Monday, 2 February 2009

film VS digital capture: revising old work

Setting the Scene

An important thing for learning and discovery is that as you learn more its handy to go back and revisit old works that you've done. Soon after I got a 20D digital SLR I was interested to know how well it compared with my (used for a long time, comfortable with the results) 35mm film. It didn't take long to sus out that the smaller sensor on the 20D (compared to 35mm film).

So, soon after getting my new toy I wanted to test which was better (as clearly I understood which was cheaper to take photographs with ;-)

Initially (we're talking 2005 here) I used only ACR to convert the RAW files and had to process then in Photoshop to make my images.

Since I like to take an image with my camera that looks like what I want (not simply what the lens forces me to) it was not easy to compare the two systems I took an image with each camera using two lenses from the same spot for evaluation.
  1. Canon EOS 630 EF 50 f1.8 (@ f8) I used 200ISO negative film.
  2. Canon EOS 20D EF 18-55 @ 35 (@f8)

My first results were as to the left with quite different colours on both systems. Initially I felt that the image from the 20D was more neutral and was impressed with how close they were. The shadows rendered on the digital from the 20D were cleaner than the film and there was over all.

So while I liked the digital image for its clean appearance I thought that the film image had better colours and tones. Note: while it was much clearer the 20D image was much smaller than the film scan.

I've downsized the Epson segment to match the native size of the segment from the 20D and pasted them side by side here to see.

The image from the 20D seems sharper but you can't get it to show as nicely on a print because 1) you can't see 100% view on the paper without a magnifying glass, and 2) if you print it so magnified then the pixels look funny.

So essentially while it has fewer pixels they're 'nicer looking', so you can upsize it about 70% to effectively the same size (as the 20D could tolerate uprezzing to the same print size as I could get from the film). I placed that discussion here on my personal pages which contains all the details.

I didn't have access to a good scanner at the time I did the above mentioned www page, I only had an Epson 4870 scanner and so when I eventually sent the negative to a friend with a Nikon LS-8000 I was surprised how well it did. Below is a sample from each scanner (I've resized both to 4000 dpi) they are closer than I expected.

The Nikon brings the balance back more towards film being a better image than my 20D in both tone and clarity at a large printable size. So now with the background set, lets look at the tone mapping image.

New Tools applied to old RAW files

Recently I've started using Photomatix for making better "goes" of rendering RAW images. I've been pleased with the results (as in that blog entry), so it recently occurred to me to revisit the above tested RAW image and compare it with the film scan.

My first thought when I got it how I wanted it to look in Photomatix was that looks really good. then I thought: I wonder what it would look like compared to the Negative.

So here it is ...

Surpirsed? I was!

The tone mapped RAW image brought out the sorts of contrast enhancement which the natural 'organic' feeling compression (heel and shoulder) that negative film does naturally.

But the now the digital (which does a better job of recording low contrast details than film does) brought out the clouds and textures of the clouds better than my negative and certainly better than my ACR conversion had done.

This scene is quite a low contrast light scene (taken in Finland in late spring) which neatly fits within the range of a single digital capture. Negative on the other hand would be able to cope with a much brighter or contrasty scene because it would be able to still expose for the shadows and the highlights would not clip as the digital would.

For those with an eye (or interest in) the details I've put a 200% magnification of the tone mapped 20D RAW file below to compare with the film scans above.

I think that it shows that tools like tone mapping goes close to bettering what the results from scans of negative film can achieve with far less expense and technical (photoshop and or scanning) skills needed.

So, 7 years into the age of the digital SLR we now have the tools to get the image from a high quality APS sensor digital SLR into the same ball park that supermaket grade film and a good scanner can do.

I've phrased it like this to draw emphasis to what I believe is an important perspective:
  • that the tools are both very similar in what they can do
  • as the digital tool sets continue to develop (with tools like HDRI and Tone mapping Photomatix) we can make better images from our RAW images (another reason to use RAW)
  • that as I come to learn more about digital I find how really good the results were from my film images
I used to argue that the main drawback against digital was the upfront cost of investment, back when I got my 20D (2006) it was AU$2000 for a body only and that would perhaps also require you to buy different lenses (because a 24mm is no longer wide and a 50mm standard becomes a telephoto) if you bought one. At the same time I could buy a Nikon LS-V scanner for AU$700 and get scans as good or better than the one above from the LS-8000. Back then I argued that one was better off to get a film scanner and keep using you 35mm SLR.

But since 2006 that field has changed, with used 20D's and equivalent cameras to be had for less than $500. Its nearly a toss the coin decision.

If you already have a compact point and shoot digital camera I think it comes down to how much you expect to use your camera for serious images and perhaps personal choice.

But still an old 35mm SLR like my 630 has a much bigger and brighter view finder (helpful for critical focus) and with just a 24mm and a 50mm lens makes a much lighter travel companion that my DSLR with the lenses it needs.

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