Sony A7R III digital photography workflow for fall 2019

Sony A7R III digital photography workflow for fall 2019

OK, I seem to update this everytime I use the camera, but this should also apply to the A7R IV, although I don’t quite have one. Here are the recommendations based on the three different types of photos you can take

Use RAW on a Mac or PC for regular photos

Although the JPEG processing in the thing is good, the RAW still comes out better with PC processing.

I tried using an iPad just to do this and the problem is that the RAW files are massive and if you have iCloud Photos then suddenly your iPhone is trying to deal with 80MB RAW files and that is really unfun.

The processing through on Photos is actually quite good. The default auto works well. And with the new PadOS, using an SD connection or even connecting your camera as a USB device actually works really well since both are USB devices.

So with that out of the way, what are the best tools on a PC? Well, I tried a few:

  1. RawTherapee is freeware that does Raw processing but not quite as detailed as DxO. It is free and not for the faint of heart. It doesn’t handle distortions, but with the lenses I’m using (50mm F/1.4 Sony and 25mm F/2.2 Zeiss), that doesn’t seem to matter much. The vignetting and distortion are really minimal. However, I’m not quite sure how to turn things and the TIFF and JPEG that come out don’t seem quite a sharp (even with USM turned high)
  2. DxO PhotoLab. I’ve been using them for a while. The main advantage is that they have really good distortion control, but they do update every year, so they are effectively $59/year. Still, they are not Adobe and I like supporting smaller companies. Also their latest defaults called DxO Lighting feel to me to be less aggressive than than Adobe Lightroom, so I tend to use it.

For Bracketed Photos

If you have a scene with lots of contrast, then you want to shoot a bracketed photo. The Sony has over 14 EVs of dynamic range, but if you have lots of darks and lights, you can exceed that. By comparison, the human eye is much more complicated. If it is bright outside, we see about 10EVs (using the cones in our eyes), but when it is dark we can see 20EV (using the rods). Moreover, when we sweep a scene, we constantly adjust, we are not like a camera that takes the entire scene at once, we can focus on the bright sky, then look down to the forest and we adjust.

The net is that there are times in landscapes when you want to shoot bracketed. The Sony allows you to shoot 5 shots at 0, +3, -3, +6 and -6 EV, so you get in effect 12EV plus the 14EV of each scene or 26EV. And you have to merge the five images into one by matching pixel to pixel and hoping that things don’t move too much better shots (what is called ghosting).

As a quick review an Exposure Value or f-stop measures a doubling of the amount of light, so 10EVs means you can see 2^10 or 1,024 levels of light. This was well chosen because each EV means you need another bit of color, so a 10EV dynamic range image needs 10 bits for each color (red, green and blue). A JPEG has 8-bit color (so 24-total bits), so you have to compress the images. A TIFF is normally 16-bit, so can easily store the 14-bits that the camera has. However, to store an HDR, you need 32-bits worth.

Finally, a display can’t show these kinds of colors. A good LCD panel shows 10-bits of colors, so with HDR images, you have to map the 32-bit image and you can’t print that much either, normally.

So how do you actaully work with this, well you can use Photoshop, but I’ve found that there are two other solutions that work very well:

  1. Photomatix Pro. This is a third party application that is just dedicated to fusing images together. They have a huge number of different techniques and most importantly, they can deal directly with the RAW images out of cameras like ARW from Sony. The big thing you give up is distortion correction, but for most landscapes, I normally use a low distortion lense that is 24mm or so. And vignetting isn’t as much of a problem for big landscapes, so you don’t give up much going directly from RAW to producing an HDR image in real 32-bit and then doing the smart compression to get you a nice 8-bit JPEG image.
  2. Luminance HDR. This is open source system but it only deals with TIFFS, so you have to take DxO Photolab and use it to produce TIFFS and then go with this to get your HDR images. A bit of a pain.

Pixelshift Images

The final mode that the Sony cameras have is called pixel shift, this takes four images (16 with the Sony A7R IV) and shifts the images by one pixel. This gets rid of the Bayer Filter so each pixel in fact sees a full color dot. Most images are actually doing interpolation, in a Bayer grid that is a 2×2, there are two greens and then a red and a blue.

However processing this is a pain:

  1. Rawtherapee claims to do this, but I haven’t quite figured out documentation wise how to deal with it.
  2. There is a beta tool called PixelShift2DNG that figures out which images are actually the collection of four (or 16) and then merges them into a single gigantic DNG file for processing. The problem is that DxO for one has no idea how to handle this, but it is handy because it will tell you which images are PixelShift family images.
  3. The best way seems to be to download Sony Imaging Suite and then you open up the image with the Viewer. (This is a little strange since the Viewer actually is a convertor). If you select any one of the set, then it will figure it out and then you choose Output and you get a new file called an ARQ that has all four images together.
  4. Then with the Sony Edit tool, you can put it all together and produce the TIFF and JPEG. You don’t get the other DxO controls, but at least it understands the formats

Stitching a Panorama

Seriously, you can do this, but the best tool is actually an iPhone or camera phone that just does this, but if you want high resolution with 14EVs of contrast, then you should get a tripod and take images one after the other in a panorama. Then you need to process them:

  1. Hugin. This is an open source package. The main issue is that it doesn’t know how to deal with ARW or other RAW files, so you first have to push it through DxO to get TIFF files.
  2. PTGui Pro. This one does cost money and I’ve paid it, but it is worth it.
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