LCD Screen Zoom.

About 6 to 7 times approximately.

Sorry, I thought the K20D was 6-7 times zoom and that the K10D would be different due it's lower resolution.

I'm guessing that terje's K200D is about the same screen size as the K10D although that is a guess!

Cheers, Kris

From the original post

at what zoom level is equal to 100% on a computer screen

Which is rather explanatory ... what size and resolution of computer screen

If you read the whole of Tel's original question --- which I'll admit wasn't very well phrased (sorry Tel) --- you can see that he wanted to know what zoom level on the camera is equivalent to looking at picture at 100% on the computer screen. Most of the rest of the thread has been discussing exactly that question.

Somebody elsewhere has commented that the phrase "100% crop" is not very accurate although it has, through common usage, come to mean "part of an image viewed at 1 pixel = 1 pixel" and, as you are obviously aware, has become a common way of assessing the sharpness of an image.

What we are all trying to get at --- I think! --- is the simple issue of how far to zoom into the preview image to check the focus of a picture.

Best wishes, Kris.

The difference of the K100D/K10D vs the K200D/K20D is that the former have a 210000 pixel screen, whild the latter have a 230000 pixel screen.

The height/width relation is (to be confirmed):
K10/K100: 397x529
K20/K200: 416x554

The rest is a simple calculator job to get the ratio of your picture size vs. screen size. In my case: 2592 (picture height)/416 (screen height) = 6.23 (zoom factor).

This was what I was asking

KRIS No offence taken
---------------------------------------------------------------
Terry,
Thank you for taking the time to work it out.

Thanks to all for your input.

Hate to be the party pooper but I think all your calculations are wrong!

Thats because the LCD does not have 230,000 pixels, but 230,000 dots! Check on the official Spec sheet here.

Each pixel needs 3 dots, Red Green & Blue.

This relates nicely to the actual resolution of the camera LCD to be 320 x 240 pixels resolution or QVGA (320x240x3 = 230400), which is an industry standard size.

So, divide the height of the image (3120 pixels) by the height of the LCD (240 pixels) and your answer is exactly 13.

Unlocker was just ahead of me.
The LCD has indeed only 320x240 pixels.
Nikon has a DSLR with a 640x480 screen, I don't know if any other manufacturer uses a higher resolution screen.

Oh... fiddlesticks. Thanks for the correction. Back to the drawing board!

If that is the case, how can you then explain the following fact:

This is a 554x416 pixels cut from the original 3872x2592 pixels picture (see also previous page):
[IMG]http://i233.photobucket.com/albums/ee91/terje-l/554x416.jpg[/IMG]
and it is (within a mm) the same view I see on my camera at 6.7x zoom (2.7 x 3.5 mm of the rulers)!
At 11x zoom I see only 2.2 x 1.7 mm of the rulers, and the image is noticeably blurred.

I believe the specifications use the expression "dots" for "pixels", after all it is a TFT screen, which is normally spec'ed in pixels. So, unless I see an official statement from Pentax telling me otherwise, I stick to my calculations.

Woahaa! This is getting controversial!!

I thought of creating a JPG image with a fine 1-pixel striped image (black-white-black-white etc) and viewing on the camera LCD. Trouble was I couldn't get the K20D to playback any JPG I'd messed with.

I tried Photoshop and I even tried IrfanView (with the paint tools) and saving with original EXIF. Didn't want to play ball

In practice, I normally view at around 11x to check focus - and that's seemed to work well (and at least agree with the 13x suggested here).

Matt

I just keep zooming until I can see where the point of focus is on the tape.

shim

Does this only apply to photos in landscape format? When you turn the camera to portrait format the image on the screen rotates and shrinks to fit so the image height is 4672

4672 / 240 = 19.5 (ish)

If your checkin' for focus and sharpness then x16 is where its at. At x13 you could be missin' stuff and goin' home with unsharp images at 100%.

The Pentax K20D can produce very sharp images with lots of detail at 100%, but 'cos of the size of 'em they're more likely to show focus and sharpness errors, and so for that a x16 magnification is a must.
I print my images up at very large sizes and if you do then you will know that x16 is the the way to go.

Not sure about the other side of this argument, I thought it was the same thing.