cameraf4 Loc: Delaware

Just wondering if any of you other folks do stuff like this. I got out all (now) 4 of my DSLRs (Nikon D700, D800, Df, D850) along with my Bogen 3221 "heavy-as-a-tank" tripod and my trusty Nikkor 50mm f1.4 AF-D lens. Set camera to Spot Metering, Manual Focus/Focus assist, Standard Picture Control, f/8 and Aperture Priority Semi-automatic Exposure and started at ISO200 (Lowest native ISO for D700). Set-up a subject with readable print 90 feet from the front of the camera (figured that would be near resolving limit of lens and if 90 feet is good enough for MLB, it's good enough for me). WB set to Direct Sunlight (which it was). Exposure delay set to 5seconds or closest-to-that camera setting. Took first exposure w/each camera at those settings, then switched Picture Control to "Landscape" (Hey, I'm a Landscape kinda guy, what can I say) and took another exposure. For those cameras with a lower "native" ISO, I repeated the test for ISO100 and, for the D850, ISO64. Yes, I'm a NERD.

deer2ker Loc: Nashville, TN

Anxiously waiting to see what you found out!

PixelStan77 Loc: Vermont/Chicago

I did it outdoors with my D800 and a new lens I bought to test, a 200MM Micro Nikkor. I used test target to fill the frame at varying feet, 5,10,20 feet. The lens was a keeper and did not go back to B&H. I am not a NERD!

Kmgw9v Loc: Miami, Florida

I have the 700, 800E, Df.
Based on your camera shoot out, how badly do I need the 850?

cameraf4 Loc: Delaware

OK, Stan. But I AM a nerd, and fiercely proud of it.

rook2c4 Loc: Philadelphia, PA USA

I think you have a bit too much time on your hands, cameraf4.

cameraf4 Loc: Delaware

Early retirement, rook. What can I say? And kmgw, I have always been a detail fanatic, going back to my film days. Some of my very favorite OAT images were made with my D700 (http://www.uglyhedgehog.com/t-497005-1.html). I thought the D800 was amazing (still do). But now I wish I could go back and retake every photo I've ever taken with the D850. It's pretty darn good!

Kmgw9v Loc: Miami, Florida

BHC Loc: Strawberry Valley, JF, USA

I also am a nerd, a geek, and am also proud of it. I have four cardigan sweaters, my eyeglass frame is thick rimmed black (and the last time they broke, I went to my 36 year old medical kit to find some white adhesive tape to temporarily fix them) AND, if you look in the bottom right drawer of my desk, you’ll find two slide rules, a K&E and a Pickett, both of which I have used to completely baffle my children and grandchildren.

jerryc41 Loc: Catskill Mts of NY

Sounds interesting. I'd like to see some results.

rmalarz Loc: Tempe, Arizona

You didn't mention what format you used for the images you took. Was it RAW or jpg, or something else?
--Bob

cameraf4 Loc: Delaware

Bob, I shot Jpeg, 45.4M, Fine. Still trying to "understand" RAW, I once heard that RAW files are only "computer code" and that to actually "see" them, photo editing software has to "do something" to it to make it a visible image. Figured that most folks would probably use Jpegs to share images, anyway (I do), and Nikon apparently no longer provides software CDs with their cameras so I wasn't sure that what I have will open a D850 NEF.

f8lee Loc: New Mexico

Think of a digital imaging chip as a matrix of rows and columns, where an array of 6000 by 4000 would yield 24 million "dots" or pixels (picture elements). An image file consists of pixels that have clearly specified colors in terms of Red, Green and Blue values (RGB). So, for each pixel of an image file, there is a precise RGB value.

A raw file is the stream of data that comes from the sensor. With a few exceptions (Leica's monochrome, Foveon) ALL digital sensors, from that new Hasselblad to your smart phone camera, work as follows: while they too have a matrix of dots (called photo sites), each of those photo sites is covered with a colored filter that is either Red, Green or Blue. This is because the sensor chip itself is natively "color blind", each photo site can only register how many photons have struck it when exposed. The pattern of those colored filters (called the Bayer pattern) is R-G-G-B (for upper left, upper right,, lower left, lower right) - and there are twice as many green filters as there are red or blue because the human eye is more sensitive to green. Fuji's X-Trans chip uses a different pattern, but the concept is the same.

When an exposure is made, the data captured by the imaging chip is a bunch of values that represent how much light hit each photo site - and those measurements are all based on the light that made it through those filters. As a thought experiment, imagine a subject that was only pure blue - the photo sites with red and green filters above them would not register anything! Lots of black gaps in that file, eh?

So a raw file first needs to be rejiggered to become a true image file, where each pixel has a stated RGB value. On the raw file, each spot has only an R OR a B OR a G value, but they are not blended. That process is called de-mosaicing, and the output of the process is the resultant image. Obviously there are a lot of calculations required to do this, but that's what the computer built into the camera (or phone) does. Cameras that only output JPEG do in fact generate raw files to start with (there is no other option) but they quickly do the calculations and discard the raw file when the JPEG is created. And I believe Apple just announced that the next iteration of iOS will allow for raw file storage.

So, unlike a JPEG or TIF etc. file, the computer processing a raw file must interpret what actual color should appear at a given pixel, based on the readings made from the surrounding photo sites. There is no absolute lookup table, as there is for image file RGB values, to decide what color purple a given spot should be if one adjacent red reading was 500, another from the blue filter was 644 and yet another from a green filter spot was 42, or whatever. For those who say "yeah but you need a computer to interpret" any digital file!" I say that is actually incorrect - where a JPG specifies that RGB value (and leaves it to the hardware drivers and gear to not screw it up) the various demosaicing programs can actually result in different outputs from the same original raw file. Apple includes demosaicing software in OS X, but DxO, Phase One's Capture One, Adobe and others (including the camera manufacturers themselves) all have their own demosaicing software. While different software won't completely change the look of a given image, the subtle tonalities can well be different if you take an image and process it with C1 and compare that to the same raw file run through Adobe Lightroom.
By the bye, since you CANNOT see a raw image what you are looking at (on the back of the camera when you chimp, or on a computer screen) is a demosaiced image that has been interpreted by a computer, be it in the camera or on your desktop.

That is the difference between a raw and JPEG file.

Rich1939 Loc: Pike County Penna.

Although Nikon doesn't include a CD they do provide downloadable software.
http://downloadcenter.nikonimglib.com/en/download/sw/101.html
I haven't used this program personally but it will get you started.
I personally feel that to only use a digital camera for jpgs is like buying a Shelby Cobra and only running it on 6 cylinders. Once you work with raw files and learn how much more you can do with the image file, you might look back but, I doubt it.

cameraf4 Loc: Delaware

Wow! Very nicely explained, Lee. I think I finally understand much better now, thanks.