I used to carry my DSLR with me most of the time. You never know when you will see something that needs to be captured.
Since they improved the camera on my iphone, I have carried my “real” camera less. I figured that I had a reasonable camera just in case. But I have wondered how big a difference it made to use a DSLR instead of my phone.
One evening I had a chance to find out. I had already put my DSLR back in the studio towards the end of a party we were having. My wife came running up to tell me that I had to take a picture of this cute scene of a young child sleeping with her Etch-a-sketch. At first I said no, since I had already put the DSLR away. But then I realized that I had an option: the iPhone in my pocket. I went over to the girl (it really was a cute scene) and captured an image with the phone.
Then, since she wasn't going anywhere soon, I figured I would go get the big camera and capture the scene again. Now I had two images of the same scene: one taken with the phone, one taken with the DSLR. I could do the comparison that I had wondered about.
Here are the two images to the left.
The images were cropped, to make the aspect similar.
Each image was tweaked in Lightroom, to bring the best out of them.
Can you tell which is from the phone?
They were both taken of the same scene, and have similar framing. But they have a different perspective. This is due to the different lenses.
In case you are having any trouble figuring it out, let me show you close ups from the two images, with equal pixels:
The diffences in the two close ups would show up if you made prints any larger than a snapshot.
Obviously the top image in each pair was taken with the iPhone. The DSLR image just had more pixels to work with. That gives you smoother tonal changes and better detail. The iPhone image is much grainier, but that might be due to my lighting choices. I avoid using the flash on the iPhone. The flash is so close to the lens that it creates very flat images. With the DSLR I used a flash pointed away from the subject, with a diffuser. This is why the shadow side of her face is not as dark. With less light the phone also had to use a high ISO (sensitivity) than it would have liked. This would cause more graininess.
However the ISO on the phone was much lower than the DSLR (1000 vs. 3200).
Another factor that causes grain is the size of each receptor on the sensor. The receptors on the iPhone are sub-miniature compared to the receptors on the full-frame DSLR I used.
In conclusion: if the images are only going to be used online (blog, facebook, etc.), the iPhone is probably fine. And the iPhone is certainly better than nothing (see The Best Camera ).
However if I want quality images, that are more flexible, I should still carry my DSLR.