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#21
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Funky IR Artefact
On Thu, 26 Apr 2018 02:05:37 -0700 (PDT), Whisky-dave
wrote: On Thursday, 26 April 2018 04:28:03 UTC+1, Eric Stevens wrote: On Wed, 25 Apr 2018 05:32:11 -0700 (PDT), Whisky-dave wrote: On Wednesday, 25 April 2018 13:07:56 UTC+1, android wrote: On 2018-04-25 11:31:01 +0000, Whisky-dave said: How can you take an IR photograph while yuor camera has an IR filter to cut out IR from getting to the sensor. Do some thinking... come on then tell me how IR gets through the lens to the camera sensor and through the IR filter that is on the sensor so it doesn't reposnd to IR 'light' All he has to do is travel towards the subject at a speed sufficiently high to shift the IR into the visible part of the spectrum. He'll get that wrong too, he'll travel so fast it'll get into the UV specrum and he;'ll annoucnce that the universe has disapeared because he canlt see it. He will need to use a high shutter speed. That's the least of his problems. Not unless he wants to take the image before he crashes into the subject. -- Regards, Eric Stevens |
#22
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Funky IR Artefact
On 4/24/2018 12:16 PM, android wrote:
On 2018-04-23 17:29:56 +0000, PeterN said: On 4/23/2018 1:34 AM, android wrote: On 2018-04-22 18:53:51 +0000, RichA said: On Sunday, 22 April 2018 05:40:30 UTC-4, androidÂ* wrote: Trée arty but... WTF is it??? https://dl.dropboxusercontent.com/s/mjfnh2d0s1wulli/i180422%2311638.jpg For the record: I used a IR filter on a unconverted EOS M with high ISO settings. Hard to work without an OVF, witch I have... -- teleportation kills I tend to use a Leica viewfinder in the hotshoe, a wide angle lens set to f/8 so proximity focus is easy.Â* A mild IR filter (cutoff, around 800nm on a camera with its IR filter removed can easily be handheld in daylight or even overcast, but a deep IR cutoff (1000+nm) means using a tripod.Â* A camera with the IR sensor filter in-place is a pain, cutting out so much of the IR than any exposures with an IR filter over the lens means seconds of time. I've got a 760nm totally black filter, so there is an overlapping gap between the high end of the visible spectrum and low end of the IR one and that can be used at high ISOs sunny days. If you got steady hands, there is another example from a few years ago in the gallery on my blog. https://wp.me/P3strj-7Y I've gotten it down to where I can convert an old Nikon D70 (the easiest camera to convert) in 15 minutes. I might just pull the the filter stack out of the EOS M eventually. Can't be that difficult... You might lose autofocuse. The near IR light has a different wavelength. On a mirrorless? Don't think soo... You may be right. I had the IR filter pulled on my P&S, and did not lose autofocus. It may depend on the size of your sensor. According to articles I've read, you lose AF if you try that on a full frame. -- PeterN |
#23
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Funky IR Artefact
On 4/24/2018 12:16 PM, android wrote:
On 2018-04-23 17:25:54 +0000, PeterN said: On 4/22/2018 5:40 AM, android wrote: Trée arty but... WTF is it??? https://dl.dropboxusercontent.com/s/mjfnh2d0s1wulli/i180422%2311638.jpg For the record: I used a IR filter on a unconverted EOS M with high ISO settings. Hard to work without an OVF, witch I have... Did a quick and dirty post, (surface blur and increased fog a bit,) just to get rid of most of the artifacts. https://www.dropbox.com/s/97ubvg4wj71xn2d/i180422%2311638.jpg?dl=0 I did a q n d myself in a follow up to the OP. The file is broken so I did not take it any further... The white streak to the left is that what puzzles me. Do you know what it is? if you're talking about the curved line, I think it's the edge of a curtain, that is OOF. -- PeterN |
#24
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Funky IR Artefact
On 2018-04-27 02:11:45 +0000, PeterN said:
On 4/24/2018 12:16 PM, android wrote: On 2018-04-23 17:29:56 +0000, PeterN said: On 4/23/2018 1:34 AM, android wrote: On 2018-04-22 18:53:51 +0000, RichA said: On Sunday, 22 April 2018 05:40:30 UTC-4, android* wrote: Trée arty but... WTF is it??? https://dl.dropboxusercontent.com/s/mjfnh2d0s1wulli/i180422%2311638.jpg For the record: I used a IR filter on a unconverted EOS M with high ISO settings. Hard to work without an OVF, witch I have... -- teleportation kills I tend to use a Leica viewfinder in the hotshoe, a wide angle lens set to f/8 so proximity focus is easy.* A mild IR filter (cutoff, around 800nm on a camera with its IR filter removed can easily be handheld in daylight or even overcast, but a deep IR cutoff (1000+nm) means using a tripod.* A camera with the IR sensor filter in-place is a pain, cutting out so much of the IR than any exposures with an IR filter over the lens means seconds of time. I've got a 760nm totally black filter, so there is an overlapping gap between the high end of the visible spectrum and low end of the IR one and that can be used at high ISOs sunny days. If you got steady hands, there is another example from a few years ago in the gallery on my blog. https://wp.me/P3strj-7Y I've gotten it down to where I can convert an old Nikon D70 (the easiest camera to convert) in 15 minutes. I might just pull the the filter stack out of the EOS M eventually. Can't be that difficult... You might lose autofocuse. The near IR light has a different wavelength. On a mirrorless? Don't think soo... You may be right. I had the IR filter pulled on my P&S, and did not lose autofocus. It may depend on the size of your sensor. According to articles I've read, you lose AF if you try that on a full frame. We are talking mirrorless here... -- teleportation kills |
#25
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Funky IR Artefact
On 2018-04-27 02:15:34 +0000, PeterN said:
On 4/24/2018 12:16 PM, android wrote: On 2018-04-23 17:25:54 +0000, PeterN said: On 4/22/2018 5:40 AM, android wrote: Trée arty but... WTF is it??? https://dl.dropboxusercontent.com/s/mjfnh2d0s1wulli/i180422%2311638.jpg For the record: I used a IR filter on a unconverted EOS M with high ISO settings. Hard to work without an OVF, witch I have... Did a quick and dirty post, (surface blur and increased fog a bit,) just to get rid of most of the artifacts. https://www.dropbox.com/s/97ubvg4wj71xn2d/i180422%2311638.jpg?dl=0 I did a q n d myself in a follow up to the OP. The file is broken so I did not take it any further... The white streak to the left is that what puzzles me. Do you know what it is? if you're talking about the curved line, I think it's the edge of a curtain, that is OOF. No. I have files taken att the same time and it's not there. Probably a hot spot with floded photon wells with the surplus photons following gravity... -- teleportation kills |
#26
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Funky IR Artefact
On 2018-04-27 10:24:51 +0000, Whisky-dave, AKA Dense Dave said:
Well that certainly is funny, are you sure it's not microscopic aliens No, it's photonics lemmings... -- teleportation kills |
#27
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Funky IR Artefact
In article ,
Whisky-dave wrote: Focusing with a mirrorless Cameras don't use the mirrors to focus the image, slrs have a secondary mirror behind the main mirror for the autofocus system to work, which has its own sensor. mirrorless focus using the main sensor. Really, when I focus my M3 I use the focusing ring on the lens for manual focus. whooooooosh. |
#28
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Funky IR Artefact
In article ,
Whisky-dave wrote: Focusing with a mirrorless Cameras don't use the mirrors to focus the image, slrs have a secondary mirror behind the main mirror for the autofocus system to work, which has its own sensor. mirrorless focus using the main sensor. Really, when I focus my M3 I use the focusing ring on the lens for manual focus. whooooooosh. Gone right over yuor head hasn;t it, why do they but IR markings on lenes and this gose back well before mirrorless are yuo really climing that IR light focussess differntly for mirrorless cameras ? whoooooosh even higher. plus, modern lenses don't have ir markers anymore. |
#29
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Funky IR Artefact
On Apr 27, 2018, Whisky-dave wrote
(in ): Gone right over yuor head hasn;t it, why do they but IR markings on lenes and this gose back well before mirrorless are yuo really climing that IR light focussess differntly for mirrorless cameras ? Yes. Mirrorless cameras have the ability to AF IR light without focusing issues found in DSLRs. Typically with IR converted DSLRs camera/lens combos have to be calibrated, not so with mirrorless. With mirrorless cameras AF happens via the sensor, and you get a realtime preview of the image before capture in either the EVF and on LCD. Here is one photographer's experience. https://neilvn.com/tangents/mirrorless-cameras-and-bw-infrared-photography/ -- Regards, Savageduck |
#30
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Funky IR Artefact
In article ,
Whisky-dave wrote: Focusing with a mirrorless Cameras don't use the mirrors to focus the image, slrs have a secondary mirror behind the main mirror for the autofocus system to work, which has its own sensor. mirrorless focus using the main sensor. Really, when I focus my M3 I use the focusing ring on the lens for manual focus. whooooooosh. Gone right over yuor head hasn;t it, why do they but IR markings on lenes and this gose back well before mirrorless are yuo really climing that IR light focussess differntly for mirrorless cameras ? whoooooosh even higher. plus, modern lenses don't have ir markers anymore. So WTF has that got to do with it. IR works in the same way it has done since the big bang whether or not lenes have a mark on them is irrelivant. what you fail to understand is that a mirrorless camera focuses off the actual sensor, while slr has a *separate* focus module. in other words, with mirrorless, what you see is what you get. lens markings do not matter. different wavelengths do not matter. if it's in focus in the viewfinder or on the rear display, it will be in focus on the actual photo. always. with an slr, the focus module is separate, using a secondary mirror behind the main mirror to reflect light to the focus sensor module. it is calibrated for visible light, so for infrared, either you adjust for the difference (using lens markings) or the focus system needs to be recalibrated for infrared. |
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