Saturday, July 16, 2011

24TSE Mk I vs Mk II

I had always been happy with the Mk I lens on my cropped camera (30D)--okay maybe there was a bit of chromatic aberration (CA), but it was manageable--but I just wasn't happy with it on my 5D2. The Mk II version of the lens was reputed to be better, but my question was: is it enough better to justify the extra expense?

So, on a recent trip to the mountains, I borrowed a Canon 24 TSE Mk II to compare against my Mk I version on my full frame camera (5D Mk II). The weather on the trip ended up being less than wonderful, but I did get a chance to make a pair of test shots. The whole frame (reduced in size, of course) is shown below for both lenses (both on the 5D2). I have done nothing to the images beyond running them through RAW conversion in ACR 5.7. This includes a small amount of capture sharpening. But there is no further processing, and no output sharpening. CA was not addressed in any way.

The images below were taken with the camera horizontal, and the lens shifted upwards by 6 mm (on the scale on each lens). Yes, I know I cut off the top of the mountain--I did that so there would be some detail at the top of the frame.
Mk I

You can't see much in those web-sized images. So I'll show some 100% crops below. The first two are from near the top of the image--since the lens is shifted up, this means these are from near the edge of the lens' image circle.
Mk I

The next crops are from much lower down in the image--i.e., from closer to the middle of the image circle (recalling that the lens is shifted up).
Mk I
Mk I

For the images at the edge of the image circle, there is a world of difference, both in sharpness and in CA. The Mk II lens is most definitely improved over the Mk I! Near the middle of the image circle, however, there is almost no real-world difference in sharpness. The Mk II has essentially no CA in these images, while the Mk I has only a tiny amount.

Conclusion: For a 5D2 (or other full frame camera), the Mk II version of the lens is definitely superior. For a 1.6 crop camera, however, a Mk I version in the used market would be a very good value and most users would be happy with the results.

Other points:
1. The Mk II is noticeably larger and heavier (780 g vs. 570 g -- a 37% increase in weight).
2. The filter size is 82 mm on the Mk II as compared to 77 mm on the Mk II. I have other lenses with a 77 mm filter size, but none with 82 mm, so this means buying more (probably a circular polarizer and a ND filter) and also carrying them in the the field (even more weight).
3. The Mk II has the ability to adjust the tilt and shift planes independently of each other, while the Mk I had them 90° apart. (Okay, you could modify the Mk I so they were in the same plane, but this was not something for the faint of heart, and certainly not in the field.)
4. The Mk II has a lock lever to lock the lens at a tilt of 0°. Like the Mk II, there are still tightening knobs to "lock" the tilt and shift at any position, but the positive lock at 0° tilt is a welcome addition (speaking as one with lots of field experience with the Mk I lens).

The weight and increased filter size are a downside, but the overall quality is excellent. While I didn't test the lens with filters (I don't have any 82 mm filters), I strongly suspect that the larger filter size will reduce or eliminate vignetting when a filter is in place and the lens is fully shifted.

I still maintain that the Mk I version of the lens is very good on a 1.6 cropped camera. (Minor CA can be dealt with in processing.) But on a full frame camera, the Mk II is far superior, despite the extra weight and need for larger filters.

Tuesday, October 26, 2010

My HDR Technique

Since I keep referring to it over on NSN, I thought I'd write a short post on what my HDR processing technique really looks like...

Shooting: AEB +/- 2 stops. (Occasionally, I'll do five exposures at +/- 2 stops, but neither of my cameras allows for this easily, so I only do when I really think I need the extra stops, like when the sun is in the frame.) Manual exposure mode to make sure I really get +/- 2 stops--if you're in an auto mode, if the light changes, so could the exposure. ISO 100 for the lowest noise (on most Canon cameras anyway--50 might give lower noise on the cameras that have it, but at the expense of dynamic range). Tripod, mirror lock-up, cable release. Level the camera, and shoot away. Check the histograms to see that in the darkest shot, the highlights aren't blown and in the lightest shots, there is some space on the left side (lots of space, preferably, since that's where noise lives).

But this post is really about the Processing:

I'll do this by example. This is a shot I recently posted on NSN. First, the three individual exposures:

This scene probably didn't need an HDR treatment, but I think it can still be improved by it.

These images were first converted to TIF in ACR. The only adjustment I made in ACR was to set the white balance, and I set it the same on all three shots. This is important--if your camera is set to AWB, you could get different white balances for the different exposures. It's also important not to make any other changes in the RAW conversion step. (Well, there are probably some changes that would be okay, but I'm not going to go into that.)

I take these into Photomatix and generate an .HDR file (or .EXR file--for most practical purposes it doesn't really matter which format). I set Photomatix to "Align source images by matching features", to "Reduce chromatic aberrations", and to "Attempt to reduce ghosting artifacts--background movements (eg water or foliage)" with "High" detection. I actually do this in batch mode, since I'll come back from a trip with perhaps dozens of sets of images to make into HDR files.

I can then open the HDR file and do tone-mapping. This is where it gets complicated in Photomatix, as there are so many options and sliders to play with. My main warning here is that the image you see on the screen doesn't have to look like the final result. In fact, it probably won't, as I'll show. I actually do two tone-maps for my image, one using the Details Enhancer (DE) method, and one using the Tone Compressor (TC) method. The DE operates locally, trying to maximize local contrast across the image. The TC method acts globally, to map the HDR space into a LDR space in a uniform way (so that two pixels with the same HDR values in different parts of the images will have the same LDR values). The DE method can result in halos, while the TC method will not. But don't worry about that now...

Here are my two tone maps for the above image. I have no idea what settings I used for each of these--I just play around until I get something I'm happy with.

Here's the DE version:

And here's the TC version:

Neither one is something I'd be happy with. The DE is very flat, and the TC is very contrasty--in particular the gradation in the sky has been emphasized. (Note that in the DE version it actually reduced this gradation from the original.) If we zoomed right in, though, we'd see better detail in the DE version.

Next, I take these two images and put them into Photoshop. My technique is to put the DE layer on the bottom and the TC layer on top, with an Overlay blending mode and an opacity somewhere between 20-40% (I forget what actual value I used here). When we do this, we get the following:

Now we're getting somewhere. I think this is better than either of the individual tone maps, and certainly better than the "0" exposure by itself. But every image I do any processing on (whether it's HDR or not) gets an optimization treatment of levels, curves, and saturation, often with masks to selectively apply the effects to different parts of the image. The treatment is always done manually to get what I feel at the time is the best presentation I can get from that image, while staying true to what I remember the scene looking like in my mind.

Below, I'll show what I got when I applied these optimizations to both the above blended HDR image and the original "0" exposure alone.

First, the HDR:

And what I'd have gotten if I didn't shoot HDR and just optimized the "0" exposure:

To me, there's really no comparison. The HDR really is more vibrant than the other. And at the same time, it has less gradation in the blue sky, which I know is objectionable to some people.

But to be fair, I'd have done a couple of things differently if I hadn't shot for HDR. First, I'd have shot a bit more to the right (as I had more room on the right side of the histogram in the "0" exposure than I did on the left). This likely would have helped with noise in the shadows (which you can't really see at this web-size anyway). Secondly, I would likely have done some adjustments in ACR (like "fill light"--or other tools in that part of ACR). But for this image, I don't think I would have done much.

So there you go. My basic HDR technique in a nutshell. I shoot every landscape image with bracketing, on the assumption that I will apply this technique to it.

Friday, October 8, 2010

Featured Image #2

My next featured image is more recent. I took this in Jasper NP last weekend.

This is an HDR panoramic image taken from the Wilcox Pass trail, looking toward the Athabasca Glacier. On the left is Mount Athabasca (and the secondary peak is Andromeda), and on the right is Mount Kitchener (with the snow-covered peak). The glacier is obvious between them. If you look really carefully, you can see the moon on the right.

An interesting tidbit: the river that comes off the Athabasca Glacier is not the Athabasca River, but the Sunwapta. Likewise, the river than comes down from the Athabasca Pass is not the Athabasca River, but the Whirlpool River. Both are tributaries of the Athabasca, though. The Athabasca River comes off the Columbia Glacier, just a few kilometres from the Athabasca Glacier (both come off the Columbia Icefield). The Columbia River, though, has nothing to do with the Columbia Glacier or the Athabasca River--it heads west to the Pacific, while the Athabasca River flows north to the Arctic. But the source of one or more tributaries of the Columbia River also come off the Columbia Icefield, just a few kilometres away. Additionally, the source of the North Saskatchewan River, which flows east to Hudson's Bay (and on to the Atlantic) also comes off the Columbia Icefield, making it the only place on the continent which drains into three oceans.

Frankly, though, I've always thought the concept of Hudson's bay flowing to the Atlantic is a bit weak. I guess it depends on whether the Arctic Archipelago is in the Arctic Ocean or separates the Arctic and Atlantic Oceans. But if you don't accept that, then you have to have two continental divides, and the one that splits north and east ends up in Ontario. (Actually, even with the traditional Hudson's bay=Atlantic argument, we have two divides, but the north section becomes quite small--just Northern Alberta, a corner of BC, and the Northwest Territories--and we don't worry much about it.)

Anyway, this picture was taken from the Wilcox pass trail which is in Jasper, but just a stone's throw from the Banff border. Actually, some of Banff is in the picture, on the left edge, since the Banff/Jasper border goes up to the peak of Mt. Athabasca. This trail is strenuous but not technically difficult as it goes straight up the side of the mountains. It doesn't switchback,but angles up to the north, quickly getting above the treeline to views like this. Generally, you'd expect to see a group of male bighorn sheep up here, but for some reason this day there were none. One photographer from Montana I ran into on the way up (who was on his way down) said that he'd been coming here at around this time for 26 years, and it was the first time he'd been skunked.

It was shot with a Canon 5D Mk II, and a 28-135 IS lens. That's certainly not my favourite lens, but I wanted to keep the weight down, considering I was also carrying a 300/2.8 IS. If I'd had my 17-40 instead, there'd be a much bigger gap between the two lenses--since getting the 5D2 (my other camera has a 1.6 crop factor) I've missed having a lens between them, so on this trip I dusted off the old 28-135 IS. (It had been sitting on a shelf since I got the 17-40.)

I shot it with several frames, with the camera oriented vertically. Each frame had three exposures. The three exposures were all the same for each frame, so this was done in M mode. Stitching becomes nearly impossible if you use different exposures across a pano. Back at the computer, I ran each set of three exposures through Photomatix to get an .EXR file (which is an HDR format). I didn't tone-map them yet. I took the EXR files into AutoPanoPro to stitch into one larger EXR file. That now went back into Photomatix to tone map. As usual with my HDR work, I tone-mapped it twice, once with the Details Enhancer mode and the other with the Tone Compressor mode. These two images went into CS4 as separate layers. I put the TC layer on top of the DE layer, set the blending mode to overlay and adjusted the opacity to taste. (I think it ended up around 40% in this case.) Then I did the usual levels and curves adjustments. The saved layered 16-bit TIF file is around 2.5 GB in size. Ouch. I really wish someone would figure out a way of losslessly compressing 16-bit TIF files!

Thursday, September 23, 2010

Featured Image #1

When I started this blog, I always had the intention of featuring images from time to time. I figured I better get around to it... So, here is the first.

This isn't one of my favourite images, and it certainly has its faults, technically. The reason I'm selecting it is that it takes me back to the beginning. This is from the first roll of Velvia I ever shot. (Remember that stuff called slide film?) I've been shooting pictures for as long as I can remember. I started with a 110 format camera. (If you're under 30-35, you may never have seen this format, which really never went beyond the point and shoot cameras--although someone--Pentax? and maybe others--did make a 110 SLR; click here for the Wikipedia page to read about it.) I then got a 35mm P&S and my Dad taught me to develop and print B&W film in the basement (using some antique equipment that he hadn't used for years before). Before long, I moved up to a 35 mm SLR (by Ricoh). That was soon replaced by a series of Pentax cameras over the years, until I made the switch to Canon (after a burglar cleaned out most of my gear) in 2003. I went digital a bit over a year later, in 2004. But step back a bit... In 2002, I discovered NPN and started posting pictures for critique. At the time I was shooting exclusively colour negative film. It didn't take long for me to realize that the best shooters (of those who hadn't made the switch to digital yet) were shooting slide film, and Velvia was the film of choice for landscapes. So, in the summer of 2002, I bought a couple rolls of Velvia and headed to the mountains. I had two cameras, so I put Velvia in the manual focus one for landscapes, and kept colour negative film in the AF one for other pictures. The rest, as they say, is history.

So, this shot. It's of the upper falls in Johnston Canyon, in Banff National Park. This waterfall is 97 feet high (and was once the highest waterfall run in a kayak--that record has since fallen). It's a walk of approximately 3 miles to get here, on a well maintained, semi-paved trail. Parts of the trail are on catwalks suspended from the canyon wall. This makes the walk easier, since you're not going in and out of the canyon, but also lets you enjoy the canyon far more than if you were walking up at the top rim. The downside, from a photographic point-of-view, is that many shots are going to have the catwalks in them. You can either make use of them in your compositions, or shoot to avoid them--there are certainly lots of opportunities to shoot without including them. This canyon can be very busy at times, especially summer weekends. Most of my visits have been in the evenings when it's quiet. But sometimes you just have to go during the day to get sunlit shots that wouldn't be possible when the sun is low. Winter trips provide a wealth of different shots, but you need something like YakTrax on your feet, as the trail is not maintained in winter, and the large numbers of visitors quickly pack the snow into ice.

a bit more about this shot. As I said, it's shot on Velvia slide film (Fuji, ISO 50). The Velvia colours clearly shine through! I've got digital versions of this shot (including one with a rainbow), but I find that digital just doesn't give the same impact as Velvia. (Not that I have any intention of going back to film, though!)

I shot this with a Pentax SLR, with a cheap, consumer-grade 28-80 zoom lens--or something like that. (It was another year or two before I started investing in good glass.) I don't remember if it was polarized or not, but I'd guess it was. The upper falls have two viewing platforms--one each at the top and bottom. This is obviously from the bottom. The platform is not large, so angles are limited. I'd love to have been able to shoot this from a few feet further right, but it was not to be. (I have done it in winter, though, shooting from out on the rocks and ice, but that wasn't possible at this water level.)

Enjoy. I'm sure I'll feature more Johnston Canyon shots in the future...

Tuesday, September 21, 2010

Not so superior after all

On a recent topic at NSN (Click Here) people were discussing the "interesting" behaviour of tourists visiting the wilderness, especially at significant places like national parks. I had started to reply to the thread with some examples of things I'd seen, but then I started to reflect on my own actions and decided that perhaps I shouldn't act so high and mighty.

A couple of the worst things, not involving animals, I've seen are in these two pictures (coincidentally taken on the same weekend):

This one is Sunwapta Falls in Jasper NP

And this one is at the Natural Bridge in Yoho NP. The kid is probably 10-12 years old.

This kind of thing makes me upset-in both cases those people crossed fences to get where they were. It was a busy weekend-not high summer, but the end of June with wonderful weather, so it was busy enough-with lots of people around to witness the stupidity. These shots seemed like the perfect examples of things to add to the thread, and make all of us more experienced wilderness visitors feel even more superior. But then I started thinking about things I've done myself.

The first thing is crossing fences. I've done that. There a couple of differences between what I did and what those guys did, though. First, where I crossed fences, it was in places where a fall would not be life-threatening-in fact, unless I leaped headfirst down the slopes, a fall wouldn't have done more than get me dirty. (In the two pictures above, a fall would have been uniformly fatal at the water levels that weekend.) Secondly, when I crossed the fences, there was nobody around-I don't like to set a bad example. While crossing those fences wasn't particularly dangerous, I don't want to give people ideas to do what the people above did!

At Punchbowl Falls in Jasper, the vantage points from which one can see the falls at all (other than from the bridge above) are beyond a fence. There's a bit of a trail beyond the fence, below which is a dirty slide down to the streambed.

At Johnston Canyon in Banff, there are a lot of fences, most of which would be rather dangerous to cross. To get this shot, I had to cross one, though, but this one just has a few yards of rocky slope below it, no steeper and much more stable than any scree slope.

So at first I was thinking that what the guys in the first picture had done was far worse than what I had done. But as I kept thinking, I realized that I had also been to places at least as dangerous as where those guys were-only that I hadn't crossed a fence to get there.

I'm quite sure that before the Icefields Parkway as we know it now was opened in the late 1960s Beauty Creek (in the picture above) was a very popular (at least in terms of the numbers of people driving the Banff-Jasper road as it existed at the time). The trailhead and the mouth of the canyon are right at the old roadbed. But the new highway is a hundred yards away, and there's no sign, and just a tiny parking area. It's described in any decent tourist guide, but all those just driving by miss it completely. Heck, I'd been going to Jasper for ten years before I made a point of finding it. Because it's not a major draw in the modern litigious era, it doesn't have the guardrails and fences that the more popular spots do. It's a sheer canyon, with several significant waterfalls, and not a fence in sight. I found myself at least as close to the canyon edge, shooting pictures, as those guys in the first pictures were. And a fall here would not be nice-perhaps not as uniformly fatal as Sunwapta Falls-but I don't relish the idea of being injured, possibly seriously, at the bottom of a remote canyon with no way out that didn't involve going down a few waterfalls.

I'm not entirely comfortable standing right at the edge of a canyon or other cliff, but I've certainly gotten near enough at Beauty Creek and many other places, such that simply tripping and falling could be fatal. But another problem at such precipices is that we just don't know how stable the rock is-erosion continually makes canyons deeper and wider, and pushes other cliffs backwards. The rock at the edge may still be there a thousand years from know, or it could tumble into the chasm tomorrow. Or right when you're standing there.

Am I really that much better than those guys who stand on the brink at the more tourist-friendly locations? I keep my more dangerous behaviour to myself, but it's still there.

This is another semi-remote location. It too is just off the old Banff-Jasper road, in a spot where the new Icefields Parkway takes a slightly different route. This one is further south, in Banff NP, near the "big bend" switchback. There used to be an observation point, complete with a few parking spaces, on the old road, but I took this picture by scrambling down the slope from the old roadbed a bit further up the road from that spot, so I could get a close-up shot, looking up the falls. I haven't been able to find the name of this stream coming off the side of Mount Saskatchewan. If I had become incapacitated for any reason here, it would have been a long time (if ever) before I was found. I've hiked this section of the old road a few times, and not once seen another person on it.

I'm not about to give up this kind of photography. I just like the wilderness far too much. I do what I can to minimize the risk, but there's nothing that can eliminate it. I carry a small emergency kit that I could use (to start a fire to keep warm, for example) in the event I sprain an ankle or something else happens that leaves me unable to walk. But that wouldn't help me if I had a heart attack (not that I expect one at my age-but one never expects these things) or some other kind of seizure. I usually try to tell my wife approximately where I plan to be, and I give her a call before I leave cell coverage and tell her that I'll call in a few hours when I get back in cell range. If I didn't call back, she'd know to call the Park Wardens and tell them where to start looking. But it would be hours later, probably getting dark. If something really bad had happened, it wouldn't help me much-just make it easier to find my remains. At least those guys flaunting it at the tourists spots would be found quickly (well, the authorities would be notified quickly), or if the bodies were swept away never to be found, their families would know exactly what happened, if not why.

As I'm writing this, the family of a young man named Jordan Darda is waiting to find out how he died. He went camping in Banff by himself-something I've done many times-and was not heard from again. His truck was found a week or two later. (I'm still not sure why it took so long to find the truck-there are only so many places to stop along the Icefields Parkway, and those could all have been checked by Park staff within hours, if they knew what vehicle to look for. But it turns out that he had parked at a trailhead just outside the park on the David Thompson highway-for a trail that went into Banff. I guess nobody thought to check outside Banff since he had apparently told people he was going to Banff.) His body was found not long after the truck (probably since they had a better starting place to work from), face down in a creek. There was no evidence of foul play, animal attack, or large trauma. Hopefully, the autopsy will shed some light on the exact cause of death. The news reports are very light on details, but it could be a simple as slipping and falling while crossing the creek, and knocking himself out on a rock, unfortunately landing face down in the water. That is, of course, speculation, and there could be many other causes. But if something like that were the cause, he would likely still be alive had he been with someone else.

I'm not going to criticize him for going alone, though. That would be extremely hypocritical of me, since I've done the same thing many times-going hiking and camping by myself in remote locations-and I have no intention of stopping. But anyone doing that needs to have the understanding that there are more risks alone than in a group. A relatively minor accident when you're with someone can turn serious, even fatal, when you're alone.

Like I said earlier, am I really any better than those guys standing out at the brink of Sunwapta Falls? When I consider my thoughts on this more closely, I think what bothers me most about their actions is not the danger of the activity itself, but more the public flaunting of the rules by climbing the fence and standing out there in front of dozens of other people. But why does that bother me so much? I don't think I have an answer to that.

Wednesday, July 21, 2010


Some recent posts in the Landscapes forum at NSN have discussed the issue of disclosure of shooting details. There is certainly a range of options for what people actually disclose about shooting. I'm talking here about the technical details, not things like locations. (That could be a separate topic...)

Some people say nothing about how they took the shot. Others seem to dump the entire EXIF meta data from the file into the post. Most fall somewhere into the wide continuum between these extremes. Personally, I'm usually posting from a machine where I don't have access to the EXIF data (which is stripped when I save for the web), so I don't usually have all the details at hand. But even if I did, I probably wouldn't include everything, anyway. I usually know which lens and camera I used, so I'll say that much. If I remember if I used a polarizer, I'll say that, too. (I almost never use any other kind of filter.) I'm not trying to hide anything, but I just don't see the value in posting everything. General exposure information is pretty much useless to anyone--the light is never the same twice, and you can't see what the light really was like in a picture, so knowing the exposure really doesn't do much for anyone.

But, the exposure information consists of three things: ISO, shutter speed, and aperture. There are times when one or more of these might be especially important, so I'll say so. If I'm shooting at a high ISO, it's probably worth saying so. (Really, I shoot almost everything at 100, 200, or 400. I really doubt anyone could tell the difference between these in a web-sized shot.) For landscapes, unless there's flowing water, shutter speed is practically irrelevant. But if there's water, it can have a huge impact on the shot. If I'm trying for a certain effect, requiring an extra long (or short) speed, I'll generally say so. Most of my landscape shots use an aperture of f/8 to f/11. I might use a bit smaller (higher f number) if I want more depth of field (knowing that it's at the expense of a loss of detail to due to diffraction). Or if I'm trying to reduce DOF, I'll go the other way. For birds and animals, though, I'll often shoot with a wider aperture (smaller f number) to get more light and a faster shutter speed to capture any motion. Again, if I'm doing something different than the usual, I'll generally say so.

But in general, I don't think there's much to learn from knowing someone else's settings, so I don't bother to post mine, unless, as I said, I did something different from my normal routine for a specific reason.

On the other hand, I think people who are new to the forums and don't have professional experience in photography, can probably get better critiques from people when they do post their settings. For example, some people shoot at f/22 with a wide angle lens and nothing really near the camera. There's no need for f/22 in that situation (unless you are trying to get a slow shutter speed for some specific reason). But f/22 introduces diffraction (which probably won't be noticeable in a web-sized image, but may reduce detail and sharpness in a larger print), and the longer shutter speed may result in some objects blurring from their motion, or that of the camera (if it's not on a sturdy tripod). Or there could be the opposite problem, where someone has low DOF due to a wide aperture. Knowing the aperture and shutter speed allows people to make comments to help the new shooter improve. Likewise ISO--normally you don't want to shoot with a higher ISO than necessary (as it introduces noise), and I've seen people comment on it.

So including this information can help people give you better critiques, when you're new to getting critiques, or are trying a new area of photography. But outside the "special" situations, I really don't think posting your details will help *other people* take better shots.

I do think posting camera and lens information (including actual focal length for zooms, if it's known) is useful. And I do like to see general locations where pictures were taken. (Avoid the specifics if you want to keep a secret, but something like "Banff National Park" is useful without giving anything away.) And I do try to include this information on my posts.

Now if you're out shooting with someone, sharing information can indeed be helpful, since you're shooting in the same light. But that's different...

Wednesday, July 14, 2010

Deja vu all over again

I hadn't planned on shooting at that same spot on Medicine Lake on my recent trip there. (See my earlier blog post titled "Deja Vu?") The sun comes up in the wrong place at this time of year for sunrise work. (People who don't live this far north might not realize that there is about a 90° variation in the position the sun rises at the two solstices--pretty close to NE in summer and SE in winter. The sun only really rises in the east near the equinoxes in March and September.)

But despite the mid-afternoon light, I decided to stop and shoot anyway. This is what I got. Click on the image to see a larger version.

Canon 5DMkII, 17-40L, HDR

I think the HDR really worked well in taming the harsh afternoon light and giving me something worth posting. But really it's the sky that makes this stand out (I think).