Using PocketWizard FlexTT5/MiniTT1 with non-Canon Cameras

If you want to use a PocketWizard FlexTT5/MiniTT1 on a non-Canon (make that non-Nikon if you have the recently released Nikon version) camera, you can do so by using Basic Trigger Mode which has been available starting with FW 4.100.

It’s quite simple to set up, if you know the magic sauce.

We will set Basic Trigger Mode in configuration C2. That way configuration C1 will remain available for use in ETTL mode. To keep things simple, we’ll use a MiniTT1 as transmitter and a FlexTT5 as receiver. You can actually use many FlexTT5 to drive multiple flash units. In this case, repeat the procedure for the FlexTT5 described below for every unit.

MiniTT1 (Transmitter)

    1.    Start the “Pocket Wizard Utility” on your computer. The screenshots below are from version 1.35. Other versions may differ a little. You can download the utility here for Mac and Windows.
    2.    Hook up the MiniTT1 to your computer using the supplied USB cable. The MiniTT1 should be turned OFF.
    3.    Go to Configuration C2 >> Channel and set the Standard Transmit Channel. The default is 2, you may want to change it to a different value if you expect to be shooting around other people with PocketWizards.

    4.    Go to Configuration C2 >> Misc and check the box Basic Trigger Mode.

    4.    Now press the button Apply Changes, confirm the question in the dialog box, and wait until the changes have been written to the device.

You are now done with the transmitter.

FlexTT5 (Receiver)

    5.    Now hook up the FlexTT5 receiver unit using the same USB cable. You can leave the PocketWizard Utility running, just remember to turn of the FlexTT5.
    6.    Go to Configuration C2 >> Channel and uncheck Use ControlTL for Receive Channel. Then set the Standard Receive Channel to the same channel you used as the Standard Transmit Channel in step 3. In this example, I used 7.

    7.    Press the button Apply Changes, confirm the question in the dialog box, and wait until the changes have been written to the device.

You are done with the receiver.

Repeat the receiver procedure with any other receivers you want to trigger simultaneously.

Let's test it to see if it works:

Hook up a flash to the FlexTT5, turn on the flash, and set it to M (manual mode). Then turn on the FlexTT5 to setting C2.

Next, attach the MiniTT1 to the hot shoe of your camera and turn it on to setting C2. Then turn on the camera.

If you press the camera shutter release button, the flash should fire. Congratulations, it works!

I tried this using an Olympus E-P1 with a Canon 580 EX II and it works just like a cable - without the wires. ;-)

Image Clarity 101: Depth-of-Field

In the last post, we looked at how a sharp image is created optically. In this post, we will look at how the physics render non-flat objects.

If all the points of the subject are in the same plane, they will all render with the same size circle of confusion in the image plane. This is the case if the subject is perfectly flat.

For non-flat subjects, the points of the subject are located at different distances from the image plane. So the projected points will have a minimal circle of confusion in different image planes. Since there is only one image plane, the projected points will all have different size circles of confusion - which means they will all be of different sharpness.

Each circle of confusion that is small enough will appear to be sharp. The distance from the nearest to the furthest point which are just rendered sharply is the depth of field.

The depth of field is determined by the distance of the subject from the camera, the focal length of the lens, and the aperture.

Some simple rules of thumb are:

1.  The further the subject from the lens, the greater the depth of field for a given focal length.

The greater the absolute distance between subject and lens, the smaller the relative difference in distances for different points of the subject. Because of this, the size of the circles of confusion are very similar in size.

If you look at the distance scale on a lens, you will notice that the distance between markings decreases the closer you get to infinity. And, speaking of infinity, there is a point from which on everything is in focus if you focus the lens to infinity.

2. The shorter the focal length, the greater the apparent depth of field at a given distance.

The hyperfocal distance, or the distance from the image plane past which every subject point is acceptably sharp if the lens is focused on infinity, decreases the shorter the focal length of the lens. This is because the magnification decreases, so the circle of confusion for a given subject point is also magnified less.

Remember though, that this is true only for a fixed distance!

3. The smaller the aperture, the greater the depth of field.

The smaller the aperture, the smaller the cone of light rays that passes to the image plane. Because the cone is smaller, the circle of confusion is also smaller.

In the illustration below, the aperture blocks the blue cone of light rays, only the red cone gets through. The circle of confusion on the image plane is smaller, so the image is sharper.

Illustration 3: A smaller aperture reduces the circle of confusion

Note that in practice, diffraction becomes a problem at small apertures. Diffraction will be discussed later in this series.

Bigger is not better

One important thing to keep in mind is that bigger is not necessarily better with depth of field. An image may actually be improved if (unimportant) parts are kept out of focus because the eye tends to focus (pun intended) on the part of the image which are sharp and tends to give the unsharp parts only cursory attention.

That said, if you are trying to render your image as clearly (sharp) as possible, you want to select your depth of field in such a way that the closest and furthest subject point which you want sharp are in focus.

For example, have a look at this image:

Image 1: The forget-me-not in the foreground is sharp, the background blurred.

The forget-me-not flower in the foreground is rendered in focus. The (rather cluttered) background is rendered out of focus.  The eye of the beholder will pass over the out of focus parts, thereby de-emphasizing the non-essential parts and concentrate on the subject in the foreground.

Image Clarity 101: What makes an image sharp?

A common problem with photos is lack of sharpness. The image is either soft, or out of focus, or the wrong part of the image is in focus, or ... the list of possible issues is a long one.

Just like exposure, focus is one of the parameters that the photographer must learn to control in order to create images that show what he or she visualized before pressing the shutter release.

This is the first of a series of posts that I will call "Image Clarity 101". The name is a tip of the hat to John B. Williams who wrote the excellent "Image Clarity: High-Resolution Photography", which - alas - seems to be out of print.

I am going to look at what causes an image to be "sharp". In later postings, I will explain what equipment and techniques to use to actually get an image to be "sharp".

Focus

If we imagine that a subject is made up of an infinite number of minuscule points, each of these points emits an infinite number of light rays that hit the entire area of the camera lens. As the light rays pass through the lens, they are focussed on some point (the focal point) behind the lens, creating a cone of light.

Parallel to the lens plane is the focal plane, which holds an infinite number of focal points for all the visible points of the subject.

All of this is shown in the illustration below.

Illustration 1: Focus Explained (simplified)

The image plane is the surface the image is projected onto. This is where the film or image sensor is located. For an image to be in focus, the image plane must be the focal plane.

When you twist the focus ring on a lens, you are effectively moving the focal plane. When the image is sharp, the focal plane is located on the image plane.

Are you with me so far? Good!

Circle of Confusion

Now it gets a bit messier: since we are dealing with the real world, the light rays do not actually all converge on a single point, but form a small area, the circle of confusion. 

In the illustration above, you can see that in the focal plane most of the light originating from a single point of the subject hits the small circle. As the image plane moves away from the focal plane, the light is spread over a larger area.

If this is too circle of confusion business to too confusing, have a look at the following, simplified illustration:

Illustration 2: Cone of Light

The subject is projected by the lens as a cone of light rays which strike the image plane. The tighter the cone is at the image plane, the close the image plane is to the focal plane.

If the circle of confusion is small enough, the human eye will register it as a single point. How small the circle needs to be is perhaps a topic for another post. For the time being, we can assume that if the circle of confusion is somewhat smaller than a single photo site on the sensor, it will not be a limiting factor for the overall sharpness of the image.

Illustration 3: As the circle of confusion increases, the image becomes less sharp.

So we reach a simple conclusion:

If a single point of the subject is rendered as a small enough circle of confusion, it will appear sharp in the image.


There is one important point to consider: all of what has been discussed above is only true for flat subjects and ideal lenses. In the next installment, we will look at sharpness for a non-flat subject.

You may find a used copy of the excellent Image Clarity here:
Amazon USA Amazon UK Amazon DE

If you don't feel like getting an old book, you might try perusing the good old Wikipedia which contains much more on the subject.

[Book Review] Within the Frame - The Journey of Photographic Vision

[amazon ASIN=0321605020]Within the Frame - The Journey of Photographic Vision[/amazon] by David duChemin may easily be the most unusual - and best - book on photography that I have read this year. It is unusual in that it manages to bridge the gap between books about photography as art and photography as technique, delivering both. In my opinion, that is what photography is about.

The first chapter is devoted to vision - what it is that you see and want to communicate. The second chapter focuses on what feeling, idea, or impression you may want to capture and what subjects may show this to the viewer. The third chapter on gear and technique required to get the image you want. I think that the focus not on creating technically perfect pictures but on how to turn something you want to communicate into a picture is spot-on. The author really nails it here!

The fourth chapter is about storytelling in pictures - how to tell a story in a single frame or in a photo essay, how to create interest in the viewer. This chapter is a must if you want to go from mere visual candy to a four-course meal.

The next chapters are about photographing people, places, and culture. I really enjoyed the chapter about people (I love photographing people and got a number of useful tips and ideas from the chapter), but found that my attention flagged halfway through the places chapter, and did not pick up to the end of the book. It seems to me that the essential message of the previous chapters are repeated a bit too often.

The pictures in the book are compelling and beautiful, the printing is of high quality. You can find a number of them on his website at www.pixelatedimages.com if you are interested. Despite all of the pictures having been taken in what amounts to "exotic" locations for most people from Europe or North America, I would not say that it is about travel photography. Everything in the book applies to taking pictures of your home town. Maybe even more so than when you are abroad ...

I feel great respect for the way David duChemin approaches his subjects as human beings, not just props in his pictures. I feel the same way and I became aware of a lot of things that I have done without ever thinking about them. I have also learned a few very useful things about how to approach people.

The same applied for his treatment of technical aspects: he makes things that I have been doing intuitively become conscious decisions, giving me much more control. For example, I wish that I had read what he has to say about lens choices much earlier, it has taught me the value of wide-angle lenses, which I rarely use. This will definitely improve my ability to show my vision to the world. (Interestingly, he apparently went through a similar development, starting with telephoto lenses and only gradually learning to use wide lenses.)

Finally, I learned ever so much from his approach of treating photography as storytelling. If this is - as to me - a closed book (pun intended), you will benefit greatly from [amazon ASIN=0321605020]Within the Frame[/amazon].

As I mentioned before, my attention and interest flagged towards the last two chapters. Maybe it was just too much to absorb? Maybe the chapters are simply weaker than the previous ones? I do not know. But I do know that even without the last two chapters the book is definitely required reading for anyone interested in photographing people, so it gets five stars!

[caption id="" align="alignnone" width="111" caption="5 stars (out of 5)"] [/caption]

Fireworks over Church Tower - How to Photograph Fireworks

Freising is having it's 80th annual fall fair this year and the town celebrated the last day today with some spectacular fireworks:

[caption id="" align="aligncenter" width="600" caption="Blue Fireworks over Church Tower."] [/caption]

In case you are wondering, it is actually quite easy to make this kind of photo if you know what you are doing:

1. Set your camera on a tripod and use a cable release or a remote control (infra red remote, RadioPopper, PocketWizard, you name it) to trigger the exposure. I use a simple remote control cable.


2. Turn off the auto-focus and manually focus the camera (usually to infinity). This is faster and more reliable than having the AF hunt the night sky.


3. Crank up the ISO as far as you are willing to live with the noise. For example, on a Canon 5D, ISO 800 is great and ISO 1600 is acceptable. A Nikon D3X will go even higher, as will a Canon 5D mark II. A pocket digicam will probably struggle at ISO 400 and above. Experiment - preferably before the big event.


4. Use manual exposure mode and open the aperture as wide as it will go.


5. Still in manual exposure mode select a good exposure time. I find that between 1/125s and 1/8s works well.


6. Expose at will and enjoy the show!

[caption id="" align="aligncenter" width="600" caption="Green Fireworks over Church Tower."] [/caption]

I usually use the camera screen to judge exposure. That is, I set the aperture wide open and shoot at whatever exposure time I have guessed. Usually 1/60s is a good place to start as any.

It is normal to see some blown highlights in the middle of the explosions and at the back of the rocket engines. Because of this the histogram and the blinkenlights are useless. Instead, ensure that the night sky is black and that the fireworks are clearly visible.

If the sky is too light, shorten exposure time and/or reduce the ISO. Similarly, if the fireworks are too dark, lengthen exposure time and/or increase the ISO.

Once I have set up the exposure correctly I point the camera at a likely section of sky and snap away. Since the exposure will not change, I only change it to get a different effect. There is no need to check every image.

In fact, I simply snap away until either the fireworks stop or I grow tired of taking pictures. It's a good idea to have some spare batteries and memory cards on hand ...

That's it. Have fun!

Marmelade Fly on Yellow Flower Reprise

In the last post I showed a picture of a marmelade fly on a yellow flower. I would like to revisit that picture to show how much an image can change depending on how - and with which tools - it is processed.

The original image was captured in RAW format. I then processed it in Adobe Lightroom 2. The result is this:

[caption id="" align="aligncenter" width="600" caption="Marmelade Flies on a Yellow Flower processed in Adobe Lightroom 2"] [/caption]

While I was reasonably happy with the image, I had to do some testing in Capture One Pro and decided to see if I could do better. I have long thought that Capture Ones color rendition is much better than Lightrooms. But judge for yourself:

[caption id="" align="aligncenter" width="600" caption="Marmelade Flies on a Yellow Flower processed in Capture One Pro and Photoshop"] [/caption]

Quite a difference, don't you think? The first rendition looks almost like a painting while the second is so real you can almost touch it.

So how was it done?

I first opened the file in Capture One and set the exposure so that none of the color channels would clip. This part is identical to what I did in Lightroom. Note that the yellows are a bit darker in the C1 rendition than in LR. I then exported a 16-bit TIFF file to Photoshop from C1.

In Photoshop I created a mask to darken the green part to the left of the flower using a curve. A second mark darkened the bright leaf to the left and below the marmelade fly. Then I removed some spots from the yellow petals which were really there (i.e. not dust on the lens or sensor) but which I did not like. All of these steps are identical to what I did in Lightroom except that I did not darken the single bright leaf in LR.

I then added a watermark copyright note and reduced the size of the file. Finally, I used Pixel Genius PhotoKit Sharpener for output sharpening. All of this is fully automatic during the Lightroom export.

In total I spent about five minutes in Lightroom to get a decent image. I spent about half an hour in Capture One and Photoshop to get an excellent image. There is clearly a trade-off time for quality here.

That is why I usually perform all my culling, keywording, and rough editing in LR. When I have identified the handful of images with real potential I spend more time on them in C1 and PS. Now if only I could take the LR settings and use them in C1 so that, for example, I do not have to re-crop ...

HDR using Photoshop vs. Photomatix

Processing multiple exposures into a single HDR (high dynamic range) image turns out to be more of a subjective process than I initially thought.

Have a look at the following image, which was processed using Photoshop CS4 and the "Merge to HDR" feature:

[caption id="attachment_366" align="alignleft" width="534" caption="Image processed from 3 exposures by Photoshop CS4 "Merge to HDR"."][/caption]

Not bad, really, at first glance. But notice at the right edge, about halfway down the image, how the arch coming in from the wall is completely blown out?

Now look at the same source exposures converted by Photomatix:

[caption id="attachment_367" align="alignleft" width="533" caption="Image processed from 3 Exposures by Photomatix Pro."][/caption]

The highlights are not blown out, the tonality of the image is smoother, the reddish cast is reduced. All in all, the image is much closer to the intended look than what Photoshop allows.

Given that Photomatix allows me a lot more control to tweak the result than Photoshop, I think the money is well spent on Photomatix ...

Church Ceiling

The ceiling of the Freising cathedral.

The previous cathedral burned down almost exactly 850 years ago (April 5, 1159). Work on the current church started almost immediately but it took almost 100 years until the church was finally consecrated.

The interior was remodeled a number of times with the current rococo ceiling having been created by the Asam brothers around 1724. Everything looks shiny and new because major renovation and restoration works were completed recently.

The difficulty in capturing a scene like this is that the light coming in the windows is extremely bright while the shadow areas can be very dark. Most digital cameras can not handle the dynamic range in such a scene.

The solution is to use HDR (high dynamic range), which is a technique to squeeze more extreme light and darkness into an image than the camera sensor can capture. The trick is to create several exposures of the same scene (a tripod really helps :): one frame exposes the highlights correctly, the next the midtones, the final frame the shadows. Software magic then combines everything into one image. Because most monitors are 8-bit-per-color-channel devices (and JPEG supports only 8 bits per color channel) the resulting image is then rendered down into an 8 bit per channel representation.

The difficulty lies in the number of choices that must be made at every step. It takes a bit of experimenting to get good results.

[HOWTO] Install Xubuntu 8.10 Intrepid Ibex on Asus EeePC 900A

Amazon just offered a really good deal on the Asus EeePC 900A, which is very much like the original 701 (which I purchased for my trip to India last year) in outward appearance, but offeres a bigger screen with higher resolution and a much faster CPU. The internal SSD [solid state drive] grows to 8 GB, but it uses MLC instead of SLC, which makes is slower than the 701.

Anyways, I will not review the 900A in this post, maybe that will come later. Instead, I provide a detailed account of how I replaced the less than stellar Xandros Linux with the more than decent Xubuntu.

Caution: By following these instructions you will completely erase any data that may have been stored on your EeePC, including the Xandros Linux it came with, and any and all files you have created. Make a backup before you proceed!

General Disclaimer: I describe what worked for me. Your mileage can - and will - vary considerably. Consider this a travel report, not a guided tour. Know what you are doing, don't play with matches, and do not run with scissors! You have been warned. :-)

Book Review: face to face

Rick Sammon's Complete Guide to Photographing People is just that: a comprehensive, in-depth look at how Rick Sammon takes pictures of human beings on his travels.

Rick starts by explaining that the camera looks both ways, which means that there is always an emotional connection (or lack thereof) between the photographer and his or her subject. This connection is at least as important as the technical aspects of taking the photo, since it determines the content. I believe that it is far too common for photographers to become far too focused on the technical aspects of photography instead of the content, so I like being reminded of this simple fact.

Using Lightroom and Expression Media to Modify Metadata

A reader asked the following question:

My specific question is regarding how you were able to use both LR and XM2. Did you upgrade from iVMP and added LR into your Workflow after it got released?

I used iVMP before, but am exclusively using LR. However, being frustrated with its DAM capabilities, i am looking to go back to XM2. Were you able to migrate your LR catalogs to XM2? Any thoughts welcome. Thanks in advance.

I understand the frustration with the DAM (Digital Asset Management) capabilities of Adobe Lightroom - looking at both Bridge and Lightroom I sometimes feel that Adobe just don't get DAM. But there is always hope for LR2. ;-)

I have Lightroom and Expression Media working together nicely (see here ). The way that works for me is to write the metadata changes I make in Lightroom directly to the image files instead of to XMP sidecar files. This works well with JPEGs and DNGs.

XM can import the metadata changes (you have to initiate this manually).

If you simply want to go one way from Lightroom to Expression Media you are done at this point.

If you want to work with both programs you then write the changes you make in Expression Media to the files (manual command). Lightroom can import the change and you can continue editing in Lightroom.

This way of working is not perfect because it requires that you to remember to manually sync, but it seems to preserve all the data.

Backup Strategies for Photographers

Photographers create assets - images. Ideally, these assets can be used for the life of the photographer and beyond.

In the "good" old days of film, the problem was keeping the materials, i.e. negatives and prints, safe from harm (fire, flood, mildew, theft, etc.) and in pristine condition. The latter could be a problem if the materials where not of archival quality or contaminated or whatever.

As "digital" photographers our assets are by nature primarily digital files. The advantage of digital files compared to negatives or prints is that the problems associated with those are easily mitigated or can not occur because of the different nature: keeping a digital file safe from harm is easy is enough copies are kept in enough different physical locations. And deterioration is also not a problem for digital files.

There are, however, a number of risks and issues specific to digital files:

• All currently available media deteriorate over time.


• Files may suffer from "bit rot", usually through copying errors or because of media deterioration.


• Hardware becomes obsolete and it may not be possible to use todays media in 10 or 20 years because the physical connectors are no longer supported, because there are no drivers, or because hardware can not be replaced if it fails.


• File formats become obsolete and are no longer supported.

Let's look at the specific problems.

Media Deterioration

An old quib is that it is not a question wether a hard drive will crash but when. Hard drives are mechanical devices, so it is just a matter of time until they wear out or dust gets inside or something else goes wrong. And if you think that keeping the hard drive in a cool, dark place will help I have to disappoint you: the lubricants deteriorate and eventually the hard drive will fail. In fact, a drive that is spun up regularly (every few weeks) will last much longer than a drive that is just kept in storage.

Optical media, such as CDs and DVDs will deteriorate quickly if not stored perfectly. And even if they are stored under perfect archival conditions, there is ample evidence that the expected data retention time is much, much lower than the time claimed by manufacturers. A friend of mine, for example, found that after 5 years 20-50% of his burned CDs and DVDs show one or more errors that can not be corrected.

Magneto-Optical (MO) media where guaranteed for 30 years and it seems that these claims where accurate. Unfortunately, this is obsolete technology and the drives are no longer being made.

Ultra density optical (UDO) media are interesting, with manufacturers guaranteeing 50+ years of data retention.The drives start at about USD 1000, media are about USD 2 per GB, so UDO is not cheap. This may still be a viable option if the data is valuable enough.

Solid state memory, i.e. flash, is usually able to retain data for 10 years. After that, all bets are off.

There is, of course, an easy way to deal with these issues: copy to a new medium regularly. Regularly means that you must guarantee that a copy (better: two) is created well before errors can be expected.

Bit Rot

Data may change as the medium it is stored on deteriorates. Data can also change due to copying errors.

There are various techniques to detect and correct bit rot. They all involve checksums and error correction codes to correct problems.

Hardware Obsolecence

Hardware becomes obsolete with time. Do you still have a ZIP drive to read ZIP media? If you do, does it work with your current computer? And what happens when the drive breaks and you need a new one?

It is relatively easy to protect against this if you copy to a new medium (that is going to be supported for a number of years) regularly.

Format Obsolecence

If you have data stored in a proprietary format, chances are that you have experienced this problem already. It seems that every new version of Microsoft Word, for example, seems to introduce subtle differences in the way old documents look.

Data stored in an open format, preferably with one or more open source implementations for reading and writing the format, is much safer from becoming obsolete. It seems that JPEG and TIFF, for example, will be around for a very long time, if not forever.

 

So how does this translate into a viable strategy for keeping my digital assets safe for a long time?

First off, I keep all my data in open formats. For digital negatives, I use DNG files with XMP metadata. Processed files are stored as TIFF. I must admit that I sometimes also use PSD (Adobe Photoshop), which is proprietary and not open, but only to store working copies, which really only make sense in Photoshop anyways.

I then calculate an MD5 hash over each file which is stored with the file. This way I can easily detect changes to the file.

The files are stored on multiple hard drives. I use a combination of FireWire and USB external drives and internal drives that are quickly swapped using a Sharkoon SATA QuickPort which is a docking bay allowing a SATA drive to be connected to a USB port.

The drives containing multiple copies of the files are stored at home, in the office, and offsite (bank vault, friend's house, etc.).

I have a regular calendar task to check the hashes on every drive every few months. If a single error is found on a drive the entire drive is tossed. This is not a problem as long as there is still a good copy on a different drive. The integrity check has the added benefit of ensuring that the lubricants of the drive get a good workout.

There is another calendar task to replace every drive after it is 3 years old. With the inevitable march of technology increasing the capacity of hard drives, I can consolidate the content of two old drives on a single new drive.

 

This strategy is probably not perfect, but it does give me a high degree of confidence that the files will still be useable in the distant future.

Using Lightroom with Expression Media to Add Metadata to RAW Files

In the past, I have used Capture One Pro (C1) to edit the RAW files (which I exclusively shoot) and then output JPEG files. I would then employ iView Media Pro to add metadata to both the RAW the JPEG files. I exported the metadata to a XMP sidecar file for each RAW file and archived the RAW with the sidecar XMP.

It turns out that this workflow is far from ideal: both the RAW and the JPEG files' metadata needs to be kept in sync. If I go back to create another JPEG from a RAW that has already be processed, I have to manually copy the metadata from the RAW to the new JPEG because C1 3.x looses most of the metadata during processing.

When Adobe Lightroom (LR) came out, I started using it and eventually replaced C1 with it because (among other reasons) it supports XMP metadata very well. I can now add metadata to a RAW file and it will be preserved no matter what I do with the file in Lightroom (or Photoshop, for that matter).

But here the problems started: