So when you read blogs about the latest big thing, in my case recently, the Sigma DP1, you are usually getting the opinion of someone who really, really wants this thing to be good. Even if it is not.

The DP1 looks like a marvel on paper. The (Foveon) sensor is giant-sized amongst its rivals, which means it should be less noisy, and have better dynamic range than most. By all accounts, it seems to. The optics seem reasonable. It is quite a capable camera. People are comparing them to SLRs, and suggesting the DP1 is more like an “affordable” digital rangefinder. The wheels start to wobble when you find out that the focal distance (minimum 16cm) is quite limited and the lens is only f/4.0—especially when compared to rival cameras. Image-wise, it should be better than its rivals, but it doesn’t seem to be significantly better, and new images would suggest that it is amazingly better. But some things are pretty disappointing, like the very slow write times. Up to 12 seconds a shot… perhaps less with a faster card.

But everyone wants it to be good.

Enter Carl Rytterfalk, blogger. You can’t say that he isn’t enthusiastic about the DP1. His posts cover a range of excitement, disappointment, workarounds, and excitement again. Luckily, he is posting informative stuff on the camera… and some entertaining videos (he also blogs about the Sigma SD14, similar sensor but in an SLR body). The nice thing about his reviews are that he is unapologetic in his enthusiasm, but he doesn’t ignore the problems:

Btw, as someone said at the forum already - turning off quick preview makes the DP1 faster between shots. And I also tested a normal SD card that came with another camera - it’s SOOOO SLOW! It really takes ages. So please. Use fastest card you can find, it’s a huge difference!

Timed save times RAW (light blinking):

SanDisk Extreme III 4GB: 2.5s

Canon SD SDC 32MB: 10s

Time before you can take another shot (single mode): 3.8s and quick preview off.

If you look at his site, you’ll see he’s thorough. He even compares it (somewhat tenuously) to the RED Mysterium sensor.

It is also worth considering that so-called “bloggers” could be paid shills for whatever company they are promoting. Ever wondered how some of these guys get their hands on stuff way before everyone else? On the other hand, now that bloggers “get there first” with reviews, you have to wonder at the number of posts that are less to do with reviewing and more about soothing buyers regret. People like Carl Rytterfalk, excepted.

And the camera? Its quirks guarantee it will be a cult hit.

More reading.

I was wondering when this would happen, while there have already been a few, this auction is for a “soon to ship” RED One body (the idea being you can skip the waiting list… a bit like those people that stand in line for you at Disneyland!) Check it out here. One day to go…

However, by the looks of this exchange, it would seem that RED is keeping that information very close to their chests (they have promised to release it to third parties in April). So for now you can only access their LUTs through REDAlert, REDCine, or SCRATCH. Even then, the conversion through the RED software is slightly nebulous, because your only choices for working with the outside world (under their workflow) is to go linear (not desirable for film) or to use the ill-defined PDLog (supposedly a R3D-to-Cineon spec). But who would know…

Not making these LUTs available as documents is like finding out your shiny new toy didn’t come with batteries on a public holiday. It’s not an insurmountable problem, but irritating. I guess we’ll have to keep rolling our own.

*Definiton: A LUT - look up table - describes how the colours and luminance of an image should actually look. Your computer uses one to show images on the screen, although maybe called something else - like ColorSyncâ„¢. They are used for everything from inkjet printers, to computer monitors, to printing to 35mm film - like Ansell Adam’s zone system on steroids - and they are supposed to keep an image looking the same despite the viewing format.

UPDATE: I am quite enthusiastic about the RED, and don’t want to get down and dirty on what is, to be fair, a revolutionary camera. However, I thought this was quite interesting:

This is a crop of a PDLog 685 output from REDAlert. It maps the peak values (like the sparkle above the eye) to 685 (of the 1023 scale). Under the Cineon spec, 685 is white. The rest of the values (to 1023) are headroom. Rolling off at 685 effectively removes any notion of headroom.

This is a crop of a PDLog 985 output from REDAlert. It maps the peak values to 985 (of the 1023 scale). From what I can tell, this has a closer correlation to the original REDLog file, however, it lifts the black point significantly, so I am unsure as to the application of this except that it uses more steps of the available 10-bit scale. If this was designed to cheat in more headroom, then the black point would probably not want to lift any higher than it is in the 685 version.

Stu Maschwitz has also pondered this problem (referenced previously); he uses REC709 as a consistent (non-log) reference to explain both the theory of digital negative, as well as where someone should aim with exposure on the RED. His conclusion? To get headroom something like PanaLog (Panavision Genesis format), you need to under-expose by 2.6 stops. Having tested this, I wouldn’t do it… if you are willing to ignore the noise, however, you do get more headroom! (I will post results shortly).

As I suggested previously, Stu talks in terms of REC709 (which seems to have caused a furore), where he maybe should have talked about “linearized” images. Having seen all sorts of hijinks over correct conversion of Cineon files in the visual effects industry, it is amazing to see them all over again with this camera. I guess when people “own” the technology (camera, etc), things get a bit more emotional. When people position themselves as “experts” it gets even worse.

UPDATE to the UPDATE: And now this. I guess I should stop whining. A bit of a delay, but looks like RED are on it. I’d be interested to know what the “tiered partner” thing is about, though…

As part of expanding our workflows and our partner base, we are creating a tiered partner program that will roll out in full this year. This program will be how other companies can access R3D as is appropriate for them and for us. The first step is establishing RED Lead Development Partners. Apple and ASSIMLATE are the first and currently the only companies here. We have always said we will open up R3D to other partners, and we will. But we are going to do it right.

I’m not referring to sensor crop, or any other lens aspect-based change. Rather, this is more about why digital images look “flatter” or resolve distance/light differently than their analogue equivalents. This article is more about lens design, but has little nuggets of information that apply in a this context:

The emulsion layer that holds the light sensitive silver halide grains has a certain thickness and contains up to twenty layers of grains, any one of which can be struck by photons and therefore is part of the latent image. Light rays that strike the surface of the emulsion layer at an oblique angle will travel through the depth of the gelatine layer and will be stopped by some grains in the lower layers. So the angle of incidence is no problem at all. Ideally the film plane should be plane, but film is never flat at the film gate and will bulge. But the depth of the emulsion layer and the depth of field tolerance will offset this state of affairs and optical designers can use this characteristic to compensate the problem of the curvature of field…

…The main characteristics [of a] sensor are the fact that the sensor is flat (plane), constructed as a discrete matrix of pixels and not transparent (has no depth). The flatness of the sensor is bad for the curved nature of the image created by the lens. The opaque nature of the sensor cells implies that the oblique angle of incidence of the light rays striking the sensor surface must be limited. Otherwise only a few photons will be captured. [link]

So to paraphrase: film scatters the light in a gooey, flawed (but nice), analogue sort of way, whereas a sensor is a bit more “clinical”… yes, wild, over-simplification…

An interesting footnote is the Foveon X3 sensor, which is built more like film - red, green and blue all layered on top of each other (other sensors are usually one layer, arranged like a checkerboard). Sigma markets a series of cameras which use this sensor. Supposedly, it gives a more “film-like” look, as well as less noise and a higher dynamic range than other sensors. I can’t tell, from what I have seen online.