Darren wrote this at 12:54 am:
No doubt inspired by the attention the new EOS 5D has been receiving, Edwin over at CameraHobby.com has just posted an article asking why we need full-frame 35mm digital sensors. The posts there don’t seem to have permalinks, so you’ll need to look for the August 24, 2005 entry on either the CameraHobby main page or on the Archives page (if you’re reading this sometime in the future when it’s scrolled off the main page). I think I agree with Edwin’s conclusions, but wanted to elaborate a little.
Besides the two arguments Edwin gives for full-frame 35mm DSLRs (the hassle of figuring out the 35mm-equivalent focal lengths of your lenses, and the problem of trying to shoot wide angle when you’ve got a 1.5x crop factor), there are three additional issues I can see:
A larger sensor gives reduced depth of field, which appeals to some people. I have several fast prime lenses, and love working with narrow depth of field – the fact that I have an EOS 20D with a 1.6x crop factor works against me a little bit there.
A larger sensor has larger individual pixels than a smaller sensor with the same pixel resolution (pretty obvious). This will always mean a better signal-to-noise ratio in the larger sensor’s image, meaning higher quality output (given the same technology used to manufacture and control the sensor and post-process the raw data). The corrollary of this is that a larger sensor with the same pixel size as a smaller sensor will produce a higher resolution image.
A larger sensor is going to cost more to manufacture than a smaller one, even given the same economies of scale, technologies, processes, etc.
If we’re going to question “why choose the 35mm frame size?”, I guess we really need to question “why choose the APS-C or APS-H frame size?” as well. The only reason we currently have them is because they were a reasonable trade-off between cost (larger sensors cost disproportionately more to manufacture than smaller ones) and the practicality of continuing to use 35mm lenses and body designs. Basically the smaller sensors are good enough, but a much better price.
If you could ignore your legacy investment in lenses and accessories, then:
- if size, weight and cost matter most to you, you’d go for the smaller Four Thirds format and a camera like the Olympus E-1
- if absolute image quality, resolution, and control over depth of field are your main concerns, you’d go for a medium format digital back like one of the Phase One P series
APS-C (1.5x and 1.6x crop), APS-H (1.3x crop) and full-frame 35mm are just points along the path between the extremes of SLR bodies: Four Thirds format (18mm x 13.5mm) at the small end and 645 medium format (60mm x 45mm) at the big end. Each of those points represents some kind of trade-off between all the factors mentioned above, and so each represents an ideal solution for some group of photographers. As long as each group of photographers is an economically-viable size, various manufacturers will be there to meet their needs.
I can see the niche APS-H format eventually being phased out (it’s only offered by Canon currently, and then only on expensive bodies optimized for sports shooting), but I think the others will probably be with us in DSLRs for a while yet.
What are your thoughts? Do you think there’s a place for full-frame 35mm digital sensors? Are the Nikon guys just jealous? 
Filed under: Nikon,Software
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