Wednesday, July 29, 2009


That has to be the most beautiful lizard I've ever seen!

Pentax K10D + Zeiss Sonnar 85/2.8

Friday, July 24, 2009

A close look at my lawn

There's a whole world of shapes, colors and shades going on in my lawn. Capturing it is an interesting exercise in composition and lighting.

Pentax K10D + Zeiss Sonnar 85/2.8 + extension tube + off-camera flash

The round prickly things on the photo above were about 5 mm in size.

Tuesday, July 21, 2009

Highway underpass

Portugal has an excellent highway system nowadays. One can get from here to there in no time at all. As a consequence, some areas of the countryside are now striped with highway patterns. This is specially evident in the more densely populated Northwestern region.

The photo below shows a highway underpass we crossed during a country road hike this Spring. It is convenient to drive on it, but quite a nuisance to hike under it. By the way, that's my family over there: daughter, wife and son (on my wife's back).

Pentax K10D + Zeiss Distagon 25/2.8

Friday, July 17, 2009

Even more difficult: two flashes at the same time!

Back to my off-camera flash endeavors.

Pentax K10D + Zeiss Sonnar 85/2.8 + 2 off-camera flashes

I used two flashes on this photo, both diffused with an open white plastic bag. One was on the same table as the flower, to the left, and the other on a tripod, to the right and slightly higher. I tested different power ratios on both flashes, until I got the exposure I found appropriate. The camera was handheld, as I wanted to be free to try different perspectives.

Then I tried a version with more selective lighting. I put my cardoard snoot on the flash that was on the tripod, directing the light to fall just on part of the petals, and tried different positions for the other flash, still diffused with the plastic bag. After only a few tries I obtained something I liked, shown below. The fact that one can obtain instant feedback from the camera's display facilitates the flash use immensely. In the times before digital, it could be a complex task to accurately predict how the light would fall on the subject. To overcome that, photographers often used modeling lights, but these could still be difficult to adjust in order to properly reproduce the flash output.

Instead of flashes, one can, of course, use continuous light sources (regular tungsten even) to obtain similar results. However, flashes present some important advantages in terms of portability and versatility. Besides, the intensity of light delivered in a short burst allows for using short exposures and can even make the use of a tripod unnecessary. For the same effect, a continuous light source would need a high power rating and imply significant heat release, unless "cool lights" are used, like compact fluorescent light bulbs. Another problem might be properly correcting white balance when light sources with different color temperatures are used.

Tuesday, July 14, 2009

A portrait

I have some reserve towards displaying family photos on the net. One never knows where they will end up - see this post at The Online Photographer for a disturbing example. And since I'm not into photographing anonymous people, I end up not having any portraits to show on the blog. Well... that's not quite true. Here's a great portrait of my in-laws dog:

Pentax K10D + Zeiss Sonnar 85/2.8

I'm quite proud of this photo. The restlessness of the model turned using a manual focus lens into quite a challenge. And just look at the oozing creaminess of that bokeh!*

* Private joke for those who read this older post.

Friday, July 10, 2009

White flowers and dry branches

What makes this photo visually interesting? Correct! That darker diagonal line that divides the image and somehow introduces some order on the otherwise chaotic composition of randomly oriented small branches.

Pentax K10D + Zeiss Planar 50/1.4

Monday, July 6, 2009

Will the Pentax K-7 be a high-ISO disappointment?

I have written before that I would like to use a camera capable of generating high ISO (well above 1600) images with negligible digital noise and artifacts (like banding). Such cameras exist in the full-frame sensor range, the Nikon D700 being an extraordinary example. Even some cameras with APS-C sized sensors show quite "clean" results, like the Nikon D300.

The announcement of the new Pentax K-7 has created a lot of fuss around it's noise performance. After all, the official news release announced: "With the adverse effects of digital noise greatly reduced, the sensitivity can be increased from ISO 100 up to the highest level of ISO 6400 (via a custom function) without worry." When photos taken with pre-production cameras started showing up all over the internet, people started closely inspecting the quality of the pixels originated at high sensitivity levels, burning their eyelashes against computer screens over countless sleepless nights. A lot of the commentary seems to indicate that, in terms of digital noise, the K-7 is similar to the K20D, which is not exactly spectacular (but is not that terrible either). Many Pentaxians went into deep depression after knowing this. I'll wait to see the first "official" reviews from the sources I trust - a few photography magazines and websites - before making my own opinion. But I find all this discussion a bit... let's say... irritating.

I like to look at an image as a whole - admiring the noiseless smoothness of 100% crops seems a bit geeky.

I have a K10D, which can only go up to ISO 1600 (the K20D goes up to 6400, same as the new K-7). At ISO 800, noise is already so evident that many "pixel-peepers" would vomit over the computer screens, unable to control their repugnance. At ISO 1100-1600 the images are considered unusable by many, unless they can be saved by some specialized noise reduction software. Actually, many consider that ISO 1600 is unusable even on the K20D!

Even though - allow me to repeat - I would appreciate being able to experiment with a camera capable of producing cleaner images, I'm far from despising the high ISO output from my K10D! Let's look at a quick and dirty example. I've taken the photo below (two objects placed on our black dining table, under the room's regular tungsten lighting) with the camera set to ISO 1100 and the in-camera noise reduction turned off, even though I think it only kicks in at longer exposure times. Note that similar results were obtained with ISO 1600, I'm showing this example just because I like the composition better. The photo was taken at 1/15 sec and f5.6. The exposure was set manually, as I didn't want to go lower than 1/15 sec in this handheld shot. The image below was converted from the original RAW file, using Silkypix 3, setting all the noise reduction parameters to zero (that means no noise reduction applied) and without any exposure or color adjustments.

Pentax K10D + Zeiss Sonnar 85/2.8 (ISO 1100, unprocessed RAW file)

It doesn't look very good, really, but that isn't necessarily because of the noise. So I used Silkypix to make some modifications and try to obtain the result I had in mind. But I kept all the noise reduction settings at zero - I actually was going for a "grainy" image - except for the false color control, which stayed at the default value of 30%. I used the tone curve to adjust contrast, making the table top darker and the coffee cup lighter. I also adjusted the white balance. It is a known fact that the auto white balance in Pentax cameras does not (intentionally?) correct the yellowish tint caused by tungsten lighting. That's OK, sometimes one want's to preserve that warmer tone.

Same photo as before, after tone curve and white balance adjustments

So how does the image look like now? Quite nice, in my humble and biased, opinion. How did this happen? Darkening the shadow areas helped a lot. The table top became closer to solid black and the noise speckles less intrusive. The image is still noisy, as you can see it in the crop on the left - the cup was outside the depth of field, so please don't comment on sharpness. But does this mostly untreated digital noise render the photo unusable? Not at all, I actually think it looks nice and fitting to the context of the image. Some professional photographers work at high ISO specifically to get some "grain" on their images. Others use software to simulate that fabled "film grain" look.

The K-7 seems to be an interesting camera in many aspects. High ISO perfection might not be one of them. How important is that, though? Digital noise can be seen as an image property, just like exposure or white balance. As long as one is shooting RAW, it can usually be manipulated within a reasonable range, in order to produce results in accordance to the photographer's personal taste. Complete elimination of visible noise is not necessarily the desirable goal. There are exceptions, of course - I would avoid a noisy output if I were trying to preserve detail in a macro shot. A different issue is when one wants to shoot JPEG straight out of the camera. In that case, the post processing possibilities are much limited and a camera with a "cleaner" output might be a wiser choice, if one intends to work at high sensitivity levels.

Thursday, July 2, 2009

The subtle art of lighting

For a while that I've been willing to gain some serious experience with off-camera flash(es). However, the concepts of automatic flash or (P- or E- or A-) TTL have always seemed a bit awkward to me. In other words, I just wasn't having much fun using those "advanced" features. Besides, the TTL and P-TTL modes on my Pentax flash don't even work with the "manual" lenses I'm using now (no electronic communication between the lens and the camera body).

That's when I started perusing over the "Lighting 101" and "Lighting 102" archives at the Strobist blog, by professional photographer David Hobby. That's an extraordinary place to learn how to properly light a scene, using small flashes, a few props and a lot of excellent ideas. Most of all, it sparks one's creativity with well conceived examples and challenges. If you know that blog already, reading the rest of this post will not teach you anything new, but if you don't, then please don't click on that link yet! Before I loose you to the addictive world of strobing, let me describe what I've done so far.

Thank you! One of the things that I enjoy in David's approach to lighting is that he uses the flashes in manual mode, dialing down the appropriate power ratios based on the feedback from the camera's display. Perfect! He also suggests the use of several accessories, some improvised and inexpensive, like "plant-cookies" (check it out yourself), others more specific and a bit more costly, like radio triggers or umbrella diffusers. My family is not yet prepared to see me assemble light stands, diffusion boxes and umbrellas around the dining room, so I'll be using some simple, low profile and improvised gear for a while. At least until I'm taken a bit more seriously on my photographic endeavors...

There was one gadget I could not improvise: the remote trigger/receivers. Off-camera mounted flashes are essential if you want interesting lighting results. My Pentax AF-540 flash can be remotely actuated by the K10D, via an optical signal, but this feature is disabled when using manual lenses. So I got a Cactus V2s system, composed of one trigger and two receivers. This way I can use both my Pentax AF-540 and my old Contax TLA-30 simultaneously. The Cactus radio trigger/receiver sets are much cheaper than the more professional alternatives, like the Pocket Wizards. However, they have been getting some bad publicity for being unreliable. I've had no problems so far, even on outdoors use, but I haven't tried large triggering distances yet.

Let's talk about my first experiments. I decided to attempt a low-key photo of a complex subject, rarely seen in still-life work: an apple.

Pentax K10D + Zeiss Sonnar 85/2.8 + extension tube + Pentax AF-540 flash off-camera

OK, I'm kidding, everybody and his cousin has already taken close-up photos of apples... But I really like the painting-look of my photo. The only post-processing consisted on contrast adjustment, mainly to make the background uniformly black. I used a single flash, placed about 20 cm (8 in) to the left, slightly higher than the apple. I covered the flash head with an open white plastic bag, which worked as a diffuser. This way I got a soft light wrapping and avoided a harsh highlight reflection on the curved surface.

After deciding where to place the flash, I could manage the light intensity using three factors: flash power rating, lens aperture and ISO sensitivity. In this case I set the aperture to f11, in order to get an appropriate depth of field, and the sensitivity to ISO 100. Then, after a few trials, I found that the best power ratio was 1/32. The shutter speed was 1/180 sec - the maximum sync speed on the K10D - and the camera handheld.

The background must be kept strongly underexposed, so it is a good idea to stay away from walls and other light surfaces that may reflect stray light. By the way, the room lights were kept turned on, to help focusing and composing. At 1/180 sec and f11, the camera can't really capture the ambient light.

Another example: an image of a hydrangea flower lying on top of a water-filled glass. I didn't want any direct light to hit the glass, since this would create several distracting reflections. So this time I used a snoot instead of a diffuser. My snoot was a black cardboard cylinder slipped onto the flash head. This way the light can be directed to fall only on a very small area. This was my favorite image:

The flower gets most of the light, as intended, and the glass is not intrusive at all, being reduced to only a few subtle reflections, which I find quite beautiful.

This is simple stuff, really. Most of it has to do with experimenting and keeping a few key guidelines in mind. OK, thanks for bearing with me. Now you can go to the Strobist and learn with the pro!