Every once in awhile I like to remind myself of a few things. Right now I am thinking about the benefit of MP and how many MP I need, with a nearly confirmed rumor of a R5 with 40-45 MP, a R6 with 20 MP, the 1DX III with 20.2 MP and the rumored "high MP" camera that is potentially 82 MP. Of course, that is just Canon. Sony and Nikon are sporting 40-65 MP in their current cameras. Fuji just released a 100 MP "medium" format camera.
But there are a lot of people talking about all the MPs and needed more MP. Yet, I recall doing the math when I bought my first DSLR, the Canon 7D, and concluding it was time to invest in a DSLR as that was enough resolution at 18 MP.
Being an engineer, I like numbers....so here is a table I put together this morning....
| Camera |
Megapixels |
Horizontal Pixels |
Vertical Pixels |
Horizontal PPI at 24 inches |
Vertical PPI at 24 inches |
Horizontal inches at 150 ppi |
Vertical inches at 150 ppi |
Horizontal inches at 300 ppi |
Vertical inches at 300 ppi |
|
|
|
| 5DIII |
22.3 |
5760 |
3840 |
240 |
160 |
38.4 |
25.6 |
19.2 |
12.8 |
|
|
|
| 5DIV |
30.4 |
6720 |
4480 |
280 |
187 |
44.8 |
29.9 |
22.4 |
14.9 |
|
|
|
| 1DX III |
20.2 |
5472 |
3648 |
228 |
152 |
36.5 |
24.3 |
18.2 |
12.2 |
|
|
|
| Rumored R5 |
45 |
8208 |
5472 |
342 |
228 |
54.7 |
36.5 |
27.4 |
18.2 |
|
|
|
| Rumored High MP |
82.7 |
11136 |
7424 |
464 |
309 |
74.2 |
49.5 |
37.1 |
24.7 |
|
|
|
| 7D |
18 |
5184 |
3456 |
216 |
144 |
34.6 |
23.0 |
17.3 |
11.5 |
|
|
|
| M3 |
24.2 |
6000 |
4000 |
250 |
167 |
40.0 |
26.7 |
20.0 |
13.3 |
|
|
|
| M6 II |
32.5 |
6960 |
4640 |
290 |
193 |
46.4 |
30.9 |
23.2 |
15.5 |
|
|
|
| G7X II |
20 |
5472 |
3648 |
228 |
152 |
36.5 |
24.3 |
18.2 |
12.2 |
|
|
|
I picked a few of the metrics as:
The largest print in my house is 24 in x 16 in. I have images up of that size shot with the 7D, 5DIII, and 5DIV. As far as I am concerned, they all look good. Maybe the images shot with the 5DIII/IV are a bit better, but I was also shooting with better lenses by that time.
I've always heard/read that at normal viewing distances, the human eye can start to discern ~75-150 dots per inch resolution. So, I went with 150 ppi (and yes, I am assuming DPI = to pixels per inch (ppi)).
Then, at least at one point, it was common for magazines to require images at 300 ppi. Maybe because of this, I've always heard 300 dpi/ppi regarded as the higher end standard.
So, given all that, you can see how the cameras stack up. My old 7D was greater than 150 dpi for the 24x16 prints I have up. The 5DIV is just short of 300 dpi/ppi (280 ppi) for a 24 x 16 inch prints.
So, do I really need more than my 5DIV for printing? I am thinking no. Even if I wanted to go really large, I could use my current 30.4 MP sensor and print up to 44.8 x 29.9 inches and still be at the 150 ppi threshold. I do, at some point, want to do a multiple frame image on a wall, you know, three prints that when combined show the whole image. I've always assumed I would do a panorama and stitch together an image for that, which would be much higher resolution. Looking at this, I might not have too.
So, other than getting caught up in a "Megapixel War" what are more megapixels good for? The thing I keep coming back too is cropping. I do not crop much for my family photos. I do not crop much for my landscape photos (sometimes just to reframe a bit). But, for wildlife that is not close...which does happen, I crop. Sometimes, I crop a lot. Could I use more resolution for wildlife? Sure...always. But, I am finding the 5DIV really has been sufficient for any print that I've made. Also, the more pixels on target you have, the better the technique you need, etc. Just because you have the pixels doesn't mean you'll see the benefit.
The next thought going through my mind, is if I am cropping for wildlife, do I really need FF? Really, it is pixels on target. For example, I scaled up the M6 II's 32.5 MP sensor to get the 82.7 MP sensor size for the "rumored high MP" sensor. But, in terms of pixel density, they are the same. In terms of pixels on target if I am cropping by 1.6x or greater, they are the same. If you think about it, taking a 500 mm f/4 lens on a FF 82.7 MP sensor and crop it down to 32.5 MP, it will even have the same bokeh and same resolution as that same 500 f/4 lens mounted on the M6 II. By cropping, you loose the benefit of FF. So, I am beginning to see the rational of why several wildlife photographers who are constantly distance challenged prefer crop sensor cameras. Granted, if you aren't distance challenge....FF.
As for the argument I've heard that more MP "is just memory and memory is cheap." Yeah, but it is also slower processing time (probably the biggest issue). Your cards fill up faster and I am typically keeping 6,000 to 10,000 images per year. That memory adds up to typically 250 to 450 GB including the jpgs I create. Backups take longer and I have to buy drives more frequently, etc.
Anyways...just some random thoughts as some evening plans got messed up. Of course, I would be interested in anyone else's thoughts on this.
Thanks,
Brant
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