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02-13-2016, 04:26 AM   #106
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QuoteOriginally posted by jonlg Quote
More AF points are helpful whether you're shooting motor racing, tennis, birds in flight, dancers in low light or your kid playing football in the park. The K3 has proved itself pretty good in this respect and miles better than any previous camera I've used - but it could still be better. If as Kenspro has alluded to Pentax are thinking of going for all the pro markets they will need their autofocus tracking to match Canon and Nikon.

A main area of weakness at Pentax historically has always been autofucus performance - it's the one area where I have to concede defeat to my EOS 5D mk3 owning friend (61 AF points I think) so I really really hope and pray Pentax have addressed this in their new design.

jonlg
I think this is complex subject... 33AF points are likely enough for a user to select the AF point he want for some precise composition. Having more would be counter productive: more time to select the right point.

Now, what is required in term of coverage for the camera to have a good idea of the scene depth map, combined with the scene colors map (the metering sensor) is another topic and would depend also heavily of the design of such sensors. Pentax tend to have mostly cross sensor while many competitors tend to have simpler ones. The surface each sensor is covering is also quite important and that was the issue of the K5 body. Each one was covering a wide area, so it would "see" a small subject but it was not able to figure out what to take.

I would say it really matter to have enough sensor to detect the subject and ensure it is fully in focus. For most case of composition, has sensor don't cover borders a reasonnable subject should cover a few sensor AF point even if it is quite small. It the subject isn't seen by at least 1 AF point and is in the AF area, that mean the subject is less than 1/60 of the frame and that outside of some specific composition would need heavy cropping couting it would also have less than 1/60 of the pixels.

What can be best managed with this AF design is quite complex to figure out as the software can make as much or more difference than the hardware, really.

02-13-2016, 04:39 AM   #107
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What's up with the wide format of the viewfinder screen (looking into the lens mount on the mirror)?
02-13-2016, 04:40 AM   #108
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QuoteOriginally posted by Nicolas06 Quote
I think this is complex subject... 33AF points are likely enough for a user to select the AF point he want for some precise composition. Having more would be counter productive: more time to select the right point.
You speak for you I agree, because you have seldom or never seriously done sport photography. So in your opinion, AF point selection is used to select an AFS point to focus on a subject that is not in the center, and you could do that by using a single point and recompose. Now, consider a moving subject and you what to track the subject off the center of the frame. Please do yourself a favor, go out with your K-3 and shot moving subjects with AFC multi-points. You want a nicely framed moving subject (for instance by the rule of third), the camera would lock focus on the preselected AF point (default is the center point), and then the AF servo tracks the moving subject with adjacent points when the subject moves away from the first lock point. If you'd do that experiment, you'd realize that K-5 could not do it to the 1/3rd rule, and the K-3 could barely do it, and since the FF sensor is larger, 33 AF points on a full frame camera is about the same of when you had 11 points AF on the K-5 and previous 11 point AF Pentax cameras, it isn't much by today's standards. I visited your gallery of photos, several times, and you have a number of really nice photos, but, for what you do, I'm sure that you have to test AFC tracking in the situation I indicated to understand how valuable is large AF zone with many point in those situations. When you'll have played a bit with AFC, you can discuss. That being said , again , for static subjects, you don't even need 11 AF points, one very low light sensitive center point is sufficient.

Last edited by biz-engineer; 02-13-2016 at 05:21 AM.
02-13-2016, 04:58 AM   #109
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it is a d810 sensor with the goodies of pentax
1/affordable price
2/SR
3/PS
4/BIG OVF
...
NO COMPLAINS

02-13-2016, 05:24 AM   #110
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QuoteOriginally posted by zmohie Quote
1/affordable price
Yes, that would be for sure very attractive if the rumored price is true. But so far it is a rumor.
02-13-2016, 05:54 AM   #111
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QuoteOriginally posted by zmohie Quote
it is a d810 sensor with the goodies of pentax
1/affordable price
2/SR
3/PS
4/BIG OVF
...
NO COMPLAINS
Some sources say it's new sensor, not used anywhere yet
02-13-2016, 06:00 AM   #112
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QuoteOriginally posted by biz-engineer Quote
You speak for you I agree, because you have seldom or never seriously done sport photography. So in your opinion, AF point selection is used to select an AFS point to focus on a subject that is not in the center, and you could do that by using a single point and recompose. Now, consider a moving subject and you what to track the subject off the center of the frame. Please do yourself a favor, go out with your K-3 and shot moving subjects with AFC multi-points. You want a nicely framed moving subject (for instance by the rule of third), the camera would lock focus on the preselected AF point (default is the center point), and then the AF servo tracks the moving subject with adjacent points when the subject moves away from the first lock point. If you'd do that experiment, you'd realize that K-5 could not do it to the 1/3rd rule, and the K-3 could barely do it, and since the FF sensor is larger, 33 AF points on a full frame camera is about the same of when you had 11 points AF on the K-5 and previous 11 point AF Pentax cameras, it isn't much by today's standards. I visited your gallery of photos, several times, and you have a number of really nice photos, but, for what you do, I'm sure that you have to test AFC tracking in the situation I indicated to understand how valuable is large AF zone with many point in those situations. When you'll have played a bit with AFC, you can discuss. That being said , again , for static subjects, you don't even need 11 AF points, one very low light sensitive center point is sufficient.
My point of view...
You're both right...Nicolas06 and you.
Why making it so complicate?
The more AF points you get the better? Not always. Software and internal processing have to be real quick to evaluate and calculate every criteria in time...and there's where Pentax was not strong yet and I've experienced myself and read quite a few comments re this happening when using AFC including all AF points. Recommendation then was to reduce number of AF points in order to make the AFC perform a tiny bit faster...
On the opposite, assuming the new device is coming close to performance of AI-servo of Canon or 3D-tracking of Nikon due to much enhanced processing power, it will be extremely appreciated to make use of any extra AF points..., obviously... 😉
02-13-2016, 06:38 AM   #113
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QuoteOriginally posted by rawr Quote
If there were 150 or 400 AF points, do you think they would all be individually identifiable in a tiny diagram on the back of the viewfinder? Not practical sometimes.

Point being, the 33 points displayed in the small diagram may not necessarily show all the AF points in the camera.
I hope you are right man!

02-13-2016, 07:02 AM   #114
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QuoteOriginally posted by Enrique S Toso Quote
Originally posted by rawr
If there were 150 or 400 AF points, do you think they would all be individually identifiable in a tiny diagram on the back of the viewfinder? Not practical sometimes.

Point being, the 33 points displayed in the small diagram may not necessarily show all the AF points in the camera.
I hope you are right man!

The display is obviously wider - by two rows of three AF points on a similar shaped sensor as the K-3- BUT - the sensor area is 2,25x the size, so the AF points would have to be either bigger or further apart - neither of which is particularly good? Let's hope we're not seeing everything - in in the end, after all, it's performance that matters and the assumption that more is better is not always valid
02-13-2016, 07:29 AM   #115
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This is not off topic Weight of the K-3 grip

I am trying to imagine the weight and feel of the FF which seems to be approx 125gms more than the K-3. Does anyone know how much the K-3 grip weighs? I cannot find it in the usual places. B&H only lists package weight for shipping. Thanks. I imagine that K-3 +grip + battery would be close in weight to the FF.
02-13-2016, 07:36 AM   #116
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QuoteOriginally posted by Mikesul Quote
I am trying to imagine the weight and feel of the FF which seems to be approx 125gms more than the K-3. Does anyone know how much the K-3 grip weighs? I cannot find it in the usual places. B&H only lists package weight for shipping. Thanks. I imagine that K-3 +grip + battery would be close in weight to the FF.
about 410g with AA, 340g with lithium
02-13-2016, 07:39 AM   #117
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Fun fact is that the AF sensor (part of the AF system which includes a number of lenses as well plus most is pure software) in the K-3 already provided 45 (5x9) cross type F5.6 sensors from hardware availability perspective (plus the 3 horizontal F2.8 line sensors. For some unknown reason (probably some real life restrictions) they just didnt use a number of them.

The interesting part here is:
a) did they change the AF lens system to create a wider coverage (this is espcially about the set of four parallel lenses for the four required ray bundles you need for a cross type sensor)?
b) will they allow smaller AF point sizes (this is 100% firmware decision, nothing to do with hardware)?

Side note:
Due to the way AF sensors work they could create basically unlimited numbers of line sensors even on the current AF sensor module. It's a software choice only, limited by the effects of doing this.
02-13-2016, 07:41 AM   #118
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QuoteOriginally posted by ffking Quote
about 410g with AA, 340g with lithium
Thanks ffking! That is good news. If I carry the K-3ii around with its grip until the FF arrives the FF will feel light and petite, like a Pentax should.
02-13-2016, 07:52 AM   #119
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QuoteOriginally posted by beholder3 Quote
Fun fact is that the AF sensor (part of the AF system which includes a number of lenses as well plus most is pure software) in the K-3 already provided 45 (5x9) cross type F5.6 sensors from hardware availability perspective (plus the 3 horizontal F2.8 line sensors. For some unknown reason (probably some real life restrictions) they just didnt use a number of them.

The interesting part here is:
a) did they change the AF lens system to create a wider coverage (this is espcially about the set of four parallel lenses for the four required ray bundles you need for a cross type sensor)?
b) will they allow smaller AF point sizes (this is 100% firmware decision, nothing to do with hardware)?

Side note:
Due to the way AF sensors work they could create basically unlimited numbers of line sensors even on the current AF sensor module. It's a software choice only, limited by the effects of doing this.
Doesn't one of the patents describe a lens system allowing wider coverage of a bigger than aps-c sensor using an aps-c af sensor?
Brian
02-13-2016, 07:52 AM   #120
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QuoteOriginally posted by beholder3 Quote
Due to the way AF sensors work they could create basically unlimited numbers of line sensors even on the current AF sensor module. It's a software choice only, limited by the effects of doing this
interesting - so what are the reasons why they wouldn't? (not unlimited, obviously, but a figure which gives confidence to people worried about Pentax AF and into big numbers)
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