Exporting to a Higher Megapixel

[deepm99383774]

Hi Friends,

I exported images at 300DPI and 100 resolution on Lightoom Classic. After editing dozens of photos for my canvas prints, I realized I forgot to set the megapixels as needed to ensure best quality.

Therefore, I uploaded the 300DPI/100 'edited version' photos again and exported them at the correct megapixels. I compared post-edit photos from the original export (300DPI and 100 resolution) with post-edit photos with the correct megapixesl (300 DIP, 100 resolution, 87 megapixels) by zooming in on my computer and I could not see any difference.

I plan to use the the correct megaxpixels version to avoid having to edit the photos all over again. Should I be ok, or do you suggest editing the photos over again and exporting them at the right megapixels from the start to ensure the canvas prints (36x24) look good. 

The only thing I know for sure, is that there was slightly more memory used for the second post-edit option, as I was uploading essential 4 photos (each photo had 4 photos around it to enable me to make a mirror wrap canvas prints). Therefore doing it all over again, editing one photo without 4 images around it, would save me memory.

I am tempted to order two of the same canvas prints with both post-edit versions to see if I can tell of any difference.

Any help appreciated.

Thank you,

Deep Matharu

[Chuck Uebele]

It's not the PPI (Pixels per inch) that matters, but the actual pixel dimension. PPI is relative. You could have a 100 PPI image that has the same pixel dimension of a 300 PPI image. Is there any difference in the total pixel dimension of the images that you're importing? 

[JJMack]

It is the number of Pixes and the quality of the pixels that determine Image quality.  If you 24 million pixels from a high quality digital camera with a high quality lens that was not focus well. You have 24 million poor quality pixels.   I you have a 1MP camera  and it well focus and a good exposure you have a high quality 1mp image.  If you  interpolate the 1MP image to a 24MP image you will loose some image quality for the image was interpolated from a 1MP image by a computer.  The poorer 24MP image quality will still have a higher quality then  the out of focus 24MP image from the good camera.

[deepm99383774]

Thanks guys! My NikonD610 shoots at 24Megapixels. I uploaded the image at this resolution, then exported it without adjusting megapixels. 

Realizing a 36x24 requires a higher megapixel count, I uploaded the edited 24megapixels (based on my NikonD610) so there is a difference in megapixel count. I am thinking that by uploading my original exports (24 megapixels), and exporting it again with a higher megapixel (78 megapixels) I should be ok.

Only real way of knowing for personal satisfaction is ordering two of the same prints. 

[JJMack]

Why does  36x24 requires a higher megapixel count.  Higher than how many MP.  What is required most of all are high quality pixels.  A Billion poor pixel will be a poor image.  Large image need high quality pixels and so do small image.  A Small image may require more pixels then large picture because you view small images closer than you view large images.   If you have a 16MP camera like it do and do not crop one.  If you print a 6" x 9" it will print at 816PPI resolution my printer can do that my eyes can not do that but they will see a A Great Sharp  6"x9" picture because I took it.  If I print it 20"x30" it will be printed  at 163PPI but my printer can not do that it can only print up to 13"x19" If it could the image would most likely look good to my eye after all they will become  80 year old this year.  The 13"x19" print will have a 257ppi the image will be great to my eyes.

It like watching Netflix 8 MP 4K content on your small Google Pixelbook Go display look great and the same 8MP Content looks good on the 70" 4K TV hanging on the wall across the room.  Your eyes can not see the individual pixels on either. However if you get a foot away from the 70" 4K TV you will be able to see its larger pixels. The 70" TV image has a 62PPI resolution the Google device ppi is over 300ppi.. If you are young with good eyes if you hold the google devixe 2" or 3" frorm your eyes you may be able to see its pixels. You still will need some visual aid to see the red, green and blue components of the pixels