I totally agree with you Ken. Who looks at their images at 100% on a computer screen, other than during editing? Printed at a reasonable size or reduced to a normal web size (1000, 800 pixels), the grain just isn't an issue.

Colour noise / mottling can be an issue, but chroma noise can be hit hard in post processing without making the image mushy.

Look at a scan of supposedly fine-grained ISO100 film, and the grain is quite prominent when viewed at 100%, but you know it will still make a great print.

Shutter button here. I tried the rear button for a while, but kept (I'm embarrassed to admit) forgetting to focus! Now I have the rear button set to cancel AF, so I can actually take a picture when doing focus/recompose (if the red dot is on something which isn;t in focus, the shutter won't fire - I think this may be because I have catch in focus enabled but not sure.

I may try the rear button again, but the position isn't the most accessible it could have been.

The judge may not be aware that a larger version is available, or may be disinclined to click through to it on every image if there are a lot of entries - so may only see the 600px resized version. OK the difference is subtle, but annoying if you have made sure your original is pixel-sharp.

John, the images are processed into two sizes if you upload larger than 600px images to the gallery. I uploaded this one at 800px: LINK

The first image you come to is 600px, and this is its URL:

https://www.pentaxuser.com/images/gallery/2012/07/normal/jesus-on-the-mainline_1...

When you click on it, the larger image appears, in this case 800px:

https://www.pentaxuser.com/images/gallery/2012/07/large/jesus-on-the-mainline_13...

Note the two URLs are different, one says 'normal', and one says 'large'. The large one is the original, which has been processed to make it fit the standard 600px format. To me, it looks slightly softer (look at the face). The large one is the unaltered 800px image.

Geoff - look again at the images in the screen grabs. the 72PPI image, and the 300PPI image have the same number of pixels (1400 x 1050). They are the same image, containing the same number of pixels.

Your example stipulates a size in pixels (1400 x 1050). No mention was made of a 'document size'. The actual document size will be the output of the projector, not the 'document size tagged to the image in the computer. As long as your image is 1400 x 1050 pixels, it will look just the same as the next guys image even if your 'PPI' is wildly different, when projected to fill the screen. It will also have the same sort of file size for emailing.

I recently entered an online competition, where the rules asked for a 300PPI shot, which I dutifully provided. After grinding my teeth. Of course I made sure I unchecked the 'resample image' box, or the image would have been interpolated to 4x it's original size and degraded by the interpolation process!

This does make some sense, as you can view your image at the real 'print size' on the computer screen, so you may get a better idea of how your changes are going to impact the print. It doesn't really matter what size the image is for cropping or straightening though.

Geoff, what I think you have done is resample the image. You have changed the number of pixels. Is it really still 1400x1050 pixels? I'm going to go out on a limb and say your resized image was 336 pixels long. Do you think you could check that?

I have just done my own test:







The 72PPI image, and the 300PPI image have the same number of pixels (1400 x 1050), and were both 1.9MB when saved as max. quality jpegs.

That's not quite right John - upload a full size shot and the forum will resize it to 1000 pixels and compress it to hell.

In the standard gallery view, the normal size image before you click on it for the large version, you will see the image at 600 pixels - further degrading the quality.

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If you resize your shot to 1000 or 800 pixels, the large version will look fine, but the default gallery view of 600 pixels will be a tad softer. A competition judege may not have the patience to click on every shot for the large view, so...

But when you set the image to print at, say A3, the printer will map the image to fit it to that paper size (unless you print at 100%). We've established that a K5 image has enough pixels to provide the printer with about 300PPI at A3 so why not simply send it to print, selecting A3 as the output size?

That's for sure, Algi!