A thought I had about dual pixel raw and the future of postprocessing

[Kit Lens Jockey]

It seems like the general consensus about DP Raw on the 5D4 is that it doesn't offer you the range of adjustments in post that really justify setting the camera to record images that are a full two times the normal file size. And indeed, so far I've been ignoring DP Raw and just enjoying the great camera that it is, even without the feature.

But there's no questioning that shooting with DP Raw turned off is most definitely throwing away data that the camera could be capturing and saving, even if, at this point, the added data of saving images in the DP Raw format doesn't seem like it provides many additional opportunities in post processing.

But I got to thinking, and please understand these are just my own thoughts, I have no real basis for this... If you save an image in DP Raw format, which allows for at least very minor tweaks to the focus point after the fact, isn't it conceivable that at some point in the future, with more processing power and more advanced algorithms, that perhaps a program could read in a DP Raw file, and actually extrapolate out adjustments in focus that go beyond what is currently possible in Canon DPP?

I mean, right now you have two identical photos taken with slightly different focus points that DPP can blend together to allow small adjustments in focus. But is it really that far fetched to think that, in the future, a piece of software might be able to read in that same data, compare the differences in the two images, and actually allow for a wider range of correction in focus by approximating what the image would look like if you were able to adjust the focus beyond the range that is currently possible in DPP?

It's far fetched, I know, but with advances in machine learning and things like that, is it really that crazy to think that a computer may be able to look at the two images captured in a DP Raw file and extrapolate out a greater range of focus correction than what you can do with them now?

Just something to think about when considering whether to save images with DP Raw turned on or off. Ultimately, my guess is that the DP Raw technology will continue to advance, and no one will bother to put in the effort to develop a program to do anything like what I'm saying, because this DP Raw file format will be old news by the time anything like that is possible.

 

[Mikehit]

If you want to be obsessive about detail, then I agree - there may well be a reason for recording Dual Pixel images in the hope something better comes along.
But under what circumstances - the only people I have read who are enthusiastic about it are portrait photographers who may miss focus on the eyes. But even a year's time (let alone the several years you imply) that contract is long gone and the client won't care.

As for wildlife, the restrictions on shooting speed and write times mean that they will not use DP raw. And for action, the focus errors will vastly outweigh any benefits in DP raw.

It's time will come, I am sure. But until the software appears I can't see it sue beyond very specific situations.

 

[Jopa]

Stupid Canon can't bring this feature to the 1dx2

 

[ISO64]

Dual Pixel post processing works only in the direction in which the pixels are split, in this camera it is horizontal. So, you can correct for depth only for vertical lines in the image, and only if very close to optimum sharpness plane.

The natural extension of this idea would be to split the pixels top/bottom and create 4-to-1 quad pixel, 9:1, 16:1,... But, this is already covered by Lytro Field Camera patents and Canon is skating around by staying one dimensional.

DP sounds nice, but practical limitations are hard to overcome.

 

[chauncey]

If you want to be obsessive about detail

If you aren't obsessive about detail, you should discard that camera.

 

[Mt Spokane Photography]

Adobe has said they plan to support it, and I'm sure that many have ideas that they want to try out.

Supercomputers can process out of focus images to some extent, but there is a reason why Hubble had to have a corrective lens installed, you just cannot see data that is not there. If a feature is so poorly focused that it is not detectable in the image, the supercomputers will put something false in the image based on a guess.

 

[tron]

Stupid Canon can't bring this feature to the 1dx2

I have a 5D4 and I have tested this "feature". Believe me you lose nothing!

1. It does not really fix focus in post it just does selective sharpening which is not the same and the result is almost useless.

2. Buffer suffers so much that 5DsR would seem a speed freak compared to DP 5D4.

So after a test (actually I had forgotten this ON after the test and it had slowed me down on the field a lot) I turned it off for good.

If you do not believe it you can read a detailed test in tdp site. (I was referring to focus tests only)

 

[bvukich]

I've had a 5D4 since launch day, and haven't gotten around to even trying it. What you can do with it now, just doesn't interest me. Plus the couple of weeks I was stuck using DPP waiting for Adobe to add camera support, has made me resistant to ever launching it again if I can help it.

What does interest me about it though, is what the Magiclantern devs will come up with when they start really playing with it.

 

[amorse]

To be honest, I've been on the fence over buying a 5Div for a while now. I am more curious to see if early reports of using DP Raw to increase dynamic range can be made usable and practical. I primarily do landscape photography, and I find myself getting clipped a lot even with ND graduated filters on a 6D.

I saw an article indicating that the DP Raw files actually contain two images, one generated by adding values from the left and right side of the pixels, and one from just one side of the pixels. The recorded values from the A and B pixel sides are added together to give a full exposure, but because the DP Raw also has info from only one pixel side, that side is under exposed by 1 stop, meaning that 1 stop can be recovered in the highlights.

I imagine that I'm in the minority of thinking this way, but if Canon/Adobe could use the DP Raw format to generate an extra stop (or more?) of recovery in the highlights I'd deal with the extra image size and buy a 5Div in a heart beat. Personally, I'd love to see that technology adapted to create single shot HDRs.

If anyone doesn't know which article to which I'm referring - http://www.imaging-resource.com/news/2016/09/01/dual-pixel-raw-redux-forget-focus-tweaks-canons-new-tech-can-yield-an-addit

 

[tron]

To be honest, I've been on the fence over buying a 5Div for a while now. I am more curious to see if early reports of using DP Raw to increase dynamic range can be made usable and practical. I primarily do landscape photography, and I find myself getting clipped a lot even with ND graduated filters on a 6D.

I saw an article indicating that the DP Raw files actually contain two images, one generated by adding values from the left and right side of the pixels, and one from just one side of the pixels. The recorded values from the A and B pixel sides are added together to give a full exposure, but because the DP Raw also has info from only one pixel side, that side is under exposed by 1 stop, meaning that 1 stop can be recovered in the highlights.

I imagine that I'm in the minority of thinking this way, but if Canon/Adobe could use the DP Raw format to generate an extra stop (or more?) of recovery in the highlights I'd deal with the extra image size and buy a 5Div in a heart beat. Personally, I'd love to see that technology adapted to create single shot HDRs.

If anyone doesn't know which article to which I'm referring - http://www.imaging-resource.com/news/2016/09/01/dual-pixel-raw-redux-forget-focus-tweaks-canons-new-tech-can-yield-an-addit

You ask for too much (at least for the current generation). Canon has a dual amplification patent but they have not applied it to 5D4. But who knows maybe in a few years...

 

[amorse]

To be honest, I've been on the fence over buying a 5Div for a while now. I am more curious to see if early reports of using DP Raw to increase dynamic range can be made usable and practical. I primarily do landscape photography, and I find myself getting clipped a lot even with ND graduated filters on a 6D.

I saw an article indicating that the DP Raw files actually contain two images, one generated by adding values from the left and right side of the pixels, and one from just one side of the pixels. The recorded values from the A and B pixel sides are added together to give a full exposure, but because the DP Raw also has info from only one pixel side, that side is under exposed by 1 stop, meaning that 1 stop can be recovered in the highlights.

I imagine that I'm in the minority of thinking this way, but if Canon/Adobe could use the DP Raw format to generate an extra stop (or more?) of recovery in the highlights I'd deal with the extra image size and buy a 5Div in a heart beat. Personally, I'd love to see that technology adapted to create single shot HDRs.

If anyone doesn't know which article to which I'm referring - http://www.imaging-resource.com/news/2016/09/01/dual-pixel-raw-redux-forget-focus-tweaks-canons-new-tech-can-yield-an-addit

You ask for too much (at least for the current generation). Canon has a dual amplification patent but they have not applied it to 5D4. But who knows maybe in a few years...

Well, I'd certainly call it a good sign for the future if they have a dual amplification patent! And to be fair, the 5Div already does have ~1.5 stops more DR than my 6D as it is, so the 5Div would be a huge step forward on this front already. But if the DP Raw files have been used to recover clipped highlights as they currently are, I don't see why processing software couldn't be updated to take advantage of this? Full disclosure, I can't claim to fully understand the technology - it just seems logical to me that if it can be done right now with some effort, why can't it be made more accessible to re-capture some detail in highlights using third party editing software on a computer (not in camera)?

This article claims to have used third party software to re-capture clipped highlights using a DP Raw as it is (it just doesn't seem practical yet) - http://www.rawdigger.com/howtouse/canon-dual-pixel-mode-highlights-are-there