Pentax May Outing: Helix Bridge

For our May Pentax outing we went to the new Helix Bridge, a new footbridge spanning the Singapore River. The shape of the twisted metal is supposed to represent the helix structure of DNA. All very nice but unfortunately I just think it is just a vanity project to beautify the skyline and to complement the new integrated resort (read casino).

Being very warm and sunny, it was a perfect day to shoot some IR images. Took this shot of the Singapore River using the DA 21mm Limited. An IR image that was converted to black and white.

For the actual photos of the bridge, I decided to use a pseudo high contrast HDR treatment to the images. Used the DA 10-17mm fisheye and the DFA 100mm Macro WR for the close-up.

More From MacRitchie Reservoir

A few more infrared images with the DA 18-55mm II kit lens. These were taken near the Singapore Island Country Club.

Some Images From MacRitchie Reservoir

About two weeks ago we had our September Pentax users outing at the MacRitchie Reservoir. We had quite a good turnout as well as workout walking through the park and forest trail. Took more shots with my infrared modified *ist DL2 than with my K20D.





Been really busy with work that I've just not been able to upload the images that I took. Here's a selection, all with the DA 18-55mm II kit lens, truly a very useful lens for IR photography.



Along the forest trail, the light was diffused and light levels were pretty low, making shooting a challenge.





Particularly liked the shots under a bright intense sun with water in the foreground.

Training Alone

Took a walk around a park with my Pentax *ist DL2 when I came across this wheelchair bound person doing his workout. He was approaching very fast and was a picture of pure determination. Thought about shooting him as he approached but as I saw the road markings I knew it would make a strong composition, and made the shot as he passed by.


Pentax *ist DL2 DA 14mm f/2.8

Kids & Dogs

Took these IR shots of kids with their dogs at the Singapore Botanic Gardens. Particularly like the sensitive expression of the girl with her dog. In contrast, the three boys were pretty rough and tumble in their play. All taken with the Pentax *ist DL2 with the FA 28-200mm zoom.

DA 14mm Tryout

Just a couple of days ago I was at the office of Shriro, the local Pentax agent here in Singapore. The friendly folks there offered to let me try out the DA 14mm f/2.8 wide angle for a couple of days. Since I let go of my DA 16-45mm f/4 a few months back, I don't have a rectilinear wide angle that goes wider than the DA 18-55mm II. So I welcomed the opportunity to satisfy my curiousity and get acquainted with this lens.





In making a choice between the current crop of Pentax wide angle lenses, it's a toss-up between the DA 14mm prime and the DA 12-24mm f/4 that Pentax jointly developed with Tokina. The prime has the edge in maximum aperture while the zoom has the versatility of having a range of focal lengths and it also goes wider. It is also more expensive than the DA 14mm.



Looking at specifications alone isn't enough as wide angles offer a dramatic perspective that one needs to appreciate first hand at the viewfinder. I opted to try out the DA 14mm. My reasons were threefold: to see if the f/2.8 really made a big difference, to find out if the angle of view was wide enough and to see if the lens was IR friendly (no hot spots). The answers to all three questions were a resounding yes.



I'm sure I would like the DA 12-24mm for the focal length versatility, but I've been told it hot spots when taking IR images, which is unfortunate to say the least. The DA 14mm is very solidly made, is optically sharp to my estimation, controls flare quite well and focuses very fast. I've enjoyed my brief tryout with it and this will certainly be one lens that I'll definitely be on the lookout in the near future.



Here I've taken a few images using my IR modified Pentax *ist DL2 at a reservoir near my home. I've managed to enjoy the camera more and have gotten the hang of fine tuning the post processing the IR images. Post processing was done with Photoshop.

Getting Familiar With Shooting IR

A few more IR explorations. Took these scenic landscapes with the *ist DL2 with the DA 21mm Limited. As I mentioned awhile back, digital IR photography is essentially a 2 step process: capturing the IR image on camera and secondly, post processing the images.



In the short period that I've been shooting digital IR, I've found that I've needed to pay attention to a few areas prior to shooting. First order of the day is to establish the baseline white balance of the camera. This applies to both modded IR cameras or a DSLR with an IR filter attached. Taking a manual white balance reading from something that reflects a lot of IR light like a patch of green grass/leaves in bright light is the proven method. The key issue here is taking the WB reading in bright sunlight. Take a WB reading on an overcast day and you're likely to get a somewhat different result when post-processing later.



IR images look best when there is good contrast in the scene. That said, it is pretty important to get the exposure right to reduce subsequent post processing issues. Because only a fraction of the light spectrum is recorded on the camera's sensor, I tend to think the camera's dynamic range is reduced a little.



Underexpose and you're likely to have flat or noisy images. Blow the highlights and you lose detail. The best aid in exposure determination is using the camera's histogram on the LCD as it can be difficult to eyeball the reddish brown images captured on-camera. As exposure can vary according to the scene, it is a good idea to bracket. It is also a good practice to delete those images that for want of a better word, "cannot make it".



Shooting in Manual mode offers the best control but shooting in Aperture priority with +EV compensation is another workable method. Focusing wise, autofocus is definitely useful. To compensate for the slight shift in wavelength, some tweaking of the AF in the debug menu (for a modded IR camera) is good, but if you're using a standard DSLR with screw-in IR filters, stopping down will cover the slight focus shift. Use the lowest ISO setting possible.



The images here were taken just a few days after I got the modded camera. They aren't perfect in my opinion. The WB wasn't really spot on and I was a little rusty in the post processing department, but these so-so shots provide good feedback on small details that need to be worked on to get one's personal look in IR lanscapes. I'll post some information on the post processing that I use in a later post.

Going Ga-Ga Over Infraread

Yesterday, my Pentax pal dropped me a text message that he had a Pentax ist DL2 that had been converted for infrared (IR) photography available. Decision time, so without hesitation I immediately jumped on the offer.


Pentax *ist DL2 with the DA 14mm f/2.8

The *ist DL2 was the last iteration of the Pentax *ist series DSLRs and was introduced just a few months before the K100D. Pretty much identical in specification to the K100D with the exception of in-camera Shake Reduction and fewer AF focusing points.



The *ist like the K100D series uses the excellent 6.1 megapixel CCD sensor. It's favored for IR because the sensor is particularly receptive which allows exposure times to be relatively short. On an IR modified camera, the camera simply has it's sensor's low pass filter removed. In it's place a very thin infra-red filter is installed. In this case wavelengths lower than 720 μm are filtered out.



Well you may be asking what's the practical benefits of having a IR modified camera as opposed to a conventional DSLR with a R72 IR or equivalent filter mounted? Basically there two. Firstly, as there is no IR filter in front of the mounted lens, the view in the viewfinder is clear, just like a normal DSLR. This greatly speeds up the process of picture taking.



The second obvious advantage is in exposure times. The IR filter mounted at the sensor is much thinner than a conventional screw-in filter. This allows exposure times to be reduced well within the limits of hand holdability. Roughly speaking, depending on the subject, exposure is typically between +0.7 to +2.0 EV over what the camera's TTL meter suggests. The shorter exposure opens up a wider realm of picture taking opportunities.



Shooting people is always a challenge because of the exposure times but the examples of a wedding couple that I shot show the capabilities of a modded camera. Skin tones take on a ghostly shade of white, but after all that's the fun of shooting IR. Lens used was the FA 28-200mm zoom.



With newer DSLRs with larger megapixel count being introduced, the generation of 6.1 megapixel cameras of the *ist and K100D series now seem to be overshadowed. The option to convert these cameras to be dedicated IR only cameras is an option I would recommend for those of use contemplating buying the newer crop of DSLRs. IR photography is fun, and a converted camera definitely brings the fun back.

IR & Hot Spots

Just a few days ago, I decided to try out a IR filter that I had ordered off the internet from a Chinese seller a while back. At about S$23 inclusive of postage for a 52mm size, I figured it was a small enough amount and I was curious to find out how it would compare with the Hoya R72 filter I already had.



After a visit to a client and having some time available, I decided to drive to the Upper Pierce Reservoir to try out the new filter in combination with my Pentax FA 50mm f/2.8 Macro and Sigma 28mm f/2.8, both sharing a 52mm filter thread.



One thing that I noticed when compared to the Hoya R72 is that the quality isn't half bad. The filter ring is pretty solid and actually heavier than the Hoya and the filter itself is made of glass. Looking through it, it isn't as red as the Hoya and honestly I have no idea whether the markings match the cutoff frequency. Oh well, time to give it a test.



Most of my shots were taken with the 50mm Macro. To my disappointment, the lens exhibited quite a tell tale hot spot when I post processed them later. This is yet another Pentax lens that showed hot spot, the other being the Pentax DA 16-45mm. Fortunately, I also carried an older Sigma 28mm and it helped salvage the session (last three images).



Hot spots become more distinct as the lens is stopped down. This makes it kind of useless when one needs to take scenics where maximum depth-of-field is needed. As for the effect of the made in China filter, it works. Images after a channel swap are quite similar to the Hoya R72 but where the Hoya has more prominent yellow/browns, this one is a little bluer.

IR Skyscapes

Here's a couple more IR images taken at different locations in Singapore. Taken in between visits to my clients. It was a bright sunny day but I still shot at ISO 1600 in jpeg.


Boon Keng

The noise is apparent, and I've been told is more apparent in IR because as the IR filter cuts out most of the visible spectrum (especially blue), only a portion of the sensor is active to record the image. With a high ISO setting, this exaggerates the noise level. Honestly I can't conclusively verify this bit of info but looking at the results, it's plausible.


Beach Road

I normally don't like grainy pictures, perhaps a carry-over from the time I shot 35mm black and white, but I think it works here. Images taken with the kit lens with R72, all cropped in manual mode. Images processed with a channel swap in Adobe Photoshop and minor tweaks with curves to adjust contrast and exposure.


Collyer Quay

Neighbourhood Kitty in infra-red

Shooting IR usually means long exposures and that typically means using a tripod. Fortunately the Pentax K100D sensor is pretty sensitive towards infra-red, allowing a manageable shutter speed for hand holding to be used in bright sunlight. Here's where the camera's in-body Shake Reduction also helps to ensure pictures turn out sharp.


Well I decided to try shooting hand held at ISO 1600 on the K100D. Many IR images are typically associated with landscapes with lots of green vegetation, so I thought it would be interesting to find out how a subject like a friendly neighbourhood cat would turn out.


One thing I noticed is that the cat's ginger coat appears different when shot in IR. The first picture is straight from the camera before post-processing as it has the characteristic sepia coloured tone. However the cat's ginger brown patches takes on a purplish tinge. Actually the image doesn't look so bad and can look quite nice if it's desaturated a little. The second and third images have had a channel swap in Adobe Photoshop's Channel Mixer.


Another thing I noticed is that at such a high ISO setting, there is a noticeable difference in the noise level when shot in jpeg as compared to RAW. Image quality is so much better when the jpeg file is saved from a RAW file as compared to a straight in-camera jpeg. Images taken with the DA 18-55mm and a Hoya R72 filter straight from camera with no cropping.

Dabbling in IR Photography

Infrared photographs intrigue me. Ordinary scenes take on a new look when given the IR treatment and suddenly the mundane become extraordinary.

Recently I took the plunge to try out IR photography using my Pentax K100D by buying a Hoya R72 infrared filter. That R72 refers to the cutoff wavelength where visible light gets filtered out, in this case below 720nm. The Hoya R72 is about the cheapest branded IR filter available, though there are online sellers from China that sell their unbranded IR filters quite a bit cheaper.


I've taken pictures for quite a while now and thought that taking IR pictures would be pretty simple. Was I dead wrong! My initial pictures turned out all red. Not knowing what to do next, I was prepared to abandon all thoughts of dabbling in IR. Fortunately help came in the guise of a friend on the photographic forum Clubsnap. Not only did he gave a detailed walk through of the IR work flow but a hands on shooting session helped clear up any issues.


My initial pictures were taken with the Pentax DA 16-45mm during dreary overcast weather, not the sort of weather conducive for nice IR images. The DA 16-45mm exhibited some hotspots and a washed out centre. Not the most suitable lens for IR.

The images here are from my second attempt using the DA 18-55mm kit lens at the Singapore Botanic Gardens. Surprise, surprise, this lens proves to be excellent for IR photography. One thing to note is that since plants and leaves reflect a lot of infra-red, they will appear brighter while blue skies have little or no infra-red and thus will appear darker in IR photography. All images shot handheld with the Pentax kit lens at ISO 1600 with no cropping using a 52mm Hoya R72 IR filter.


Essentially, taking IR photographs is a 2 step process: taking the image and post processing.

To shoot IR you need your DSLR, an IR filter for your lens and a tripod. The Pentax K100D is in this respect better at taking IR than the K10D. The K100D sensor is more sensitive to IR and allows shorter exposures than the K10D. Setting the custom white balance is also easier.


This instruction applies to the K100D but if you're using the K10D or some other camera, you'll need to experiment accordingly. Thanks to Wee Kiat for the following pointers.

WB Setting
With the IR filter attached to the lens filter mount, take a custom white balance reading of something green (like green grass or leaves) in strong light. Make sure the entire frame is filled by the green subject. Getting the custom balance right makes all the difference in the colours you're gonna get later. There are other methods to set WB that I have yet to try, like using a custom WB filter but this one works.


Shooting
Remove the filter from the lens, compose the scene in the viewfinder, affix the filter again and look at the camera's meter reading. You'll need to do this because once the filter is in place, you'll see next to nothing in the viewfinder. It would be a good idea to use a tripod because exposures can exceed 1 second, depending on the subject brightness, weather condition/time of day and aperture setting.


Setting the camera to full manual mode and using RAW mode is best. Ensure that the exposure combination you set indicates between +2.5 to +3.0 times over the what the camera's meter reading indicate. Using identical K100Ds, my friend and I found out that IR sensitivity can vary slightly from camera to camera. Take a shot. To check if the exposure is spot on, look at the histogram curve on the LCD. It should be kind of even and your image should appear to have a sepia like tone. Bracket if necessary.


Post Processing
The second step relates to post processing. If you're using Pentax's Photo Laboratory, click the grey point setting on something that you know is green in the scene (a leaf, tree, etc.). Save the file. The image then needs a channel swap to give it the characteristic IR look. In Adobe Photoshop, go to Channel Mixer and change the following settings:

1) Red channel : Red 0 Green 0 Blue 100
2) Blue channel: Red 100 Green 0 Blue 0
3) Green channel: Red 50 Blue 50 Green 0 (you can experiment on the red and blue amounts but it should add up to 100)


From here onwards, you can experiment freely by adjusting saturation in Hue/Saturation, curves, add a tone, adjust shadow/highlight etc. limited only by the effect you want and your free expression. For example, the shot above has been post processed a little differently.

IR definitely is fun and the K100D with the kit lens make an excellent combination. Go try it!