I thought it would be fun to run the same tests on the new Pi cameras that I did on the original one back in May 2013. Unfortunately my first Pi camera 2.1 was faulty so I had to wait an extra day before I could do it. (It’s the first time out of about 50 Raspberry Pi products that I have ever had a faulty one.) But now here are the results. I’ve compared both 2.1 cameras with both 1.3 Raspberry Pi cameras.
I shot the scene out of an open window, trying to get all three cars and their registration plates into view. All four cameras were used, one after the other as quickly as I could swap them over. The latest camera software was used in the default maximum resolution for each camera. I had to do some vertical and horizontal flipping, depending on which camera I was using.
The idea was to try and get the same conditions for each shot. It was partially cloudy though, so not ideal weather. But what we have serves the purpose for a quick comparison. The 2.1 shots are larger because they are 8 Megapixels vs the 1.3’s 5 Megapixels. You can click the image to get a 1500px version…
Wider Field Of View – Bit Less Exposure
The Pi camera 2.1 seems to give a nice colour balance compared to 1.3, but this shot appears a little dark and underexposed. It may be because of the wider field of view and more sky in the shot. Auto-exposure is a bit of a black art. It will be interesting to see what happens in other scenes and lighting conditions.
This seems to be consistent as we got the same difference between the NOIR versions too. This is hardly surprising since they’re the same cameras without IR filter. But it gives us a nice cross-check.
I also shot the scene with my Nikon D90 on an auto mode (aperture priority at f/8) to compare. I normally shoot exclusively in manual mode with this camera but thought it would make an interesting comparison. Obviously the sharpness of a £400 DSLR is in a completely different league, but it gave an exposure result in between the two Pi camera models…
What About Resolving Power At Distance?
When I tested the Pi camera 1.3 it was capable of resolving a car registration plate across the street. Fortunately my neighbour hasn’t changed vehicles since then, so I thought I’d do the same again. That’s the reason for the choice of shot – not because the view out of the window is particularly fabulous.
So here I’ve cropped in on the parts containing the three cars. You can click the image for the 1500px version…
If you want the full resolution (6 MB) version, click here.
Now Let’s Zoom Right In to 200%
To make it easier to compare resolving power, I’ve gathered together and enlarged the registration plates to 200%. If you click the following image you’ll get the full-size version…
In the above less magnified shot, the Pi camera 1.3 looks a little clearer. If you click the above photo to go to the fully magnified shot, you’ll see that the newer Pi camera has slightly more resolution. The 1.3 camera looks a little “blocky” for the first registration plate. It’s similar for the middle one, but the one on the right is not very sharp on the newer camera. For that one, the older camera is noticeably clearer. Some lenses perform better around the periphery than others. It looks as if the 1.3 has a slight edge here on ‘peripheral vision’.
Both the NOIR cameras were a little less sharp on the registration plates compared to their IR-filtered couterparts. I imagine this is the ‘nature of the beast’ and is due to the IR hitting the sensor.
Lots More Testing To Do
This is just one use-case and one set of lighting conditions. There’s a lot more playing to be done. I look forward to seeing the output from other people’s cameras.