When screens are adjusted so as to crop the image does this also cut down on the number of pixels
Apr 6, 2022 21:39:39 #
cyclespeed
Loc: Calgary, Alberta Canada
I just realized I can place 2 digits on the screen of my iPhone and crop down on a subject. If later I'd like to get an enlarged print will it be as "digitally dense" as compared to the same image taken from a closer perspective and thus not needing to be cropped on the iPhone screen when the image was captured?
I hope this makes sense. I'm sure there are correct terms I am unable to use at this time.
To those who reply, thank you for your response.
I hope this makes sense. I'm sure there are correct terms I am unable to use at this time.
To those who reply, thank you for your response.
Apr 6, 2022 21:55:12 #
Yes cropping as you describe eliminates part of the image.
The iPhone tells you the size of the image in bytes before you send it and I just now did this experiment using my phone.
(1) original image 6.3 MB
(2) after cropping the image 454 kB
You can try it yourself. Crop it then mail it to yourself. You will see the size.
The iPhone tells you the size of the image in bytes before you send it and I just now did this experiment using my phone.
(1) original image 6.3 MB
(2) after cropping the image 454 kB
You can try it yourself. Crop it then mail it to yourself. You will see the size.
Apr 6, 2022 22:11:11 #
If you start out with a 24 Mpx image and you crop 50%, you end up with an image size of 12 Mpx. If you crop you are removing some of the image.
Be careful about image size vs file size. You can have the same image size, but due to jpg compression can have different file sizes.
Be careful about image size vs file size. You can have the same image size, but due to jpg compression can have different file sizes.
Apr 6, 2022 23:36:06 #
cyclespeed wrote:
I just realized I can place 2 digits on the screen of my iPhone and crop down on a subject. If later I'd like to get an enlarged print will it be as "digitally dense" as compared to the same image taken from a closer perspective and thus not needing to be cropped on the iPhone screen when the image was captured?
I hope this makes sense. I'm sure there are correct terms I am unable to use at this time.
To those who reply, thank you for your response.
I hope this makes sense. I'm sure there are correct terms I am unable to use at this time.
To those who reply, thank you for your response.
The Specs for your particular phone will tell you what's happening. The latest Iphone has 12 megapixel resolution. Optical zooming (3X on the latest iphone) doesn't reduce the resolution but digital zoom does.
Apr 7, 2022 20:49:25 #
After rereading your post, I realized that while my original response is correct, it didn't really address your question. I'm interpreting your question as "will I get better results if I crop in-camera vs crop post-processing, using an iPhone." So here's a more detailed response WRT an iPhone 12 Pro. Results may be different using earlier models.
First, whether you shoot at an optical zoom of 1x or 2.5x, the image size will be 4032x3024px. However, when you zoom past 2.5x you're now digitally zooming the camera, but the image size remains the same at 4032x3024px also. Having the same image size in all cases was a surprise. The digital zoom was at a lower resolution, as expected.
So, the next question is whether the in-camera digital zoom was any different than cropping in post-processing. Again, I was pleasantly surprised. It turns out that the in-camera digital zoom was significantly better than just cropping in post-processing.
The following images show the results of a simple experiment demonstrating those results. The first image is an image taken at 1x (the background was manually blurred but the book image is original). The second image is an in-camera zoom on a part of the book taken at the same distance as image 1. The third image was created by cropping the first image to the same zoom as the second image. As you can see, the in-camera results are significantly better. Just an example of computational photography at work. I suspect that it is using a combination of the main lens and the telephoto lens working together to increase the digitally zoomed resolution.
Hope this explanation helps answer your question.
First, whether you shoot at an optical zoom of 1x or 2.5x, the image size will be 4032x3024px. However, when you zoom past 2.5x you're now digitally zooming the camera, but the image size remains the same at 4032x3024px also. Having the same image size in all cases was a surprise. The digital zoom was at a lower resolution, as expected.
So, the next question is whether the in-camera digital zoom was any different than cropping in post-processing. Again, I was pleasantly surprised. It turns out that the in-camera digital zoom was significantly better than just cropping in post-processing.
The following images show the results of a simple experiment demonstrating those results. The first image is an image taken at 1x (the background was manually blurred but the book image is original). The second image is an in-camera zoom on a part of the book taken at the same distance as image 1. The third image was created by cropping the first image to the same zoom as the second image. As you can see, the in-camera results are significantly better. Just an example of computational photography at work. I suspect that it is using a combination of the main lens and the telephoto lens working together to increase the digitally zoomed resolution.
Hope this explanation helps answer your question.
Image 1 - shot at 1x
(Download)
Image 2 - digitally zoomed in-camera. Note the image size.
(Download)
Image 3 - Cropped (zoomed) from image 1 in post-processing (using PS)
(Download)
Apr 8, 2022 11:00:13 #
Oh my, cyclespeed.... am I embarrassed. I made a very amateurish mistake using photoshop in my previous post that may have lead you astray. While adjusting the crop of the 1x image I failed to set the layer as a smart object. As I adjusted the crop multiple times, the crop degraded due to photoshop, not the camera.
Here is a revised example. There seems to be degradation in just cropping in post-processing vs in-camera but the difference is much smaller that my previous example.
My apologies.
Here is a revised example. There seems to be degradation in just cropping in post-processing vs in-camera but the difference is much smaller that my previous example.
My apologies.
Apr 8, 2022 11:24:59 #
cyclespeed
Loc: Calgary, Alberta Canada
Thanks very much. Here is what I came away with from these replies.
1. Check your phone to know if it physically adjusts the zoom or is it all done digitally.
2. I can now see my phone has no change possible except digitally.
3. I will look into newer phones to see what zoom range physically speaking is available now.
I own a iPhone 6 btw.
1. Check your phone to know if it physically adjusts the zoom or is it all done digitally.
2. I can now see my phone has no change possible except digitally.
3. I will look into newer phones to see what zoom range physically speaking is available now.
I own a iPhone 6 btw.
Apr 8, 2022 11:51:28 #
cyclespeed wrote:
Thanks very much. Here is what I came away with from these replies.
1. Check your phone to know if it physically adjusts the zoom or is it all done digitally.
2. I can now see my phone has no change possible except digitally.
3. I will look into newer phones to see what zoom range physically speaking is available now.
I own a iPhone 6 btw.
1. Check your phone to know if it physically adjusts the zoom or is it all done digitally.
2. I can now see my phone has no change possible except digitally.
3. I will look into newer phones to see what zoom range physically speaking is available now.
I own a iPhone 6 btw.
The “6” definitely does not have optical zoom.
Another option to consider is an accessory telephoto lens that clips on to the phone. Companies make them. I have no experience with them but in theory it seems like it should work.
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