How much light does a polarizer really eat?

My recent post about the amazing abilities of modern cameras was based on my bewilderment that I ended up with ISO2500 (using auto ISO) for an otherwise pretty "normal" photo, except that I was using a polarizer. Following that post was a nice discussion on Buzz too, it was interesting to read all the different thoughts.

Jao was rightly wondering what I was really doing there :) as the "sunny 16" rule should apply and that the polarizer would maybe cost some amount of light. Today, I tried it. Another mountain hike, about the same conditions. Bright sun, elevation about 1800m, polarizer... sunny 16 rule with polarizer yields this result:


Sunny 16 rule with polarizer (NIKON D700, 1/200s @ ISO 200; f/16, 24 mm (in 35mm)

Now, add a whopping 3 1/3 stops and you have the correct exposure, as indicated by the camera's light meter. Yes, 3 1/3 stops. Not one or two, more than THREE! Good heavens. Now I know why Singh Ray can get away with that price for their "light and bright" polarizers. ;)


Add 3 1/3 stops... (NIKON D700, 1/20s @ ISO 200; f/16, 24 mm (in 35mm)

The hike went to the peak of the Karlkogel at 2195m; I didn't make it to the peak of the Kammerlinghorn (2483m) (which was my original intention) because I'm about to catch a cold as it seems, I felt too exhausted to continue on to the Kammerlinghorn once I reached the peak of the Karlskogel.

Both are peaks of the Hochkalter or more precisely Hocheis group. Even with an itchy nose and a scratchy throat, the hike was extremely delightful - the area is unbelievably beautiful at this time of the year - turning leaves, larches changing their color from green to orange, the pastures turning from a thick green to a mixture of green and beige (photos will of course follow in a Picasa Web Album.) The Nationalpark Berchtesgaden is a real gem.

The camera DOES matter

One of the things that I repeatedly read anywhere in the photo-sphere :) on the web (and everywhere) is: the camera doesn't matter. The photographer matters. It's meant in the way that a fool can make a trashy photo with the most expensive gear, and a good photographer can make a compelling photo with something as cheap a camera (camera!) like the iPhone.

However... there's another aspect: modern cameras and technology enables us to go, photography-wise, "where no one has gone before" - the advance of technology that makes it possible to simply "get the shot". Because after "the best camera is the one you have with you", the best photo is the photo that you made - and if technology enables me to get photos in situations where it wouldn't have been possible before, the camera DOES matter.

It striked me when I was browsing the photos of my hike on the "Kleine Reib'm" (translates from Bavarian dialect to "the small round"). It was morning, I had the polarizer attached to my non-stabilized Tamron 24-135mm lens, to avoid shake at 24mm focal length I chose an exposure time of 1/60s, and since I made my experiences with the shallower depth of field on a full frame sensor I thought "what the heck" and set my aperture to f/16 - the camera, in Auto-ISO mode (which is the best thing since sliced bread in full manual mode I must admit) then chose a sensitivity of... ISO2500?!? Yes, really...

Please click here for a closer evaluation of the photo with 1600 pixels on the long side. No tripod, hand held, all the fun I could have, travelling light weight with a 5.5x zoom lens - my goodness, that is amazing (think of the grainy ISO1600 black & white films for a second, please, OK?). ISO2500.

Yes, I'm already spoiled by the D700 very much I must admit. But it's not limited to the Nikon D700/D3/D3s - they're going "extra high" for sure, but in general, most modern cameras produce VERY usable results even at ISO1600. And noooo, that wasn't quite so with my old Nikon D70s (and as of writing this, that camera is only 6 years old, it was introduced in 2004). With my D700, I can make photos in low light situations, and hand held, were I could not have made any photos with my D70s, or my Fuji S5pro. Or in a lazy and more comfortable way, without hauling the tripod around on a 9 hour hike, like above...

Or look at it the other way around: image stabilization. It's either built into most modern cameras, or into the lenses. The gain is something in the range of 2 to 4 stops. For the above photo, it means I could've made that photo at something like 1/10s and get a steady image - hand held of course (which also meant I could've used something as low as ISO640).

Here's to the advance of technology. Cheers! :)

Post Scriptum

My Picasa Web Albums friend Otto "telekia" Hauck shared his thoughts after my tripod post in a post on Google Buzz.

Jao van de Laagemat responded to my post about Chrome on Buzz and provided a solution to make Chrome at least respect the local monitor profile - you have to add the commandline switch --enable-monitor-profile to turn it on. Why is that not turned on by default?!? Chrome does not support embedded color profiles on Windows though (and I still have to solve that sharpness/resizing issue).

I added links to Franz Sussbauer and Norbert Maier in the side panel of my blog. Their landscape & nature photography is very much what I like.

Google Chrome: it's not meant for viewing photos

For quite a while, the presentation of my photos in my Picasa Web Album bothers me. I'm using a 21" TFT (1600x1200 pixels resolution, 4:3 aspect ratio) and my browser window is relatively big. When I open my Picasa Web Album the Picasa Web server delivers my 1600 pixel wide original upload downsized to 1152 pixels. However... when I look at the photo it's somewhat blurry and I always suspected the lack of sharpening for the scaled down version.

But that is not the case, because the right-click save-image-as version of that photo is not blurry. So it can't be the Picasa Web servers - it must be Chrome. For comparison, I made a screenshot and cropped the contained photo to it's visible borders - and guess what? The saved photo is one pixel higher than the version on screen. I checked and double-checked. It's true. I tried Firefox then, and when I had the Firefox window at the size where I would get the 1152 pixel version of my photo, I compared again - and the photo is not blurry in Firefox either.

Chrome does something weird to photos. It does not display the photo in the size that the Picasa Web server delivers it to me, it scales that (already scaled) image again - by one pixel! And that makes the whole photo blurry.

But that's not all. Chrome also does something terrible to the colors, and I stumbled upon it while making the above comparison with Firefox. In the past, I blamed the sRGB color space for that, but it's Chrome! I export all my photos directly from Lightroom to my Picasa Web Album and use the sRGB color profile. However, in Firefox the colours (especially blue!) appears exactly as it should be, but in Chrome, it's simply way off.

Here are the two screenshots (just click on the for the full size file, both files are about 1.7MB) as lossless PNG files, first Chrome:



And now Firefox. Look at the blue of the sky:



What can I say... Google delivers an excellent photo hosting service that gives us ultra-fast navigation, biiig photos, and lots more, but the appearance of the photos sucks when you're using Google's own browser. That's quite a pity, isn't it? I love Chrome, but I wonder how many photos I looked at were the colors where not what they should be. Ouch, that really hurts.

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Addition on 18-Sep-2010: Please read the Post Scriptum follow-up, too. :)

The best tripod...

Just like the best camera is the one that you have with you, the best tripod is the one that you carry. And just like I replaced a more complete set of lenses with the Tamron 24-135, I stopped carrying my regular tripod on my hikes for convenience reasons. I think that a tripod in general is just too heavy to carry around, and it's uncomfortable and somewhat bulky too - not exactly the thing you want to haul around on hikes that last a couple of hours. No, I'm not a masochist, and with modern camera's high ISO image quality, it's not really necessary to carry a tripod all the time, anyway*.

Except for the occasional long time exposure. On my way back down to the Heutal from the Sonntagshorn peak I was attracted by the beautiful creek that runs along the last part of the trail:


Hochalmbach (NIKON D700, 10s @ ISO 100; f/25, 34 mm (in 35mm)

I made it a habit to carry an old and veeery very lightweight tripod with me on my hikes, it seems to weigh no more that some 300-400 grams, and I used it for this photo. And it occurred to me that I should document this, so I made a photo of that wonderful helper, too:


Featherweight tripod (NIKON D700, 1/60s @ ISO 500; f/5.3, 82 mm (in 35mm)

It's really really only suited for a compact camera, but it holds the D700 + Tamron 24-135 if I only extend one of the leg sections (as shown in the above photo) which is enough for many situations. I didn't have my cable release with me, so in order to minimize camera shake on that flaky little tripod, I set the camera to a self-timer and turned on the automatic mirror pre-release (the mirror is moved up and only after a short delay the shutter is opened to reduce the shake from the mirror movement).

Well, perhaps it wasn't really necessary, because using a polarizer and stopping the lens down as far as possible to get an exposure time long enough to nicely blur the water degraded the image quality anyway. :-)

*) Yes, blasphemy - what about the precise framing, composition, etc. etc. - I hear you, I hear you... :)

And a late PS: I wrote about capturing water in motion before here. I'm glad that what I said is true for the above photo of the brook - 10 seconds are required to make it really smooth. This is especially important because of the little pond - the water creates reoccurring ripples and bubbles there that move in circles, and anything below 10 seconds just doesn't look good. 15 or more seconds would have been ideal, but I didn't have my neutral density filter with me.

Am I Understood?

Last Sunday I made the hike to the peak of the Sonntagshorn (link goes to the German Wikipedia article; the English one is a stub) once more - it's the highest peak in the Chiemgau Alps region, close to 2000m (about 6500ft.) and it's a relatively easy hike from Heutal (only about 1000m - 3300ft. - total climb). The weather... well, it could have been better. The day started with fog that quickly dissolved with the morning sun, but before noon already clouds started to move in.

But I think that clouds with mountains are a great mixture, and during the ascend at some point the trees on a ridge kept appearing and disappearing in the clouds - I really liked that and waited with the camera for a good moment to make this photo:


White Out (NIKON D700, 1/200s @ ISO 320; f/11, 105 mm (in 35mm)

As I stood there waiting with the camera another hiker already on the descend passed me by and the lady looked at the thick white wall of clouds I was looking at and asked me: "what are you making a photo of?" (and yeeeeeeees, there was a good amount of bewilderment in her voice). I told her. I don't know if she really understood.

Actually, that happens quite often: the photos that I like best are not the ones that receive the most praise from the audience. I think that the difficulty in making successful photos is to keep it on a "sane" level that everyone can understand and appreciate.

For example - I do like the challenge of submitting photos to SeenBy, but the photos that receive the most comments and "likes" in my Picasa Web Album are not the ones that made it through the approval process of SeenBy.

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And just for the sake of completeness, here's the de-speckled :) version of the photo I showed in the previous post:


Ridge in Clouds (NIKON D700, 1/200s @ ISO 200; f/11, 100 mm (in 35mm)

Clouds and Sensordust

Want to find out how much dust you have gathered on the precious sensor of your DSLR? Just make a photo of a very bright subject (like the trees on a ridge in a cloud on a September day while hiking... like I did... or use the technique that I described in my "Californa Screaming" article), use Lightroom's Auto Tone function, and apply John Beardsworth's "Ultra Clarity" Lightroom preset:


Clouds and Sensordust (NIKON D700, 1/200s @ ISO 200; f/11, 100 mm (in 35mm)

Click on the photo for a 1600px version (not opening in the Lightbox this time)...

It's shocking. And I bet it's not quite the usage that John Beardsworth had in mind when he created the preset. The good thing is that without this preset, not much of it is really visible. And now excuse me while I use Lightrooms clone tool for the next 3 1/2 hours - because I kinda like the above photo with that preset applied. ;)

Developing your own photos

Recently I've been following one of the countless discussions about raw data vs JPEG in a forum (once more). Frequent readers of my blog know that I am all "pro raw" for various reasons, but of course, there are enough reasons to not use and store raw data, either*.

In the end, it's just a question of personal preference. For me, it boils down to: what do you want to do with your photos after you made them? Get artistic and utilize all of the tonality, dynamic range, detail? Or do you prefer to make only some basic adjustments, then print them or show them online quickly?

That's how the discussion went. One "pro raw" participant said that developing his own photos from raw data is not a burden to him, but a joy - he compared it with spending time in the darkroom, getting the best out of your (analogue, film) negatives. Working in the digital darkroom is a part of the creative process, and I couldn't agree more with that!

I remember how I used to be "stuck in JPEG think" when I began my exploration of digital photography. I couldn't imagine why I would need or want anything else but that what the camera JPEG already delivered. I began working with raw data not for artistic reasons, but to circumvent the shortcomings of the (somewhat aged) JPEG engine of the camera I was using back then (the Nikon D70s) - I could salvage an enormous amount of detail in both the shadows and the highlights when using raw data. That was the key for me.

The more I worked with raw data, the more I realized that I have a lot more possibilities to work on the photos my way and present my vision to my audience. So... I want to explain and discuss my own thoughts when working on a photo with this post to maybe, maybe ignite the artistic flame, and encourage those to be creative who wish to leave the path of "photography is an accurate representation of reality" (in the end, you have to find your own way - but just as usual, I'm only trying to offer a hint, a direction, a shortcut based on the experiences I made).

I picked this photo from a recent walk in the woods near Hofstadt in Austria for that. This is the small creek that feeds my beloved Huckinger See where I've spent countless hours (and made countless photos, too). After a rainfall, it was much bigger than normal, and its sound made me leave the usual track and find out where it comes from. This more or less the "camera neutral" rendition of the file, with Lightroom's "Daylight" white balance preset:


Creek in the woods Original) (NIKON D700, 6s @ ISO 100; f/16, 24 mm (in 35mm)

My first thought when I looked at it was: I must "carve out" that quality of the light, how it shines through the trees in the upper left and illuminates the water surface of the creek. A strong black & white edit seemed to be most fitting for that: take away the color and reduce the photo to the shapes and light & shadow only.

I increased the luminance of the green tones and reduced the luminance of the blue tones because I like the greens very bright in black & white. I also applied a perspective correction with Lightroom and made some further adjustments until I ended up with this:


Creek in the woods (black & white) (NIKON D700, 6s @ ISO 100; f/16, 24 mm (in 35mm)

However... the longer I looked at it, the more I felt that the black & white interpretation was "too hard". It was early in the evening and except for the calming sounds of the creek, it was very quiet and peaceful. The black & white transported the quality of the light very nicely, but not the overall mood. I wanted a softer rendition. A "quiet" rendition:


Creek in the woods (final) (NIKON D700, 6s @ ISO 100; f/16, 24 mm (in 35mm)

I decreased the overall Clarity a lot for this version, and partially added it again just in the middle of the frame on the green leaves with the local adjustment brush. I carefully used the Recovery function and tone curve to reduce the hard highlights on the water surface while preserving a good amount of contrast. Vibrance has been reduced a good amount too, to decrease the impact of the colors, and to further "flatten" the color impression I used the Split Toning function (cyan toning the lights, magenta toning the shadows). I wanted to preserve color, but I didn't want it to be dominant (I slightly adjusted the crop too to avoid the cut in half tree in the upper right; I didn't notice that black line at first).

Would it have been possible to get the same result from a JPEG? I don't know for sure (but I don't think so - without raw data, I wouldn't have been able to adjust the highlights so nicely), but that's not my point, anyway. Working with a tonality and dynamic range wise limited JPEG can sure be a show stopper, so my point is that I can be sure that I do have the possibility to be creative like this when I'm using raw data. Needless to say, the "final" is my favorite version. :-)

Have a nice weekend, everyone!

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*) for example, I lent my S5pro to a friend who wanted to try what it is like to use a DSLR - and since he was using only point & shoot cameras so far, I configured the S5pro so that it would be most easy for him to make his first steps (a "shake safe" Auto ISO configuration, program automatic, matrix metering, autofocus activation on the shutter, etc. etc.) - and I of course configured the camera to store JPEG: first, he can fit thousands of photos on the memory card that way and just go ahead and let it click as much as he likes, and second, he has photos that he can immediately view, transfer to his computer, etc. (and the S5pro creates beautiful JPEGs, of course).