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11-15-2013, 04:30 PM   #31
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QuoteOriginally posted by Kunzite Quote
You surely did (though it would have been nice to know the test conditions and results in more details). The effort of trying to cover so much in a review - one that was quickly published - is commendable. Of course you can't do everything, and perfectly so.

What I'm saying is that your conclusion, that "Pentax hasn't revolutionized its autofocus performance with the K-3", should be based solely on the comparison with the K-5II, and not with the D610.
And from your review, we're seeing a significant increase in keeper count (60%), and we have a completely new (for Pentax) territory to explore - linking AF with RGB metering is opening new possibilities for Pentax. Because raw speed is one aspect of performance, the other is being able to properly select and follow the subject (and the K-5II is pretty much "dumb" in this matter).
I agree. The company can't always be worried about what other companies are doing all the time. We know that the K-3 is better than any previous Pentax DLSR and that it competes with more expensive offerings and as long as I know that isn't the end of the road, I'm happy.

11-15-2013, 04:34 PM   #32
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I just want to post some results of testing that CNET did with the Nikon D7100 in continuous RAW mode - my sense is the K-3 would run circles around the N7100 (the Nikon competitor to the K-3) in auto focus performance by almost any measure for photographers interested in RAW - personally that is all I shoot.
Here's the reference Nikon D7100 Review - Digital cameras - CNET Reviews
Here's the quote from their test:
For single-shot photography in bright light, the D7100 is about on par with the D5200, but earns its price premium for low-light autofocus and continuous shooting. It delivers an excellent 6.3 frames per second for an effectively unlimited number of highest-quality JPEGs (equipped with a 95MBps SD card, at least). I was a little disappointed with the raw burst, which maintains a 5.8fps rate, but only for six shots. Once the buffer's full, it drops to about 2.9fps.

I can just see myself shooting eagles in flight with the 7100 in RAW mode -
11-15-2013, 04:48 PM   #33
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QuoteOriginally posted by Kunzite Quote

If you want to see if Pentax K-3 with a 60-250 can keep up with a D610 with a 70-200 ($2700 vs $4400 setups), then you have to compare them. However, this won't tell you if Pentax "revolutionized" or not its autofocus.

.
Actually I'd like to see: (K3 + DA* 60-250) vs. (D610 + Sigma 100-300 f4 HSM.) That would be about $2700 vs. $3300, and would more accurately match the equivalent focal lengths to boot.

.
11-15-2013, 05:59 PM   #34
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QuoteOriginally posted by bxf Quote
If you want the best performance for a limited budget, it has everything to do with it.
My comment was in response to the frequent statements in the comments above equating a higher price with the expectation of better/faster/more accurate auto-focus. Just because a lens or camera costs more does not mean that a particular feature should or would work better. Heck, one of the most expensive brands I am aware of (Alpa) does not provide any focus mechanism that allows the film or sensor to be present at the same time that focus image is present. Fast focus is not its forte'.

Likewise, my least expensive camera (a made-in-Ukraine rangefinder film camera) just happens to be a speed demon in the focus department and it is manual focus at that.


Steve

11-16-2013, 07:47 AM   #35
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QuoteOriginally posted by Adam Quote
Focal length does not change based on the format being used, hence the aperture value does not change either. If you shoot with the 60-250mm @200mm on the K-3 and the 70-200mm @200mm on the D610 at F4 and the same ISO, you will need to use the same shutter speed on both cameras.
A 200mm lens on FF is not equivalent to a 200mm lens on APS-C, especially not at the same aperture. ISO is irrelevant as a comparator, because it varies wildly depending on camera design (e.g. ISO 400 on a Q, vs Sigma DP-1 vs Leica M9). Signal to Noise Ratio is what concerns photographers, not ISO.

For true equivalence, all of these parameters must be the same; Shutter speed, FOV, DOF and SNR.

It's easiest to demonstrate with a 4/3 vs. FF because of the convenient 2X crop:
- Shutter speed is a constant
- FOV: 200mm on FF = 100mm on 4/3
- DOF: f5.6 on FF = f2.8 on 4/3
With sensors from same generation, same manufacturer, the noise will scale similarly, therefore 2 stops:
- SNR: ISO 400 on FF = ISO 1600 on 4/3

Full-frame 200mm f/5.6 & ISO 1600 vs. Four-Thirds 100mm f2.8 & ISO 400, and the same shutter speed, will provide true equivalence. Same exposure, FOV, DOF and SNR.

Last edited by audiobomber; 11-16-2013 at 08:49 AM.
11-16-2013, 08:37 AM   #36
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It would still be nice to see the Z-3 and Nikon D7100 tested with the Sigma 70-200 2.8 lens common to both. This lens will certainly not cripple the Nikon's 2,9 fps raw performance. Add the Canon D70 with the same lens and you have a pretty valid comparison showing how three different camera bodies compare with regard to their continuous shooting AF performance. In this case you could like do the test with a $10,000 Nikon lens and it would likely still finish dead last, even versus the K-5.
If the Forum is interested in testing various full frame cameras, obviously excluding Pentax at this time, that is another issue. But the D610 with the high performance Nikon lens was not a valid way to compare anything versus the K-3 other than to conclude a full frame camera and high performance lens that costs about 60% more than the K-3 tested with a lower performance lens took fewer photos than the K-3 in continuous mode but did deliver 40% more keepers.
You certainly couldn't conclude Pentax has a long way to go versus Nikon since both the K-3 total shots and K-3 keeps would eclipse the total shots and keepers of the equivalent Nikon, the D7100 using both the same lens, the Sigma 70-200, or for that matter any Nikon lens on the D7100.
What you might be able to sat is the the Pentax K-3 auto focus performance far exceeds the focus performance of the Nikon D7100 in RAW mode.
I feel the forum should, as a minimum, test the K3 versus the Nikon d7100 in raw mode and if the forum feels the need to show Nikon some mercy, then also include a jpg test.

Last edited by RockvilleBob; 11-16-2013 at 08:45 AM.
11-22-2013, 03:53 PM - 1 Like   #37
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QuoteOriginally posted by stevebrot Quote
Likewise, my least expensive camera (a made-in-Ukraine rangefinder film camera) just happens to be a speed demon in the focus department and it is manual focus at that.
Manual focus appears to be a 'lost art'. I can't get my head round why is everyone raving about the K-3 having 27 or whatever focus points when they are still crammed into the centre of the frame. Does everyone just take boring shots with the main subject at dead centre ?

On a snap like this (M50 f1.4 wide open on an ancient K-7) any current Pentax autofocus would have failed miserably


11-22-2013, 05:54 PM   #38
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QuoteOriginally posted by RockvilleBob Quote
.... is like comparing a car that costs $31,000, for example a Nissan Maxima, to the Chevy Corvette costing $51,000. ........
prefer a Japper any day

11-23-2013, 03:32 AM   #39
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QuoteOriginally posted by Adam Quote
F4 on APS-C = F4 on full frame = F4 on the Q = on any format
Yeah, but the area of a FF sensor is 864mm*2, while the area of an aps sensor is 419mm*2. or 2.06 times greater.

Which means twice as much light will be available to the 24 mp of a D610 sensor at F2.8 as the 24mp of the K3 or D7100 sensor at F2.8. One can't ignore the benefit of that additional light to a camera's ability to AF.

PC Magazine did some measured AF times for the K3 and the D7100: http://www.pcmag.com/article2/0,2817,2427379,00.asp

QuoteQuote:
With ample light the K-3 can lock focus and fire its shutter in as little as 0.05-second, but in very dim light the focus speed can slow to about a second; the D7100 matches the 0.05-second speed and is just a little bit faster in dim light at 0.9-second.

Contrast detection autofocus takes over when you switch to Live View, and the K-3 puts up impressive marks for a traditional SLR. In ample light it locks focus and fires in about 0.9 second, and it slows to 3.1 seconds in very dim light. The D7100 is a bit longer to focus in ample light (1.7 second), but slightly quicker in dim light (2.8 seconds).
This review also mentions that the K3 27 AF points cover a larger area than those arrayed in the D7100, and also include 25 cross sensors on the K3, 10 more than the 15 of the D7100.

With these kinds of related data, the K3's tracking may very well exceed that of the D7100. Of course the lenses chosen for such testing can affect the final results, but if that is the case, thats not a deficit of the camera itself.

The PC Magazine crew decided that the K3 was now the Editor's choice for this sensor size over the previous camera - the D7100.

Last edited by philbaum; 11-23-2013 at 03:58 AM.
11-23-2013, 03:44 AM   #40
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QuoteOriginally posted by philbaum Quote
Which means twice as much light will be available to the 24 mp of a D610 sensor at F2.8 as the 24mp of the K3 or D7100 sensor at F2.8. One can't ignore the benefit of that additional light to a camera's ability to AF.
This is true only if the AF system scales up with the format; but the D610 is using an APS-C AF system.
11-23-2013, 04:05 AM   #41
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QuoteOriginally posted by Kunzite Quote
This is true only if the AF system scales up with the format; but the D610 is using an APS-C AF system.
Yes, but we don't know that the AF detect sensors themselves aren't benefiting from the increased size and light gathering ability. Unless you can quote a source???
11-23-2013, 05:24 AM   #42
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Source for what?
You are assuming the imaging sensor's "increased size and light gathering ability" can be expanded to the D610's AF system; but is it true? The AF system is physically independent of the imaging sensor, and if you're putting the D7000's AF system into a "full frame" camera it will perform identically - except that it would cover less of the frame; exactly what we're seeing with the D600/610.

Pentax used the same SAFOX IX+ into its APS-C DSLR but also the 645D. On the 645D, it wouldn't get any more light - because the AF points areas are unchanged (and appears as small points clustered in the middle of the frame, instead of being nicely spread out like on APS-C)
11-23-2013, 07:42 AM   #43
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QuoteOriginally posted by kh1234567890 Quote
Manual focus appears to be a 'lost art'. I can't get my head round why is everyone raving about the K-3 having 27 or whatever focus points when they are still crammed into the centre of the frame. Does everyone just take boring shots with the main subject at dead centre ?

On a snap like this (M50 f1.4 wide open on an ancient K-7) any current Pentax autofocus would have failed miserably
While something similar could be said about a sublime six-speed automatic transmission in a plebian sedan by someone who can still use his left foot while shifting, that doesn't diminish the technical brilliance of the new transmission.

Did you know in some American schools they no longer teach Cursive handwriting? No more Palmer Method! I suppose they figure no one will ever hand-write a letter, so why bother.

You do have a point of course. I lament the loss of the pages describing how to hold an SLR and how to focus the camera that were once part of every Pentax camera User Guide. But your sentiment has been building for quite some time.

Some years ago my daughter took an intense, six week B&W landscape seminar. The location was in the Red Rocks country in New Mexico in winter, so the course required a fully mechanical camera and lenses (batteries and motors can get cold), Y2 and O2 filters . The days were broken into sections - chemistry, physics (light), technique instruction (lab and field) and finally field work or lab work. The first week technique instruction included how to make a stable platform without a tripod (hold a camera) and how to focus. The instructor didn't presume even advanced photography students could properly manual focus in the field.

It's just change.
11-23-2013, 11:36 AM   #44
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QuoteOriginally posted by Kunzite Quote
Source for what?
You are assuming the imaging sensor's "increased size and light gathering ability" can be expanded to the D610's AF system; but is it true? The AF system is physically independent of the imaging sensor, and if you're putting the D7000's AF system into a "full frame" camera it will perform identically - except that it would cover less of the frame; exactly what we're seeing with the D600/610.

Pentax used the same SAFOX IX+ into its APS-C DSLR but also the 645D. On the 645D, it wouldn't get any more light - because the AF points areas are unchanged (and appears as small points clustered in the middle of the frame, instead of being nicely spread out like on APS-C)
Ok, i accept what you're saying about the AF points, but does the D610's AF system benefit from the more powerful processing unit of the ff camera? Or does it have its own aps system processor carried over? (BTW, its interesting to me how mfr carry over "nuts and bolts" from previous designs. saves a lot of time and expense where it works)
11-23-2013, 12:09 PM   #45
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QuoteOriginally posted by monochrome Quote
While something similar could be said about a sublime six-speed automatic transmission in a plebian sedan by someone who can still use his left foot while shifting, that doesn't diminish the technical brilliance of the new transmission.

Did you know in some American schools they no longer teach Cursive handwriting? No more Palmer Method! I suppose they figure no one will ever hand-write a letter, so why bother.

You do have a point of course. I lament the loss of the pages describing how to hold an SLR and how to focus the camera that were once part of every Pentax camera User Guide. But your sentiment has been building for quite some time.
....
It's just change.
Excellent discussion on change!

A cliche about change:

QuoteQuote:
The rate of change has never been as fast as it is now, and will never be this slow again.
People, probably myself included, tend to remember changes in our lives we don't like, and forget those changes we enjoy every day. We can become very angry about change because of that cherry picking. On the other hand, cultures are not defenseless against change, there are any number of change merchants who have gone bankrupt because people couldn't get interested in the product.

I don't know about other parts of the world, but we have these recent "reality" TV shows that show ordinary people like us living off subsistence hunting/farming methods in primitive areas of Alaska, i.e. non-urban areas. Many don't have grocery stores to go to, If they didn't store up food during the summer, or find additional game during the colder months, they go hungry. But they have freedoms and skills we often don't have in the lower "48" states.

Is change good or bad - don't know - it just is.
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