The Problem of Mega Pixels

I love the capabilities of modern digital cameras, especially the wonderful sensors and great lenses available. But nothing is free, and I’m not just talking about the price of the gear. Having too many mega pixels can cause problems you may not anticipate.

Resolution is wonderful

I love extreme resolution. I’m not a fanatic about it, but I really appreciate it. I have not gone to 100+ MPixel sensors yet and I don’t normally do very large panoramas. Still, I get a thrill when I zoom in to 1-to-1 and see the great detail that is there. Then when I sharpen or contrast it more and the detail pops – wow!

Having large resolution allows me to create large prints. It is a necessary thing since I do this for a living. It is also something I really like to do. I don’t think an image is complete until it is printed. For me, a print is the physical expression of the image.

All things being equal, which they seldom are, higher resolution usually leads to sharper images. I love certain images to be “crunchy” sharp with great detail. It is part of my values that I can’t get away from.

Also, larger files allow for more cropping freedom. I try not to rely on this. It is much better to compose the image the way I want it at capture time. But sometimes it cannot be avoided. Maybe the image works better in a square format, or maybe I’m only carrying a lens that goes to 70mm and I want to shoot something I can’t get close enough to. In that case I have to “zoom” in post processing by cropping the image.

Or maybe I realize later that the real interest is in a smaller part of the frame. I have to crop the image heavily to salvage it. It’s not good practice, but I admit to doing it on occasion.

For me, a great print from a well executed, high resolution file is a joy.

Resolution is a pain

On the other hand, high resolution can be a pain. It increases the cost and time of all the downstream stages.

Every time I press the shutter it drops around 60 MBytes on my memory card. That is just the raw capture. It requires CFExpress or XQD cards to keep up. They are very expensive.

As long as I can process the image in Lightroom the size stays around this, but when I step into Photoshop each image balloons to several hundred mega bytes. And that is even without adding a bunch of layers.

Did you know that a Photoshop psd file (the native Photoshop format) cannot exceed 2 GBytes? Or that a tiff file cannot exceed 4 GBytes? I have found this out the hard way. Some of my images now have to be stored as psb files, the large file format version of Photoshop’s data.

Processing and editing time goes up with pixels. I use a powerful computer with 64G RAM and very fast Thunderbolt3 disks, but it can take seconds to do a simple stroke when I am masking or burning or dodging. I have seen multi GByte files containing one or more embedded smart objects take 2 minutes just to save to disk.

And you have to get to know disks in multiples of Terabytes. If you have a disciplined backup strategy, something I am fanatical about, then there are layers and layers of them.

I have bought in to the need of powerful and expensive equipment for editing and storing my images. The biggest problem, though, is the slow editing speed. This interrupts the flow of my mental process. I don’t like waiting on the computer.

Technique

One of the unfortunate truths they seldom tell you when you are looking at a shiny new high resolution camera is that it is harder to take good pictures with it. This is partially because of the geometries you are dealing with.

A full frame sensor, by convention, is 36 x 24 mm. My Nikon Z7 places 8256 x 5504 pixels in this space. That makes each pixel site 0.004 mm square. That is 4 microns from the center of one pixel to the center of the next. If you do not work in the world of integrated circuits or advanced physics you may have trouble conceiving these sizes. We do not directly encounter these dimensions in the real world.

As an example, human hair ranges from 17 to 180 microns in diameter. Therefore the thinnest strand of hair you can possibly find would cover over 4 of these pixels. An average sized hair, around 50 microns in diameter, would cover a strip of at least 12 pixels wide across the sensor.

A fun fact, but so what? The so what is that with each pixel being so small the problems of focusing and holding the camera steady are greatly compounded. Focus is critical and you almost have to rely on the very sophisticated focus system in your camera. Especially if it is contrast detection – meaning that it is searching for the best contrast, hence sharpest focus, measured directly on the sensor pixels.

And for the sharpest results, don’t even think of taking a picture without using a good tripod. I don’t know how steady you think you can hold something, but consider that for optimum sharpness the camera cannot move or shake as much as 0.004 mm while the shutter is open. I can’t do that, especially after coffee.

You need new lenses

Another sad truth is that to realize the full benefit of your high resolution sensor you need lenses designed to match it. Current lenses achieve resolutions significantly better than was the norm a few years ago.

The requirements for lenses for these new sensors greatly exceed the standard required for film or, say 6 – 10 MPixel cameras from just a few years ago. I have tried older lenses on my Z7. The results might be usable for some things, but nowhere up to the quality of something like a Z 24-70 f/2.8 designed specifically for the Z series.

So another cost and problem of trying to achieve very high resolution is that you need to use lenses that will achieve the quality you are seeking.

Why have lots of Mega Pixels?

With all those problems, why should you want to shoot high pixel images? Maybe you don’t. That is what I am leading to here.

Your gear should be chosen based on your intended use. These days many people will only post images on social media or put together a slide show of a trip or event. If they print at all it will probably be 8.5×11 inches (about A4 for you in the rest of the world). Quite honestly, a good 6 MPixel camera is all you would need for any of these things. Almost any mobile phone is great, except for the lack of lens choices.

I have images from a 6 MPixel camera in my portfolio.They are good files and the quality of the pixels is good. I just would not try to print them very large.

About the only thing that requires huge files is making large prints. This is a world I live in, but if you don’t then why bring these other problems on yourself? A good 12-16 MPixel camera is probably more than adequate for most people. They are smaller and lighter and cheaper. It is easier to take good pictures with them, it is easier to process them if you want to, and they require far less disk space. You can probably keep most of the images you want in online storage.

But human nature being what it is, we can’t discount the lust factor. Pixel lust. Just like I know people who do some woodworking and have a workshop outfitted with an array of near commercial quality equipment. An expensive overkill, but if they have the space and money to burn, why not? You might need it someday.

If you want to be logical and save some money and time, resist the lust for lots of mega pixels. You won’t need them.

Its an OK problem to have

Some of us are convinced we need them. Some of us just want the biggest and best. Many are just caught up in the hype of shiny new products.

If you are going to have a high mega pixel camera, be aware going in of the costs and problems. But if you “need” it, go for it! The results are marvelous if you use the tools well.

I love the results I get so much that I forget about the size and processing problems. I love the results so much that I gladly learn the required techniques to achieve them. They make all of my images better.

Cameras and gear have advanced to the point where many of us cannot achieve the maximum they are capable of. But that is an astounding problem to have. What an embarrassment of riches! If we are the weak link in the process, we can learn and improve. We get better and our results get better.

It’s a great time to be a photographer.

What have your experiences been with high resolution photography? Let me know!

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