frame-it Posted May 27, 2018 Share #101 Posted May 27, 2018 (edited) Advertisement (gone after registration) and a few more at 850nm, very different from using plugins and presets..sensor was converted by Kolari Vision Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Edited May 27, 2018 by frame-it 11 Quote Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/284529-infrared-image-thread/?do=findComment&comment=3526230'>More sharing options...
Advertisement Posted May 27, 2018 Posted May 27, 2018 Hi frame-it, Take a look here INFRARED-Image-Thread. I'm sure you'll find what you were looking for!
farnz Posted May 27, 2018 Share #102 Posted May 27, 2018 this is an 850nm IR shot, converted sensor camera [not a Leica, just for reference ] dead fish skin, surreal eyes Sharpest focus seems to be on her left sleeve - was that the intention? Pete. Quote Link to post Share on other sites More sharing options...
frame-it Posted May 27, 2018 Share #103 Posted May 27, 2018 nope..she was simply walking quite fast towards me...and its a shaded street market...hence the focus mishap..but she looks elegant in a zombie-esque way Sharpest focus seems to be on her left sleeve - was that the intention? Pete. 1 Quote Link to post Share on other sites More sharing options...
pico Posted May 27, 2018 Share #104 Posted May 27, 2018 So, putting this thread into the bin I conclude that no 35mm photographers are aware of or care about center filters. Pity. Quote Link to post Share on other sites More sharing options...
farnz Posted May 28, 2018 Share #105 Posted May 28, 2018 RE: Hot Spot - we have not explored the earlier mentioned ND center-filter. If one can be borrowed it might help settle the question. Hi, Pico, I haven't explored it because I'm fortunate that the lenses I use have no hotspot when used wide open (which I usually do to allow me to shoot handheld). I assume that you're wondering whether the same phenomenon applies here as does to the 90/2.2 Thambar soft focus lens where blocking the rays entering through the centre of the lens forces the use of off-centre and oblique rays. You might well be correct in thinking that using a spot filter would give even exposure across the frame but I suspect that it would be at a lower exposure value than the hot spot's exposure value and some of the benefit to produce stark white foliage would be diminished or lost. This might not matter to others but it would to me; I want all the radiant energy in the infra-red band I can get. I have a theory that the term 'hotspot' is a misnomer and it should more correctly be termed 'cold periphery' but that's not as catchy a name of course. What I mean is that I believe the lens actually attenuates infra-red energy towards the edges of the image circle (and frame) rather than - as the name hotspot suggests - concentrates or amplifies it at the centre. I have seen this over the years while trying out various lenses at different apertures and in my opinion there is a correlation between aperture size and hotspots. The wider the aperture, the less evident the hotspot tends to be. However stopping right up on a lens that has a hotspot doesn't remove the hotspot in my experience but stopping down makes it more obvious. I can't support this scientifically, only evidentially. So, while using a spot filter (of an undetermined attenuation*) might reduce the hotspot I think it would also reduce the infra-red effect in the picture. *The logical assumption would be to use a metal spot filter such is used on the Thambar that stops all radiant energy (axial rays) from entering the centre of the lens but in this instance having a spot filter that only attenuates some of the 'central' infra-red energy might produce a quite different effect since some of the oblique rays will enter through the centre of the lens but be blocked along with the axial rays. The size of spot filter would probably be quite important and I suspect would need to be determined through trial and error and is likely to vary with aperture. Pete. 3 Quote Link to post Share on other sites More sharing options...
amansjeanphilippe Posted May 28, 2018 Share #106 Posted May 28, 2018 (edited) Hello edit: oops! I haven't realise that it is "leicaQ topic" sorry for my mistake... M8+TV CANON TV 50F0.95+IR-720 or M8+ZM25+BW092 same with IR-cut BW486 filter J.Ph. Edited May 28, 2018 by amansjeanphilippe 6 Quote Link to post Share on other sites More sharing options...
bags27 Posted May 28, 2018 Share #107 Posted May 28, 2018 Advertisement (gone after registration) Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! 10 Quote Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/284529-infrared-image-thread/?do=findComment&comment=3526889'>More sharing options...
Leica Guy Posted May 28, 2018 Share #108 Posted May 28, 2018 *drydock IR.jpg Must be the Navy’s latest stealth ships. Radar can’t see them and neither can people. :-) 2 Quote Link to post Share on other sites More sharing options...
uffehagen Posted May 31, 2018 Share #109 Posted May 31, 2018 Got my Hoya filter, and this is my first try. Some lens flare, I forgot to get shade over the camera, but somehow I like it. PP in Capture One 11 Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! 9 Quote Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/284529-infrared-image-thread/?do=findComment&comment=3528806'>More sharing options...
bags27 Posted May 31, 2018 Share #110 Posted May 31, 2018 I've taken this captain's tower before, but this was serendipitous in the setting sun, and therefore handheld at >6000 ISO, and a bit grainy. But the shadows are nice, I think. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! 6 Quote Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/284529-infrared-image-thread/?do=findComment&comment=3528944'>More sharing options...
bags27 Posted June 1, 2018 Share #111 Posted June 1, 2018 Downtown Providence Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! 9 Quote Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/284529-infrared-image-thread/?do=findComment&comment=3529241'>More sharing options...
gbealnz Posted June 1, 2018 Share #112 Posted June 1, 2018 Same ghost following you Ken? Really getting the hang of it by the looks.Gary 2 Quote Link to post Share on other sites More sharing options...
zampelis Posted June 3, 2018 Share #113 Posted June 3, 2018 (edited) I didn't have the opportunity the last days to post some findings on the IR bright spot as my laptop was broken! Its funny how computers have become such an integral part of photography in the digital era! In the mean time, I did some investigation on how to help reduce the hot spot. I will have to agree with Farnz that the hot spot may contain the ideal amount of IR and the periphery of the lens probably gets less than optimal amount of IR light. Experimenting with 50mm cropped images stitched to a panorama could be a good option for taking fully advantage of the IR in the hot spot area. In case you don't want to go with the panorama solution, it seems it is easier to reduce the spot rather than to increase the light in the periphery at least during editing. I read this article about IR photography https://www.davidkennardphotography.com/blog/976-creating-kodak-eir-aerochrome-style-digital-photos.xhtml#hotspothttps://www.davidkennardphotography.com/blog/976-creating-kodak-eir-aerochrome-style-digital-photos.xhtml#hotspot In this article there is a reference on how to use the application called Cornerfix in order to reduce the IR hotspot. https://sites.google.com/site/cornerfix/ As on most lenses, it seems that the spot is variable depending the aperture size. Here are some samples of the hotspot pointing on the wall. I have created a series of profiles for the Cornerfix app based on the above shots. The maximum aperture I have saved as a profile is 5.6 as above that I dont see any significant differences on the size of the hotspot (Also the texture of the wall starts become prominent on aperture sizes smaller than that, I should have tested it on a smooth area!). Leica Q Cornerfix profiles Of course this is a crude way to fix it - (more an opportunity for experimentation), as each of us is using a different IR filter and the amount of IR reaching the sensor is different from photo to photo. It is something though that doesn’t hurt to try and see if there is any improvement.. Edited June 3, 2018 by zampelis 5 Quote Link to post Share on other sites More sharing options...
bags27 Posted June 3, 2018 Share #114 Posted June 3, 2018 Same ghost following you Ken? Really getting the hang of it by the looks. Gary Thanks, Gary. I had forgotten that there was somewhere walking there until you mentioned it! 2 Quote Link to post Share on other sites More sharing options...
bags27 Posted June 3, 2018 Share #115 Posted June 3, 2018 I didn't have the opportunity the last days to post some findings on the IR bright spot as my laptop was broken! Its funny how computers have become such an integral part of photography in the digital era! In the mean time, I did some investigation on how to help reduce the hot spot. I will have to agree with Farnz that the hot spot may contain the ideal amount of IR and the periphery of the lens probably gets less than optimal amount of IR light. Experimenting with 50mm cropped images stitched to a panorama could be a good option for taking fully advantage of the IR in the hot spot area. In case you don't want to go with the panorama solution, it seems it is easier to reduce the spot rather than to increase the light in the periphery at least during editing. I read this article about IR photography https://www.davidkennardphotography.com/blog/976-creating-kodak-eir-aerochrome-style-digital-photos.xhtml#hotspothttps://www.davidkennardphotography.com/blog/976-creating-kodak-eir-aerochrome-style-digital-photos.xhtml#hotspot In this article there is a reference on how to use the application called Cornerfix in order to reduce the IR hotspot. https://sites.google.com/site/cornerfix/ As on most lenses, it seems that the spot is variable depending the aperture size. Here are some samples of the hotspot pointing on the wall. I have created a series of profiles for the Cornerfix app based on the above shots. The maximum aperture I have saved as a profile is 5.6 as above that I dont see any significant differences on the size of the hotspot (Also the texture of the wall starts become prominent on aperture sizes smaller than that, I should have tested it on a smooth area!). Leica Q Cornerfix profiles Of course this is a crude way to fix it - (more an opportunity for experimentation), as each of us is using a different IR filter and the amount of IR reaching the sensor is different from photo to photo. It is something though that doesn’t hurt to try and see if there is any improvement.. This is such fantastic stuff; I am so very intrigued by and grateful for your discoveries. For reasons known only to the same computer god that caused you such distress, I cannot upload any presets right now on either one of my versions of Lightroom or in Photoshop! I am completely stymied by this. Once I can figure out the cause of my troubles, I so look forward to trying this. thanks so very much. P.S. Μηδὲν ἄγαν: Aristotle? 1 Quote Link to post Share on other sites More sharing options...
gbealnz Posted June 3, 2018 Share #116 Posted June 3, 2018 I didn't have the opportunity the last days to post some findings on the IR bright spot as my laptop was broken! Its funny how computers have become such an integral part of photography in the digital era! In the mean time, I did some investigation on how to help reduce the hot spot. I will have to agree with Farnz that the hot spot may contain the ideal amount of IR and the periphery of the lens probably gets less than optimal amount of IR light. Experimenting with 50mm cropped images stitched to a panorama could be a good option for taking fully advantage of the IR in the hot spot area. In case you don't want to go with the panorama solution, it seems it is easier to reduce the spot rather than to increase the light in the periphery at least during editing. I read this article about IR photography https://www.davidkennardphotography.com/blog/976-creating-kodak-eir-aerochrome-style-digital-photos.xhtml#hotspothttps://www.davidkennardphotography.com/blog/976-creating-kodak-eir-aerochrome-style-digital-photos.xhtml#hotspot In this article there is a reference on how to use the application called Cornerfix in order to reduce the IR hotspot. https://sites.google.com/site/cornerfix/ As on most lenses, it seems that the spot is variable depending the aperture size. Here are some samples of the hotspot pointing on the wall. I have created a series of profiles for the Cornerfix app based on the above shots. The maximum aperture I have saved as a profile is 5.6 as above that I dont see any significant differences on the size of the hotspot (Also the texture of the wall starts become prominent on aperture sizes smaller than that, I should have tested it on a smooth area!). Leica Q Cornerfix profiles Of course this is a crude way to fix it - (more an opportunity for experimentation), as each of us is using a different IR filter and the amount of IR reaching the sensor is different from photo to photo. It is something though that doesn’t hurt to try and see if there is any improvement.. Wow, you have way too much time on your hands Zamp, but thank you for this, an excellent reference. So, it appears that the Q lens (and I assume every Q lens is similar/same as yours) from the dreaded hotspot. I'd say stitching a panorama would be an absolute nightmare, but add that of the images shown in this thread so far, some have exhibited it more than others, so maybe there is additional factors to consider. Either way, the system works, we are all having fun at minimal cost, and images are being taken, all is good. Gary 1 Quote Link to post Share on other sites More sharing options...
pico Posted June 3, 2018 Share #117 Posted June 3, 2018 (edited) Center filters (CF) are very commonly used in formats larger than 35mm. I am a bit surprised by how they are misunderstood so far in this thread. Simply, a CF filters is a graduated neutral-density spot on the filter that is dense at the center, then gradually falls off to even out the exposure for the whole sensor/film. Given the technical challenge of doing wide-angle IR photography I believe that exploring CF filters might be worthwhile. One thing - to make a CF filter work it is almost always necessary to stop down three stops from wide-open or it won't work. It's a mechanical thing. I don't do any 35mm IR. 6x6cm is the smallest format for such. So, explore! Enjoy! Ah, jes ferget the opaque center spots, Thambar spot, all that silly stuff. Totally off-track. A CF here. Edited June 3, 2018 by pico 1 Quote Link to post Share on other sites More sharing options...
farnz Posted June 3, 2018 Share #118 Posted June 3, 2018 .... Ah, jes ferget the opaque center spots, Thambar spot, all that silly stuff. Totally off-track. Whatever. 1 Quote Link to post Share on other sites More sharing options...
frame-it Posted June 5, 2018 Share #119 Posted June 5, 2018 wonder if its possible to order a custom Q from Leica with no IR blocking glass Quote Link to post Share on other sites More sharing options...
farnz Posted June 5, 2018 Share #120 Posted June 5, 2018 wonder if its possible to order a custom Q from Leica with no IR blocking glass If Leica would allow it remember, and it might be of no consequence to you at all, that the hot spot will still be there. Pete. Quote Link to post Share on other sites More sharing options...
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