K-7 has image distortion and CA correction


digikid-tv

Link Posted 21/05/2009 - 22:02
Just been reading Mike Johnston's review on the K-7 which is mentioned in another thread.

link

In it he gives a specification for the camera including the line "With JPEGs, the camera will automatically correct for distortion and CA for every specific DA lens." I was thinking that for someone like myself, a stills shooter who is not interested in the video features, that this in camera correction of distortion and chromatic aberration would be a worthwhile feature.

But won't this change the dynamic of the lens market? Pentax will be able to build the relevant look up tables for their lenses into the camera firmware. But will they include any values for third party lenses such as Tamron and Sigma? Will these third party lenses become less desirable because of this?

Or do enough people carry out these corrections in software to make these concerns irrelevant?
John

iceblinker

Link Posted 21/05/2009 - 22:13
Pentax barely acknowledge the existance of Tamron and Sigma, so you can bet it won't include any values for them.

Quote:
Or do enough people carry out these corrections in software to make these concerns irrelevant?

Yes, I think so, or enough people who just leave the images uncorrected.
~Pete

Mike-P

Link Posted 21/05/2009 - 22:17
It is only for DA lenses plus the 2 D-FA Macro lenses.
Apparently there is also a 4-5 second delay after each shot while the camera processes the image.

No continous AF in video mode either.
. My Flickr

sanderscapes

Link Posted 21/05/2009 - 22:27
Sorry but just looked at the link John which says it's pentax's flagship model which is smaller than the K20.

How can we have a flagship model smaller than a non flagship model

Anvh

Link Posted 21/05/2009 - 22:32
Mike-P wrote:
No continous AF in video mode either.

That's very strange, why not???
Stefan


K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ

viewfinder

Link Posted 21/05/2009 - 23:45
K7 appears to have it's video capability purposefully crippled. The only reason would seem to be that pentax want to 'let the cat out of the bag' slowly so that they can spread video integration over several models. In that way they get the punters to buy several new cameras instead of just one........

......all makers will likely commonly subscibe to this policy, so not just pentax. Their problem is going to be Panasonic which is not a camera maker and is large and powerful enough to go it's own way. The Panasonic GH1 is going to have full video integration from the outset and unlike k7 will have unlimited file size, full HD spec, and video oriented zoom lens with incremental zoom control,....in short a truly dual purpose camcorder with convincing still AND video capabilities.

golfdiesel

Link Posted 22/05/2009 - 07:49
viewfinder wrote:

......all makers will likely commonly subscibe to this policy, so not just pentax. Their problem is going to be Panasonic which is not a camera maker and is large and powerful enough to go it's own way. The Panasonic GH1 is going to have full video integration from the outset and unlike k7 will have unlimited file size, full HD spec, and video oriented zoom lens with incremental zoom control,....in short a truly dual purpose camcorder with convincing still AND video capabilities.

Unlimited filesize could be a problem.
I was wondering why the filesize was limited with all manufacturers but the reason is very, very simple.
We all use memory cards which use the FAT32 filesystem and what is maximum filesize on a FAT32 filesystem? Yes, 4GB.
So the 4GB limit has nothing to do with the processing power of the camera, but it has everything to do with the filesystem used on memory cards.

So if Panasonic is going to give you unlimited filesize they will have to resort to a new memory card with a different filesystem (ext2, hfs or ntfs for example) or they could use a special method for writing just like DVD recorders use (1GB per file) so you end up with more then one file for one take.
Sony's SxS card and Panasonic's P2 card are both to large for use in a DSLR.
Camera:K20D|Ist*DS|Spotmatic II|MZ-10
Pentax Lenses: DA16-45|DA50-200|50A 1.7
Tamron Lenses: 28-200
Takumar Lenses: SMC 55 1.8
Sigma Lenses: EX DG 50-500 'Bigma'|EX 50mm Macro
Flashes: Metz 58 AF-1|Samsung SEF-36PZF|Pentax AF-220T

johnriley

Link Posted 22/05/2009 - 08:00
Yes, there isn't always an underhand or devious reason for everything that happens. I'm sure manufacturers want to produce the most attractive products that they can and any limitations will be a result of the limitations of current technology.
Best regards, John

shim

Link Posted 22/05/2009 - 08:39
DVD's seem to use UDF v1.02 file system, so that could probably be used on cards. Panasonic will have it all sorted out.... don't worry.

They all seem to use 30 fps which is not PAL compatible and all the files they produce have to be converted to something else. Plus you need enormous computing power for editing. I'm not sure but, I suspect the final format would have to be Blu-Ray disks which is more expense.

The handiest camcorder is one that goes straight onto a DVD as an Mpeg-2 file they can be put in the computer, edited and burn't straight onto a DVD very quickly.

shim

golfdiesel

Link Posted 22/05/2009 - 10:02
shim wrote:
DVD's seem to use UDF v1.02 file system, so that could probably be used on cards. Panasonic will have it all sorted out.... don't worry.

They all seem to use 30 fps which is not PAL compatible and all the files they produce have to be converted to something else. Plus you need enormous computing power for editing. I'm not sure but, I suspect the final format would have to be Blu-Ray disks which is more expense.

The handiest camcorder is one that goes straight onto a DVD as an Mpeg-2 file they can be put in the computer, edited and burn't straight onto a DVD very quickly.

shim

Yes they can use a different filesystem, but then you have to use a new type of memory card as well because the SD specification does not allowe different file systems (ok, you can format them to a different format but it doesn't allways work properly).

30fps isn't a real problem these days with modern TV's allmost every TV produced in the last 10 years will be able to sync to 60Hz for a 30fps framerate. And if you use HD video with a TV that handles HD inputs the whole framerate issue becomes irrelevant. I have a CRT TV which has both a HDMI and a component input and it handles HD content to 1080i. Since it is a CRT and it is 28" in diameter it doesn't matter if you go above 720p because it is physically not able to display more lines.
Camera:K20D|Ist*DS|Spotmatic II|MZ-10
Pentax Lenses: DA16-45|DA50-200|50A 1.7
Tamron Lenses: 28-200
Takumar Lenses: SMC 55 1.8
Sigma Lenses: EX DG 50-500 'Bigma'|EX 50mm Macro
Flashes: Metz 58 AF-1|Samsung SEF-36PZF|Pentax AF-220T

shim

Link Posted 22/05/2009 - 10:52
PAL is 25 fps not 30 fps and any conversion uses the 1st frame and interpolates the one's in between that and the 30th or drops a few frames which creates a jerky picture.

There's only really one half decent piece of software that can do it (Atlantis) and that costs $195. But even that's a compromise.

shim

golfdiesel

Link Posted 22/05/2009 - 12:20
shim wrote:
PAL is 25 fps not 30 fps and any conversion uses the 1st frame and interpolates the one's in between that and the 30th or drops a few frames which creates a jerky picture.

There's only really one half decent piece of software that can do it (Atlantis) and that costs $195. But even that's a compromise.

shim

Yes PAL is 25fps but as I wrote it is hardly relevant anymore when you look at halfway modern TV's. Most of them are multi-standard anyway.
LCD TV's don't care a bit on what you feed to it, they are all multi-standard.
When I use the HDMI input on my TV it can display 24, 25 and 30fps without anyone noticing it, it uses either a 50, 60, 75 or 100Hz refresh rate.
Camera:K20D|Ist*DS|Spotmatic II|MZ-10
Pentax Lenses: DA16-45|DA50-200|50A 1.7
Tamron Lenses: 28-200
Takumar Lenses: SMC 55 1.8
Sigma Lenses: EX DG 50-500 'Bigma'|EX 50mm Macro
Flashes: Metz 58 AF-1|Samsung SEF-36PZF|Pentax AF-220T
Last Edited by golfdiesel on 22/05/2009 - 12:20

Unlocker

Link Posted 22/05/2009 - 12:58
Not to mention the PS3 can kick out 1080P at 60 FPS!

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Robin128

Link Posted 22/05/2009 - 13:01
johnriley wrote:
Yes, there isn't always an underhand or devious reason for everything that happens. I'm sure manufacturers want to produce the most attractive products that they can and any limitations will be a result of the limitations of current technology.

It's all about competitive advantage.

What I am worrying about is what compromises have been made to include video...at the cost of still photography quality and flexibility? EG any limit on lens capability, as a function of what system is using the lens at any one time? What about the extra (huge) call on file storage and power? Any limits/constraints on the sensor(s)? Does the processor have to be faster, more expensive? What will top end camcorders do that this K7 cannot?

No, not for me....its a bit like buying a car, with a free motor bike thrown in!



Rob

Rob
K20D
MZ 50
Pentax lenses....DA* 55mm f1.4 SDM ....F 35-80 f4-5.6....DA 18-250 f3.5-6.3....F 100-300 f4.5-5.6, D FA Macro 100 WR f2.8.

Centon mirror lens 500mm.

Pentax Flash ....AF 360FGZ

JVC 3ccd GZ MC 500EK camcorder

johnriley

Link Posted 22/05/2009 - 14:01
But you haven't even seen it yet to assess these doubts in your mind, so how can you say it's not for you?
Best regards, John
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