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11-06-2010, 04:35 AM   #1
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zoom to 100%

Hi,

When i've taken a picture i always tend to zoom in on the live view to make sure it's sharp. I was wondering though how far do i have to zoom in (on live view) to see what the picture would look like at 100%?

I've the k-5 which is 16mp.

Thx!

Regards

11-06-2010, 06:17 AM   #2
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You have to zoom to 7.7X on the K-5. If you zoom in more it gets blurry because the camera is interpolated. That is one of my pet-peeves on the K-7 as well, it is possible to zoom past 100% and therefore everything gets blurry.

- Itai
11-15-2010, 02:53 AM   #3
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Hi there!

What about the same question but for K-X? I have problems with focusing (I`m new into this and problem is definately in me) so I also use zooming to check if I have focused correct.

Thnx
11-15-2010, 05:14 AM   #4
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I don't know what the exact size of the k-x lcd is (only that is has 230000 pixels) but based on that i would say either 6.7X or 8X magnification.

Easiest way would be to paint a one pixel wide line in a foto and open it on the camera, but somehow my camera refuses to open edited files...

11-15-2010, 08:02 AM   #5
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On the K-x, that would be about 13X actually.

The lower resolution your screen is the more you have to magnify the image so that
one pixel in the image becomes one pixel on the display. That's why you have to
magnify less (6.7X) on the K-r even though images have the same resolution.

- Itai
11-15-2010, 09:16 AM   #6
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Ehh, how did you calculate this exactly? Might want to check your calculations on the other camera's numbers too.

Lets run the numbers:

K-x makes 12 megapixel pictures, 4288 x 2848
The k-x lcd has 230,000 pixels, in a 4x3 ratio that would be something like 415*550

So, at 1x notification all 4288 pixels are resized to 550 pixels.
if we want to magnify this to an 1:1 pixel view we would *numbercrunch* magnify to (4288/550=) 7,8 times magnification...
That would leave to believe the 8 times magnification is correct.
11-15-2010, 08:08 PM   #7
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QuoteOriginally posted by basditz Quote
Ehh, how did you calculate this exactly? Might want to check your calculations on the other camera's numbers too.

Lets run the numbers:

K-x makes 12 megapixel pictures, 4288 x 2848
The k-x lcd has 230,000 pixels, in a 4x3 ratio that would be something like 415*550

So, at 1x notification all 4288 pixels are resized to 550 pixels.
if we want to magnify this to an 1:1 pixel view we would *numbercrunch* magnify to (4288/550=) 7,8 times magnification...
That would leave to believe the 8 times magnification is correct.
Because I know something you don't Manufacturers count LCD pixels the same was as camera makers count megapixels. A 230,000 pixel screen is 320x200 pixels actually. They multiply by 3 because it's RGB. Technically they should say 230000 dots but then you get companies who cheat and say equivalent-dots when the use field-sequential displays!
Once you know this, your calculations will give you them same results as me. Also, most
cameras fit images to the width in case of discrepancy between the aspect ratio of the
photo versus the LCD.

- Itai
11-15-2010, 11:49 PM   #8
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Thanks guys!
But you can continiue this digit discussion, so many new and interestings things for me!

11-16-2010, 11:52 AM   #9
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Argh! Tricked by the marketing department!

Calculating for 320x240 i get 13,4 magnification, but on k-x you can only magnify to 11x or 14x, so 14x would be closest
11-16-2010, 12:32 PM   #10
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OP, it sounds like you are referring to reviewing the image, not previewing the image in live view. Just fyi, if you are referring to AFTER taking the picture, then the rest of this thread is relevant. If you are referring to BEFORE you take the picture, then you are in live view mode. The problem is that live view mode uses binned pixels like video mode, so no matter what you zoom in to, it will look like crap.
11-16-2010, 12:54 PM   #11
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Ok, i've found the way to view edited photo's on the camera (saving them with faststone viewer did the trick ), loaded a jpeg with some alternating 1 pixel black & white lines (horizontal to make sure sub-pixel layout didnt mess anything up), and zoomed in to 11 and 14 times magnification. Then got a magnifying glass (my pentax-a 50mm ) and checked the pixelreproduction.

Neither was true 1:1 magnification, there was some interpolation going on on all levels. Seems there is some fast-resizing algorithm at work.

(also something i noticed, in 1x magnification, you are shown the thumbnail for half a second while the main image is being pulled from memory & resized to fit. After this the view is changed to the resized image and you are allowed to zoom in on it.)
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