What is the focal length equivalent for an iPhone? Or my Android phone?

That can change from one phone model to the next. The safest bet to get info about your phone is to open one of its photos in a tool that can read exif data.

For example, the iPhone 5 has "Focal length" 4.1 mm and "Focal length (35mm)" 33.0mm. That means that it is roughly as wide as your favourite 33mm prime lens on your FX camera. Or as wide as your 22mm on your DX camera.

A Galaxy S4 has "Focal length" 4.2mm and "Focal length (35mm)" 31mm.

An iPhone 6S plus has a "Focal length" 4.2mm and "Focal length (35mm)" 29mm. The reason the 35mm equivalent is different from the Galaxy S4 is certainly that it the size of the sensor is different.

To read exif data you can use for example:

• Adobe Photoshop
• Adobe Bridge
• Aperture
• Preview (Mac OS X)
• exiftool
• ... and many others.

The only snag is that not all exif-readers display the equivalent value for 35mm, and not all cameras actually store the 35mm equivalent. If it does not work for you, don't be too disappointed. Just make sure you try with at least one of the tools listed above. If you still have no luck, just buy a new phone. There is probably a new model on the market anyhow.

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.

What use is Adobe Photoshop - for a photographer?

Adobe Photoshop CS4 is probably the most powerful image editing tool on the planet right now. It can do a vast number of things and integrates well with other programs like InDesign (for publishers) or Dreamweaver (for web designers).

Some basic functions that apply for photographers is described in the following.

The program Adobe Bridge, which comes with Photoshop, contains tools to display and organise photos of a wide range of formats, including RAW files from a large number of manufacturers. With Bridge one can also initiate actions in Photoshop like stitching a number of pictures together.

From Bridge, one can open RAW pictures in the program Adobe Camera Raw (ACR) which also comes with Photoshop. In ACR one can adjust RAW files, remove noise, change brightness, convert to black-and-white, fix vignetting and chromatic aberration and a ton of other things - much like one can in Aperture, Lightroom, Capture NX or DPP.

Once the image looks good, one can save it in one of several formats or open it in Photoshop. In Photoshop, one can cut and paste pieces of the different photos and mix them. One can add patterns, text and a lot of other things. The final picture may be resized and saved for use on the internet.

With smartobjects, one even mix layers of different colour spaces and file formats.

If one fully masters Photoshop, there is a good chance that one does not need any other image editing or RAW conversion software at all.

To explore Photoshop further, one can often download a trial version from Adobe.

Things you did not know about Bridge

To open a new window with another folder, command-doubleclick the folder.

You can get a flat view of all images in all subfolders of a folder with the menu View > Show Items in Subfolders.

To skip Camera Raw, shift double-click in Bridge. This will open the file directly in Photoshop.

Bridge's raw xmp files

Whenever Adobe Bridge updates a raw file, it stores the data in an external "xmp" (Extensible Metadata Platform) file with same basic file name as the original. If your raw file is called "sunrise.nef", then the corresponding xmp file is "sunrise.xmp".

The idea behind this is excellent. The raw file contains exactly the data that came out of the camera and nothing else, and you can trust that nothing has been changed - by Bridge.

The drawback is of course that you have two files that need to stick together. If you move all files created a certain date from a folder, it is not at all certain that the raw and xmp files are created the same date, so they may get separated.

Nikon's Capture NX instead stores all modifications in the nef file itself. That may be seen as a drawback - a raw file is no longer what came out of the camera. However, there are ways inside Capture NX to remove the modifications, so it is not that much of a drawback.

Aperture has yet another approach. It stores the modification in its own database. When you export the Master you get the choice whether you want to include the IPTC data or not. The IPTC is the only data Aperture allows to change in a raw file. The rest of the image is intact, as it came out of the camera. Other changes need to be exported through other file formats, like tiff or jpeg.

Index of NEF files with keywords

There are plenty of good reasons to use RAW file format instead of jpeg. However certain things get trickier. One of them is keywords.

The great thing with metadata like keywords and IPTC fields is that you quickly can search your entire harddisk for files about a certain subject, taken at a specific location or by a specific photographer. You just have to make sure that the information is stored in your files.

That is fairly easy with JPEG files. You update the metadata with, for example, Bridge, and the files can be searched in Bridge itself, in Aperture or Spotlight.

However, if you update NEF files or other RAW files using Bridge, the data is not stored in the files themselves, but in the associated xmp files. This means that for example Spotlight does not find the image, but just the xmp file. Neither does Aperture see the field, if the file is imported to Aperture.

The only way I found to make sure that they keywords are found by both Bridge, Spotlight and Aperture, is to use Nikon's free application View NX to set the metadata.

This is a funny roundabout way of doing things as View NX itself does not have any search engine. In other words: you need to use one tool to set the metadata, and another to look for it. Well, that is how things work today anyhow.

Copyright info and Aperture - EXIF or IPTC

With the firmware update 110 for the Nikon D300 one has the option to add a copyright note in the images, just like one could already before with the Nikon D3.

This is excellent news. It would have been even more excellent news if the information had been easy to find outside the world of Nikon.

There are now three fields to play with in the camera. They are all entered under the Setup menu.

1. Image Comment is entered under the menu heading "Image Comment".

2. Artist is entered under the heading "Copyright Information".

3. Copyright is also entered under the heading "Copyright Information".

If you use low end products like gimp (2.6.1), Preview or iPhoto (7.1.5), none of this information is to be seen anywhere.

The following explains how some more high end applications display the fields.

Image Comment

• Aperture - field not visible.
• Bridge CS2: "Camera Data (EXIF)". Field called "User Comment".
• Capture NX: "Camera Settings" > "Shooting Info". Field called "Image Comment"

Artist

• Aperture: EXIF field called "Artist". It does not seem to be visible unless you go in and customize the Metadata displays.
• Bridge CS2: "IPTC Core", field called "Creator" AND "Camera Data (EXIF), field called "Artist".
• Capture NX: "Camera Settings" > "Shooting Info". Field called "Artist"

Copyright

• Aperture: Field not visible. There is a field in Aperture called "Copyright notice", but it is not filled with the information of the Copyright field in the D300.
• Bridge CS2: "IPTC Core". Field called "Copyright notice".
• Capture NX: "Camera Settings" > "Shooting Info". Field called "Copyright". (It is not under IPTC as it is in Bridge.)

In Nikon View NX all the three fields appear with the same name as in the Camera, but under the heading "File Info 2".

Spotlight finds information in the Image Comment field but not in Copyright or Artist.

Clearly Nikon's own software is the best option to view data entered using Nikon's cameras. If you happen to be somewhere without access to Nikon's software, you can look for dedicated EXIF readers that will fine at least some of the data. For example the free little application EXIF-O-Matic, is able to display the fields Artist and Copyright.

Editing your NEF in Photoshop and Camera Raw

If you want to edit your nef in Photoshop, you will have to pass through Camera Raw - directly or indirectly. You double-click on the nef in Finder, Explorer or Bridge, and Camera Raw will open. You make the adjustments you want and can then edit the file in Photoshop. When you save the file, you will have to choose a standard format, like psd, tiff or jpeg.

If you do not want to see the Camera Raw dialogue, you can shift-doubleclick on the file in Bridge, and it will go straight to Photoshop, applying the Camera Raw conversion in the background.

You can also save directly from Camera Raw, but you cannot save to the original raw file. You will have to choose a new name and the raw extension dng or another file format. From each file, you can always go back to the "original" by choosing "Camera Raw Defaults" as Setting. Talking about an "original" is a little awkward, as the original just is a dump of camera data. You have to display it in some way, and that way is through the Settings.

If your nef files are not supported directly by Photoshop and Camera Raw and Bridge, you may be able to convert them to dng, which is Adobe's attempt at a unified raw file format. Version 4.4.1 of the free Adobe DNG Converter handles both D60's and D300's nef files.

In case you wonder, the raw conversion in Adobe Lightroom uses the same engine as Adobe Bridge, so there is no advantage trying to edit a file in both tools.