20D DSLR vs a 35mm film system

This article follows and suppliments the testing that I did on the 10D vs Film, so please review that test if you haven't already :-) The main difference between this and that test (apart from the 10D vs the 20D) is that the testing here provided images of the same angle of view by using 2 different lenses

Summary of findings

index

background
testing premise and assumptions
what I did
known deficiencies in the testing procedures
the result images
my take on the findings

Like the other testing, my findings from this test are also that there is not much in it. Certainly not the 'chalk and cheese' people would have you believe.

Background

I started into digital photography by scanning film in around 1996 with a Nikon Coolscan 1000. My first digital camera was not until 2000. I owned early Coolpix "swivel body" cameras many digital cameras since that time.

For quite a few years I felt that it was not economic to buy a DSLR, remembering that these things cost thousands of dollars until as recently as 2005.

Eventually I came into ownership of a 20D (thank you Anthony).

My initial 'feelings' of the 20D were that it wasn't so much of an improvment on my film bodies, and that to make maximum use of it, you need to be either using mainly telephoto (portrait of sports photography) and the flash system I already have no longer works. I liked the camera, although it showed that it didn't necessarily make economic sence for me, it certainly helped me to crystalise much of the impressions into results like these pages.

I was initially annoyed by the lack of cost effective "wide" angle, and so I fished about for a second hand 18-55 Zoom. These are cheap, and while they cover the same angle of view as a 28 on my film body, do not have the same quality as the EF24 I already had.

Premise

My feeling at the beginning of my test was that anything over 2700dpi scans of 35mm film were going to be very close to what a digital SLR camera could yeild. I expected film to even perhaps exceed it in specific situations. Accordingly I expected to see the results being close. I was going to have to lug around the weight of an SLR system, that I didn't need to be forking out an extra $2000 for the priveledge of calling it a digital one.

Essentially the premise of this test is the same as that in my other test on the 10D. So please refer to that for further detail here.

The testing

Having recently purchased a 18-55 zoom, I wanted to see how closely I could compare images taken with the same field of view. This lens allowed me to get as close as possible what I could in the view finder of both film and digital SLR bodies First, lets look at the problems with my test:
Ideally, all differences should be minimized. Problem is, that these two cameras have different formats of image sensors:

35mm film recording area = 36x24mm
20D recording area = 22 x 15mm.

This results in the same lens recording different amounts of the picture in each scene. I could either use the same lens and vary the taking distance to the subject(fine for test targets, but not practicle with scenery photography) or use different lenses to get the same angle of view. Since this is what I normally do (compose for what I want in a scene with my zoom lens or lens choice) I have chosen lenses to do this on the different cameras. Accordingly, I have chosen for the test:

The film body is the EOS 630, using an EF 50 f1.8 lens
The 20D body was wearing the EF 18-55 Zoom

Both were set for f8.
Here is the overview image

I used supermarket grade ISO 200 film, which in my opinion leans the tests towards the digital, because of its superior sensitivity. Further leaning towards the digital is that the film is scanned with an older Epson 4870 flatbed scanner at 4800 dpi.

This scanner is certainly not the hottest scanner on the market (even when I bought it), and scanners such as Nikons LS-4000 will do a much better job of getting details from the film. This is a handicap for the film capture system as I am not getting the best that I potentially could from that system.

So, what did we get?

The table below contains 2 images, the left hand image is a segment of the image from the 20D, while the right hand image is the same segment as scanned by my Epson. To make it easier to observe the images, I have made the left hand image swappable with a scaled down version of the film image. To view this hover your mouse over it to switch between the two.

20D (hover mouse to compare to reduced size film) film image segment as scanned

While there may possibly be some advantages in tonal clarity of the 20D image its not screamingly better. Further, my scanner is quite the limiting factor here as the test image below shows. Compare this scan comparison between a Nikon film scanner and the same Epson 4870 flat bed.

So, while it could be observed that the 20D image is slightly sharper than the scaled down image from the film scan, the film scan in turn is likely to be significantly improved by access to a better scanner. Clearly the image size from the scanner is much larger, allowing you to make prints at much greater sizes.

Using negative film brings 20D and film SLR very close indeed
While the 20D image here might be limited by the poor optics of the 18-55, this is likely to be the case unless you spend over a thousand dollars on a better wide angle lens

DISCUSSION

As I mention in my other pages the size advantage of the 35mm film scans mean that you can then downsize the image and print at 300dpi and still make as good a print as anything other than a full frame DSLR.

The bottom line for me is that if you are wondering will you will get a benefit from moving to a digital SLR that you won't be getting a print size or print detail advantage compared with scans of 35mm film with well lit and contrasty subjects.

So if you already have a 35mm film SLR, and your not using it for making money and taking many many pictures with it, you will have to be gaining the advantage of one of the other advantages of DSLR (*such as instant feedback, convienence, time saved in scanning) to make it worth your while buying a DSLR.

My current view is that if you aren't taking action shots telephoto wildlife or sports then you should explore if a compact digital camera will do what you need. I have found that for many picture taking situations that compact digital cameras are very capable choices. They are just good versatile image making tools, especially if you work with macro. Have a read of my comparison with my Coolpix 5000 and my 20D

Lastly there are many sites out there telling you that digital capture clearly exceeds film, my findings are that its not as cut and dry. So as a balance check the results on this excellent test here which shows that digital SLR and 35mm film SLR are close, but consistently with my findings 35mm is slightly better for detail.

I hope that I've been able to provide you with some helpful information. If you are interested in making any comments or provising any feedback on this article, then you can e-mail me at I'd be glad to have a chat ...