Introduction, Raw Scans, Neg Film, Highlight Compression, Slide Film, PhotoShop, Conclusion

Introduction

Some time ago I wrote a well received article about getting the most from colour negative scans with VueScan. Since writing the article my workflow has changed significantly, and these are the main reasons why:

• It takes far too long to profile the film base colour using VueScan, scanning isn’t fun at the best of times and I’m an impatient person.
• I’m now shooting a lot more colour slide film, and wanted something that would work equally well if I needed to tweak colour.
• I’m shooting 8×10 & 4×5 sheet film which doesn’t have an area of clear base that I can sample.
• I realised that the old method didn’t stop me having to tweak colour in PhotoShop, and that often the output was worse than from a film preset.

By chance A friend, Raoul Gatepin (Who is an awesome photographer) introduced me to the PhotoShop plugin, ColorNeg, and since then I’ve not really looked back.

ColorPerfect is the latest incarnation of ColorNeg (it amalgamates ColorNeg & ColorPos for slide film) and is the plugin I use on a daily basis, I’ll do my best to describe my workflow here using both text and imagery.

Note: this article does not cover Screen or Scanner profiling, both are critical to good colour workflow, it’s particularly important to ensure your screen is profiled otherwise how will you know if you are making good colour decisions?

Raw Scans

For ColorPerfect to work at its best we need to ensure that VueScan does not do any image processing on our scans whatsoever, for this reason we must save our scans as 16 bit RAW Linear files. Before going any further with this article you will need to own a licensed professional version of VueScan otherwise RAW output is unavailable.

I’m also very much of the opinion that sharpening, dust removal, etc should be done selectively and by hand in PhotoShop so I disable things like ICE & sharpening, here’s a quick run through of how I think you should configure VueScan.

The first thing I turn off in viewscan is the automatic saving of scans – I often find that the scan shows an imperfection that the preview does not, meaning I’ll discard the scan, so why waste disk space keeping a copy?

Although we’re going to save our scans as RAW files it’s important to keep VueScan’s Media setting configured to ‘Color Negative’. With this setting enabled VueScan scales the output of each colour channel so that they are roughly the same. There is typically 1 EV difference between each channel with red being brightest and blue darkest.

Increasing the number of samples helps to eliminate noise in the shadow areas of the scan, obviously the more samples the longer the scan will take so I opt for 3 as a minimum number to average out error.

Next you need to untick every format except ‘Raw file’ on the Output tab, be sure to leave Raw DNG unticked! Set the ‘Raw file type’ to ’48 Bit RGB’. I also like to set Printed Size to ‘Scan size’ to stop VueScan resizing the output.

Now that you have a baseline configuration for ColorPerfect you should save it for future reference. It’s time to start scanning.

Neg Film

Once you’ve scanned, saved and opened your image in PhotoShop you should have something looking a bit like this:

The orange cast of the film base is very apparent, our next step is to start the ColorPerfect plugin via the Filter menu in PS (Filter->CF Systems->ColorPerfect).

I’ve deliberately chosen a difficult film stock here, it’s a cheapo Boots Chemist 200 speed film, most branded films are a doddle to colour correct because the film preset is obvious but in this case some internet searching showed the film to be a Fuji rebrand. So with this in mind I simply chose the film base that gave the most natural looking colour – although you can see that there’s a slight magenta cast to the sky/neutrals.

You’ll notice that I have ringed the three areas of importance in red, film brand, film type, and gamma input mode. The Gamma Input mode should always be set to L for colour negatives (which should always be Linear 16 bit scans), the other setting of G is for use with positive files produced from Slide Film.

Again, this film stock is generic, and although we know the approximate brand we’ve no way for sure to know the actual film type. Even when we know the brand and stock, individual batches can be quite different from one another. The development process throws even more variance into the mix. In short, it’s quite obvious that the inbuilt profiles may never actually give us the best match when we know a film stock, let alone when we don’t. This is where a great new feature of ColorPerfect comes to the rescue, it’s a feature called Filmtype

You can see in the screenshot above that I’ve selected the ‘FilmType’ setting in the main dropdown. All that you need to do after this is find a neutral gray area in your image and click on it. For this photo I clicked about in the grey parts of the cloud until the overall balance was as close as I could get it. Now here’s the nifty bit, by dragging the main slider up and down ColorPerfect varies things just slightly, and typically somewhere in the entire slider range you’ll hit the sweet-spot.

Things still aren’t quite right, the contrast looks a little off, so now it’s time to adjust Gamma.

Change the main drop down setting to Gamma, then simply adjust the main slider until the blacks look about right. That’s it. Often these changes may be marginal, but it’s what feels right that is usually best.

So now that I’m happy I simply click ‘OK’ and use PhotoShop to ultra fine tune colour and levels.

Highlight Compression

Another great feature in ColorPerfect is the ability to compress the highlights in your image, essentially, this stops highlights being blown when you are trying to boost shadow detail. This is important because although colour negative film has a dynamic range which is often in excess of 14 stops, a typical positive image (be it on screen or print) has far fewer. Naturally you’ll need to represent as much of this information as you can but in a non linear fashion.

The above example exhibits significantly blown highlights. I’ve ringed the highlight compression box, this consists of 3 settings, these are, from left to right: the number of stops correction(or off), range of values, & the image percentage being blown out/clipped. So, for this example you can see that the compression is off, the range is 220 (default), and the clipping percentage is 18.86%

Simply by setting the compression range to 0.2 stops I’ve reduced the percentage of blown out pixels from 18.86% to 7.3%. I’ve deliberately chosen to leave a reasonable percentage of blown pixels because otherwise the image can start to look pretty flat. I believe that blacks and whites should almost always be clipped to some extent – have a play with the feature yourself and see what looks best to you.

Slide Film

This section is under construction.

PhotoShop

When I’m finished with the image in ColourPerfect I may want to fine tune some things, usually this will be levels work and fine tuning of colour. I must admit that I find the PhotoShop interface much more intuitive to work with than that of ColourPerfect so I tend to use it for fine tuning even though most of this can easily be achieved in the plugin.

Firstly I apply a ‘Levels’ adjustment layer (Layer->New Adjustment Layer->Levels…)

Next I correct any overall cast by adjusting neutral colour balance with a ‘Selective Colour’ adjustment layer (Layer->New Adjustment Layer->Selective Colour), in this image you can see that the greens have a bit too much magenta in, so I remove as many points of magenta as are needed to achieve a good overall balance to the greens:

Finally I adjust sky colour by making a white colour collection, you can see in the screenshot below that I had to drop out some magenta and boost cyan. The key is to always try and make the smallest corrections possible otherwise you can end up with clipping somewhere else in the gamut, and that normally leads to posterised colour.

As I mentioned above you can also make these adjustments within ColorPerfect using it’s colour correction (CC) filters – however, one benefit of doing this in PhotoShop with a selective colour layer is that you can easily revisit the adjustment layer to make changes. ColorPerfect is what I term a ‘destructive’ process, by this I mean that once you click OK you can’t go back without starting from scratch on the original scan.

And that’s pretty much it for PhotoShop other than any selective contrast and sharpening work I would normally perform

Conclusion

ColorPerfect saves me a lot of time when using VueScan. Before my use of ColorPerfect I had to perform time consuming exposure locking and film base colour sampling all because VueScan has very limited film profile support. Even after carrying out these long correction procedures, I was still having to fine tune colour in PhotoShop: and sometimes it was more course than fine tuning.

So now I have the best of both worlds, I can use my preferred scanning software, and spend minimal time in post production. I figure I spend about a minute per image correcting colour, and ColorPerfect is usually just a few seconds of that time.

I am quite sure that far more can be done with ColorPerfect, and I’ll update this article as I discover new techniques, and perhaps offer contrasting views if I believe that the same can be done more quickly in Photoshop. If I had one wish, it’s that ColourPerfect could be an adjustment layer rather than a plugin. But nothing is ever perfect.

I do hope that this is of use to some of you and please remember that you’re very welcome to post your own workflow and process improvement suggestions right here.

See my photos on flickr.

I no longer use this method, click here for my new ColorPerfect method

Introduction, A Few Simple Options, Film profiles suck, Scanning

Using The Histogram, & The Finished Article

Introduction

Hamrick Software’s VueScan is perhaps the most flexible and powerful piece of scanning software available to photographers today. Many people fall foul of its myriad features and options – it can be quite daunting when you first start the software and begin to explore the different option pages. I’m going to explain how to get the best out of VueScan with the minimum of fuss, the least fiddling, and the least deviation from the software’s default options.

If you’ve already got the software installed (at the time of writing the latest version is 8.4.70), then now is perhaps a good time to reset the options to default, you can do this from within the file menu “File->Default Options”

A Few Simple Options

The first thing I turn off in viewscan is the automatic saving of scans – you’re probably going to want to do things like adjust white balance, white point, and blackpoint before committing your scan to disk, so there’s just no need to have this option enabled.

You’ll also want to turn on VueScan’s histogram Graph, you can do this from the Image menu “Image -> graph b/w”, or by hitting ctrl-2. You want the b/w graph because this allows you to adjust white and black point using 2 graphical sliders (explained later in the article).

Film profiles suck

VueScan comes with some pre-configured film profiles, you may think that these are just great, but in reality they aren’t – they just take control away from you, and will more than likely deliver a scan that just does not come up to scratch. Why? Because each and every roll of negative film you shoot has it’s very own slight variations in both manufacturing tolerance, exposure, film fogging (heaven forbid), and most importantly development. All of these combine to change the film’s base colour density – so by choosing a preset you are using a ‘best guess’.

The good news is that there is absolutely no reason to settle for a best guess, and this is because VueScan will allow you to sample the base colour of your film directly. These tips are available on the VueScan homepage, but I’ve combined them with some screenshots to make it even more clear. So without further ado, here’s how it’s done…

Firstly you need to preview your film. Click the Preview button! When the preview finishes you should select an area of clear film between frames (or in the film leader). If the ‘Lock Exposure tickbox is ticked, untick it (see the picture below this one)

Hit the preview button again, when the preview finishes tick the “Lock exposure” tickbox.

Hit the preview button once more, when the preview finishes tick the “Lock film base colour” tickbox.

With these simple steps you have calibrated your roll of film. You only need to do this once per roll, it can be a pain, but it will save you major headaches in post processing.

Scanning

Now that you’ve optimised VueScan for your current roll of film, you’ll want to go ahead and scan some photos. A lot of people like to keep the film borders and frame numbers in their scans, I think this is a complete waste of time – it will also give you more hard work setting levels in post processing because your beautifully crafted photo will be competing with the levels of the border & bright yellow frame numbers. The answer is simple: use the frame crop box to highlight a scanning target just within the borders of each frame.

When you’re happy that you’ve got the frame correctly selected hit the Scan button.

Using the histogram

Now that your scan is in memory you can do some adjustments, there are 2 main ones you’ll probably want to do, the first of which is using the histogram to produce a nice flat image which can easily be adjusted in PhotoShop. Drag the sliding pointers to left and right so that all elements of the graph are between them – if you want to clip some areas then adjust accordingly.

The final adjustment you may want to make is the white balance – find an area in the scan which is neutral and right click on it (hold down control on mac). VueScan will automatically adjust white balance, if you picked the wrong area just try again until you get something that looks correct — You’ll probably only want to do this once per roll (or once for each set of photos with the same lighting conditions) to ensure your scans are colour matched. Double right clicking resets the auto white balance.

The Finished Article

So now it’s time to save your frame, click on the disk icon or use the save image option in the file menu.

Hopefully you should now be able to successfully scan colour negative film and be sure that you’ll get consistent results. You’ll need to use Curves and Levels in PhotoShop to get the best out of your scans. Good Luck!