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06-22-2009, 03:08 PM   #151
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QuoteOriginally posted by falconeye Quote
AP magazine's announcement earlier today made me phone Pentax Europe and clarify the matter. The result is three posts up.

I understand that AP magazine would refrain from running their lab test software, as the figures they would obtain may not be fully correct to the last digits. But it isn't a real concern for the blog articles which have been published so far.

That wasn't this clear to me before my call to Pentax. So, I hope this information is helping others as well.
If you can find it in a "test", SOMEONE will see it in reality...

06-22-2009, 03:09 PM   #152
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Has anybody read this review Pentax K-7 full review - full production Pentax K7 with firmware 1.00 test | Digital SLR's | What Digital Camera
and what is your opinion on this? me myself i don't understand how the canon 450D scored better than the K-7 and even on IQ sorry i don't by this.
06-22-2009, 03:17 PM   #153
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Thanks for the catwalk photos! All in the life of a physicist .....
06-22-2009, 03:56 PM   #154
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QuoteOriginally posted by glanglois Quote
Thanks for the catwalk photos! All in the life of a physicist .....
Surely You're Joking, Mr. Feynman! - Wikipedia, the free encyclopedia

My personal hero If I only were as bright as he was ...

06-22-2009, 04:32 PM   #155
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QuoteOriginally posted by falconeye Quote
Surely You're Joking, Mr. Feynman! - Wikipedia, the free encyclopedia

My personal hero If I only were as bright as he was ...
A salute to Dr. Falk, the physicist, from Dr. Sailor, the organic chemist.

The catwalk shots sort of typify organic chemistry. The subject is made up of carbon-based molecules, and it's been said (by Bill Bryson) that carbon is shamefully promiscuous; willing to bond to almost any other element, carbon is the "party animal" of the elemental world.

Seriously, thanks for all the hard work you've put into your "alpha testing". I appreciate it.

Jer
06-22-2009, 04:46 PM   #156
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QuoteOriginally posted by falconeye Quote
Surely You're Joking, Mr. Feynman! - Wikipedia, the free encyclopedia

My personal hero If I only were as bright as he was ...
Fascinating man, fascinating book, and I am resolutely not making any references to partons.

Last edited by glanglois; 06-22-2009 at 04:47 PM. Reason: Add smiley
06-24-2009, 11:06 PM   #157
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Hi falconeye,

I have questions regarding the SDHC card that you are using, in particular for video.

Firstly, I'm assuming that writing to the card, video imposes a heavier demand than shooting still photos, even continuous shooting.

What Class card are you using?

For my Panasonic HD videocam, the manual recommends Class 4. But AVCHD produces much smaller file sizes than MJPEG. In the K-7 manual, it only states that a "fast" card should be used. Is Class 4 fast enough if I video HD at the best quality?

Thanks.
06-24-2009, 11:53 PM   #158
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Thanks for the hard work, you may want to read some comments from JohnCPentax on dpreview. No tester or reviewer has seen the abilities of the K-7 at high ISO. Its a secret, really. And its improved over the K20D

Its unfortunate that IMO some translation errors occurred, I would not be happy being told I have a near finale (within 5% of IQ) then test hard and find I don't have a sensor from the new K-7 ;( so I am not trying to be a jerk. Just want people to know they should wait to make finale judgments on the K-7 when its out in the streets in full production.

If you want links to JohnCpentax words I can provide it. No tester has anywhere near a production sensor in IQ to make any judments at high ISO.

06-25-2009, 12:19 AM   #159
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QuoteOriginally posted by watchthewaves Quote
I have questions regarding the SDHC card that you are using, in particular for video.
[...]
Is Class 4 fast enough if I video HD at the best quality?
I used a Sandisk Extreme III (which I happened to have). AFAIK it is class 6 and 30 MBytes/s (MB/s) read/write.

In practice, videos in highest quality stream at about 45 MBit/s which is a bit less than specified (the specification is based on the conservative (read high) bitrate estimate which is also used when displaying remaining recording time and is meant to be on the safe side).

45 MBit/s or just under 6 MB/s is 5x under 30 so there should be a lot of headroom. Note however that 6 MB/s is already full Class 6 speed! So indeed, the card should meet class 6 spec. And the max. bitrate specified in the K-7 manual exceeds the minimum bitrate specified for Class 6. I don't know if there is a Class 8 ...


Actually, I managed to stream hi burst rate beyond the buffer size limit and this is 1.6 MB x 5.2 /s or 8.3 MB/s (66 MBit/s). So, burst can actually use better than Class 6. Note that production cameras may not be able to do this, though


Note that video is demanding in capacity. So, I would probably get a 32 GB card. The Sandisk Extreme III isn't available in 32 GB size. As it seems, 32 GB cards are limited to just meet the Class 6 spec (6 MB/s write speed).


So maybe, I would go with one of the few 32 GB Class 6 cards (all no name, don't use for contract work...) plus a smaller 30 MB/s card. Or a single 16 GB 30 MB/s card like the Sandisk Extreme III.


Update:
Strangely, the Sandisk Ultra II is available in 32 GB and specified at 15 MB/s write speed but it isn't specified Class 6 !? And the Sandisk Video HD and Ultra II are priced the same but Video HD is only targeted for AVCHD (currently 2.2 MB/s only!).

Last edited by falconeye; 06-25-2009 at 12:32 AM.
06-28-2009, 04:46 PM   #160
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K-7 and its precision autofocus

New blog entry:
K-7 and its precision autofocus


The alpha test isn't over yet

I completed my study of the AF.S auto focus.

one sample focus audio mp3

Please, visit the blog for the full story (link above). Note that the article isn't posted as the most recent one, so doesn't appear on top of the blog!


My conclusion copied here:

My conclusion is that the new SAFOX VIII+ as deployed in the K-7 is a significant improvement over the previous installment (the K-m). The 40% faster focus motor and 1 stop extra performance in low light are well balanced with the overall improvement in the K-7 which has a faster shutter and 50% faster burst. The improved accuracy in tungsten light was asked for by many and as it seems, has now been delivered in the K-7.

The K-7 auto focus isn't the revolutionary step some had hopes for. I.e., you will still be able to miss shots But when actually shooting with the K-7, it certainly feels much better than just an evolutionary step. Numbers don't tell the whole story.



Enjoy
06-28-2009, 11:30 PM   #161
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QuoteOriginally posted by falconeye Quote
I used a Sandisk Extreme III (which I happened to have). AFAIK it is class 6 and 30 MBytes/s (MB/s) read/write.

In practice, videos in highest quality stream at about 45 MBit/s which is a bit less than specified (the specification is based on the conservative (read high) bitrate estimate which is also used when displaying remaining recording time and is meant to be on the safe side).

....
I have been wondering about cards myself, as you say it should be a 32gb card since the k7 doesnt have dual slots and the prices are down so much now that a 32gb card doesnt cost a fortune. Sandisk has announced a class 10 32gb card although I am guessing it will be quite expensive. Panasonic has a fast 32gb card too but it is very expensive.

The sandisk ultra II is very affordable 32gb and I would prefer to buy Sandisk as long as the card is not too slow. It is class 4 as you say.

Right now I am leaning towards the transcend 32gb as it is class 6, ever so slightly more expensive than the sandisk ultra II.

Would be cool if dslr makers gave specs on cards so you would know what to buy to not slow down the camera, and would be able to avoid buying a card that is specced too high.
06-29-2009, 12:19 AM   #162
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QuoteOriginally posted by falconeye Quote
I used a Sandisk Extreme III (which I happened to have). AFAIK it is class 6 and 30 MBytes/s (MB/s) read/write.

In practice, videos in highest quality stream at about 45 MBit/s which is a bit less than specified (the specification is based on the conservative (read high) bitrate estimate which is also used when displaying remaining recording time and is meant to be on the safe side).

45 MBit/s or just under 6 MB/s is 5x under 30 so there should be a lot of headroom. Note however that 6 MB/s is already full Class 6 speed! So indeed, the card should meet class 6 spec. And the max. bitrate specified in the K-7 manual exceeds the minimum bitrate specified for Class 6. I don't know if there is a Class 8 ...


Actually, I managed to stream hi burst rate beyond the buffer size limit and this is 1.6 MB x 5.2 /s or 8.3 MB/s (66 MBit/s). So, burst can actually use better than Class 6. Note that production cameras may not be able to do this, though


Note that video is demanding in capacity. So, I would probably get a 32 GB card. The Sandisk Extreme III isn't available in 32 GB size. As it seems, 32 GB cards are limited to just meet the Class 6 spec (6 MB/s write speed).


So maybe, I would go with one of the few 32 GB Class 6 cards (all no name, don't use for contract work...) plus a smaller 30 MB/s card. Or a single 16 GB 30 MB/s card like the Sandisk Extreme III.


Update:
Strangely, the Sandisk Ultra II is available in 32 GB and specified at 15 MB/s write speed but it isn't specified Class 6 !? And the Sandisk Video HD and Ultra II are priced the same but Video HD is only targeted for AVCHD (currently 2.2 MB/s only!).

I had done some reading and regarding the class 6 specification of a SDHC card, it means the card has a minimum speed of 6 MB/s and not lower. so it's normal that a CLASS 6 SDHC card could go beyond 10MB/s. the ADATA SDHC I got has an advertised read/write speed of 22MB/10MB. some actual tests about the card revealed that it goes beyond 22 and reaches 26MB read speed while the write speed has an average of 15MB/s. this btw, is the Turbo version SDHC card. I got 2x16 instead of getting a single 32. it saved me around 22 bucks less for a capacity of 32GB. I might consider buying a faster SDHC when and if the need for it arises on saving valuable DATA or use on the K-7. til then, I'll just be happy to have a big storage.
06-29-2009, 02:38 AM   #163
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QuoteOriginally posted by falconeye Quote
I completed my study of the AF.S auto focus.
Nice to have some hard numbers now. Thanks!
Since the K100D there have been a number of improvements from model to model so the difference should be rather impressive.
I don't find the K100D slow, BTW, and even with the 18-250 it obtains focus in really low light.

You wrote:
QuoteQuote:
So, I had a close look at the autofocus system in AF.S mode, the mode normally used to achieve highest precision.
Is it true that AF.S is better for achieving optimum focus than AF.C?

Assuming a still subject, am I losing out on ultimate precision if I use AF.C and keep pressing the OK button (this is on a K100D) until the camera has obtained focus? (And then let go of it before I take the shot, so that the focus setting cannot change anymore).

I would not have thought that AF.C uses wider tolerances than AF.S.

I know that you can release the shutter with AF.C even if the subject is not in focus so in that respect AF.S is better to avoid such OOF shots, but I hope with still subjects there is no difference, or is there?

BTW, you said you found the D300 to be less hesitant to find focus. I guess you have not checked whether accuracy is at the same level?

One but last question: Did you have to calibrate your lens first using the fine adjustment feature? If so, how did you check for optimal focus?

Last question: How did you check that the focus was optimal in the AF tests?
06-29-2009, 04:07 AM   #164
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QuoteOriginally posted by Class A Quote
1. Is it true that AF.S is better for achieving optimum focus than AF.C?
[...]
2. BTW, you said you found the D300 to be less hesitant to find focus. I guess you have not checked whether accuracy is at the same level?
[...]
3. Did you have to calibrate your lens first using the fine adjustment feature?
[...]
4. How did you check that the focus was optimal in the AF tests?
1. I only said "mode normally used". Don't know if it is better really, if compared to AF.C in the way you described it.

2. No, I didn't check.

3. No.

4. The black lines (with visible paper micro structure) were sharp at 1:1. In other tests, I compared shots to a manual focus series. The images from the K-m have been sharp as well, but "pixel peep sharp" with 10 MPixels is easier to achieve than with 15 MP. Also, the tungsten images from K-m may have had a 1/4 px less sharpness.
06-30-2009, 10:49 AM   #165
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K-7 as a movie camera

New blog entry:
K-7 as a movie camera


I compiled some of my experience with the K-7 video mode into a three part blog article.

It may contain some interesting tricks and bits for those interested in the video feature.
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