B
biglou
A little background: I'm shooting a Canon Digital Rebel SLR, the 6megapixel version, that I bought last year, with a Canon 28-90mm f4.5 lens with a UV and a polarizing filter. I'm looking to get killer MX action shots-as killer as possible given the equipment. It's my understanding that the glass (lens) is the biggest part of picture quality for shooting at my level. To that end, I've been doing a bunch of reading online today, and have a few questions for those with the knowledge:
1. Depth of Field: Am I correct that a larger aperture will produce a shallower depth of field? Meaning, the subject in the photo is in focus, and the background is blurred? How does the shutter speed affect DoF for a given aperture setting? i.e.: Faster shutter speed = shallower Dof, etc.?
2. Lenses: I'm looking at several 70-200mm f2.8 lenses. Other than those obvious specs, what else should I be looking for? Does the diameter of the lens play any part in its picture quality, DoF, etc., if the length ranges are the same? There's the Sigma brand for ~$750, and a Vivitar Series 1 brand for less than $300 at Wal-Mart. Both 70-200mm f2.8. What else should I consider when choosing a lens?
Links to two lenses I'm looking at:
Sigma Lens
Vivitar Lens
3. My Digital Rebel has several "auto" modes. Would not using a manual mode, such as to set the largest aperture setting, be better? Seems like at the largest aperture, the shutter speed would be the fastest (best for shooting MX). I can select aperture or shutter speed priority, or full manual. Chili says the AI autofocus is paramount for shooting action like MX. Thoughts?
4. I also have a "portrait" auto mode which says it produces a shallow depth of field. When a buddy shot pics of us at a race last year, we were blurred. Is the shutter speed simply too slow in this setting?
5. Lens Filters: Do the UV and Polarizer filters distort the image appreciably? Does using both simultaneously cause any problems?
6. Lens Hoods: They look cool, but what do they do? Do the affect lens filters in any way, good or bad?
7. Known limitations of the Rebel: The only way to get the AI Servo focus is to use the automatic "action" mode (running guy icon on the selector dial). This mode is key for stopping the action, but eliminates the ability to set the aperture manually. Additionally, the autofocus has 7 focus points, which can be picked, down to a single one, but it is only for one shot. This kills shooting in "burst mode", where I pull the best shot(s) out of the burst of 4. I wonder how effectively and consistently one could shoot in full manual, selecting the largest aperture, and adjusting the shutter speed to adequately stop the action?
8. So if I get a 200mm lens, will that in itself guarantee me a shallower depth of field, especially given the fact that using the "action" mode will automatically set both aperture and shutter speed? I'm guessing some experimentation in full manual might get me where I need to be.
9. Last one, ISO: What effect does ISO have on aperture and shutter speed? In full manual mode, I have control over this setting. Any suggestions on setting this manually for daylight actions shots like MX?
OK, that's all I got for now! Big thanks to anyone that can offer up any advice!
For review, some large images from Red Bud using the equipment listed at the top of the page. "Not bad considering the glass you were using" Chili says! :)
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I'm thinking of how awesome some of these would have been if I'd had a longer lens...
1. Depth of Field: Am I correct that a larger aperture will produce a shallower depth of field? Meaning, the subject in the photo is in focus, and the background is blurred? How does the shutter speed affect DoF for a given aperture setting? i.e.: Faster shutter speed = shallower Dof, etc.?
2. Lenses: I'm looking at several 70-200mm f2.8 lenses. Other than those obvious specs, what else should I be looking for? Does the diameter of the lens play any part in its picture quality, DoF, etc., if the length ranges are the same? There's the Sigma brand for ~$750, and a Vivitar Series 1 brand for less than $300 at Wal-Mart. Both 70-200mm f2.8. What else should I consider when choosing a lens?
Links to two lenses I'm looking at:
Sigma Lens
Vivitar Lens
3. My Digital Rebel has several "auto" modes. Would not using a manual mode, such as to set the largest aperture setting, be better? Seems like at the largest aperture, the shutter speed would be the fastest (best for shooting MX). I can select aperture or shutter speed priority, or full manual. Chili says the AI autofocus is paramount for shooting action like MX. Thoughts?
4. I also have a "portrait" auto mode which says it produces a shallow depth of field. When a buddy shot pics of us at a race last year, we were blurred. Is the shutter speed simply too slow in this setting?
5. Lens Filters: Do the UV and Polarizer filters distort the image appreciably? Does using both simultaneously cause any problems?
6. Lens Hoods: They look cool, but what do they do? Do the affect lens filters in any way, good or bad?
7. Known limitations of the Rebel: The only way to get the AI Servo focus is to use the automatic "action" mode (running guy icon on the selector dial). This mode is key for stopping the action, but eliminates the ability to set the aperture manually. Additionally, the autofocus has 7 focus points, which can be picked, down to a single one, but it is only for one shot. This kills shooting in "burst mode", where I pull the best shot(s) out of the burst of 4. I wonder how effectively and consistently one could shoot in full manual, selecting the largest aperture, and adjusting the shutter speed to adequately stop the action?
8. So if I get a 200mm lens, will that in itself guarantee me a shallower depth of field, especially given the fact that using the "action" mode will automatically set both aperture and shutter speed? I'm guessing some experimentation in full manual might get me where I need to be.
9. Last one, ISO: What effect does ISO have on aperture and shutter speed? In full manual mode, I have control over this setting. Any suggestions on setting this manually for daylight actions shots like MX?
OK, that's all I got for now! Big thanks to anyone that can offer up any advice!
For review, some large images from Red Bud using the equipment listed at the top of the page. "Not bad considering the glass you were using" Chili says! :)
pic1
pic2
pic3
pic4
pic5
pic6
pic7
pic8
pic9
pic10
pic11
pic12
pic13
I'm thinking of how awesome some of these would have been if I'd had a longer lens...