pascal_meheut Posted January 16, 2007 Share #1 Posted January 16, 2007 Advertisement (gone after registration) I know the subject has been discussed already but as my M8 was at Solms, I did not read all the threads. I was wondering if such intense reflections were common and if the happy few who have a "Leica filter" to test (i.e. Sean Reid) have the same problem. Here is the example, both shot at the same place, same time with the 75mm. First with a 486 filter, 2nd without. As you can see, the ghost image on the right of the sign on the left is quite precise. Without the filter, there is still something in this area of the picture but much less noticeable. 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! 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/13623-ghost-images-with-486-ir-filter/?do=findComment&comment=143699'>More sharing options...
Advertisement Posted January 16, 2007 Posted January 16, 2007 Hi pascal_meheut, Take a look here Ghost images with 486 IR filter. I'm sure you'll find what you were looking for!
ho_co Posted January 16, 2007 Share #2 Posted January 16, 2007 Pascal-- That's a clear disappointment. Just for clarification, have you checked whether your 486 has the IR-cut side forward? That seems to vary. Sean has said that the Leica filters will apparently be supplied with the anti-reflection coating toward the lens and the IR-cut side away from the lens, but my only B+W 486 is oriented the other way. Actually, as offensive as the reflection is, it looks weak enough that your filter glass may be oriented the "right" way. --HC Quote Link to post Share on other sites More sharing options...
canlogic Posted January 16, 2007 Share #3 Posted January 16, 2007 I think if you did the same shot with any film camera with a filter on you would get the same result. I have only been useing my IR filters when ir is going to be an issue with the results otherwise Jamies profiles are generally all I need. Quote Link to post Share on other sites More sharing options...
Guest smep_reloaded Posted January 17, 2007 Share #4 Posted January 17, 2007 Please read page 126 of the M8 manual "for lenses": [ATTACH]22029[/ATTACH] The problem that "filters can cause unwanted reflections in certain backlight situations and with high contrasts" is well known to Leica! Quote Link to post Share on other sites More sharing options...
drjon Posted January 17, 2007 Share #5 Posted January 17, 2007 I think if you did the same shot with any film camera with a filter on you would get the same result. I have only been useing my IR filters when ir is going to be an issue with the results otherwise Jamies profiles are generally all I need. I concur; almost any camera would struggle with the shot in question. I have the IR cut filters now and in combination with a grey card and with Jamie's profiles (CS3) or with Brian's profiles (Raw Developer) the results are excellent. There may be some very specific backlight situations with black neoprene or the like in shot where the need for an IR filter may be an issue; a small and manageable penalty to have the M8. But my view is biased - I love the M8 so I see it through magenta-tinted spectacles. Have fun. Quote Link to post Share on other sites More sharing options...
clou Posted January 17, 2007 Share #6 Posted January 17, 2007 Perhaps it is possible to do a third picture, with a classical UV filter to see the difference, if any ? Quote Link to post Share on other sites More sharing options...
Your Old Dog Posted January 17, 2007 Share #7 Posted January 17, 2007 Advertisement (gone after registration) I concur; almost any camera would struggle with the shot in question. . You got that right. The $10,000 Canon lenses we use in TV news have to have the filters removed for shooting rainey and snow covered weather shots at night. We get a ghosting image of every headlight on every car. If I had the cash I'd take anyones "magenta issued" M8 off their hands if it bothers them. The problem don't amount to a hill of beans to me and I don't care if the camera cost $10,000 ! I understand it may be a big problem for others and this is just my opinion and nothing else, certainly not an indictment of those who disagree with me. The weak ball detent spring in the on/off switch has me more concerned. I want to know the shutter is going to trip when I want it to. Quote Link to post Share on other sites More sharing options...
Riley Posted January 17, 2007 Share #8 Posted January 17, 2007 good on ya Ray is it entirely necessary to use IR filters at night ? Quote Link to post Share on other sites More sharing options...
plasticman Posted January 17, 2007 Share #9 Posted January 17, 2007 If I had the cash I'd take anyones "magenta issued" M8 off their hands if it bothers them. The problem don't amount to a hill of beans to me and I don't care if the camera cost $10,000 ! Ray - still in the queue for mine, but when it comes, you can have it for $10,000. Anyways, just for some perspective, i know when there's even minor criticism of the M8 on these pages, a dozen people jump in and say either: - the M8 is better than every other camera anyway or: - the M8 is no worse than any other camera anyway or: - both the above. Keeping it real. Quote Link to post Share on other sites More sharing options...
marknorton Posted January 17, 2007 Share #10 Posted January 17, 2007 The weak ball detent spring in the on/off switch has me more concerned. Ray, as I've posted elsewhere, the on-off switch is much improved when the camera goes in for update, or so I am told. Quote Link to post Share on other sites More sharing options...
AlanG Posted January 17, 2007 Share #11 Posted January 17, 2007 I don't think ghost images are limited to the filter and certainly are not limited to the M8. I think that what happens is a very bright object can bounce off of the sensor and then off either a filter or one of the lens elements in order to form a faint mirrored image. Here is an example of one that happened to me with a 1DMKII and a Zenitar 16mm fisheye. http://goldsteinphoto.com/bethesda.jpg Note that in this case the word "cinema" was so bright that it only is readable in the reflection, so it is an extreme example requiring a very bright source. I can't say I've noticed it with other lenses (I bought the Canon fisheye recently.) And I shoot a lot of night shots where this might show up. The only filters that I use are polarizers, and I can't say I've tried to see if a filter will cause such a reflection with any of my other lenses. I wouldn't expect to be able to see this in the DSLR viewfinder as the reflection will have to come off of the sensor. Quote Link to post Share on other sites More sharing options...
jaapv Posted January 17, 2007 Share #12 Posted January 17, 2007 It surprises me that the 75 ( I presume Summilux) produces the same flare, albeit much attenuated, in the second example. I have never seen my Summilux do that. Was the front lens dirty? The green spot on the righthand top is typical IR filter flare. I have had to clone that on a number of shots. Quote Link to post Share on other sites More sharing options...
AlanG Posted January 17, 2007 Share #13 Posted January 17, 2007 It surprises me that the 75 ( I presume Summilux) produces the same flare, albeit much attenuated, in the second example. This is a reflection, not flare. And the letters in the sign are extremely bright compared to the rest of the scene. It seems clear that you get a little reflection off of one of the lens elements, and a lot of reflection off of the filter. I doubt if the type of filter would matter as it is surely reflecting off of the interior surface. Maybe a multi coated filter would make a difference. Quote Link to post Share on other sites More sharing options...
jaapv Posted January 18, 2007 Share #14 Posted January 18, 2007 In exactly the same place? Quote Link to post Share on other sites More sharing options...
AlanG Posted January 18, 2007 Share #15 Posted January 18, 2007 In exactly the same place? I presume you are asking how could a reflection off of the filter be at the same place as the reflection off of a lens element. It can't be what we normally think of as flare as it is a sharp mirrored image. Well the two surfaces (back of filter & a lens element) could be near enough to each other to mirror in the same place. We really can't say it will be in exactly the same place. The reflection without the filter is so faint it is hard to tell if it is producing a focused reflection. As you can see from my example without any filter, the word "cinema" clearly is a reflection off of the sensor and back off of a lens element. I think this can happen with any digital camera if you have the right combination of a very bright subject on one side, a darker area on the other that would show the reflection, and a lens element or a filter that is in the correct location to produce a focused reflection. Otherwise maybe you'll just get a blurry reflection or some loss of contrast on that side, possibly you could consider a very blurry reflection to be a kind of flare. But it is not what we typically think of when we consider flare. This probably happens all of the time with all digital cameras when shooting a subject that contains a very bright area. The light that bounces off of the sensor has to go somewhere doesn't it? If it gets absorbed by by the black interior of the camera, then there is minimal effect. If it reflects back into the lens you might get a reflected image or a much broader regional or overall flare. So I guess in some situations you might consider it to be a type of flare. Just as some lenses produce a starburst type flare image of the sun or other bright source as result of internal reflections between elements. A simple test would be to photograph an extremely dark black background (such as black velour) and then shoot the same image with a bright point light source in front of that background aiming only at the camera lens (not illuminating the background in any way.) If both images were made at identical exposures, you could see if flare caused a section or all of the black background to get lighter. I guess if it produces a mirrored image of the light it is a reflection, if it brightens the whole background, it would be flare. I guess that this isn't so common with film cameras as the surface of film is not nearly as reflective as a sensor's coverglass is. I remember the Kodak 14N was especially susceptable to this problem with specific Nikon lenses. Users called it a "red blob" and it apperaed in the center of the image when there also was a bright highlight near the center of the subject. Quote Link to post Share on other sites More sharing options...
sean_reid Posted January 18, 2007 Share #16 Posted January 18, 2007 Pascal--That's a clear disappointment. Just for clarification, have you checked whether your 486 has the IR-cut side forward? That seems to vary. Sean has said that the Leica filters will apparently be supplied with the anti-reflection coating toward the lens and the IR-cut side away from the lens, but my only B+W 486 is oriented the other way. Actually, as offensive as the reflection is, it looks weak enough that your filter glass may be oriented the "right" way. --HC Hi Howard, Other way around <G> IR coating facing front lens element and AR coating facing out. More once I get a chance to read the whole thread. Cheers, Sean Quote Link to post Share on other sites More sharing options...
ho_co Posted January 18, 2007 Share #17 Posted January 18, 2007 Other way around <G> IR coating facing front lens element and AR coating facing out. You are correct, of course. Before posting, I re-read what I had written several times because I had the feeling something was wrong--and then posted trash. Thanks for the correction. Or, with Shakespeare: Meet it is I set it down, the A/R coating goes to town! --HC Quote Link to post Share on other sites More sharing options...
rvaubel Posted January 18, 2007 Share #18 Posted January 18, 2007 Hi Howard, Other way around <G> IR coating facing front lens element and AR coating facing out. More once I get a chance to read the whole thread. Cheers, Sean Unfortunately, it doesn't really make that much difference which way the AR coating is facing. I know that it should...in theory. But as an experiment take an uncoated filter vs a coated one (a UV filter is fine) and try to create a filter reflection flare. Unfortunately, this is rather easy to do. Go out and take some pictures of automobile headlights at night. That will do it for sure. As a person who used to believe that protective filters were the agent of the devil, it was VERY hard for me to accept these rather grotesque reflections. It was little consolation that the "protective" filter crowd had been doing it for years. I just thought that they were overly anal and were willing to sacrifice quality in order to protect their hardware. My dad was like that..he would but cheap vinyl seatcovers over his leather carseats. I don't know why...so the next guy could appreciate his investment? All I knew was my butt would stick to that tacky vinyl and I promised myself that if I ever got rich enough to afford leather, it would be MY butt on the leather. Anyway, I had to learn to love filters if I wanted an M8. The way I finally rationalized it was to notice that in almost every case of filter reflection flare, no harm would come to the picture if I simply took the filter OFF . Purple penquins are rarely the subject matter in the middle of the night. Or in a club, who cares that much about color balance? Rex Quote Link to post Share on other sites More sharing options...
waterlenz Posted January 18, 2007 Share #19 Posted January 18, 2007 It surprises me that the 75 ( I presume Summilux) produces the same flare, albeit much attenuated, in the second example. I have never seen my Summilux do that. Was the front lens dirty? The green spot on the righthand top is typical IR filter flare. I have had to clone that on a number of shots. The upper righthand green spot matches the streetlight below the lighted sign. The reflection is inverted. I suspect the main source of the reflection is the sensor itself. Look at the sensor and you will see how reflective it is. This is also the case with other digicameras. T Quote Link to post Share on other sites More sharing options...
ho_co Posted January 18, 2007 Share #20 Posted January 18, 2007 Rex-- You are right, filters are the work of the Devil. But you're also right, the M8 needs them. Check Sean's article on the subject: Per Schneider, the IR-cut coatings are more sensitive to abrasion than the MRC side. (You might also be interested in the claims they make for the MRC on their website, by the way--quite interesting.) Anyway, since the AR side will take better to cleaning, it should be outermost. (See, Mr Reid, I *did* read it and *can* articulate it even if I do blow it from time to time. ) --HC Quote Link to post Share on other sites More sharing options...
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