The Hoyarex filter system was really good: high quality filters.. Great variety of options in the range. Some glass filters. Solid holder. And a really useful rubber hood. But the Hoyarex System had a big flaw! And that has become evident over the years as more and more filters become scratched.

It’s not due to use either! These scratches occur when the filters are stored in their plastic case. The resin filter catches the edge of the case, which usually bends a bit in the middle. So after being jostled around in a camera bag the rubbing effect causes the resin to mark or scratch.

So here’s a tip to prevent further wear. Buy a packet of lens tissues and wrap one over the filter at the top end that sticks out of the case. Then the filter wont get rubbed. You can use toilet tissue, but a lens tissue is softer and has no fibres that will come off and cause dust problems.

View the entire range of Hoyarex filters here

In the last article we showed you how to make a custom slide duplicator for 35mm negatives and transparencies. And the first problem you will encounter when you start scanning your colour negatives  is how to convert the result to a positive digital file.

When you use a proper film scanner it has built in settings that convert the negative to positive automatically, but the digital files from a slide duplicator look just like the original –  negative image with an orange colour.

We’ll not go into the colour – you can find all those technical details here: Why is colour negative film orange?

You may think it’s simply a case of pressing the invert button in your image editing software. That does make the photo look positive, but the orange inverts to a blue colour and that needs fixing.

Here’s how I process photos in Lightroom. You can do similar with most image editing programs.

Below is the imported negative in Lightroom. Scroll down to the tone curve. Notice the line in the graph goes from bottom left to top right.

Click on the bottom left corner and drag to top left, then click top right and drag to bottom right. This inverts the image – notice the blue cast.

Using the WB dropper click on a neutral part of the image to adjust the white balance. I chose the black hair of the boy  facing us. This makes the colours  more natural. Now adjust the tone sliders to beef up contrast darken shadows and brighten highlights.

The result is a fairly good conversion of your digital negative