These following images stem from an Youtube Discussion on one of my videos where I was being accused of ‘lying’ and being a ‘horrible’ teacher, to which I take issue.
This is a quick and dirty comparison of the DOF between the Canon 5Diii and the iPhone 5, specifically to demonstrate the image differences between a full frame sensor and a teeny tiny sensor (iPhone), trying to keep all other variables to be somewhat comparable.
Some will argue that quick and dirty is never good, I beg to differ; I try to do quick and dirty before investing a lot of time and effort into “thorough and clean” and in the past this has answered and prevented many problems in deeper testing.
The effective focal length on both cameras are about the same ~35mm. (There is an important distinction between ‘actual’ focal length and ‘effective’ focal length’, but most commonly effective focal length is accepted as what we are talking about)
While the ISO and Shutter Speeds are different, this shouldn’t play into DOF too much. The aperture on the iPhone is 2.4 and the 5Diii is actually 2.8, which should actually result in a deeper DOF than 2.4. Both shots were taken from the same chair, at very close to the same distance. An important note is that actual file size and resolution of the 5Diii is much larger at 22MP.
What do you see? What can explain this?These following images stem from an Youtube Discussion on one of my videos where I was being accused of ‘lying’ and being a ‘horrible’ teacher, to which I take issue.
This is a quick and dirty comparison of the DOF between the Canon 5Diii and the iPhone 5, specifically to demonstrate the image differences between a full frame sensor and a teeny tiny sensor (iPhone), trying to keep all other variables to be somewhat comparable.
Some will argue that quick and dirty is never good, I beg to differ; I try to do quick and dirty before investing a lot of time and effort into “thorough and clean” and in the past this has answered and prevented many problems in deeper testing.
The effective focal length on both cameras are about the same ~35mm. (There is an important distinction between ‘actual’ focal length and ‘effective’ focal length’, but most commonly effective focal length is accepted as what we are talking about)
While the ISO and Shutter Speeds are different, this shouldn’t play into DOF too much. The aperture on the iPhone is 2.4 and the 5Diii is actually 2.8, which should actually result in a deeper DOF than 2.4. Both shots were taken from the same chair, at very close to the same distance. An important note is that actual file size and resolution of the 5Diii is much larger at 22MP.
What do you see? What can explain this?Anyway, if anyone thinks I am completely crazy or wrong, I sure would love to see you get that same 2.8 DOF with an iPhone that I did with my 5Diii above.
I could be wrong, just having a hard time wrapping my mind around the images above if DOF is always the same between all sensor sizes, all things being equal, which I have disagreed with.
What do you think? Should I do a more clean and thorough test? Maybe a video?
I hope this demonstrates my position from a “ practical , actually shooting position” in creating an image, not from the perspective of “hey lets just argue for the sake of it.”
Of course sensor size matters. I think you are absolutely right, Michael. Sensor size does make a big difference where depth of field is concerned. That is why most tiny sensor, compact digital cameras with "fast lenses" cannot achieve bokeh (background blur) that DSLR APS-C or full frame sensor cameras can achieve with fast lenses. The person who called you a liar obviously does not understand the mechanics of cameras and lenses. I can tell by your teaching that you are a man of integrity, and I’m sorry you had to be subjected to that.
Kind regards,
Clinton
Sensor size definitively play a role in DOF. Don’t waste time on that sort of argument. Instead, suggest the person to read the book "Science for the Curious Photographer", amongst others… I have seen a video where an individual goes as far as using the crop factor to multiply the aperture as well, for an equivalence in DOF. While that does sound weird (I am not sure I actually agree with it 100%), it points into the right direction, as an iPhone "crop factor" would play a major role in changing the "effective DOF", or "similar bokeh". If you want a pointer to such video send me an email (I thought that it would be inappropriate to post a link here).