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05-22-2009, 01:08 AM   #76
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Why not PM each other so we can get back to AF discussion

05-22-2009, 03:27 PM   #77
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Good Report on K-7 AF Here

No measurements but another opinion from someone who handled the K-7:

I have tried the K-7 [Page 1]: Pentax SLR Talk Forum: Digital Photography Review

Sounds encouraging and at least two are going back to see it again, so stay tuned.

Ray
05-23-2009, 10:16 AM   #78
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Sorry to take so long to get back on this thread; business has been mercifully good. There really is no comparison to the D90 in most aspects, as the more fair comparison is against the D300. Given the D300 has no video, this is one advantage for Pentax. There remain a couple of advantages for the Nikon, although I find them nuanced advantages such as the 3D matrix metering and the active viewfinder AF system. The faster frame capture with the grip on the D300 is also nice, and the higher flash synch is also nice. However, given the stregths of the K-7, size, build quality, built in SR, legacy lens compatibility of the highest degree, the pricing and the availability of VERY affordable WR lenses I feel compelled to say the K-7 is the hands down victor over the D300.

With all of the above said, the D300 is supposedly at the end of its life and a D400 is emerging on the horizon, so we should reserve the comparison for another day. However, I highly doubt that Nikon would bring another SLR to market whose price would so closely approach the D90 that I confidently say the K-7 will remain the best value in DSLR cropped sensor cameras for a very long time.
05-23-2009, 10:35 AM   #79
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QuoteOriginally posted by jsherman999 Quote
Before it beats the D300 it has to beat the D90, and from what I've read so far about the AF improvements, I'm not sure it will - I'm hopeful, but not certain.

My D90 beats my K20D in AF-lock speed hands-down in any lighting situation. We need the K-7 to match the D90 if possible - it may be too much to ask for it to match the D300 (especially with grip.)


.
The K-7 and DA*55mm f/1.4 SDM rather handily thrashed the focusing speed of the Nikon D90 and the 50mm f/1.4G lens. The focusing difference between the D300 and the D90 certainly explains this. I can't imagine I would get any disagreement that the D300 AF is better than that in the D90, so for those who are concerned that the AF in the K-7 won't be as good as the D90...be concerned no more. With the DA* lenses, I will take the Pepsi challenge against Nikon's AF-S lenses any ol' day of the week.

Now for those who point to my use of Pentax products to say my bias is badly slanted toward Pentax, I am objective enough to present the advantages and disadvantages of each brand. The health of my store depends on that.

05-23-2009, 10:55 AM   #80
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QuoteOriginally posted by pingflood Quote
Now go grab a D300 and a K20D and go do some actual shooting and see which one performs better.

Honestly, I find it hard to believe that people claiming the K20D is as fast as or faster than the current prosumer cameras from the competition have ever shot with them. You can keep picking tests or setups that'll show an advantage, but in the end photography is done in the real world and that's where the true performance shows. The K20D is a very good, no a GREAT camera, but it doesn't smoke the competition in every area. You can keep trying to prove it does, or keep deluding yourself into believing so, but from somebody who's shot and handled a multitude of bodies going from ancient Leicas to viewcameras to current pro gear, IT AIN'T SO. Believe me, I didn't want to spend thousands more to get what I really wanted in a camera, but the difference was significant enough that I couldn't ignore it.
Funny thing about the AF speed comparison between Pentax and the other brands. It seems to me to be largely lens dependent as I can take Pentax's D FA100mm f/2.8 macro and measure it's AF speed with a calendar when compared with the 100mm f/2.8 Macro from Canon and Sony. Oddly the Nikon 105VR seems a bit slower than Canon and Sony, but still much faster than the Pentax. However if you take the DA* 55mm f/1.4 and compare it to the Nikon 50mm f/1.4G, the Canon EF 50mm f/1.4USM and the Sony 50mm f/1.4, there is not a person on the planet who can prove to me that one of these lenses focuses appreciably faster than another.

To me, the lenses that make the AF shine in the other brands mostly shows up in the lens types where Pentax does not participate. The Sony 70-400G, Nikon 80-400VR and Canon EF 100-400L just don't have a Pentax equivalent. I rather quickly condede the focusing speed advantage on these and a number of other lenses where Pentax is slower (above mentioned macro, DA 18-250 and the DA 17-70). However I have convinced many folks, many more than have subsequently jumped on the Pentax bandwagon but convinced nonetheless, that Pentax stacks up very nicely against the other brands as we walk around the grounds of the mall where the store sits.

The long and the short of things is some folks will be disappointed with Pentax's AF, but ironically it is the real world shooting where the difference between Pentax and the others becomes rather small. Think also of the other benefits inherent to the Pentax system. How much do Canon and Nikon charge for their IS or VR 50mm lenses? How much do they charge for their glorious rendering 50-135 lenses?
05-23-2009, 11:19 AM   #81
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QuoteOriginally posted by dnaseigel Quote
Funny thing about the AF speed comparison between Pentax and the other brands. It seems to me to be largely lens dependent as I can take Pentax's D FA100mm f/2.8 macro and measure it's AF speed with a calendar when compared with the 100mm f/2.8 Macro from Canon and Sony. Oddly the Nikon 105VR seems a bit slower than Canon and Sony, but still much faster than the Pentax. However if you take the DA* 55mm f/1.4 and compare it to the Nikon 50mm f/1.4G, the Canon EF 50mm f/1.4USM and the Sony 50mm f/1.4, there is not a person on the planet who can prove to me that one of these lenses focuses appreciably faster than another.

To me, the lenses that make the AF shine in the other brands mostly shows up in the lens types where Pentax does not participate. The Sony 70-400G, Nikon 80-400VR and Canon EF 100-400L just don't have a Pentax equivalent. I rather quickly condede the focusing speed advantage on these and a number of other lenses where Pentax is slower (above mentioned macro, DA 18-250 and the DA 17-70). However I have convinced many folks, many more than have subsequently jumped on the Pentax bandwagon but convinced nonetheless, that Pentax stacks up very nicely against the other brands as we walk around the grounds of the mall where the store sits.

The long and the short of things is some folks will be disappointed with Pentax's AF, but ironically it is the real world shooting where the difference between Pentax and the others becomes rather small. Think also of the other benefits inherent to the Pentax system. How much do Canon and Nikon charge for their IS or VR 50mm lenses? How much do they charge for their glorious rendering 50-135 lenses?
thank you very much, for getting back to us
a question i would like to ask is
as i have the DA*16-50 and 50-135. should i see a vast difference in autofocus speed with the K7 over the K20D, and if yes by how much %

Dave

Last edited by dafiryde; 05-23-2009 at 11:34 AM.
05-23-2009, 11:26 AM   #82
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Hi David,

Hope you and the camera store plus family are doing well in Rockford?

You've indicated the K-7 has better AF than the D90, approaching the D300? Obviously the D300 is considered a benchmark to be compared against in it's class. What I am curious about the K-7: in lower lighting conditions, how good is the AF without the AF assist lamp? That lamp has a range limitation, so it will often not be of benefit for wildlife work at around dawn or dusk when little contrast and lighting is available.

Don't get wrong, I am very interested in the improvements and will probably buy a K-7. I big plus is having the 5 FPS for starters (thank you Pentax) and improved AF. Having used an MZ-S with SAFOX VIII in low light, it's really quick and locks fast. Therefore this would encourage me to believe the algorithms have been fine tuned to the point that I may have what I've wanted for some time: faster low light AF. Accuracy has not been an issue for me - it's generally better with Pentax.

BTW, I put John Carlson to the question at DPR about low light focusing, but he didn't have any data on it.

Best wishes,
Marc
05-23-2009, 11:45 AM   #83
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QuoteOriginally posted by dafiryde Quote
as i have the DA*16-50 and 50-135. should i see a vast difference in autofocus speed with the K7 over the K20D, and if yes by how much %

Dave
The DA* 50-135 is by far the slowest focusing lens that I own. I really think that lens' AF is lens-limited not body-limited. If I put any other lens that I own on the k20d, it is significantly faster. I don't know how the K-7 could improve AF speed on it without switching to screw drive.

05-23-2009, 12:00 PM   #84
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QuoteOriginally posted by Class A Quote

Then one seems to have a snappier performance. Only a scientific evaluation will tell you whether you are imagining things (we humans are great in seeing things which are not there) or whether there are actually facts.
That dog doesn't hunt.
If camera N gets a higher % of infocus shots of subjects doing a particular thing than camera P, then it's pretty safe to presume that camera N is more responsive than camera P. Note it isn't all about AF speed either, there is shutter lag involved as well.
Generaly higher frame rate cameras will behave more quickly than slower frame rate cameras as well, simply because they have to to be able to achieve the higher frame rate.
05-23-2009, 12:45 PM   #85
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QuoteOriginally posted by Ray Pulley Quote

Hopefully the AFC has dramatically improved, but there is very little noise about any improvement in this area, but lots of generalizations and marketing fluff about overall improvements to the system.

I have not seen one NDA'er or hands-on K7 user make a single claim about improved AFC.


Ray
Check Mark Dimo's Blog.

He clearly states:
6. AF tracking in AF-C is vastly improved

chasing light...: Initial Impressions of the Pentax K7
05-23-2009, 12:51 PM   #86
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QuoteOriginally posted by PentaxPoke Quote
The DA* 50-135 is by far the slowest focusing lens that I own. I really think that lens' AF is lens-limited not body-limited. If I put any other lens that I own on the k20d, it is significantly faster. I don't know how the K-7 could improve AF speed on it without switching to screw drive.
i am supprised to hear the 50-135 is a slow focusing lens, even a little more supprised to hear its slower than the 18-250 lens
i always found it to be a lot faster and more accurate than the 16-50
if that is the case Pentax is not what i want

Dave
05-23-2009, 01:35 PM   #87
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QuoteOriginally posted by Wheatfield Quote
That dog doesn't hunt.
If camera N gets a higher % of infocus shots of subjects doing a particular thing than camera P, then it's pretty safe to presume that camera N is more responsive than camera P. Note it isn't all about AF speed either, there is shutter lag involved as well.
Generaly higher frame rate cameras will behave more quickly than slower frame rate cameras as well, simply because they have to to be able to achieve the higher frame rate.
Not that I don't believe some of the people that have tried the K-7 AF. it's just the idea of hearing the opinion of a skeptically minded person before I race to the store and buy one.

Please tell me you plan on getting your hands on one ASAP and will let us know your impressions.

Thanks,
ken
05-23-2009, 02:01 PM   #88
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QuoteOriginally posted by dafiryde Quote
i am supprised to hear the 50-135 is a slow focusing lens, even a little more supprised to hear its slower than the 18-250 lens
i always found it to be a lot faster and more accurate than the 16-50
if that is the case Pentax is not what i want

Dave
Dave.. maybe it is just his lens.

Are you happy with yours?



Neil
05-23-2009, 02:21 PM   #89
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QuoteOriginally posted by nulla Quote
Dave.. maybe it is just his lens.

Are you happy with yours?



Neil
No it is not just my lens. I just got a brand new one back from service after the SDM failed on my first one. You can also see video from a member here (don't recall who) that shows the slow motion of the 50-135 focus ring. When I owned a 16-50, I found that it was faster than the 50-135. The 18-250 is clearly faster in AF than the 50-135.

The only reason I keep using the DA* 50-135 is that it's image quality is exceptional for a zoom, and the fact that it has a fast aperture.
05-23-2009, 02:29 PM   #90
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After reading reams of wants and wishes from members in other threads I feel that the absolute acceptance of the K7 as a "player" alongside N&C (touted as semi-pro) will mainly depend on these;

AF speed in single and servo tracking mode - as good as N d90 and C 40/50d

Lowlight af performance under normal light & artificial light

Exposure Accuracy

Noise levels > 800 ISO

All the above must be equal or better the competition

If not, I then feel that even with all it's other bells & whistles it could fail to get the serious to adopt Pentax.

Remember - the K10D was a groundbreaking product for Pentax and had groundbreaking features that N&C didn't have - yet generally the world hardly blinked and most still followed the N&C route.

Dyl
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