topic Re: Canon PowerShot SX70 HS in Point & Shoot Digital Cameras

PowerShot SX70 HS Photos at 72 dpi

SHLiung — Wed, 02 Aug 2023 13:04:58 GMT

I selected the highest quality for photographing, which is, 5184 x 3888 px

Why are all the photos taken in only 72 dpi?

72 dpi is a poor quality.

Is this because my Canon PowerShot SX70 HS is defective?

My old Canon Powershot SX10 HS photos are in 180 dpi

My other old Canon Powershot SX40 HS photos are also in 180 dpi

So how can the greatly improved Canon Powershot SX70 HS photos be in only 72 dpi?

Please let me know whether my Canon Powershot SX70 HS camera's 72 dpi is a defect and if it needs repairing. I purchased it less than a week ago.

Re: Canon PowerShot SX70 HS

Tronhard — Wed, 02 Aug 2023 08:13:55 GMT

Hi and welcome to the forum:
Can you advise if you shoot in JPG or RAW, or both please?
Also what mode(s) do you use when shooting: M, P, Av, Tv etc.?
Are you doing any in-camera processing of the image?

As an initial suggestion, I would do a camera factory reset in case the settings have been changed prior to your shooting - refer to P233 of the Advanced user guide .
I had a series of PowerShot cameras, from the SX40 to the 60, but chose to relinquish the SX60 in favour of cameras with a bigger sensor. The SX40 had a 12MP 1/2.3" sensor that was able to (IMHO) to provide better noise control and resolution. At 20MP for such a small sensor, the camera is really pushing the boundaries of what the processor can handle, which accounts for the low DPI default for JPG images.

That said, looking at a couple of JPG images taken by the SX60HS, they do show a resolution of 180DPI. I am going through the Advanced User Guide trying to find out where to set that (since I no longer have the SX60, which has the same innards as the SX70 in this context.

Re: Canon PowerShot SX70 HS

rs-eos — Wed, 02 Aug 2023 11:57:43 GMT

Don't be concerned with DPI values embedded in images. They are only a hint that may be used in certain image workflows. Rest assured that if you've set your camera to capture the highest possible resolution, that resolution is indeed being captured.

You can always set DPI if needed later.

Example:

You want to make a 15 x 10 print at 300 dpi. You'd need a total resolution of at least 4500 x 3000 pixels of which you'd have more than enough in your images.

Re: PowerShot SX70 HS Photos at 72 dpi

kvbarkley — Wed, 02 Aug 2023 13:46:45 GMT

As Ricky said, the dpi is only a hint for programs like photoshop as to how to display the image. Canon has always used that value even though modern monitors (i.e., Apple's "Retina") have much higher resolution. What counts is the number of pixels.

Re: Canon PowerShot SX70 HS

SHLiung — Wed, 02 Aug 2023 16:42:38 GMT

After formatting my SDHC card & restoring default camera settings, the photos I took were still all in 72 dpi when shot in M mode.

All photos that were previously shot in JPG using "AUTO", "SCN" & "Panorama" modes are all in 72 dpi.

Do you think this could be a defect?

Re: Canon PowerShot SX70 HS

SHLiung — Wed, 02 Aug 2023 16:53:56 GMT

I find it hard to accept that the dpi does not matter.

Even my much OLDER Canon Powershot SX10 HS & Canon Powershot SX40 HS photos were ALL in 180 dpi. So why is Canon Powershot SX70 HS photos all in only 72 dpi? My cheaper Olympus point-and-shoot camera's 4000 x 3000 px photos are all in 312 dpi and they do look better than those Powershot SX70 HS 72 dpi photos.

Re: Canon PowerShot SX70 HS

rs-eos — Wed, 02 Aug 2023 17:30:56 GMT

Again, DPI will only matter in very specific image scenarios (I will name one near the end of this reply).

For the sake of disussion, I will use PPI interchangably with DPI (Pixels Per Inch vs Dots Per Inch). Note that this measurement specifies two units (pixels and inches).

Your camera is absolutely capturing 5184 by 3888 pixels. No matter what the capture adds in the metadata regarding PPI. It will always be those exact pixel amounts.

PPI is useful when wanting to exactly drive certain output such as prints. As I noted in my earlier example, if you needed to make a print of 15 x 10 inches at exactly 300 PPI, you would need at least 4500 by 3000 pixels (which is less resolution that your images, so all is well here).

The equations for this are:

15 inches times 300 pixels per inch = 4500 pixels (note that the inches unit cancels since the first term has inches in the numerator and second term has inches in the denominator).

Same for the other dimension (10 inches).

One very specifc scenario where PPI does drive how something is displayed is on Mac computers. Any screenshot captured prior to Retina displays were tagged with 72 PPI. Whereas screenshots captured on Macs with Retina displays are tagged with 144 PPI. This gives a hint to the display system on how large to physically make the image appear on your display.

The reality though is that while some displays may have had exactly 72 PPI in the past, actual PPI of displays now is almost anything. Software that needs to display images on a screen in a real-world size will use different values to pull that off.

Beyond these very technical scenarios, again, you don't need to concern yourself with what DPI ends up in your image metadata. If you are going to use software that relies on DPI/PPI to drive the physical size (to a print or to a screen), then adjust that value as needed.

Re: Canon PowerShot SX70 HS

kvbarkley — Wed, 02 Aug 2023 19:26:28 GMT

And my guitar amp goes to 11.

It really amounts to the same thing. Your software might *display* it at lower quality, but the number of pixels is what counts.

Re: Canon PowerShot SX70 HS

SHLiung — Thu, 03 Aug 2023 13:11:52 GMT

Thank you for explaining.

However, photographs with higher dpi will look sharper and clearer. Because the higher the dpi, the more detail a photograph would contain which results in better quality when printed or when viewed on a computer.

The original size photographs from digital cameras usually need to be resized for the web because they are in a much higher resolution or dpi.

72 dpi is used for website purposes.

I would never expect the maximum size photograph from a good bridge camera to be in only 72 dpi.

Re: Canon PowerShot SX70 HS

kvbarkley — Thu, 03 Aug 2023 13:26:14 GMT

I would not be surprised if the DPI of the flagship mirrorless ILC's is still 72 dpi, that is what my T6S puts into the exif. My iPhone, too.

The *only* place I have seen dpi matter is for the little side rulers in PhotoShop, which I ignore. If dpi affects the quality of your image, you need new software.

Re: Canon PowerShot SX70 HS

rs-eos — Thu, 03 Aug 2023 13:32:22 GMT

That is not true. Your images have the same exact resolution period. If you are viewing those images on displays with a 1:1 ratio (i.e. 1 pixel of your display is displaying exactly 1 pixel of your image), you will not see any differences in sharpness at all.

What you're describing perhaps is viewing your images on displays with physically smaller pixels. That has nothing to do with the DPI value in your image's metadata.

Re: Canon PowerShot SX70 HS

Anonymous — Thu, 03 Aug 2023 18:04:59 GMT

The DPI setting that you see in the file properties for a JPG file does not mean anything until you print the photo. In your editing software or printing software, you can change the setting to suit your needs. It does not indicate a low-resolution camera. Even my Canon 5D Mark IV, a professional camera, has 72 DPI in its JPG file properties before editing. See below:

So, your camera is fine and will produce high quality images.

Re: Canon PowerShot SX70 HS

SHLiung — Fri, 04 Aug 2023 05:01:19 GMT

I take hundreds of photos. It would be a hassle and too time-consuming to change the dpi for printing or when developing photos. If the photographs' original resolution were in 180 dpi or higher, I would not need to waste time changing its dpi.

Upsampling a photo may not improve the quality of the image or make it look sharper.

Here are the dpi properties of photos from a Canon EOS 5D Mark IV and an iPhone 14 Pro Max which I received from someone. I do not know if he changed the original dpi.

Re: Canon PowerShot SX70 HS

rs-eos — Fri, 04 Aug 2023 11:26:40 GMT

We tried. Your insistence of not accepting the facts does not invalidate said facts.

Re: Canon PowerShot SX70 HS

kvbarkley — Fri, 04 Aug 2023 13:34:54 GMT

I am not sure what you want us to do. Your camera is fine. If you want to ask Canon to always use 180 dpi for future cameras, use the "+" on the Canon USA page to send feedback.

Re: Canon PowerShot SX70 HS

Anonymous — Fri, 04 Aug 2023 15:14:55 GMT

Assuming that you don't edit or crop the photo (straight out of the camera).

In your file above, the print size would be 72" by 54" at 72 DPI if printed full size. If you print it at 4" by 3" the DPI would automatically become 1296 DPI by 1296 DPI by your printing software. If you print it at 8" by 6" the DPI would be 648 by 648 DPI. So, the smaller the print size, the larger the DPI becomes. What the camera is reporting is if you print the image at its full size, which I doubt you would do.

In summation, you don't have to do any extra steps to change the DPI. Your printing software will calculate the DPI based on what print size that you chose to print at (your paper size in other words).

If you edit your photo file and resize it to your paper size, and then save the edited file, it will show the new, higher DPI in the saved file.

See this article on Dots per Inch:

https://en.wikipedia.org/wiki/Dots_per_inch

Re: Canon PowerShot SX70 HS

SHLiung — Sat, 05 Aug 2023 12:44:36 GMT

Seeking for further clarification: If I want to develop a photograph (from 6 x 4 till 16 x 12 size) or if I wish to use the 5184 x 3888 (72 dpi) image for book publication, do I need to use a software to change the dpi to 300 dpi before printing or can I just leave it as 72 dpi?

Re: Canon PowerShot SX70 HS

SHLiung — Sat, 05 Aug 2023 12:45:38 GMT

What you have been explaining is surprising. It takes time to let all that information sink in.

Re: Canon PowerShot SX70 HS

SHLiung — Sat, 05 Aug 2023 12:48:46 GMT

Canon products are made in Japan. Would it be better to send the feedback to Canon's HQ?

Re: PowerShot SX70 HS Photos at 72 dpi

Peter — Sat, 05 Aug 2023 13:42:09 GMT

Here:

$ exiftool -Xresolution=300 -Yresolution=300 *.jpg

Or if you want to be a real pro 🙃

$ exiftool -Xresolution=1337 -Yresolution=1337 *.jpg