I shoot with the Canon 5d Mark II. While officially not a pro camera, the reality is that a large fraction of professional photographers use this camera rather than the Eos-1D cameras which are faster but much bulkier and in some ways even inferior to the 5D. But it's been out a long time now, and everybody is wondering when its successor will come and what features it will have.

Each increment in the DSLR world has been quite dramatic over the last decade. There's always been a big increase in resolution with the new generation, but now at 22 megapixels there's less call for that. While there are lenses that deliver more than 22 megapixels sharply, they are usually quite expensive, and while nobody would turn down 50mp for free, there just wouldn't be nearly as much benefit from it than the last doubling. Here's a look at features that might come, or at least be wished for.

Better Pixels

More pixels may not be important, but everybody wants better pixels.

• Low noise / higher ISO: The 5D2 astounded us with ISO 3200 shots that aren't very noisy. Unlike megapixels, there is almost no limit to how high we would like ISO to go at low noise levels. Let's hope we see 12,500 or more at low noise, plus even 50,000 noisy. Due to physics, smaller pixels have higher noise, so this is another reason not to increase the megapixel count.
• 3 colour: The value of full 3-colour samples at every pixel has been overstated in the past. The reason is that Bayer interpolation is actually quite good, and almost every photographer would rather have 18 million bayer pixels over 6 million full RGB pixels. It's not even a contest. As we start maxing out our megapixels to match our lenses, this is one way to get more out of a picture. But if it means smaller pixels, it causes noise. The Foveon approach which stacked the 3 pixels would be OK here -- finally. But I don't expect this to be very likely.
• Higher dynamic range: How about 16 bits per pixel, or even 24? HDR photography is cool but difficult. But nobody doesn't want more range, if only for the ability to change exposure decisions after the fact and bring out those shadows or highlights. Automatic HDR in the camera would be nice but it's no substitute for try high-range pixels.

Video & Audio

Due to the high quality video in the 5D2, many professional videographers now use it. Last week Canon announced new high-end video cameras aimed at that market, so they may not focus on improvements in this area. If they do, people might like to see things like 60 frame video, ability to focus while shooting, higher ISO, and 4K video. I'm also interested in some audio improvements. For example, if I plug in an external mic, the camera should record both the external and the internal audio -- space is cheap. As well as other audio channels I will outline below.

I want the hotshoe to add pins for power in both directions, and I want the data protocol in it to be beefed up and made public and supported. This would provide many things, but one thing it would be great for would be hotshoe mounted microphones, which now would not need a battery and would not need a cable.

I also want bluetooth in the camera (see below) and that includes bluetooth high quality audio for video shooting. Multiple channels of it if desired. Using a trick I outlined in a previous post, you can have the remote bluetooth microphones emit a light pulse and a data pulse together, so that the video and audio can be in perfect sync even with the digital delay. Audio sync could also be done by having a protocol to synchronize clocks and then timestamping the audio packets. Remote bluetooth microphones are not common but as they become common they would be cheap and decent quality, and far superior to on camera microphones for recording people. And far cheaper and easier to use than today's wireless mics. Filming a group of people? Just pin bluetooth A2DP microphones on their lapels and go.

Ordinary cheap bluetooth headsets and headphones could also be used by camera owners to leave annotations on photos, and to silently hear audio feedback from the camera, such as autofocus beeps, audio playback etc.

Bluetooth or even WiFi

Wifi is available as an expensive and bulky add-on for some cameras, though you can put in an Eye-Fi card cheap. Still, it's time to get away from having bulky and expensive add-ons. I think a lot of useful stuff could be done by making bluetooth standard in cameras. In addition to the audio functions above, you could do a lot of useful stuff:

• Camera control, same as over USB. This allows simple bluetooth remote shutter releases, but in fact it also means most phones and laptops could act as not just shutter releases but full remote controls, with access to all camera settings. Tethered shooting without the tether.
• Low speed image downloading and low quality video preview -- but ideally one would use 802.11 for this or the Bluetooth HS protocols that do high speed adjucts to bluetooth over 802.11
• Wireless flash. Infrared control of flash just isn't as good because you can't put the flash behind you when outdoors. You would need a protocol for clock sync to synchronize shutter and flash firing, but I think these could be done. It's just silly that you need to pay $200 for an ST-E2 to do remote flash anyway. This probably means a new line of flashes since they will surely overprice the adapter that lets you convert your old flashes to bluetooth.
• Access to bluetooth based GPS receivers. These are very cheap these days. Assuming they don't just put the GPS in the camera.

Be a platform

Camera vendors just haven't gotten a message that has been a great boon to other devices like phones. They should open up and be a platform, let people write apps that run on the camera to customize it and enhance shooting. You can even have an app store. Yes, it means you have to define and support a platform, but trust me, whoever does this will soon have the most capable and popular cameras out there. Forget about tethered shooting and even the bluetooth control -- you've got a nice computer platform, tons of flash storage and a nice screen. Make the screen a touchscreen if you can and let people run apps on it. If anybody says "Can the camera do that?" the answer will become yes. Some of the suggestions I have could readily be done as apps rather than putting them in the main camera firmware.

Fix my common mistakes and other features

In spite of the bravado, pro photographers make mistakes in settings on their camera all the time. Yes, I want full manual control, but that doesn't mean that if I set for tungsten white balance shooting at night that I want it to keep that setting 10 hours later when I am working in daylight. Warn me if it's been a while since I made a manual setting and that setting is causing photos to look wrong in some clearly defined way -- wrong exposure, wrong white balance, pointlessly high ISO etc. This is the sort of thing that apps would also be good at doing and letting me customize.

Another minor feature would be an on-screen digital level, using the accelerometer in the camera. And while we're at it, it would be nice to have a crude form of image stabilization based on today's cheap gyros. This would work in low light by holding down the shutter and having the camera wait until it reaches a point of suitable stability and then shooting -- and warning you if you moved too much during the shot. There's also been useful work done in correcting blurry photos based on gyro information.

I would also like to see a mode where if I shoot, it shows me on the display the sharpest section of my photo, at 1:1 resolution or near that. If that sharpest section is blurry, I know I have a bad shot. If it is not where I thought it was, I may have focused on the wrong spot.

Go mirrorless (well, not yet)

Most people agree that eventually Canon and Nikon will go into mirrorless SL cameras (no longer SLR, the R refers to the reflex mirror.) They won't do this in the successor to a current camera, it will come in a new camera line, but the time is coming. The mirror giveth a direct viewfinder view, but the mirror taketh away so much, and the balance has really shifted of late. We get mirror slap vibration but most of all we get serious limitations on lens design, since the lens has to stay far enough away from the sensor to leave room for the mirror. People don't know it, but this is one of the big reasons that wide angle lenses are so expensive.

Yes, we would have to go to digital viewfinding. But that's getting better and higher resolution, and it can even surpass the human eye in the dark in some ways. I find that if I want to do truly accurate manual focus, using the zoomed-in on-screen focus is better anyways. I actually suspect the right choice in mirrorless will depend on the the state of the art at the time the format develops in terms of getting low noise at high ISO in a given sensor size. It should actually depend on predictions for that in the future, because I want the lighter lenses that come from that.

Once you remove the mirror you can also consider a circular or cross-shape sensor. With such a sensor, you are shooting both portrait and landscape at the same time. Or if you are choosing which one to write to the card, you can do it in software and not have to tilt the camera. Tilting the camera makes it harder to mount on a tripod and harder to shoot naturally without a big battery grip. This precludes certain styles of lens hoods on wide angle lenses but it has a lot of advantages.

Of course if you want to get really far-out, you can consider the idea of lenses with the sensors built in.

Image stabilization

Right now if you want IS it comes in the lens. That's a good place to do it, but it comes at a very high price, and you pay it per lens. I would like to start seeing sensor based IS which would give me basic IS on all lenses, and possibly help the IS when I have a lens which also features it.

At some point, we will want to see cameras take longer exposures as a series of super-fast short exposures, with gyro-readings and software stabilization. This allows effectively a virtual tripod, and HDR at the same time. It's been a common technique in Astronomy for a long time, where the stars are not moving but the atmosphere is.

Power in the hotshoe

Above, I noted a desire for power in the hotshoe, along with high speed data. I want power in the hotshoe for a few reasons. First, it would be nice if you could get a very small flash to put there, useful for fill flash and low power flash applications. Right now your only options are huge monsters. One could even have a small LED based flash there for low power use. If you needed a flash transmitter like the ST-E2 you could power it from the camera as well, though again I think this should be built in and radio based.

Even with larger flashes, you could allow charging from the camera. My camera uses custom lithium-ion batteries but my flashes use AA, meaning I have to carry two kinds of batteries and chargers. I would rather just carry more of the one type and have a less heavy flash. Or I would like to still be able to use my flash if the battery in it dies, even though it's going to eat up my main battery. And finally, I want the power to be two way, which means that the flash can possibly power the camera, or I can even get a hotshoe battery pack to give me extra power, instead of the battery grip. The data bus would also allow the microphones I describe above, and other peripherals.