each of these new files. Why? Because if you sample the orange or the black in their raw form, you'll likely end up with an untrue color, and the blurring tends to eliminate the lack of consistency. To prove this to yourself, click on the black and orange combination picture on the left, you'll see all the little different pixels, each a slightly different color. The blurring eliminates that problem.Now, with the picture of your negative front most in Photoshop, and the two pictures of the black and orange samples also visible (but not the primary pictures) select Adjust Curves, and you'll be presented with the dialog shown below. Here's where all the preparation pays off...

Now take a look at the Curves dialog box below. In photoshop with your negative, click on the small eye dropper on the right (with the white in it). This will set the white point in your negative. Move the cursor until it is over the orange sample that you created, and click on the screen. You should immediately notice a fairly signficant change in your picture of the negative. Finally, click on the little eye dropper with the black color. Similarly, move the cursor until it is over the black sample on your screen, and click. This will set the black point. You may notice a small change in the picture. It should end up looking like the picture below (corrected negative). Notice how much of the orange cast has been removed. By setting the white and black points to our orange and black samples, we've told Photoshop that the orange color is really what should be clear or white, and the black color is our darkest spot on the negative. We may end up doing a bit of adjustment to overall levels, but this'll get us most of the way there.

Photoshop white point adjustment

and black point adjustment

Corrected negative after setting white and black points
(note: larger version is 2.8 MBytes)
Finally, you then invert the corrected negative by simply selecting the Invert selection under the Image, Adjust. If your inversion results in a not quite right color leveled picture, simply try using Image, Adjust, Auto Levels.

Lather, rinse, repeat if you’re not quite happy with the results, or if you have several images to convert. The final image should now be ready to send on its merry way to a printer, web page, or whatever purpose you have for it.

A brief recap of the steps:

• Shoot a picture of the color negative
• Shoot a picture of the film leader. Do this by setting the film leader up so that you get a bit of black and a bit of orange on the same shot or, if necessary, you can actually shoot two pictures.
• Create two separate files, one with the orange and one with the black; apply a heavy Gaussian blur to each file.
• With the color negative selected, select Adjust: Curves, then individually set the white balance from the orange and black level from the black
• Select the corrected color negative, and select Adjust: Invert
• Do any sharpening or final adjustments that you feel necessary

The final picture after inversion
(note: larger version is 1.9 MBytes)