26 May 2009

DSLR modularity

Fellow blogger Miserere has called for a new DSLR paradigma with one key feature to separate it from status quo; modularity.
He points to how different photographers have different needs and how manufacturers could save money by building cameras with discrete modules to be fitted at the photographer's need.
It seems like a good idea at the surface. And indeed, Hasselblad's digital medium format cameras are taking a similar approach. What used to be film cartridges are now digital sensor modules.
My immediate thought was that if this was a good idea for the mainstream DSLR market, we would have seen modular DSLRs a long time ago already. And the more I think about it, the more certain I am that the nemesis of modularity is integration. The components of a camera are finely tuned to each other. By making cameras discrete and integrated units, one assures that the components are truly compatible and scaled to fit each other.
For example, Miserere suggests that mirror/shutter assembly and imaging sensor could be separate modules. The upcoming Pentax K-7 is an excellent case in point. It has the same CMOS imaging chip as its predecessor K20D, but with one important modification. In the new chip they have doubled the processing capacity of the output. To match this, the K-7 has a mirror/shutter assembly that moves to capture 5 frames per second (fps). In the K20D, the two components are matched to do 2.5 fps. In a modular approach, you'd need both modules to get the advantage of high fps. If you don't need high fps, you're unlikely to bother about paying extra for either module, just to make future upgrades easier.
I also notice that one component is spectacularly absent from Miserere's list. It is the one component that has caused me the most headache when building PCs from components. The power supply. When estimating the needed power for a new machine, one needs to know the power consumption of all the components. It's doable for stationary machines, but I'd never dare to choose battery for a portable computer, for examle. By the way, have you noticed how different generations of portable PCs have different batteries? And have you noticed the same trend in digital cameras? Looking at Pentax again, their first generation of DSLRs, the *istD series from Pentax used AA batteries. The K-series, however, switched to a videocam-style lithium, providing a higher and more stable power output. The K-7 will raise the bar another notch, presumably because of its higher processing power. For each upgrade bringing new and more advanced tech to the data processing parts of either PCs or cameras, it brings new power requirements. So upgrading the processing module without upgrading the power source doesn't make much sense either.
In all, I'm glad the camera manufacturers make these choises for me, rather than having to make them myself. I'd rather sell my old camera and buy a new one, just as I do with my laptops and stationary PCs. And my other advanced machines, such as cellphones and toasters. :-)


Anonymous said...

Hey Jostein,

Thanks for your comment-turned-post :-)

I've addressed the battery concern in a comment to my original post.

Regarding your other worries: are you sure the K10D's shutter cannot handle 6 fps? Do we know it's not a data transfer limitation rather than a mechanical limitation?

I still think a modular approach is possible, but that's not up to me to decide.

We are free to disagree and still be friends, right, Jostein? :-)

Alunfoto said...

I discussed the issue of fps with the service dept. of Pentax Norway a while ago, and they supported your opinion that the shutter is more than adequate for 6 fps. The weak links are mirror movement and AF performance in the K10/K20D. While the shutter itself is a standard component, produced by Seiko if I'm not mistaken, the other parts of the camera has to be scaled up accordingly to achieve high fps.
And that's my point, that the dependencies between the components probably will defeat the concept.
But don't get me wrong, it would be cool if I'm mistaken... :-)