![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
A fun day mostly
Jan. 12th, 2005 10:30 pmI’ve been a photographer for more years than I care to admit, and I’m pretty good. I’m uneven and not serious enough about it to go pro, but I’ve had a national magazine cover, made some bucks shooting weddings, and I won five prizes for four photos entered in the State Fair.
So Tuesday was going to be fun –I borrowed a really spiffy zoom lens from my Bestest Childhood Friend™ and went out to Tempe Town Lake to photograph what the City of Tempe hopes will be a rare event – they’re passing water through the dam.
The dam itself is built using inflatable rubber dams made by Bridgestone Corporation. It’s pretty cool technology, very tough, and very inexpensive compared to the cost of building a conventional dam. Since the dam blocks the Salt River, they had to have a methodology of letting water through when the Salt runs – it’s normally a dry river for those of you who don’t live in the Valley. Well, most of the northwestern part of Arizona has been washing away in the last few weeks, and water needs to flow through the Salt, so they had to lower the dam.
Tempe’s unhappiness at this is they are trying to have this a stable, pollution-free lake. You can’t swim in it, and all boats on it must be sail, electric or rowed/paddled. No motor boats. So this water passing through is going to shoot that delicate balance all to hell.
Still, great opportunity to take semi-rare photos!
I went out there a week ago and did some shooting when they were running water over one of the four spillways. That was pretty cool. But I wanted to get to the other side of the dam and didn’t have a clue where it was located. I did some driving around, but I was under time constraints and didn’t find the other side before I had to be somewhere for dinner.
So Tuesday I set out and I found the other side of the dam!
But first, a diversion to talk about the lens that I borrowed just to tick off Joe.
I’m shooting a Canon Eos Digital Rebel, it’s a six megapixel digital SLR that looks like a 35mm camera. It can use all the Eos lenses, and a friend of mine bought the same camera recently. She also got a 75-300mm zoom lens, but the cool part is that the lens is image stabilized. The natural question is: what the hell is an image stabilized (“IS”) lens and why is that significant? Well, it really has to be demonstrated to appreciate just how cool this is, but simply put, there is a free-floating lens group inside the body of the zoom lens that is spun by a gyroscope that senses camera motion and eliminates it. The net effect is that you can make hand-held shots that were absolutely impossible with unstabilized lenses without a tripod or some sort of rest. As an example, the demo we received in the store was to zoom in on a church steeple without the gyroscope turned on. Trust me, at 300mm (6x magnification approx.), it jiggled all over the viewfinder. With the gyro on, it stayed rock steady.
The gyroscope is powered by the camera battery, and it can apparently drain them in a hurry, fortunately I had two batteries with me.
With this lens, at 300mm, I hand-held 1/15th and 1/10th of a second exposures. And they’re sharp.
You can’t do that with a normal lens. It’s just not possible, not at 6x magnification. And because many digital SLR cameras have a multiplier effect on the lens, the 300mm is actually the 35mm equivalent of a 480 millimeter. That’s 9.5x zoom. And I’m hand-holding a tenth of a second!
Just freaking amazing!
Anyway, I had a great time shooting. It was a cloudy day, which makes for strong contrast and little shadow. I got some very cool shots, just what I was looking for the previous week. And better still, all four spillways were spillin’. Also neat was the waterway after the dam had a lot of plants that had grown in the Salt riverbottom when it was dry, and some birds were perching on them, so I also got some nice bird shots. I’ll be posting some of these later.
I’m going to talk about three shots specifically. One was a sequence of six shots that I took panning across the dam. The Eos comes with a photo stitcher program that joins photos together for you to create a wide panorama. Thus, my six photos combined into one, and I have a shot of the full width of the dam spilling water all the way across. The exposure is slightly uneven in one frame, I really need to use my handheld lightmeter more. Really neat shot, well, technically shots, since it took six images to make the one.
The next two ticked me off. I didn’t discover them until about 26 hours ago when I was looking over the photos. I thought that I’d shot more than two long-duration (relatively-speaking) exposures. I was shooting at ISO100 and most of my shots were in the 1/125 to 1/400ish range, depending on what depth of field I set. Most people know that faster shutter speeds freeze motion. Well, water flowing over a spillway is faster motion than you’d think. I took one shot at the slowest shutter speed possible, achieved by stopping the lens down as far as it would go, down around f/40 or so, and it dropped my shutter speed down to about a fifteenth of a second. I don’t recall the focal length of the zoom off-hand, but I’d pulled it back a little to capture two and part of a third spillways. The purpose of the slower shutter speed was to blur the water, and it worked just like I wanted. Then I took a shot at 300mm, again, stopped down all the way, of a drain pipe in the wall of the opposite side of the dam.
The shots were fine, it blurred the water just like I wanted. But it did one thing utterly unexpected – it popped a big white dot on the frame.
Both slow images. In the exact same place. One was shot with a portrait orientation, one landscape, and when the one was rotated into the other’s alignment, they were obviously in the same place. And no other photo showed this problem.
To call the white dot big is perhaps an overstatement, but the fact that it is there at all is troubling. A brief explanation – digital cameras record images through using an array or grid of what are effectively photo-transistors, each transistor representing one pixel. They record the value of the light that strike them in terms of color mix and light intensity, then that information is parsed into a JPEG file. It is unfortunately not uncommon for these transistors to fail, and when they do, they go black. Every image you take will have a tiny little black dot in the exact same position in every single frame.
A black dot. Not a white one.
Mine was a white dot. It was definitely larger than one pixel, but it’s also common that when a CCD starts losing pixels, it’ll lose them in clumps/clusters. But they go BLACK, not WHITE. So it makes no sense.
Today I took my laptop down to Foto Forum and talked to the salesman who sold my friend the lens. He was absolutely baffled. Every salesman who saw it was baffled. We talked for upwards of half an hour with no one providing a convincing explanation. We all agreed that pixels fail “black” and do so consistently, they don’t “sometimes” fail. We also agreed that it made no sense that it could be the lens. In the end we devised a testing stratagem that will test my body with two different lenses, including the 75-300 zoom. We’ll also test my friend’s body and make sure her camera doesn’t have the same affliction. Then I’ll probably burn the images onto a CD along with a VERY detailed letter of explanation and ship it off to a Canon repair facility.
Here’s the sucky part – replacing the CCD could be a $300+ repair. I believe I could buy a new body on EBay for about $450. And since the spot seems to only be appearing under certain as yet unquantified circumstances, the camera is thus unreliable. If I knew that there would always be a white spot in a certain position, I could work around it. All you have to do is compose your shot then back off the zoom just a smidge to a wider angle. When PhotoShopping the image, you then have a space around the image that you want that contains the white spot that you can easily cut out. You’ll be losing some resolution, but that’s the way it is.
Sigh. I’ll be doing the test shooting Thursday night theoretically. We shall see what the results are.
So Tuesday was going to be fun –I borrowed a really spiffy zoom lens from my Bestest Childhood Friend™ and went out to Tempe Town Lake to photograph what the City of Tempe hopes will be a rare event – they’re passing water through the dam.
The dam itself is built using inflatable rubber dams made by Bridgestone Corporation. It’s pretty cool technology, very tough, and very inexpensive compared to the cost of building a conventional dam. Since the dam blocks the Salt River, they had to have a methodology of letting water through when the Salt runs – it’s normally a dry river for those of you who don’t live in the Valley. Well, most of the northwestern part of Arizona has been washing away in the last few weeks, and water needs to flow through the Salt, so they had to lower the dam.
Tempe’s unhappiness at this is they are trying to have this a stable, pollution-free lake. You can’t swim in it, and all boats on it must be sail, electric or rowed/paddled. No motor boats. So this water passing through is going to shoot that delicate balance all to hell.
Still, great opportunity to take semi-rare photos!
I went out there a week ago and did some shooting when they were running water over one of the four spillways. That was pretty cool. But I wanted to get to the other side of the dam and didn’t have a clue where it was located. I did some driving around, but I was under time constraints and didn’t find the other side before I had to be somewhere for dinner.
So Tuesday I set out and I found the other side of the dam!
But first, a diversion to talk about the lens that I borrowed just to tick off Joe.
I’m shooting a Canon Eos Digital Rebel, it’s a six megapixel digital SLR that looks like a 35mm camera. It can use all the Eos lenses, and a friend of mine bought the same camera recently. She also got a 75-300mm zoom lens, but the cool part is that the lens is image stabilized. The natural question is: what the hell is an image stabilized (“IS”) lens and why is that significant? Well, it really has to be demonstrated to appreciate just how cool this is, but simply put, there is a free-floating lens group inside the body of the zoom lens that is spun by a gyroscope that senses camera motion and eliminates it. The net effect is that you can make hand-held shots that were absolutely impossible with unstabilized lenses without a tripod or some sort of rest. As an example, the demo we received in the store was to zoom in on a church steeple without the gyroscope turned on. Trust me, at 300mm (6x magnification approx.), it jiggled all over the viewfinder. With the gyro on, it stayed rock steady.
The gyroscope is powered by the camera battery, and it can apparently drain them in a hurry, fortunately I had two batteries with me.
With this lens, at 300mm, I hand-held 1/15th and 1/10th of a second exposures. And they’re sharp.
You can’t do that with a normal lens. It’s just not possible, not at 6x magnification. And because many digital SLR cameras have a multiplier effect on the lens, the 300mm is actually the 35mm equivalent of a 480 millimeter. That’s 9.5x zoom. And I’m hand-holding a tenth of a second!
Just freaking amazing!
Anyway, I had a great time shooting. It was a cloudy day, which makes for strong contrast and little shadow. I got some very cool shots, just what I was looking for the previous week. And better still, all four spillways were spillin’. Also neat was the waterway after the dam had a lot of plants that had grown in the Salt riverbottom when it was dry, and some birds were perching on them, so I also got some nice bird shots. I’ll be posting some of these later.
I’m going to talk about three shots specifically. One was a sequence of six shots that I took panning across the dam. The Eos comes with a photo stitcher program that joins photos together for you to create a wide panorama. Thus, my six photos combined into one, and I have a shot of the full width of the dam spilling water all the way across. The exposure is slightly uneven in one frame, I really need to use my handheld lightmeter more. Really neat shot, well, technically shots, since it took six images to make the one.
The next two ticked me off. I didn’t discover them until about 26 hours ago when I was looking over the photos. I thought that I’d shot more than two long-duration (relatively-speaking) exposures. I was shooting at ISO100 and most of my shots were in the 1/125 to 1/400ish range, depending on what depth of field I set. Most people know that faster shutter speeds freeze motion. Well, water flowing over a spillway is faster motion than you’d think. I took one shot at the slowest shutter speed possible, achieved by stopping the lens down as far as it would go, down around f/40 or so, and it dropped my shutter speed down to about a fifteenth of a second. I don’t recall the focal length of the zoom off-hand, but I’d pulled it back a little to capture two and part of a third spillways. The purpose of the slower shutter speed was to blur the water, and it worked just like I wanted. Then I took a shot at 300mm, again, stopped down all the way, of a drain pipe in the wall of the opposite side of the dam.
The shots were fine, it blurred the water just like I wanted. But it did one thing utterly unexpected – it popped a big white dot on the frame.
Both slow images. In the exact same place. One was shot with a portrait orientation, one landscape, and when the one was rotated into the other’s alignment, they were obviously in the same place. And no other photo showed this problem.
To call the white dot big is perhaps an overstatement, but the fact that it is there at all is troubling. A brief explanation – digital cameras record images through using an array or grid of what are effectively photo-transistors, each transistor representing one pixel. They record the value of the light that strike them in terms of color mix and light intensity, then that information is parsed into a JPEG file. It is unfortunately not uncommon for these transistors to fail, and when they do, they go black. Every image you take will have a tiny little black dot in the exact same position in every single frame.
A black dot. Not a white one.
Mine was a white dot. It was definitely larger than one pixel, but it’s also common that when a CCD starts losing pixels, it’ll lose them in clumps/clusters. But they go BLACK, not WHITE. So it makes no sense.
Today I took my laptop down to Foto Forum and talked to the salesman who sold my friend the lens. He was absolutely baffled. Every salesman who saw it was baffled. We talked for upwards of half an hour with no one providing a convincing explanation. We all agreed that pixels fail “black” and do so consistently, they don’t “sometimes” fail. We also agreed that it made no sense that it could be the lens. In the end we devised a testing stratagem that will test my body with two different lenses, including the 75-300 zoom. We’ll also test my friend’s body and make sure her camera doesn’t have the same affliction. Then I’ll probably burn the images onto a CD along with a VERY detailed letter of explanation and ship it off to a Canon repair facility.
Here’s the sucky part – replacing the CCD could be a $300+ repair. I believe I could buy a new body on EBay for about $450. And since the spot seems to only be appearing under certain as yet unquantified circumstances, the camera is thus unreliable. If I knew that there would always be a white spot in a certain position, I could work around it. All you have to do is compose your shot then back off the zoom just a smidge to a wider angle. When PhotoShopping the image, you then have a space around the image that you want that contains the white spot that you can easily cut out. You’ll be losing some resolution, but that’s the way it is.
Sigh. I’ll be doing the test shooting Thursday night theoretically. We shall see what the results are.
