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camdude
camdude
Known Participant
April 24, 2019
Answered

Tiffs to dng.

  • April 24, 2019
  • 1 reply
  • 1186 views

Question...I have a bunch of images taken with my iPhone, I exported as tiffs for backup purposes. I also have a bunch of raw files. I like to convert to dng simply because of the sidecar file thats associated with raw files. In camera raw I can save and export these tiffs as dngs. the tiff files now are at 72ppi. Can I leave it at 72 or do I have to increase the ppi for export as dng? I want to maintain that quality and make them non destructive so whats the best way?

Thanks

[Moved from the (mostly defunct) Photography forum and into a Camera RAW forum - moderator]

This topic has been closed for replies.
Correct answer Conrad_C

What's important is whether the original pixel dimensions (width and height in pixels) are preserved. For example, if the originals were 4000x3000 pixels, and these 72ppi TIFFs are still 4000x3000 pixels, everything is fine, you have all 12 million pixels either way. The 72 ppi value will naturally increase if resized (without resampling) for print; for example, a 4000x3000 image becomes 400 ppi when sized to 10 inches high (because 4000/10 is 400).

The only time you lose pixels with ppi is if the image is resampled to fewer pixels. For example, when you exported the TIFFs, if you specified a small physical dimension like 8 inches wide at 72 ppi, 8*72 plus 6*72 is only 1008 pixels (that is, only 1008 of the original 12 million pixels are left).

In Adobe Bridge, check the width and height in pixels. If the TIFF is the same number of pixels as the original, nothing has been lost so far. When saving to DNG from Camera Raw, you don't get to specify a ppi value, so by default you won't lose any pixels.*

*unless you select the Lossy Compression option and manually limit the pixel dimensions

1 reply

Conrad_C
Community Expert
Conrad_CCommunity ExpertCorrect answer
Community Expert
April 25, 2019

What's important is whether the original pixel dimensions (width and height in pixels) are preserved. For example, if the originals were 4000x3000 pixels, and these 72ppi TIFFs are still 4000x3000 pixels, everything is fine, you have all 12 million pixels either way. The 72 ppi value will naturally increase if resized (without resampling) for print; for example, a 4000x3000 image becomes 400 ppi when sized to 10 inches high (because 4000/10 is 400).

The only time you lose pixels with ppi is if the image is resampled to fewer pixels. For example, when you exported the TIFFs, if you specified a small physical dimension like 8 inches wide at 72 ppi, 8*72 plus 6*72 is only 1008 pixels (that is, only 1008 of the original 12 million pixels are left).

In Adobe Bridge, check the width and height in pixels. If the TIFF is the same number of pixels as the original, nothing has been lost so far. When saving to DNG from Camera Raw, you don't get to specify a ppi value, so by default you won't lose any pixels.*

*unless you select the Lossy Compression option and manually limit the pixel dimensions

camdude
camdudeAuthor
Known Participant
April 25, 2019

ive tried it, it works with using camera raw, but preview nor the finder will let me see the thumbnails..I guess a better question would be what free iPhone 8 camera app can I use that captures raw files, I know there are some and some don’t allow for zooming in

Conrad_C
Community Expert
Conrad_CCommunity Expert
Community Expert
April 25, 2019

camdude  wrote

what free iPhone 8 camera app can I use that captures raw files

There are several apps that do, but I don't know which ones are free. Because the app that I use to shoot raw photos on my iPhone is Lightroom, which is "free" in that it's included with the Creative Cloud membership (which I assume you have since you're using Camera Raw).

Shoot and edit Adobe raw DNG photos with Lightroom CC for mobile - Adobe.com

Of course the big benefit is that all photos shot with the Lightroom camera app sync straight to my desktop. I set Lightroom Classic preferences so that Lightroom phone DNGs merge into the same folders as the raw files from my main cameras.

The trick to shooting quickly with it is to add the Lightroom app widget to the iPhone lock screen, so that the camera can be opened in one tap from a locked phone.

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