Q&A: RAW files & DPI - Eric Girouard Photography

Q&A: RAW files & DPI

Question

"I am trying to figure out why I always get only 72dpi photos, even when importing RAW files. Is there any camera which gives not standard 72dpi but 300dpi?"

Answer

When you import a RAW file, the dpi number is irrelevant. In fact, a RAW file - by definition - has not yet been demosaicized and rasterized into the grid of pixels we know as a digital image.

What matters is that the full 6000px X 4000px (for a 24mp sensor, ie Fujifilm X-T2 or Nikon D750, etc) is available to you.

You can choose to spread those pixels across more or less distance according to your output needs (20" at 300dpi on a 150LPI press, or 30" at 200dpi on an inkjet printer, or 300" at 20dpi for a billboard, all for example) and you are still using the full 24mp resolution of the original capture.

In Photoshop, you can go Image > Image Size - and as long as you *uncheck* the resample option - you can change the effective density per inch of the pixels without doing any modification to the file whatsoever.

Compare this screen capture with the image at the top of this article.

Notice that in both cases, the image resolution of 7302x4873 does not change. With the "resample" box unchecked, you can vary the density of the pixels (the "dots" per linear inch) without affecting the original data.

In other words, the resolution displayed during the process of importing a RAW file into an editor such as Photoshop is completely arbitrary.

As you can see in these screen captures taken from the Adobe Camera RAW import module, your preference of pixel density can be defined in the settings.


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