Dragons Den Photography project!

[Cathus]

Maybe just stick a filter system into an extension tube setup, can be used with any lens and gives you a closer focusing lens to boot.

[James Blonde]

thats what I said!

[MattUK]

That's a great alternative Garry. Maybe we should go into business

[jet_kit]

Am I missing something here?
The answer is as simple as digital photography. You do it electronically. The sensor doesn't 'know' what colour to record, it has to be told by the firmware. In the same way you can adjust the colour balance, why not adjust everything else? OK, it would add a lot more controls to our, already overburdened camera bodies, but if that's what you want I'm sure someone will build it. Grads, Spots, Diffusers etc. are all perfectly simple.
The real project would be to figure out how to do a CPL in firmware

[MattUK]

Because then you're asking a computer to interpret the light. You'd end up with the same kind of crappy effects that cheap point and shoots have...

[jet_kit]

Sorry Matt, I think you're missing the point.
You're already relying on a computer to interpret colour, intensity, focus and everything else for you. There's no difference in instructing the sensor to record the image with a red, green, blue or pink cast to what you're already doing when you tell it what colour temperature to record. Try switching to B&W - same thing! In the same way you can tell it to record 2, 4 or as many stops of grad as you like merely by adjusting the ISO rating across the sensor.
It's all pretty simple really and the only reason I can think of for why they haven't done it already is because it would kill filter sales and, perhaps the processors just aren't fast enough yet to cope, but it will happen - and sooner than you might think.

[MattUK]

Hmm, I think I'll have to disagree.

It's one thing for a sensor to capture the light it sees. It's another for it to capture the light, then try and calculate how the light should be with a given filter or combination of filters. I'm not saying it couldn't do it, but I don't think it would be as good.

As for your reasons why it hasn't been done, why would any camera manufacturer who doesn't make filters care about another company that does?!

[jet_kit]

Hi Matt,

You're welcome to disagree, of course. But I recommend you do some research into how sensors and sensor firmware works.

The best way to imagine a pixel is a bucket, the more light it gets the more the bucket fills up. If it doesn't get any light it's black (unexposed), if it get's filled up it's completely exposed. The firmware then dictates that this particular pixel is a red one (or a green one or a blue one) and the storage device records it as being a half-full bucket of red light. The hues are achieved by clumping the surrounding different colour receptors (pixels). The sensor array is sensitive to light only, not colour. It's the firmware that decides which wavelengths to 'filter' out to each individual pixel. It's really not hard to imagine forcing the firmware to apply a cast (alter the wavelength) to any part or, all of the array.

As I pointed out before, that's exactly what you do when you change the white balance. You can shoot indoors with the WB set to Tungsten, or you can leave it on Daylight and stick a 80B filter on the front of your lens. The effect is the same. All we're postulating here is instead of having half-a-dozen WB settings, let's have a few hundred - then have an additional setup which allows these to be graduated, spotted, coned, heart-shaped or whatever you want.

[MattUK]

I love a healthy debate!

The one major factor you're forgetting is time. Consider a 10 stop ND. The light it captures has been produced over say 30 seconds. You can't expose the sensor for 30 secs without a 10 stop, as it will massively over expose. And it's the events that happen during those 30 secs (waves moving, for example) that cause the effect.

A camera can't reproduce that effect over the course of a standard exposure time.

[jet_kit]

Yeah, me too.

I think you're loosing sight of the camera's (well, the software actually) ability to adjust the sensitivity of the sensor. That's what you're doing when you crank up (or down) the ISO rating. Trust me, you have a range of options open to you to adjust the exposure; the aperture, the shutter speed and the ISO - The first two are physical and the 3rd is purely electronic. Instead of fitting a lump of black glass to the front of your lens, because you can't stop the aperture down any further and you want a slow shutter speed, why not set the ISO to EV 1?

I know you can't do that because the software has a band in which it will operate and in the quest for ever higher ISO ratings, the lower end gets left behind. My first DSLR could go down to ISO 25, my second would do ISO 50, my 3rd could do ISO 100, now my 4th (D300s) will only go down to 200 (Well, it will do strange things to simulate 100).

Camera manufacturers seem to be pushing the boundaries of ever higher ISO ratings, while we poor mugs on the ground have to spend a fortune on Big Stoppers to push it down again! Perhaps a big switch on the back of the camera that says, "Super Fast" and "Painfully Slow"