Nikon D800 - Hints and some kind of Review

This spring Nikon launched a ridiculously performant camera, the D800. According to one test with certain variables, it is the best camera in the world. However, that is of course completely irrelevant if one does not care about those particular variables. There is a good description of the camera at DPReview. This blogpost will just take up some personal notes around the camera.

The D800 by default takes photos in FX format with 36 M pixels. If one wants to take a photo for a blog or some social site, one can get away with a photo that has about 500 times fewer pixels. That means that one easily may discard 99% of the D800's pixels. However, you will store them on your memory card and your harddisk, which quickly fill up. So if one only takes pictures for blogs and social sites, the D800 is more of an inconvenience than the best camera there in the world.

One of several ways to save disk space is to shoot in DX mode. A D800 photo in DX mode is usually less than half the size of an FX photo. One can assign for example the Fn or Preview Button to quickly switch between FX and DX mode (options f4 or f5 in the camera menu). One can then use FX to get a wider angle of view, to get more detail and a more narrow depth of field, and DX to save space and speed up the number of frames per second (fps).

When one shoots DX, there is a thin black line in the viewfinder to show the image area that will be ignored on the photo. To see this even better, one can set the camera menu a5 "AF point illumination" to "Off". For some reason, this greys out the area that is removed in DX mode. Don't ask me why that menu item changes the image area display, but it does.

One of the really nifty things with the D800 is Easy ISO to change ISO directly with the command dial without having to press the ISO button. This is activated in the camera menu d7.

The d7 option does not allow you to switch between manual and automatic ISO, but one easy way to do so is to hold down the ISO button and spin the front command dial.

One of the more peculiar features is the camera option f9 - Aperture Setting. Some older lenses, like on the picture below, have a physical aperture ring to change aperture. Modern cameras usually ignore that ring and require that it be locked. If one really likes using the physical aperture ring, one can use f9 and choose "Aperture ring" instead of "Sub-command dial", and it will work exactly like it did when granddad was young. I see no benefit with this except that it is fun.

Another nice feature is the Virtual Horizon, an indication in the viewfinder if the camera is aligned perfectly horizontally. Activation can for example be assigned to the Fn or Preview Button (options f4 or f5 in the camera menu). In Live View, Virtual Horizon is activated by repeatedly pressing the Info button.

Not all of the features mentioned above are unique to the D800, but they were things that came as nice surprises to me when I started using the camera.

FX - DX - CX - Why does the sensor size matter?

There is one not so obvious difference between Nikon cameras, and that is the sensor size. The sensor is the part of the camera that senses incoming light. Some high end cameras have big sensors and low end cameras tend to have small sensors.

There are three main sizes with Nikon cameras with exchangeable lense: FX, DX and CX. The big FX sensors are used in cameras like D3, D4, D700, D800. DX is used in cameras like D3200, D5100, D90, D300. The smallest CX sensors are used in J1 and V1 cameras.

A Nikon lens made for a big sensor works with any smaller Nikon sensor. This means that any Nikon lens fits a CX camera - in theory. (You need an FT-1 adaptor, and autofocus may not work and there may be some other limitations.) A DX camera can take both FX and DX lenses. An FX camera only works well with FX lenses.

The focal length of a lens does not change with the camera. This means that magnification, zoom and angle of view are the same for all lenses with the same focal length on that camera. If you take a 200mm CX lens and a 200mm DX lens and a 200mm FX lens and put them on the same CX camera one after the other, the magnification is identical for all of them.

However, the same 50mm lens magnifies more on a small sensor than on a big one. In the picture below there are three shots of the same object with the same lens and focal length, but three different cameras. 

The FX camera (a D800) covers the widest angle. The DX camera (a D5100) covers a smaller area. It has been given a green cast to make it stand out from the two other photos. The CX camera (a J1) covers just a small fraction of the FX area. (The photos have been resized to overlap, so the density of the pixels does not correspond to the size of each photo.)

If I had wanted to cover the same angle of view with each photo, I would have had to choose different focal lengths. If the FX camera uses 200mm, the DX camera would need to be 133mm and the CX camera 74mm to give the same angle of view (or zoom factor or magnification). A table with conversions of some common values can be found here.

Advantages with large sensor cameras:

• Less noise, better dynamic range and colour depth. This is basically because the sensor has a bigger area to gather information from. However, note that a new camera with the latest technology and a small sensor can perform better than an old camera with a big sensor in these respects.
• Wider angle of view. To get the same angle as a 14mm lens on an FX camera, you would need a 9mm lens on a DX camera.
• Narrow Depth of Field and more appealing bokeh. This is actually a tricky one. If you look at the three superimposed photos above, you will notice that they have more or less the same amount of bokeh on the background. That is because they were taken with the same focal length and the same aperture. In this case the bokeh is identical, but the image area is different. It is only when you try to cover the same image area with different sensors that the difference in depth of field is apparent. The FX camera has a focal length 200mm. To cover the same area, the DX needs 133mm. With a smaller focal length, the same aperture value (e.g. f/1.4) actually corresponds to a smaller physical aperture hole measured in millimeters. A smaller aperture hole means a sharper picture overall. Therefore, to get the same depth of field at a smaller focal length, the aperture hole needs to get bigger. If an FX camera has focal length 200mm with aperture f/1.4 with a target at five meter, a DX camera will need to be set to 133mm to get the same angle of view. To get the same depth of field, the aperture may need to be set to something as large as f/1.0. As hardly any Nikon lens has an aperture f/1.0, the same depth of field is impossible on the DX camera. Ergo, FX has a narrower depth of field.

Advantages with smaller sensors:

• Smaller, lighter and cheaper lenses possible.
• Smaller camera. (This is not always the case, but an FX sensor will not fit into a really small camera.)
• Cheaper than big sensor cameras.
• Wider choice of lenses.
• Less vignetting in some cases. (If you use an FX lens that has visible vignetting on an FX camera, the DX sensor will cut that part out.)
• Bigger magnification. (To get the same zoom as a 200mm lens on a DX camera, you need a 300mm lens on an FX camera.)

Ignoring Users at DPReview

At the excellent site dpreview there are discussion forums with some very knowledgeable people who can help you with hints to get better photos and advice when it comes to cameras, lenses, tripods and so on.

However, not everyone at the forums is knowledgeable. Just like many other mildly moderated internet forums, it has its share of space wasters. The remedy at DPReview is the wonderful Ignore User button. If you click on that one for a user, all his/her entries will be collapsed to just a title. In addition, threads that are started by ignored users are greyed out and shown at the bottom of the forum overview.

The tricky thing is how to choose which users you should ignore. It depends entirely on what kind of posts you want to read, of course, but if you want some inspiration, these are some of the rules I apply to determine whom to ignore:

• People who ask for rumours, like "how many pixels do you think cameras will have next year?"
• People who give overly definite answers: "You will never need more than 10 megabytes." "That camera (lens, printer, computer, motorcycle...) is simply useless."
• People who think everyone else is just like them: "Carrying 15kg of camera gear wherever you go may seem heavy to start with, but you'll soon get used to it."
• People who use swearwords. (I do not mind swearwords actually. It just seems to be a very strong correlation between people who swear in writing and people who are space wasters.)
• People who use the expressions like "lol" or "awesome". (Same thing as swearwords. The words should be allowed, but a lot of the people who use them in writing are space wasters.)
• People who claim to already know the strong and weak points of new cameras before the camera is actually released.
• People who start off-topic threads. "I hate the parking facilities at Best Buy. Don't you?"
• People who try to start brand wars. "I heard that Nikon has much better zoom lenses than Canon. Why do you think that is?"
• People who are wrong. "Increase the shutter speed to get brighter pictures."

There are some things that do not trigger my Ignore User button - perhaps surprisingly.

• Beginners asking for trivial advice. Most questions, no matter how trivial, can generate some interesting answer from people who know the subject well.
• People who write lengthy essays as answers. A good answer is usually just a few lines, but sometimes a writer with a lot of experience has a lot of interesting things to say.
• People who claim film is and always will be superior to digital. I do not think film is inherently superior to digital, but the arguments for film are often varied and interesting, and they may make you think about how you take digital photos.
• People who feed the trolls. If one person trolls with some idiotic opinion, and another person insists on trying to rebut the idiotic opinion, it may seem logical to ignore both writers to avoid long uninteresting threads. Indeed, I often ignore both of them, but it is not automatic. Both writers have to show individually that they are time wasters before I ignore them. Sometimes a very sensible writer falls into the trap of feeding the troll, and it would be a pity to lose his input in other areas.

The last rule I apply is not to follow any rule blindly. Every now and then, I read what ignored users write to see if it has some value. In most cases it does not, but there are exceptions, and then I usually gnore (un-ignore) the writer.

Searching EXIF data with Mac OS X Spotlight

Using Mac OS X Spotlight, you can quickly search for certain camera metadata. A simple search would be "D300" (without quotation marks) entered in the field you get when you click on the magnifying glass in the upper right corner of your screen. That returns all images, both NEF and JPEG, that were taken with a Nikon D300 camera. By default you also get all other files that contain D300, like PDF files, word documents and old mails where you discussed the camera with friends. To limit the search to just images, go to "Show all in Finder". That will open a window with the title "Searching this Mac". Here you can click on a plus ⊕ symbol to get more search criteria. Click on it and select "Kind" as "Image", and you will only get image files.

If you instead of selecting Kind, select "Other", you get a vast number of search criteria to choose from, like ISO or EXIF version.

To really see all the criteria you can search from, you can use a Terminal window.

1. Open the Terminal from Applications > Utilities > Terminal.
2. Type "mdls " without quotation marks, but with the space after the last "s".
3. Go to the Finder and drag an image file onto the Terminal window. It should now contain text that looks something like "$ mdls /Users/myhome/Desktop/mypic.jpg"
4. Type "| less" after the file name and hit Enter.

What you now get is a list of searchable fields for the image, and their values:

kMDItemAcquisitionMake         = "NIKON CORPORATION"
kMDItemAcquisitionModel        = "NIKON D300"
kMDItemAlternateNames          = (
    "mypic.jpg"
)
kMDItemBitsPerSample           = 32
kMDItemColorSpace              = "RGB"

kMDItemExposureTimeSeconds     = 0.004
...

To move down to see more options, hit the Space Bar.
To move back up, type "B".
To leave the list, type "Q".

Now we can go back to Spotlight to use this information for an actual search.

1. Click on plus ⊕ again, and select "Other".
2. Select "Raw Query".
3. In the search field, type a field name from the Terminal and some appropriate value, like "kMDItemExposureTimeSeconds < 0.003"

This will display all photos with a kMDItemExposureTimeSeconds (shutter speed) that is faster than 0.003 seconds.

If you know you want to repeat the same query over and over, you can hit the "Save" button, and you will get a virtual folder for quick access, whenever you need it.

Everything that is written here actually applies to all kinds of files, not only images, but as this is a photo blog, all the examples come from the wonderful world of images.

Searching in Adobe Bridge

If you want to find all photos you ever took with, say ISO 200, you can easily do that in Adobe Bridge. You just select Edit > Find, select "ISO" as search criteria and "200" as value.

It is slightly more tricky if you want to search for all files with a particular shutter speed or aperture, as these fields do not appear as search criteria. What you can do is to search for Exposure, which is a field that contains both those values. E.g.: "1/30 s at f/2.8". This means that you have to enter the values as free form text.

Some fields, like ISO and Focal length, are numeric, so you can search for all photos where the Focal length is greater than 50mm. However, the Exposure field is a text field, so it is very difficult to collect all files with shutterspeed greater than 1/200.