Native image resolution of K-3

**Robert N** · 02-20-2020, 03:02 AM

When taking images in both DNG and JPEG formats with the K-3, I note the original image resolution, when viewing with Photoshop Elements, is 240 pixels per inch.
I am trying to establish if this is the native output from the camera, or an inbuilt default setting within Photoshop Elements (which undoubtedly uses the same algorithms as full Photoshop). It will be interesting to get other users views on this.

steephill · 02-20-2020, 04:54 AM - **2 Likes**

That isn't the native resolution, try dividing the number of pixels by the size of the sensor and you will see that it can't be. The number your are seeing in PSE is simply a suggestion for an output resolution for making a print. It has no impact on most screen viewing applications except maybe in DTP where you want a specific image size in ppi terms. You can change it to any value you want without having any effect on the true resolution of your image. Pentax cameras have used a different default number over the years, 72 and 300 ppi, so it really doesn't matter except for very specific applications.

pschlute · 02-20-2020, 07:26 AM

Originally posted by Robert N

I note the original image resolution, when viewing with Photoshop Elements, is 240 pixels per inch

In addition to the excellent answer above I would add the following:

If you view an image on any electronic device the pixels per inch (ppi) number is mostly irrelevant. Your K3 will produce an image at 6000x4000 pixels. If you view that on a screen the graphics software of your computer or tablet will take care of displaying it correctly depending on your screen resolution.

When you wish to print an image the ppi number is relevant. but it is a number that can be changed at will. So for example, if you want to print at a size 12" x 8", and the print lab says it wants images at 300 ppi you can do the maths....... 12x300 = 3600 8x300 = 2400. So you need to downsize your image from 6000x4000 pixels to 3600x2400 pixels.
The print size; ppi number; and pixel resolution of your image are three sides of the same equation.... print size x ppi equals the resolution.

normhead · 02-20-2020, 07:37 AM

When submitting work for prints, as far as I can tell the output size, 240, 300 whatever is ignored. If I accidentally leave the out put DPI at 72 they still print at the 200-300 dpi I set as my target. They fit the image I send them into the size I ask for, what ever DPI that turns out to be.

pschlute · 02-20-2020, 08:23 AM

Originally posted by normhead

When submitting work for prints, as far as I can tell the output size, 240, 300 whatever is ignored. If I accidentally leave the out put DPI at 72 they still print at the 200-300 dpi I set as my target. They fit the image I send them into the size I ask for, what ever DPI that turns out to be.

The main thing is to have the pixel resolution of your image correct. in the example I gave above if you send an image file to a lab that has been correctly resized to 3600x2400 pixels, and you have told them to print at 12x8 inches, then your image will be printed at 300 ppi. it is a simple question of maths. The ppi cannot be anything other than 300.

It is always best to resize your image to the correct pixel resolution rather than relying on their software to downsample your image.

normhead · 02-20-2020, 09:05 AM

Originally posted by pschlute

The main thing is to have the pixel resolution of your image correct. in the example I gave above if you send an image file to a lab that has been correctly resized to 3600x2400 pixels, and you have told them to print at 12x8 inches, then your image will be printed at 300 ppi. it is a simple question of maths. The ppi cannot be anything other than 300.

It is always best to resize your image to the correct pixel resolution rather than relying on their software to downsample your image.

Or upsample as well. I often expand 120 DPI, to 300 or 360 DPI before sending it out for printing. Modern printers just look better printed at the printers optimum resolution, whether or not it is the native resolution.

pschlute · 02-20-2020, 10:37 AM

Originally posted by normhead

Or upsample as well. I often expand 120 DPI, to 300 or 360 DPI before sending it out for printing

DPI is an output term relating to printers, dots per inch. Not the same as the input parameter PPI , pixels per inch.

Changing the PPI of an image in software is not necessarily upsampling/downsampling. For example in Photoshop if you change the PPI and do not have the resample tickbox checked you are simply changing the document physical size (inches or cm), and not changing the number of pixels in the image.

02-20-2020, 03:02 AM	#1
Robert N Site Supporter Join Date: Oct 2017 Location: Sale, Cheshire Posts: 249	Native image resolution of K-3 When taking images in both DNG and JPEG formats with the K-3, I note the original image resolution, when viewing with Photoshop Elements, is 240 pixels per inch. I am trying to establish if this is the native output from the camera, or an inbuilt default setting within Photoshop Elements (which undoubtedly uses the same algorithms as full Photoshop). It will be interesting to get other users views on this.

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02-20-2020, 04:54 AM - 2 Likes	#2
steephill Pentaxian Join Date: Nov 2018 Photos: Albums Posts: 590	That isn't the native resolution, try dividing the number of pixels by the size of the sensor and you will see that it can't be. The number your are seeing in PSE is simply a suggestion for an output resolution for making a print. It has no impact on most screen viewing applications except maybe in DTP where you want a specific image size in ppi terms. You can change it to any value you want without having any effect on the true resolution of your image. Pentax cameras have used a different default number over the years, 72 and 300 ppi, so it really doesn't matter except for very specific applications.

02-20-2020, 07:26 AM	#3
pschlute Moderator Loyal Site Supporter Join Date: Mar 2007 Location: Surrey, UK Photos: Gallery Posts: 8,212	Originally posted by Robert N I note the original image resolution, when viewing with Photoshop Elements, is 240 pixels per inch In addition to the excellent answer above I would add the following: If you view an image on any electronic device the pixels per inch (ppi) number is mostly irrelevant. Your K3 will produce an image at 6000x4000 pixels. If you view that on a screen the graphics software of your computer or tablet will take care of displaying it correctly depending on your screen resolution. When you wish to print an image the ppi number is relevant. but it is a number that can be changed at will. So for example, if you want to print at a size 12" x 8", and the print lab says it wants images at 300 ppi you can do the maths....... 12x300 = 3600 8x300 = 2400. So you need to downsize your image from 6000x4000 pixels to 3600x2400 pixels. The print size; ppi number; and pixel resolution of your image are three sides of the same equation.... print size x ppi equals the resolution.

02-20-2020, 07:37 AM	#4
normhead Pentaxian Join Date: Jun 2007 Location: Near Algonquin Park Photos: Gallery \| Albums Posts: 40,451	When submitting work for prints, as far as I can tell the output size, 240, 300 whatever is ignored. If I accidentally leave the out put DPI at 72 they still print at the 200-300 dpi I set as my target. They fit the image I send them into the size I ask for, what ever DPI that turns out to be.

02-20-2020, 08:23 AM	#5
pschlute Moderator Loyal Site Supporter Join Date: Mar 2007 Location: Surrey, UK Photos: Gallery Posts: 8,212	Originally posted by normhead When submitting work for prints, as far as I can tell the output size, 240, 300 whatever is ignored. If I accidentally leave the out put DPI at 72 they still print at the 200-300 dpi I set as my target. They fit the image I send them into the size I ask for, what ever DPI that turns out to be. The main thing is to have the pixel resolution of your image correct. in the example I gave above if you send an image file to a lab that has been correctly resized to 3600x2400 pixels, and you have told them to print at 12x8 inches, then your image will be printed at 300 ppi. it is a simple question of maths. The ppi cannot be anything other than 300. It is always best to resize your image to the correct pixel resolution rather than relying on their software to downsample your image.

02-20-2020, 09:05 AM	#6
normhead Pentaxian Join Date: Jun 2007 Location: Near Algonquin Park Photos: Gallery \| Albums Posts: 40,451	Originally posted by pschlute The main thing is to have the pixel resolution of your image correct. in the example I gave above if you send an image file to a lab that has been correctly resized to 3600x2400 pixels, and you have told them to print at 12x8 inches, then your image will be printed at 300 ppi. it is a simple question of maths. The ppi cannot be anything other than 300. It is always best to resize your image to the correct pixel resolution rather than relying on their software to downsample your image. Or upsample as well. I often expand 120 DPI, to 300 or 360 DPI before sending it out for printing. Modern printers just look better printed at the printers optimum resolution, whether or not it is the native resolution.

02-20-2020, 10:37 AM	#7
pschlute Moderator Loyal Site Supporter Join Date: Mar 2007 Location: Surrey, UK Photos: Gallery Posts: 8,212	Originally posted by normhead Or upsample as well. I often expand 120 DPI, to 300 or 360 DPI before sending it out for printing DPI is an output term relating to printers, dots per inch. Not the same as the input parameter PPI , pixels per inch. Changing the PPI of an image in software is not necessarily upsampling/downsampling. For example in Photoshop if you change the PPI and do not have the resample tickbox checked you are simply changing the document physical size (inches or cm), and not changing the number of pixels in the image.