Today, I would like to talk about cameras and how to determine the 'best' one. In the photography world, fires blaze across the Internets regarding this issue for years. I want to share our opinions of the matter and a little bit on how it impacts a drone user.
Full frame? APS-C? M4/3?
What are these terms? They are actually names of the different sensor sizes as illustrated below.
With aggressive marketing by camera companies, Full-frame (FF) cameras are considered the 'best' by consumers and some professionals due to their large size*.
So bigger is better right?
Mostly true - the larger the sensor, generally the better the image quality of your pictures. But whenever a potential client comes and asks : "do you carry Kawnon 5Dee?" I groan a little inside.
Why? do you like being mediocre and use mediocre cameras? You might ask me. We shall return to this insult!
Firstly, what is image quality? This question dangerously begs very technical nerd-speak which is required to fully understand the concept of "image quality", which I would like to avoid.
Perhaps the most important thing to most when evaluating a camera/sensor is the ability of it to resolve fine detail - or sharpness.
More megapixels, more detail? well yes and no. If you stuff 50 megapixels onto a smaller sensor, the quality of those pixels suffer. As the pixels (photosites) are smaller, the amount of light captured by each gets less, resulting in 'lousy pixels'.
So a FF with 50 megapixels is better than a APS-C with 50 megapixels? Well...generally, if you are using similar behaving lenses, yes**.
Lets compare an example of 2 cameras with differing sensor sizes in the flesh. One picture is by an APS-C , and another is by a M4/3. This is hardly a consistent or a scientifically controlled test, but it is illustrative enough.
Click on them to get higher res samples.
Can you tell which is better or the bigger sensor? Even I, who took the pictures, had to actually had check the images to find out which is which.
Well some of you perceptive ones may have clicked on the link, zoomed in to 100% and found an image that seems a hair sharper, Aha! that must be the bigger sensor one.
No. Sorry. Actually the very slightly sharper one is the M4/3 (smaller one) because there is a better lens attached to it.***
ANS: The top one is the APS-C, bottom M4/3.
Scratch head! Another variable thrown in the mix, lens quality! The point in this exercise is to demonstrate that most people won't be able to discern the difference of sensor sizes in most conditions, and sensor size is hardly the end-all answer in the chase of image quality.
But at this point, I will wrap things up, although truly we haven't got past the tip of the iceberg, lets avoid that slippery slope.
But want to learn more? This is a great link - PhotographyLife
Summing it up
We at Avetics can carry Full-frame cameras, and I personally have no objection to using one per-se, but it is important to qualify why one has to use it.
What is the end purpose? People have requested for Full-frame cameras, and when asked for the output, "to print on a brochure and put in website." Smack head.
It shows chasing for specification for specification's sake. As you can see with my example, for typical web use, current APS-C sensors are excellent. Even printing up to A3-A2 is good.
Even if you have a requirement to print up to a 10 meter billboard, you still have to ask yourself - what do I want?
If you want deep detail for a viewer to put his face right up against picture to view its intricacies, such as individual leaves on a branch of a tree. Then yes, perhaps you need a big megapixel Full-frame.
But even when printing large, there are heated debates on the merits of big megapixel FFs. Some argue that people don't naturally put their faces right up into a picture to view it, and once you step back to the proper viewing distance to appreciate the big picture, smaller sensors can deliver.
Case in point: Have you noticed those wonderful "Shot on iPhone 6" images on the sides of buildings?
Impressive right? That's from an even smaller sensor than FF/APS-C/M43 ! Bin these cameras then! Viva la iPhone!
Wait, this is because you are viewing them from very very afar - think distance of sidewalk (where you are standing) to the picture (high up on the side of a building). At that distance, your brain cannot discern the individual pixels.
There is a reason those uber-large pictures are mounted in places you can't walk right up to. If you could, you would probably find the individual pixels are as big as your face. Up close, the illusion fails and the picture won't look so good.
But there is nothing wrong with that! The importance is being able to articulate what you want out of the image. As brilliantly illustrated by Apple, even large prints can be carried out by small cameras of course - given the condition of viewing distance.
So how does this all relate to drones? Why not just carry the big cameras and be done with it?
Well with bigger sensors, comes bigger lenses, it is something that cannot be avoided due to physical limitations.
The weight differences between even the Sony A7R - one of the smallest in the market for the FF sensor - and its smaller A5100 APS-C Sony stablemate is significant. We are talking about a factor of more than x2 weight difference as a package.
Why is this important? Well, more weight = less flight time = less buffer time for safety.
Not to mention an FF camera is potentially a bigger rock that might fall on someone's head if Murphy imposes his law.
Safety first friends.
In the end it is all subjective and personal - the question is : what level of image quality is acceptable to you?
My personal preference is to use APS-C sized cameras, as I feel it hits the sweet spot in size to weight ratio for drone use. Improvements in image processing from smaller sensors has come to the point I feel there is no discernible difference between APS-C and FF in most common uses.
There are situations I would recommend a Full-frame, such as night photography, as FF cameras generally have better low-light performance.
But in bright daylight I won't even hesitate using 1" sensors (even smaller than M4/3!) such as Sony's RX100 models. But personally- no lower than that, as I feel poor image issues start to come apparent. ie GoPro photographs - its supposed to be a video camera anyway.
But the end of the day it is about understanding that different sensor sizes and cameras are different tools. Just find the right one for your needs.
*There are bigger sensors, such as Medium format - but they are expensive, huge, and clunky. Usually, Medium format requires more deliberate operation and been relegated it to mostly studio work - so far.
**Although dense megapixel smaller sensors can actually be beneficial - especially regarding sports with speed/pixel pitch when printing/and reach, but lets not go there, as this does not relate to typical drone operations.
*** The APS-C also has more megapixels, some would argue, that if the M4/3 camera was forced enlarged to match the APS-C in photoshop, it would then lose. I feel this is not realistic comparison, as again it comes back to the end-use of the camera.