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#21
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Meaning of ISO value in digital photography?
On 2018-06-15 22:18, Jim-P wrote:
On Thu, 14 Jun 2018 19:47:36 -0700, Savageduck wrote: On Jun 14, 2018, Ken Hart wrote (in article ): On 06/14/2018 08:05 PM, Savageduck wrote: On Jun 14, 2018, Jim-P wrote (in article ): In the film days, we used the "Sunny-16" rule: Set the shutter speed equal to the ISO (then "ASA"). In bright sunshine, use f/16. Slightly cloudy- use f/11, open shade- f/8, full shade- f/5.6. This technique would usually give a good exposure. Combine that with the "focal length equals shutter speed" rule: The longer the focal length, the faster the shutter speed to give acceptable hand-held images. For a 200mm lens, you use a shutter speed of 1/250 second. Example: 100mm lens calls for 1/100 second minimum. Set the ISO also at 100, and use the "Sunny-16" rule. Then refer to SD's exposure triangle, three paragraphs down... Let us start by asking, what camera are you using? It would still be good to know what camera the OP is using. I am using a smartphone camera. Although it is not as high quality as a DSLR the principles should be the same and I am interested in understanding them before taking my photography further. The smartphone model is a Moto G5 Plus with a Sony IMX362 Exmor RS camera module which is also used in the Nokia 7 and Samsung S7 Edge https://phoneproscons.com/794/moto-g...enfone-3-zoom/ I recall that old Sunny 16 rule and the thing which strikes me most about it now is how slow the shutter speeds were in the old days. 1/250 was one of the faster speeds I would use for day to day photography years ago but my current smartphone often uses speeds of 1/1000 or 1/2000 which is fantastic because by hand steadiness is not what it used to be. My old SLR had 1/2000 The mechanics had a trick that allowed high effective shutter speed while the shutter in fact moved relatively slowly, at 1/60 or thereabouts. And old trick, actually. It opened a slit on the rectangle, and the slit travelled the length of the aperture. If the slit was 1/5, the effective speed was the actual speed multiplied by 5. -- Cheers, Carlos. |
#22
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Meaning of ISO value in digital photography?
On Jun 15, 2018, Carlos E.R. wrote
(in article ): On 2018-06-15 22:18, Jim-P wrote: On Thu, 14 Jun 2018 19:47:36 -0700, Savageduck wrote: On Jun 14, 2018, Ken Hart wrote (in article ): On 06/14/2018 08:05 PM, Savageduck wrote: On Jun 14, 2018, Jim-P wrote (in ): In the film days, we used the "Sunny-16" rule: Set the shutter speed equal to the ISO (then "ASA"). In bright sunshine, use f/16. Slightly cloudy- use f/11, open shade- f/8, full shade- f/5.6. This technique would usually give a good exposure. Combine that with the "focal length equals shutter speed" rule: The longer the focal length, the faster the shutter speed to give acceptable hand-held images. For a 200mm lens, you use a shutter speed of 1/250 second. Example: 100mm lens calls for 1/100 second minimum. Set the ISO also at 100, and use the "Sunny-16" rule. Then refer to SD's exposure triangle, three paragraphs down... Let us start by asking, what camera are you using? It would still be good to know what camera the OP is using. I am using a smartphone camera. Although it is not as high quality as a DSLR the principles should be the same and I am interested in understanding them before taking my photography further. The smartphone model is a Moto G5 Plus with a Sony IMX362 Exmor RS camera module which is also used in the Nokia 7 and Samsung S7 Edge https://phoneproscons.com/794/moto-g...r-camera-same- amazing-sensor-as-in-xplay-6-and-zenfone-3-zoom/ I recall that old Sunny 16 rule and the thing which strikes me most about it now is how slow the shutter speeds were in the old days. 1/250 was one of the faster speeds I would use for day to day photography years ago but my current smartphone often uses speeds of 1/1000 or 1/2000 which is fantastic because by hand steadiness is not what it used to be. My old SLR had 1/2000 The mechanics had a trick that allowed high effective shutter speed while the shutter in fact moved relatively slowly, at 1/60 or thereabouts. And old trick, actually. It opened a slit on the rectangle, and the slit travelled the length of the aperture. If the slit was 1/5, the effective speed was the actual speed multiplied by 5. That is the rolling shutter effect which has returned with the advent of the electronic shutter found in smartphones, digital video cameras, and many mirrorless cameras. With some of the advantages of the electronic shutter, rolling shutter effect can produce some unwanted effects with high speed shots of moving subjects. For example athletes can be given elongated and spindlely legs, wheels can be made oval, not round, propellor and rotor blades can be unrealistically distorted. https://en.wikipedia.org/wiki/Rolling_shutter -- Regards, Savageduck |
#23
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Meaning of ISO value in digital photography?
On Fri, 15 Jun 2018 13:46:46 -0700, Savageduck wrote:
On Jun 15, 2018, Jim-P wrote (in article ): On Thu, 14 Jun 2018 19:47:36 -0700, Savageduck wrote: On Jun 14, 2018, Ken Hart wrote (in article ): On 06/14/2018 08:05 PM, Savageduck wrote: On Jun 14, 2018, Jim-P wrote (in article ): On Thu, 14 Jun 2018 14:26:40 -0400, PeterN wrote: On 6/14/2018 1:48 PM, Jim-P wrote: In film cameras, ISO referrs to the sensitivity to light of the emulsion. Manufacturers formulate different film emulsions with different sensitivites tarding increased grain with increased ISO speed. In a digital camera, presumably the sensor does not adjust itself to have greater sensitivity. Or does it? So what is happening in a digital camera when I choose a greater ISO setting? Is more amplification being used? I tried to understand this page but it got far too technical.... https://photography.tutsplus.com/art...echnical-explo ration--photo-11963 I am going to try to give you a simplified, non-technical explanation. As with most generalities it is not 100% technically accurate, but should serve as a guideline. ISO is a measurement of the light sensitivity of the sensor. Digital ISO is adjustable in many cameras. And yes, it is a matter of adjusting the amplification. If you are using a wider lens opening, and slower shutter speed, you will be able to use a lower ISO. Digital noise is one of the undesired artifacts in the image. Higher ISO will result in more digital noise, and lessor image quality. Many of the newer high quality sensors are designed to work at a higher ISO, with less noticeable noise, and reduction in image quality. There are some of us here who do not object to noise, while others have serious objections. The point at which noise becomes objectionable often comes down to a matter of taste and personal preferences. Thanks. This makes me wonder what ISO I should set, if I don't leave it on auto. In the film days, we used the "Sunny-16" rule: Set the shutter speed equal to the ISO (then "ASA"). In bright sunshine, use f/16. Slightly cloudy- use f/11, open shade- f/8, full shade- f/5.6. This technique would usually give a good exposure. Combine that with the "focal length equals shutter speed" rule: The longer the focal length, the faster the shutter speed to give acceptable hand-held images. For a 200mm lens, you use a shutter speed of 1/250 second. Example: 100mm lens calls for 1/100 second minimum. Set the ISO also at 100, and use the "Sunny-16" rule. Then refer to SD's exposure triangle, three paragraphs down... Let us start by asking, what camera are you using? It would still be good to know what camera the OP is using. I am using a smartphone camera. Although it is not as high quality as a DSLR the principles should be the same and I am interested in understanding them before taking my photography further. The smartphone model is a Moto G5 Plus with a Sony IMX362 Exmor RS camera module which is also used in the Nokia 7 and Samsung S7 Edge https://phoneproscons.com/794/moto-g...y-imx362-rear- camera-same-amazing-sensor-as-in-xplay-6-and-zenfone-3-zoom/ There is nothing wrong in using a smartphone camera. However, you are going to have limitations which you will not find in modern DSLR, or mirrorless digital cameras (MILC). Even with third party photo apps for your smartphone you are going to have limitations of physical sensor size, and adjustability of the exposure triangle. The next question is; are you intending to add a modern digital camera to your current photography kit? I need to work out how to get the best from my smartphone first. I'm new to smartphones but they take surprisingly good pictures which are almost as good as my point and shoot. They are aso very forgiving and don't need lots of setting up. I wonder what the cost is for a point and shoot giving pictures a notch above a smartphone. |
#24
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Meaning of ISO value in digital photography?
In article , Carlos E.R.
wrote: My old SLR had 1/2000 The mechanics had a trick that allowed high effective shutter speed while the shutter in fact moved relatively slowly, at 1/60 or thereabouts. And old trick, actually. It opened a slit on the rectangle, and the slit travelled the length of the aperture. If the slit was 1/5, the effective speed was the actual speed multiplied by 5. that's not a trick, but how focal plane shutters work. the speed at which the slit is the same size or larger than the film frame in the dimension the shutter is traveling is the flash sync speed, typically in the 1/60-1/250 range. as always, there are exceptions. some digital slrs have a focal plane shutter that can sync at any shutter speed. |
#25
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Meaning of ISO value in digital photography?
On Jun 15, 2018, Jim-P wrote
(in article ): On Fri, 15 Jun 2018 13:46:46 -0700, Savageduck wrote: On Jun 15, 2018, Jim-P wrote (in article ): On Thu, 14 Jun 2018 19:47:36 -0700, Savageduck wrote: On Jun 14, 2018, Ken Hart wrote (in article ): On 06/14/2018 08:05 PM, Savageduck wrote: On Jun 14, 2018, Jim-P wrote (in article ): On Thu, 14 Jun 2018 14:26:40 -0400, PeterN wrote: On 6/14/2018 1:48 PM, Jim-P wrote: In film cameras, ISO referrs to the sensitivity to light of the emulsion. Manufacturers formulate different film emulsions with different sensitivites tarding increased grain with increased ISO speed. In a digital camera, presumably the sensor does not adjust itself to have greater sensitivity. Or does it? So what is happening in a digital camera when I choose a greater ISO setting? Is more amplification being used? I tried to understand this page but it got far too technical.... https://photography.tutsplus.com/art...-technical-exp lo ration--photo-11963 I am going to try to give you a simplified, non-technical explanation. As with most generalities it is not 100% technically accurate, but should serve as a guideline. ISO is a measurement of the light sensitivity of the sensor. Digital ISO is adjustable in many cameras. And yes, it is a matter of adjusting the amplification. If you are using a wider lens opening, and slower shutter speed, you will be able to use a lower ISO. Digital noise is one of the undesired artifacts in the image. Higher ISO will result in more digital noise, and lessor image quality. Many of the newer high quality sensors are designed to work at a higher ISO, with less noticeable noise, and reduction in image quality. There are some of us here who do not object to noise, while others have serious objections. The point at which noise becomes objectionable often comes down to a matter of taste and personal preferences. Thanks. This makes me wonder what ISO I should set, if I don't leave it on auto. In the film days, we used the "Sunny-16" rule: Set the shutter speed equal to the ISO (then "ASA"). In bright sunshine, use f/16. Slightly cloudy- use f/11, open shade- f/8, full shade- f/5.6. This technique would usually give a good exposure. Combine that with the "focal length equals shutter speed" rule: The longer the focal length, the faster the shutter speed to give acceptable hand-held images. For a 200mm lens, you use a shutter speed of 1/250 second. Example: 100mm lens calls for 1/100 second minimum. Set the ISO also at 100, and use the "Sunny-16" rule. Then refer to SD's exposure triangle, three paragraphs down... Let us start by asking, what camera are you using? It would still be good to know what camera the OP is using. I am using a smartphone camera. Although it is not as high quality as a DSLR the principles should be the same and I am interested in understanding them before taking my photography further. The smartphone model is a Moto G5 Plus with a Sony IMX362 Exmor RS camera module which is also used in the Nokia 7 and Samsung S7 Edge https://phoneproscons.com/794/moto-g...y-imx362-rear- camera-same-amazing-sensor-as-in-xplay-6-and-zenfone-3-zoom/ There is nothing wrong in using a smartphone camera. However, you are going to have limitations which you will not find in modern DSLR, or mirrorless digital cameras (MILC). Even with third party photo apps for your smartphone you are going to have limitations of physical sensor size, and adjustability of the exposure triangle. The next question is; are you intending to add a modern digital camera to your current photography kit? I need to work out how to get the best from my smartphone first. I'm new to smartphones but they take surprisingly good pictures which are almost as good as my point and shoot. They are aso very forgiving and don't need lots of setting up. If it meets your needs there is little point looking for something else, but if you want more you should consider something other than a compact/P&S camera. I wonder what the cost is for a point and shoot giving pictures a notch above a smartphone. There are some excellent compact, or P&S cameras from most of the manufacturers such as Canon, Nikon, Panasonic, Sony, etc, prices, and performance vary. The big issue with the P&S cameras is, they are being killed off by smartphones. The big advantage to a dedicated camera rather than a phone camera is ergonomics. No matter how much one might argue, a smartphone is awkward to use as a camera due to its unavoidable phone shape. Personally, if one is only considering a compact/P&S camera as an upgrade from a smartphone, consider what you are going to be doing with your photography, it might be better to stick with the smartphone. Otherwise, I would suggest moving to a mirrorless camera with, or without interchangeable lenses. They can be more expensive than a smartphone, but your photographic experience will be more enjoyable. I an unabashed fan of the Fujifilm mirrorless cameras, and for somebody wanting something reminiscent of the analog days, a great fixed focal length camera is the Fujifilm X100F. https://www.dpreview.com/reviews/fujifilm-x100f https://www.techradar.com/reviews/fujifilm-x100f-review I currently own several Fujifilm bodies and a bag full of lenses. https://www.dropbox.com/s/5yeyllbh2jd8g0a/IMG_2527e.jpg To get some idea of what is out there in the compact camera range check out dpreview: https://www.dpreview.com -- Regards, Savageduck |
#26
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Meaning of ISO value in digital photography?
On 2018-06-16 02:17, nospam wrote:
In article , Carlos E.R. wrote: My old SLR had 1/2000 The mechanics had a trick that allowed high effective shutter speed while the shutter in fact moved relatively slowly, at 1/60 or thereabouts. And old trick, actually. It opened a slit on the rectangle, and the slit travelled the length of the aperture. If the slit was 1/5, the effective speed was the actual speed multiplied by 5. that's not a trick, but how focal plane shutters work. I have seen it in solid metal non focal plane shutters. Actually a part of the mirror assembly. the speed at which the slit is the same size or larger than the film frame in the dimension the shutter is traveling is the flash sync speed, typically in the 1/60-1/250 range. Yes.. as always, there are exceptions. some digital slrs have a focal plane shutter that can sync at any shutter speed. -- Cheers, Carlos. |
#27
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Meaning of ISO value in digital photography?
On 2018-06-16 01:49, Jim-P wrote:
On Fri, 15 Jun 2018 13:46:46 -0700, Savageduck wrote: On Jun 15, 2018, Jim-P wrote (in article ): On Thu, 14 Jun 2018 19:47:36 -0700, Savageduck wrote: On Jun 14, 2018, Ken Hart wrote (in article ): On 06/14/2018 08:05 PM, Savageduck wrote: On Jun 14, 2018, Jim-P wrote (in article ): .... Let us start by asking, what camera are you using? It would still be good to know what camera the OP is using. I am using a smartphone camera. Although it is not as high quality as a DSLR the principles should be the same and I am interested in understanding them before taking my photography further. The smartphone model is a Moto G5 Plus with a Sony IMX362 Exmor RS camera module which is also used in the Nokia 7 and Samsung S7 Edge https://phoneproscons.com/794/moto-g...y-imx362-rear- camera-same-amazing-sensor-as-in-xplay-6-and-zenfone-3-zoom/ There is nothing wrong in using a smartphone camera. However, you are going to have limitations which you will not find in modern DSLR, or mirrorless digital cameras (MILC). Even with third party photo apps for your smartphone you are going to have limitations of physical sensor size, and adjustability of the exposure triangle. The next question is; are you intending to add a modern digital camera to your current photography kit? I need to work out how to get the best from my smartphone first. I'm new to smartphones but they take surprisingly good pictures which are almost as good as my point and shoot. They are aso very forgiving and don't need lots of setting up. I wonder what the cost is for a point and shoot giving pictures a notch above a smartphone. They start at about 75 euros, and I see models up to 400. Wait, I see one for 1100. IMO, it is easier to get reasonably good optics when lenses are bigger, not cramped in 5 mm. On the other hand, I've seen better software on a phone than a camera of the same manufacturer. At least apparently. I mean, more features. You can have a compact of 150€ with optical zoom. I don't see a phone of that price having optical zoom. -- Cheers, Carlos. |
#28
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Meaning of ISO value in digital photography?
On Jun 15, 2018, Carlos E.R. wrote
(in article ): On 2018-06-16 01:49, Jim-P wrote: On Fri, 15 Jun 2018 13:46:46 -0700, Savageduck wrote: On Jun 15, 2018, Jim-P wrote (in article ): On Thu, 14 Jun 2018 19:47:36 -0700, Savageduck wrote: On Jun 14, 2018, Ken Hart wrote (in article ): On 06/14/2018 08:05 PM, Savageduck wrote: On Jun 14, 2018, Jim-P wrote (in ): ... Let us start by asking, what camera are you using? It would still be good to know what camera the OP is using. I am using a smartphone camera. Although it is not as high quality as a DSLR the principles should be the same and I am interested in understanding them before taking my photography further. The smartphone model is a Moto G5 Plus with a Sony IMX362 Exmor RS camera module which is also used in the Nokia 7 and Samsung S7 Edge https://phoneproscons.com/794/moto-g...y-imx362-rear- camera-same-amazing-sensor-as-in-xplay-6-and-zenfone-3-zoom/ There is nothing wrong in using a smartphone camera. However, you are going to have limitations which you will not find in modern DSLR, or mirrorless digital cameras (MILC). Even with third party photo apps for your smartphone you are going to have limitations of physical sensor size, and adjustability of the exposure triangle. The next question is; are you intending to add a modern digital camera to your current photography kit? I need to work out how to get the best from my smartphone first. I'm new to smartphones but they take surprisingly good pictures which are almost as good as my point and shoot. They are aso very forgiving and don't need lots of setting up. I wonder what the cost is for a point and shoot giving pictures a notch above a smartphone. They start at about 75 euros, and I see models up to 400. Wait, I see one for 1100. IMO, it is easier to get reasonably good optics when lenses are bigger, not cramped in 5 mm. On the other hand, I've seen better software on a phone than a camera of the same manufacturer. At least apparently. I mean, more features. You can have a compact of 150€ with optical zoom. I don't see a phone of that price having optical zoom. I don’t see a phone of any price having optical zoom. My iPhone 8+ certainly doesn’t have it, but it does have a twin lens set up which makes for some interesting portrait, and lighting features. -- Regards, Savageduck |
#29
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Meaning of ISO value in digital photography?
In article .com,
Savageduck wrote: I don¹t see a phone of any price having optical zoom. My iPhone 8+ certainly doesn¹t have it, but it does have a twin lens set up which makes for some interesting portrait, and lighting features. apple calls it optical zoom and the results are noticeably better than digital zoom with just one lens. nevertheless, there have been true optical zooms on phones, and not surprisingly, did not sell well. https://www.samsung.com/uk/smartphon.../SM-C1150ZKABT U/ https://images.samsung.com/is/image/...laxy-k-zoom-c1 15--45680117?$FB_TYPE_C_JPG$ |
#30
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Meaning of ISO value in digital photography?
On 2018-06-14 13:48, Jim-P wrote:
In film cameras, ISO referrs to the sensitivity to light of the emulsion. Manufacturers formulate different film emulsions with different sensitivites tarding increased grain with increased ISO speed. In a digital camera, presumably the sensor does not adjust itself to have greater sensitivity. Or does it? So what is happening in a digital camera when I choose a greater ISO setting? Is more amplification being used? Typically two stages: 0: the natural ISO of the sensor (whatever value it is - somewhere in the 100 - 800 range). 1: Analog gain (possibly negative) applied at the time the image is "read off" of the sensor. This will go up to some limit, eg: ISO 2000 (depending on the model it will be more or less). Noise is amplified with signal. Analog and/or digital noise filtering may be applied. 2: Digital gain applied to the data after it is read off, before it is stored on the data card. This has no limit at all except of course contribution to noise, especially quantization noise. Digital noise filtering may (and likely is) applied. -- "2/3 of Donald Trump's wives were immigrants. Proof that we need immigrants to do jobs that most Americans wouldn't do." - unknown protester |
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