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01-17-2016, 03:12 PM   #46
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Hate to jump on the necropost, but:

QuoteOriginally posted by reh321 Quote
How does focusing under Live View differ from focusing while looking thru the viewfinder??
QuoteOriginally posted by Na Horuk Quote
Viewfinder is Phase detect AF, which is the classical type. It uses AF module and has some points to select from. Points are tuned to some aperture rating
Live view cameras generally use Contrast detect, which uses CPU and simply maximizes edge contrast. It can do this for any area in frame. It is slower, but never suffers from back or front focusing, misalignment, etc. But it can still focus on the "wrong" object or it can simply not find enough contrast and will just hunt for focus. Some mirrorless cameras now have sensors with phase detect af points built-in, so that even live view would have some PD AF (but this technology is not very good so far; not as good as the highly evolved classical PD AF of DSLRs)
Additionally, depending on the camera and/or lens, the Live View focusing may actually be done with the lens at the selected aperture (rather than wide open through the OVF), which would eliminate issues with focus shift on lenses prone to it. Unfortunately, my K-30 doesn't do this (with native K-mount lenses); in Live View, it always seems to put the lens at some intermediate aperture around f/4 regardless of what is selected. Don't know about other Pentax DSLRs.

Of course, this doesn't apply to adapted lenses with apertures that can't be controlled by the camera.

01-17-2016, 03:14 PM   #47
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Of course patents aren't just about developing technology - I seem to remember that Honeywell did pretty well by taking out a patent on phase detection AF then sitting on it until the Japanese camera companies had developed and marketed it then suing them one after another for millions of $$. (even Pentax, though they had a marketing agreement with them)

Not that I think that Ricoh would be that slimey.
01-24-2016, 03:41 AM   #48
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QuoteOriginally posted by Scintilla Quote
Hate to jump on the necropost, but:



Additionally, depending on the camera and/or lens, the Live View focusing may actually be done with the lens at the selected aperture (rather than wide open through the OVF), which would eliminate issues with focus shift on lenses prone to it. Unfortunately, my K-30 doesn't do this (with native K-mount lenses); in Live View, it always seems to put the lens at some intermediate aperture around f/4 regardless of what is selected. Don't know about other Pentax DSLRs.

Of course, this doesn't apply to adapted lenses with apertures that can't be controlled by the camera.
It steps it down..and decerase light for AF
01-24-2016, 03:53 AM   #49
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QuoteOriginally posted by Scintilla Quote
Hate to jump on the necropost, but:



Additionally, depending on the camera and/or lens, the Live View focusing may actually be done with the lens at the selected aperture (rather than wide open through the OVF), which would eliminate issues with focus shift on lenses prone to it. Unfortunately, my K-30 doesn't do this (with native K-mount lenses); in Live View, it always seems to put the lens at some intermediate aperture around f/4 regardless of what is selected. Don't know about other Pentax DSLRs.

Of course, this doesn't apply to adapted lenses with apertures that can't be controlled by the camera.
Both phase detect and live view focussing could operate at narrower apperture than wide open within the limits of their specifications. So phase detect can typically operate up to f/5.6 without any problem because most sensor are f/5.6 anyway. For lenses like the FA50 that lack contrast wide open, that could make sense.

01-27-2016, 08:11 AM   #50
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One more patent concerning autofocus: this one is about using the metering sensor to perform contrast-detect autofocus and therefore increase the precision of the focus performed by the dedicated phase-detect module.

Ricoh ??????AF?AE??????????????????So-net???



Application filed on 30 June 2014, patent granted on 21 January 2016.
01-27-2016, 08:24 AM   #51
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QuoteOriginally posted by Mistral75 Quote
Application filed on 30 June 2014, patent granted on 21 January 2016.
so that's what they were waiting for to announce the FF
01-27-2016, 08:34 AM - 2 Likes   #52
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I'm like many that would love to have superb AF in my Pentax cameras. I read all these threads but am always reminded of a reply from Norm I once received that simplified the conversation to the grass roots of the debate.

Superb AF is not a matter of technology, it is a matter of cost. Want a fast and accurate AF system...Nikon makes it if you have the cash. You can't get a Lamborghini for the price of a Kia. That's not how it works. You can get a lot at a low price, more that is usually appreciated by Pentax shooters....superb cameras...but you don't get the Lamborghini. Look at the current price of the K3.....not much more than what I paid for my Fuji X10/20 Toy Cameras. You want it all? save your cash, because you will need plenty of it!

Not what you want to here...is it? There is no magic bullet.....well, maybe in Dallas, but not in the camera world.

Regards!
01-27-2016, 08:43 AM   #53
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QuoteOriginally posted by Mistral75 Quote
One more patent concerning autofocus: this one is about using the metering sensor to perform contrast-detect autofocus and therefore increase the precision of the focus performed by the dedicated phase-detect module.
Now that's interesting! Auto-fine-adjusted PD AF, anyone?

01-27-2016, 08:47 AM   #54
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QuoteOriginally posted by Rupert Quote
Superb AF is not a matter of technology, it is a matter of cost.
But technological progress keeps bringing down the cost.

To take your automotive example,
the full-time four-wheel drive systems that use to be exclusive to cars like the Jensen FF (no, not full frame!)
eventually moved down to run-of the-mill SUVs and crossovers.
01-27-2016, 11:39 AM   #55
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QuoteOriginally posted by ffking Quote
so that's what they were waiting for to announce the FF
Actually, if in a hurry, they could also use the traditionnal "patent pending" formula for the next invention included in K-1
01-27-2016, 04:23 PM   #56
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This is a very smart way to use AE and I actually thought they would do this when the K-3 was developed. I think I actually mentioned using the AE for face detection in a thread way back. Maybe they will give some of the royalties . hope this turns up in the K-1, would be nice feature for sure.
01-27-2016, 06:52 PM   #57
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QuoteOriginally posted by Belnan Quote
I think I actually mentioned using the AE for face detection in a thread way back.
Face detection via PDAF may already be working, after a fashion, in the K-3. The K-3 metering sensor has plenty of pixels (86k) to do face detection (Nikon used to claim face detection with their 1.2k metering sensor). And if you look at the K-3 EXIF, there are even data fields for 'Faces Detected', 'Face Position' etc for PDAF, as well as face data fields for LiveView shooting.

However while face data is recorded, Pentax never seem to have actually linked face detection to PDAF in the K-3, at least not in any working fashion. It would be excellent if this was now fully working in the FF.
01-27-2016, 08:55 PM   #58
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QuoteOriginally posted by lytrytyr Quote
But technological progress keeps bringing down the cost.
You do have a point there, and eventually cameras will all be more equal in abilities than they are now...and they have come a long way already, in a short time. I paid less for my K5IIs,an excellent camera, than I did for my Fuji X10/X20 Toy Cameras. That still seems unbelievable to me.

We may never get a Kia that matches a Lamborghini, but as advances come in technology and prices drop....we may not need the Lamborghini?

Regards!
01-28-2016, 03:05 AM - 1 Like   #59
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If this can do CDAF with the mirror down, it should also be able to provide peaking information with manual focus lenses while using the OVF to compose. Of course some kind of viewfinder overlay would be required to actually display that. If it could be done, it would be fantastic for manual lens users.
01-28-2016, 12:24 PM   #60
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QuoteOriginally posted by Rupert Quote
You do have a point there, and eventually cameras will all be more equal in abilities than they are now...and they have come a long way already, in a short time. I paid less for my K5IIs,an excellent camera, than I did for my Fuji X10/X20 Toy Cameras. That still seems unbelievable to me.

We may never get a Kia that matches a Lamborghini, but as advances come in technology and prices drop....we may not need the Lamborghini?

Regards!
I would add that great AF doesn't look that expensive to produce once you know how to do it. Nikon has truely great AF in D7100 and D7200 for example, I'am not even sure they could include it in lower end model if they wanted.

Now there 2 problems:
- if the innexpensive bodies have everything, there no reason to upgrade.
-if you didn't master the technology yet, the algorithms and so on, you have to invest a lot to develop it, time and money. Even if you had the opportunity to sell the AF system for 10K$ per unit, if you didn't do the necessary investment before, it wouldn't perform that much better. It is not like Pentax had perfect AF avaible for years but didn't include because it was too expensive. Either they buy from Nikon (that may refuse) either they have to design it all by themselves.
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