Patent: Autofocus Related Patent Applications from Canon

Canon Rumors Guy

EOS 1D MK II
Jul 20, 2010
7,727
359
Canada
www.canonrumors.com
HTML:
For the folks that love reading/translating patents, here are three new ones uncovered by <a href="http://www.northlight-images.co.uk/canon-camera-rumours-and-info/">Northlight</a> that are related to autofocus technologies.</p>
<p><strong>Summarized by Northlight:</strong></p>
<ul>
<li>[<a href="http://pdfpiw.uspto.gov/.piw?PageNum=0&docid=09843783">USPTO</a>] Refining AF to correct for lens chromatic aberration.</li>
<li>[<a href="http://pdfpiw.uspto.gov/.piw?PageNum=0&docid=09843728">USPTO</a>] Using AF to refine and maintain manual focus setting</li>
<li>[<a href="http://pdfpiw.uspto.gov/.piw?PageNum=0&docid=09843710">USPTO</a>] Improving focus accuracy and automating focus adjustment over the range of lens settings</li>
</ul>
<p><strong>Additionally, here are some patent applications related to image files</strong></p>


<ul>
<li>[<a href="http://pdfaiw.uspto.gov/.aiw?PageNum=0&docid=20170358058">USPTO</a>] looks at ways of reducing moire in images by detecting it for correction in processing.</li>
<li>[<a href="http://pdfaiw.uspto.gov/.aiw?PageNum=0&docid=20170359471">USPTO</a>] looks at lossy RAW encoding for faster burst mode shooting</li>
</ul>
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SkynetTX

EOS 80D
Jul 29, 2016
149
6
42
Budapest, Hungary
Lossy RAW encoding is a complete nonsense. :mad: If Canon wants faster burst mode they should include more memory in their cameras for processing. By the way, I absolutely don't care about burst mode. I use my camera to take still pictures. They should develop a true macro lens with Insect Stabilization instead. :D
 

keithcooper

EOS 7D MK II
SkynetTX said:
Lossy RAW encoding is a complete nonsense. :mad: If Canon wants faster burst mode they should include more memory in their cameras for processing. By the way, I absolutely don't care about burst mode. I use my camera to take still pictures. They should develop a true macro lens with Insect Stabilization instead. :D
Insect Stabilisation - is that a puff of poison gas out of the front of the lens?
 

Don Haines

Beware of cats with laser eyes!
Jun 4, 2012
8,153
1,689
Canada
"Improving focus accuracy and automating focus adjustment over the range of lens settings"

a good idea.....

AFMA on Canon lens means AFMA once for a prime, and on a zoom AFMA at minimum focal length and again at maximum focal length.

Then we have the Tamron 150-600.... AFMA at 150mm, 200mm, 300mm, 400mm, 500mm, and 600mm..... and at each focal length AFMA at minimum focus distance, 20M, and infinity.....

I wonder which scheme gives better results?
 

tiggy@mac.com

Pentax K-1000
Jan 20, 2014
498
186
Thetford, VT
www.ForestMetrix.com
Don Haines said:
"Improving focus accuracy and automating focus adjustment over the range of lens settings"

a good idea.....

AFMA on Canon lens means AFMA once for a prime, and on a zoom AFMA at minimum focal length and again at maximum focal length.

Then we have the Tamron 150-600.... AFMA at 150mm, 200mm, 300mm, 400mm, 500mm, and 600mm..... and at each focal length AFMA at minimum focus distance, 20M, and infinity.....

I wonder which scheme gives better results?

I just wasted 20 minutes looking at the relevant patent. Canon seems to think that AF adjustment at different zoom distances is significant. In other words, it's developing tech now, exhibited by this patent filing, to catch up to Tamron and Sigma in terms of adding additional factors that go into AFMA. In fact, it's also doing this with other variables, such as brightness, color, detected color aberrations, and a few others. Fortunately, it's also connecting this to an automatic drive system, where things get calculated, adjusted, etc. automatically. That doesn't mean it'll actually launch an auto-AFMA feature with all of these factors baked in, but it's at least staking out the idea that it can.

I was particularly interested to see how it was looking to handle the cases where correcting in one direction for variable A made variable B look worse. There are some graphs in there that show that - at least in some cases - there is logic to be used to choose the AF setting that is the best compromise. One graph shows a curve function with 2 peaks, noting that one of the peaks matches more closely with the peak function of another variable even though it wasn't quite so high as the other peak. So it might as well choose the second peak, as it would be a better overall compromise.

It turns out that, indeed, AFMA is a lot more complex than most of us thought. It will be very interesting to see how much better the excellent Canon glass can be with these sorts of fine tunings.
 

AlanF

Canon 5DSR II
Aug 16, 2012
5,758
3,111
One of the pleasures of the M5 (and other M series) is the exceptionally accurate and precisely reproducible AF, which is much so much more consistent than any of my 5 or 7 series. If only the Canon mirrorless had spot AF and speed of the mirrors.
 

jolyonralph

Kodak Brownie
Aug 25, 2015
1,098
310
50
London, UK
www.everyothershot.com
AlanF said:
One of the pleasures of the M5 (and other M series) is the exceptionally accurate and precisely reproducible AF, which is much so much more consistent than any of my 5 or 7 series. If only the Canon mirrorless had spot AF and speed of the mirrors.
They will. One thing you can be sure of is that mirror technology has pretty much reached peak in terms of performance and capabilities whereas mirrorless is still in the early stages of development. A lot of the AI development for phone cameras is inevitably going to trickle down into mirrorless system cameras - otherwise we're going to be in the sad state where people will not want to upgrade to a real camera because their phone camera "does things better".

None of this especially excites me as a photographer, because I don't want a box that does everything for me, then it's no longer truly my creation. But as a realist I know this is going to happen because it's the direction the market is heading in.
 

Chaitanya

EOS 6D MK II
Jun 27, 2013
1,118
202
33
Pune
keithcooper said:
SkynetTX said:
Lossy RAW encoding is a complete nonsense. :mad: If Canon wants faster burst mode they should include more memory in their cameras for processing. By the way, I absolutely don't care about burst mode. I use my camera to take still pictures. They should develop a true macro lens with Insect Stabilization instead. :D
Insect Stabilisation - is that a puff of poison gas out of the front of the lens?
DDT...