Woohoo, the rain stopped! I think every photographer in Vancouver was out on this seawall tonight -- I could barely move for tripod legs!
This is taken from just west of the Cambie Bridge, looking directly north across False Creek to the Yaletown district of downtown Vancouver. BC Place can be seen peeking through the gap between the pillars of the bridge, where they were doing sound checks for Paul McCartney's performance tomorrow. If you don't have a ticket, I suspect standing within half a mile of the stadium will let you hear it quite well!
This is a two-photo panorama, and started out as a much taller image, taking in the rocks almost at my feet. When I processed it the composition wasn't as strong as I'd hoped, so I cropped it down to make the buildings and bridge the main elements.
I could have easily captured the whole scene in a single exposure if it wasn't for the insanely bright lights pointing up from the bottom of the bridge. If you think they're bright now, you should have seen it before I HDR'd it...!
I'm a British software developer and photographer living in Vancouver, BC. I mainly photograph landscapes, cityscapes, night scenes, and water.
If you're interested in any...
Amazing, how do you get night shots so clear?!! I guess you have a good camera and know how to use it!
I was in Monyash only last week, it's somewhere I often visit so next time, I'll take a snap there for you. I hadn't realised you were British until after I had commented as I looked at your photos and then read your profile.
The answer to your question has multiple parts. There are a number of reasons why I chose f/8, let me try and summarise them:
Firstly, let me say that I never ever go above f/16 on my current camera unless I absolutely have to. Diffraction effects from using such a small aperture really degrade the sharpness of the image, and on my camera they kick in at f/10.5 or so. Using f/22 will lose such a huge amount of sharpness from the image that you might as well throw away half of your megapixels -- the entire image will be blurred at the pixel level.
On a camera with a smaller sensor, diffraction kicks in even earlier -- on my 50D, diffraction would start to affect image quality at just f/7.5, and I would strongly resist going above f/11 on that camera.
You can see the effects of diffraction at the link below, which will compare the same lens on a full-frame camera at f/8 compared to on a crop-frame camera at f/16. Move your mouse over the image to switch to the crop camera -- you should be able to see the very significant reduction in sharpness: http://tinyurl.com/c2z8hme
You can imagine what kind of sharpness loss you get at f/22!
Now, obviously it's important not to take this so much to heart that you never use f/22! If there is a genuine reason why I need that depth of field, and I'm dealing with moving subjects, then absolutely, a shot at f/22 is better than no shot at all! However, if I can get away with a wider aperture, either because I don't need the depth of field or because I can focus-stack two or more images, then I'll always choose to do that. (But I'll still usually take an f/22 shot, just in case I need it!)
In the case of this photo, I was happy that everything I needed in focus was in focus at above about f/5.6, so there was no need to use a smaller aperture. Bear in mind this is a super-wide lens, so you don't need as narrow an aperture as you might expect to get what you want in focus.
So I've now narrowed down the apertures I will chose from to between f/5.6 (where I have sufficient depth of field) and f/16 (where the diffraction issues degrade image quality more than I want to accept). It's probably worth pointing out that I generally don't go under f/4 for this lens, as it gets quite soft at f/2.8 -- again, this is a guideline, for star photography I need the extra light f/2.8 gives me!
The next thing I start to consider is my exposure time. Obviously the difference between f/5.6 and f/16 will have a marked effect on shutter speed, so I need to consider what I want. Do I want a long exposure to smooth the water, or do I want a shorter exposure? For this shot, I was really struggling with the water taxis going up and down the creek and mussing the water up (as well as producing not-particularly-appealing light trails). Accordingly, I wanted a shorter exposure if I could, to reduce the window of opportunity I needed to take the shot. As it was quite dark by this time, I was already going to get acceptable reflections in the water, and given that it was slightly breezy, a longer exposure probably wouldn't have done much to improve them.
The final thing to consider are the starburst effects. As I mentioned a couple of photos ago, this lens is awesome for starburst effects -- but I'm equally aware that it's very easy to overdo them. By using the depth of field preview button, I was able to see the starburst effect at different apertures, and choose the most aesthetically pleasing setting.
To be honest, reviewing it at home, I wonder if I should have gone for f/5.6, as they are a bit excessive even at f/8. However, at the time, I chose f/8 as the best setting for starburst effects, and that would give me a relatively short exposure time to get the water in an 'unruffled' state.
I hope that explains it, let me know if you have any questions!
@abirkill Wow thanks for the explanation. I can tell you're a sharp individual who really researches the technical aspects of photography. You're creative as well and having the combo of the two traits is rare. I've never heard of this before and have been taught f/22 is what you need for maximum DOF; however, no one mentioned the impact on sharpness. Indeed on that website there is a difference between the cropped versus full frame at different apertures- very interesting. I googled the topic and see there are many websites that discuss this matter.
I would be tempted to take a f/16 or f/22 shot and use a 'unsharp filter' in photoshop (20%, 50%, 0%- to start with) ; however, I understand the need to control the starbursts and that these small apertures would create more of that effect. I suppose you could mask the cityscape and apply the unsharp filter and view the results.
@brianl USM does work to counter the effects of diffraction, but only up to a point -- that's why I will go above the diffraction limit for my camera, but not far over it. Once too much detail has been lost by diffraction, you cannot recover it.
USM also will, like any sharpening technique, sharpen noise as well as real detail. There are ways to limit this, but inevitably it's not possible for sharpening software to determine with 100% accuracy what parts of an image are noise and what parts are genuine detail. There will always be a trade-off.
New technologies are coming along that can reverse the effects of diffraction more effectively. Deconvolution is a tool that mathematically models the entire image path (how the light passes through the elements of the lens, through the iris, and reaches the sensor). An accurate model of this (and it needs to be extremely accurate) can reverse-engineer the effects of both diffraction and lens sharpness deficiencies to recover detail in the image that was lost. (Basically, by modelling the camera mathematically so that you know for any given focal length, focus point and aperture setting where the light did end up, you can calculate where it should have ended up).
Canon have recently introduced deconvolution into the latest versions of their RAW processing software DPP. From what I've seen it works extremely well -- in fact, for a correctly focused image at a pre-diffraction aperture, I have to be so careful when adding additional sharpening after DLO, as it's so easy for the image to become oversharpened! It's very processor intensive -- each supported lens needs a downloaded file of over 100mb that contains all the characteristics of that lens at every different setting, and it takes over a minute on my fairly high-spec machine to apply the deconvolution. This is a promising technology, but again will not fully recover detail above about f/16 on my current camera at the moment.
Of course, none of this matters when posting on 365 where you can't display an image much larger than a postage stamp, or really that much on Flickr either. But when you're printing photos for exhibitions or selling them for high-resolution use, it's best to get every bit of sharpness out of an image that you can.
I was in Monyash only last week, it's somewhere I often visit so next time, I'll take a snap there for you. I hadn't realised you were British until after I had commented as I looked at your photos and then read your profile.
The answer to your question has multiple parts. There are a number of reasons why I chose f/8, let me try and summarise them:
Firstly, let me say that I never ever go above f/16 on my current camera unless I absolutely have to. Diffraction effects from using such a small aperture really degrade the sharpness of the image, and on my camera they kick in at f/10.5 or so. Using f/22 will lose such a huge amount of sharpness from the image that you might as well throw away half of your megapixels -- the entire image will be blurred at the pixel level.
On a camera with a smaller sensor, diffraction kicks in even earlier -- on my 50D, diffraction would start to affect image quality at just f/7.5, and I would strongly resist going above f/11 on that camera.
You can see the effects of diffraction at the link below, which will compare the same lens on a full-frame camera at f/8 compared to on a crop-frame camera at f/16. Move your mouse over the image to switch to the crop camera -- you should be able to see the very significant reduction in sharpness:
http://tinyurl.com/c2z8hme
You can imagine what kind of sharpness loss you get at f/22!
Now, obviously it's important not to take this so much to heart that you never use f/22! If there is a genuine reason why I need that depth of field, and I'm dealing with moving subjects, then absolutely, a shot at f/22 is better than no shot at all! However, if I can get away with a wider aperture, either because I don't need the depth of field or because I can focus-stack two or more images, then I'll always choose to do that. (But I'll still usually take an f/22 shot, just in case I need it!)
In the case of this photo, I was happy that everything I needed in focus was in focus at above about f/5.6, so there was no need to use a smaller aperture. Bear in mind this is a super-wide lens, so you don't need as narrow an aperture as you might expect to get what you want in focus.
So I've now narrowed down the apertures I will chose from to between f/5.6 (where I have sufficient depth of field) and f/16 (where the diffraction issues degrade image quality more than I want to accept). It's probably worth pointing out that I generally don't go under f/4 for this lens, as it gets quite soft at f/2.8 -- again, this is a guideline, for star photography I need the extra light f/2.8 gives me!
The next thing I start to consider is my exposure time. Obviously the difference between f/5.6 and f/16 will have a marked effect on shutter speed, so I need to consider what I want. Do I want a long exposure to smooth the water, or do I want a shorter exposure? For this shot, I was really struggling with the water taxis going up and down the creek and mussing the water up (as well as producing not-particularly-appealing light trails). Accordingly, I wanted a shorter exposure if I could, to reduce the window of opportunity I needed to take the shot. As it was quite dark by this time, I was already going to get acceptable reflections in the water, and given that it was slightly breezy, a longer exposure probably wouldn't have done much to improve them.
The final thing to consider are the starburst effects. As I mentioned a couple of photos ago, this lens is awesome for starburst effects -- but I'm equally aware that it's very easy to overdo them. By using the depth of field preview button, I was able to see the starburst effect at different apertures, and choose the most aesthetically pleasing setting.
To be honest, reviewing it at home, I wonder if I should have gone for f/5.6, as they are a bit excessive even at f/8. However, at the time, I chose f/8 as the best setting for starburst effects, and that would give me a relatively short exposure time to get the water in an 'unruffled' state.
I hope that explains it, let me know if you have any questions!
I would be tempted to take a f/16 or f/22 shot and use a 'unsharp filter' in photoshop (20%, 50%, 0%- to start with) ; however, I understand the need to control the starbursts and that these small apertures would create more of that effect. I suppose you could mask the cityscape and apply the unsharp filter and view the results.
USM also will, like any sharpening technique, sharpen noise as well as real detail. There are ways to limit this, but inevitably it's not possible for sharpening software to determine with 100% accuracy what parts of an image are noise and what parts are genuine detail. There will always be a trade-off.
New technologies are coming along that can reverse the effects of diffraction more effectively. Deconvolution is a tool that mathematically models the entire image path (how the light passes through the elements of the lens, through the iris, and reaches the sensor). An accurate model of this (and it needs to be extremely accurate) can reverse-engineer the effects of both diffraction and lens sharpness deficiencies to recover detail in the image that was lost. (Basically, by modelling the camera mathematically so that you know for any given focal length, focus point and aperture setting where the light did end up, you can calculate where it should have ended up).
Canon have recently introduced deconvolution into the latest versions of their RAW processing software DPP. From what I've seen it works extremely well -- in fact, for a correctly focused image at a pre-diffraction aperture, I have to be so careful when adding additional sharpening after DLO, as it's so easy for the image to become oversharpened! It's very processor intensive -- each supported lens needs a downloaded file of over 100mb that contains all the characteristics of that lens at every different setting, and it takes over a minute on my fairly high-spec machine to apply the deconvolution. This is a promising technology, but again will not fully recover detail above about f/16 on my current camera at the moment.
Here's a nice example of what DLO can do to a mildly diffraction-limited image (not mine):
http://scratch.hqphotography.com.au/images/dlo.jpg
Of course, none of this matters when posting on 365 where you can't display an image much larger than a postage stamp, or really that much on Flickr either. But when you're printing photos for exhibitions or selling them for high-resolution use, it's best to get every bit of sharpness out of an image that you can.