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What's the big deal with ISO 3200 Boost?
Whenever dSLRs get into a measuring contest with each other, the ISO
3200 "boost" is always being touted as a feature by cameras that have it. For example, I've read on several product reviews that one of Canon 30D's advantages over the puny Digital Rebel is this so-called ISO 3200 Boost. Even the most reputable reviewers are including ISO 3200 in their graph comparisons. Am I wrong in thinking that this "boost" is nothing more than software manipulation? Similar to how "Point n' Shoot" cameras are constantly peddling their "digital zooms" to anybody that would listen. Correct me if I'm mistaken, but in the case of Digital Rebel XT vs 30D, their performance over the entire spectrum (ISO 100 to 1600) are virtually identical. And if this "ISO 3200 Boost" really is fool's gold (?), that would make these two cameras equal performers in this particular aspect of digital photography... correct? |
#2
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What's the big deal with ISO 3200 Boost?
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What's the big deal with ISO 3200 Boost?
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#4
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What's the big deal with ISO 3200 Boost?
Am I wrong in thinking that this "boost" is nothing more than software
manipulation? Similar to how "Point n' Shoot" cameras are constantly peddling their "digital zooms" to anybody that would listen. That's a bit harsh, I think. It is true that you can shoot at a lower ISO and then push it in PP, and get results that will probably be as good as the 3200 that may be provided on camera - at least, if you shoot RAW. But it can be useful to being able to see the image at the "correct" exposure on the LCD - it's much easier to judge whether the shot came off well enough in terms of sharpness etc. That said, I seldom use ISO 3200, because it's still way too noisy on my Pentax *istDS (which doesn't *call* it a "boost", but as someone else says, in some sense, anything above the native ISO of the sensor is just a boost of one sort or another). --------------- Marc Sabatella Music, art, & educational materials Featuring "A Jazz Improvisation Primer" http://www.outsideshore.com/ |
#5
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What's the big deal with ISO 3200 Boost?
wrote in message
oups.com... Correct me if I'm mistaken, but in the case of Digital Rebel XT vs 30D, their performance over the entire spectrum (ISO 100 to 1600) are virtually identical. And if this "ISO 3200 Boost" really is fool's gold (?), that would make these two cameras equal performers in this particular aspect of digital photography... correct? I recall reading somewhere that if you look into a ISO3200 RAW file from a Canon camera that you will find only even numbers suggesting the values are simply doubled from a ISO 1600 exposure, 1 stop underexposed. If this is truly the case, then you can get pretty much identical results from your Rebel XT by sliding the exposure compensation down and stop and pushing by one stop in your RAW converter. This works well for me with my XT when I am already at ISO1600 and desperately want more shutter speed. It's especially helpful when you are in low light with a telephoto hand-held and weren't prepared. You get the added benefit of more headroom for highlights too that you can compress in. If you use the noise reduction in the new Canon Digital Photo Professional or Adobe Camera RAW, you can get a quite nice picture as long as you don't expect to blow it up huge and way better than high-speed 35mm film in the same circumstance. I don't think ISO3200 is a bunch of pyrite but just a convenience that Canon through in for the 10/20/30D cameras. |
#7
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What's the big deal with ISO 3200 Boost?
wrote:
Whenever dSLRs get into a measuring contest with each other, the ISO 3200 "boost" is always being touted as a feature by cameras that have it. For example, I've read on several product reviews that one of Canon 30D's advantages over the puny Digital Rebel is this so-called ISO 3200 Boost. Even the most reputable reviewers are including ISO 3200 in their graph comparisons. Am I wrong in thinking that this "boost" is nothing more than software manipulation? Similar to how "Point n' Shoot" cameras are constantly peddling their "digital zooms" to anybody that would listen. In early DSLRs it was reportedly a mathematical boost, but it newer cameras, it is not. Correct me if I'm mistaken, but in the case of Digital Rebel XT vs 30D, their performance over the entire spectrum (ISO 100 to 1600) are virtually identical. And if this "ISO 3200 Boost" really is fool's gold (?), that would make these two cameras equal performers in this particular aspect of digital photography... correct? There is a simple upper limit beyond which you won't gain anything. Each camera's electronics had a gain stage before feeding the A/D, and the gain is expressed in electrons/DN where DN is "data number," There is no point in having gain above 1 electron. Most DSLRs have that gain point between the iso 800 and iso 1600 levels. For example, see Table 1, column E at: Procedures for Evaluating Digital Camera Sensor Noise, Dynamic Range, and Full Well Capacities; Canon 1D Mark II Analysis http://www.clarkvision.com/imagedetail/evaluation-1d2 Other sensors can be found at: http://www.clarkvision.com/imagedetail and scrolling down to sensor analysis. I'll be adding several other cameras in the next few weeks. For example, preliminary analysis of the Canon S70 7-megapixel camera shows its gain at minimum is about 2 electrons/DN at ISO 50, so the gain =1 at iso 100. Minimum noise in cameras is around 4 electrons (called the read noise), so at a gain =1, read noise is well digitized. There is no need to go higher in a camera, as you can get the same result in post processing and have a higher dynamic range. I've tabulated gain data of mine and from the net he http://www.clarkvision.com/imagedeta...ignal.to.noise in Table 1. The 30D has the same sensor as the 20D, and probably the same gains. The 20D gain is 1.5 at ISO 800, and 0.8 at iso 1600. There is no advantage going above iso 1600 unless you want to not post-process images. Amateur astronomers using these cameras have independently found that iso 3200 has no advantage. Most use ISO 1600 or 800. Roger |
#8
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What's the big deal with ISO 3200 Boost?
Roger N. Clark (change username to rnclark) wrote:
snip Amateur astronomers using these cameras have independently found that iso 3200 has no advantage. Most use ISO 1600 or 800. OK thanks Roger, so it's been tested and is simply a convenience for jpeg shooting. -- Paul Furman http://www.edgehill.net/1 Bay Natives http://www.baynatives.com |
#9
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What's the big deal with ISO 3200 Boost?
"Roger N. Clark (change username to rnclark)" wrote in message ... wrote: Whenever dSLRs get into a measuring contest with each other, the ISO 3200 "boost" is always being touted as a feature by cameras that have it. For example, I've read on several product reviews that one of Canon 30D's advantages over the puny Digital Rebel is this so-called ISO 3200 Boost. Even the most reputable reviewers are including ISO 3200 in their graph comparisons. Am I wrong in thinking that this "boost" is nothing more than software manipulation? Similar to how "Point n' Shoot" cameras are constantly peddling their "digital zooms" to anybody that would listen. In early DSLRs it was reportedly a mathematical boost, but it newer cameras, it is not. Correct me if I'm mistaken, but in the case of Digital Rebel XT vs 30D, their performance over the entire spectrum (ISO 100 to 1600) are virtually identical. And if this "ISO 3200 Boost" really is fool's gold (?), that would make these two cameras equal performers in this particular aspect of digital photography... correct? There is a simple upper limit beyond which you won't gain anything. Each camera's electronics had a gain stage before feeding the A/D, and the gain is expressed in electrons/DN where DN is "data number," There is no point in having gain above 1 electron. Most DSLRs have that gain point between the iso 800 and iso 1600 levels. For example, see Table 1, column E at: Procedures for Evaluating Digital Camera Sensor Noise, Dynamic Range, and Full Well Capacities; Canon 1D Mark II Analysis http://www.clarkvision.com/imagedetail/evaluation-1d2 Other sensors can be found at: http://www.clarkvision.com/imagedetail and scrolling down to sensor analysis. I'll be adding several other cameras in the next few weeks. For example, preliminary analysis of the Canon S70 7-megapixel camera shows its gain at minimum is about 2 electrons/DN at ISO 50, so the gain =1 at iso 100. Minimum noise in cameras is around 4 electrons (called the read noise), so at a gain =1, read noise is well digitized. There is no need to go higher in a camera, as you can get the same result in post processing and have a higher dynamic range. I've tabulated gain data of mine and from the net he http://www.clarkvision.com/imagedeta...ignal.to.noise in Table 1. The 30D has the same sensor as the 20D, and probably the same gains. The 20D gain is 1.5 at ISO 800, and 0.8 at iso 1600. There is no advantage going above iso 1600 unless you want to not post-process images. Amateur astronomers using these cameras have independently found that iso 3200 has no advantage. Most use ISO 1600 or 800. Roger could you explain why there would be no advantage in using 3200? If you shoot at 1600, you have to either shoot with longer speed or with lower F number. longer shutter speed will give you blurry pic, which hundred PS programs won't remove, while you (most of the time) already shoot with lowest F possible, so nothing you can do here. SO your only option would be underexposed image, while lightening in PS will indoubtly result in even more noise, so i'd say wou'll still get less noise at 3200 then at 1600 and compensate exposure setting in PS. |
#10
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What's the big deal with ISO 3200 Boost?
Protoncek (ex.SleeperMan) wrote:
"Roger N. Clark (change username to rnclark)" wrote Amateur astronomers using these cameras have independently found that iso 3200 has no advantage. Most use ISO 1600 or 800. could you explain why there would be no advantage in using 3200? If you shoot at 1600, you have to either shoot with longer speed or with lower F number. longer shutter speed will give you blurry pic, which hundred PS programs won't remove, while you (most of the time) already shoot with lowest F possible, so nothing you can do here. SO your only option would be underexposed image, while lightening in PS will indoubtly result in even more noise, so i'd say wou'll still get less noise at 3200 then at 1600 and compensate exposure setting in PS. Amateur astronomers do use something a bit different than a standard RAW converter and it's a different game, so there may be some advantage for 'normal' photography. It would be a pretty simple test to compare underexposed ISO 1600 boosted in RAW to ISO 3200 at normal exposure. -- Paul Furman http://www.edgehill.net/1 Bay Natives http://www.baynatives.com |
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