arthury Posted February 10, 2007 Share #1  Posted February 10, 2007 Advertisement (gone after registration) Several shots tonight had these reflections when the incandescent lights were dimmer. It *only* appears when the candles were lit. There's a UV filter on the 50mm Summicron-M.  ISO 640; WB: tungsten; JPG; f/2; firmware:1.09; camera: 2nd batch  Any ideas what is causing this?  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! 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/15831-candles-reflection-m8/?do=findComment&comment=167142'>More sharing options...
dspeltz Posted February 10, 2007 Share #2 Â Posted February 10, 2007 I had the same effect a couple weeks ago. I wrote it off to internal reflection. It is weird and unexpected. Link to post Share on other sites More sharing options...
sean_reid Posted February 10, 2007 Share #3 Â Posted February 10, 2007 It's the filter. Try a shot like that with and without a filter and you'll notice the difference. Â Cheers, Â Sean Link to post Share on other sites More sharing options...
arthury Posted February 10, 2007 Author Share #4 Â Posted February 10, 2007 Why doesn't this same filter cause this type of reflection in the M6TTL? Â So, if I slap the 486 IR filter on when I receive it, I assume it's going to cause the same thing? Link to post Share on other sites More sharing options...
rvaubel Posted February 10, 2007 Share #5  Posted February 10, 2007 Why doesn't this same filter cause this type of reflection in the M6TTL? So, if I slap the 486 IR filter on when I receive it, I assume it's going to cause the same thing?  Yes it will cause exactly the same thing. This is a reflection of the candle off the sensor, back up thru the lens backwards and then of the BACK of the filter down thru the lens (a second trip) onto the sensor for a second time. That is the main problem with filters, particularly on a digital camera. The reason that a digital camera is worse than film is because the sensor is much more reflective than a film base. BTW this only is really visible when the light source (the candles ) is waaaay blown out. In other words christmas tree lightbulbs won't do it. Candles always do, as do headlights  This is why I will only purchase filters that are AR coated on the BACK side. I'm not sure if the new Leica filters are.  The only solution is to take the filter off. Don't get too excited though because in the 1000s of pictures I reviewed only a few showed this effect.  Rex Link to post Share on other sites More sharing options...
Jamie Roberts Posted February 10, 2007 Share #6 Â Posted February 10, 2007 Rex and Sean are absolutely right. And usually, the wider open you are on the lens, the worse the effect. Â My Canon 85 1.2L on the 1ds2 with a BW UV filter was hideous in this regard. Take it off--voila! Problem solved. Â Different filters also have different properties, as Rex was saying. We'll see what the Leica ones are like. Â But I just wanted to also say that you're lucky--the bad reflection lights are fantastically placed for an easy Photoshop fix (just clone or copy the wall over them!), and then you'll have a perfectly lovely shot, by the way (not that it isn't now, of course!). Link to post Share on other sites More sharing options...
Guest WPalank Posted February 10, 2007 Share #7 Â Posted February 10, 2007 Advertisement (gone after registration) Photoshop fix (just clone or copy the wall over them!), and then you'll have a perfectly lovely shot, by the way (not that it isn't now, of course!). Patch tool CS2, will do it in half a second! Link to post Share on other sites More sharing options...
chiqua Posted February 10, 2007 Share #8  Posted February 10, 2007 It's the filter.  No, it´s not! I had the same problem with my 35/1,4 Asph. without filter.  Frank Link to post Share on other sites More sharing options...
Hans Roggen Posted February 10, 2007 Share #9  Posted February 10, 2007 No, it´s not! I had the same problem with my 35/1,4 Asph. without filter. Frank  Could it be the reflection of the back of your lens?   Hans Link to post Share on other sites More sharing options...
chiqua Posted February 10, 2007 Share #10  Posted February 10, 2007 I don´t know, maybe. I corrected it in PS.  Frank Link to post Share on other sites More sharing options...
sean_reid Posted February 10, 2007 Share #11 Â Posted February 10, 2007 But I just wanted to also say that you're lucky--the bad reflection lights are fantastically placed for an easy Photoshop fix (just clone or copy the wall over them!), and then you'll have a perfectly lovely shot, by the way (not that it isn't now, of course!). Â LOL...That was my first thought when I saw it. We must both be pragmatists. Â Cheers, Â Sean Link to post Share on other sites More sharing options...
Guest guy_mancuso Posted February 10, 2007 Share #12 Â Posted February 10, 2007 As soon as I saw it i said the same thing , oh easy to clone out. Man we need to be drinking different coffee. LOL Link to post Share on other sites More sharing options...
arthury Posted February 10, 2007 Author Share #13  Posted February 10, 2007 Yes it will cause exactly the same thing. This is a reflection of the candle off the sensor, back up thru the lens backwards and then of the BACK of the filter down thru the lens (a second trip) onto the sensor for a second time. That is the main problem with filters, particularly on a digital camera. The reason that a digital camera is worse than film is because the sensor is much more reflective than a film base. BTW this only is really visible when the light source (the candles ) is waaaay blown out. In other words christmas tree lightbulbs won't do it. Candles always do, as do headlights Interesting. My understanding of the secondary reflection effect (described above) was that the effect is never so intense and I have not seen one like this in real life after using digital cameras for years.  This is why I will only purchase filters that are AR coated on the BACK side. I'm not sure if the new Leica filters are. My UV filter is a B+W MRC filter. Schneider described it as "Multicoated to minimize reflection at the filter surfaces which reduces flare and ghosting." Yes, I confirmed that if the filter is removed, the ghosting disappeared.  The only solution is to take the filter off. Don't get too excited though because in the 1000s of pictures I reviewed only a few showed this effect. Rex Taking off the filter for future usage will not work, does it? We're back to square one if the filter is an IR filter--- magenta problems. I have shot birthday images with candles using a DSLR many times. More recently, shooting it with the D2X did not stir up this issue.  May be someone is kind enough to do a test with the 486 IR filters or the Leica-issued filters on the M8 with candle lights. Link to post Share on other sites More sharing options...
nryn Posted February 10, 2007 Share #14 Â Posted February 10, 2007 This is absolutely an internal reflection due to the filter, and that problem is by no means specific to the M8. I've had this problem with both film and digital SLRs of other brands, and every single time it's a filter in a dark room with intense point sources of lights in the frame. I can dig those examples up if anyone's interested. Â arthury's point is well taken--we have a dilemma if we need an IR-cut to overcome the "features" of the sensor in the conditions described above. Having just gotten my first-gen M8 fixed and having just acquired all the requisite IR filters for my lenses, I guess this will take some trial and error, and it may well be the case that not all situations will yield acceptable photographs. With the combination of profiles and continual improvements in software and firmware, even today I feel like I have a lot more flexibility than I ever did, at least with an SLR. Link to post Share on other sites More sharing options...
rljones Posted February 10, 2007 Share #15 Â Posted February 10, 2007 I rather think multicoating will offer little help. Several years ago, Canon identified this problem in their older telephotos that used front, protective elements. These pieces of planar glass were used to protect the more delicate fluorite glass (or whatever composite they were using) inside the lens. The rear surface of this protective element was found to add reflections between itself and the digital sensor, like a 'hall of mirrors' effect. Â This led Canon to develop a meniscus shaped protective front element that eliminated this problem. It is used in the most recent versions of their 300/2.8 IS and longer APO IS telephotos. Â They found that if the rear surface of this element is curved, it no longer offers a large surface to reflect and bounce light. Ideally, a filter for digital cameras should do the same, however, when you start curving surfaces you alter the focus, and a curved front surface may not work so well with the present design used for IR filters. Link to post Share on other sites More sharing options...
LJL Posted February 10, 2007 Share #16 Â Posted February 10, 2007 Interestingly, Sigma, and some others, in their design of "digital" lenses started to coat the backside of lens elements to prevent the same reflection issues off the sensor. The idea being stop the reflection as far back as possible. May be a lot of marketing hype, but in theory, it would work better than just worrying about the front elements of a lens. Â LJ Link to post Share on other sites More sharing options...
rvaubel Posted February 10, 2007 Share #17  Posted February 10, 2007 Interestingly, Sigma, and some others, in their design of "digital" lenses started to coat the backside of lens elements to prevent the same reflection issues off the sensor. The idea being stop the reflection as far back as possible. May be a lot of marketing hype, but in theory, it would work better than just worrying about the front elements of a lens. LJ  First off, it IS the filter. With intense light sources it happens 100% of the time. I can even predict exactly where the reflection artifact will appear. So, if you don't want it, you have to take the filter off OR fix it in PP. BUT NOTE  * Color balance rarely is much of an issue when taking pictures by candlelight. In the few causes that this reflection issue comes up does exact color balance matter all that much. In fact, in most of these cases blacks come out black even without the filter because the atmosphere is so moody and dark. That is my main point i.e. in theory it is horrible but in practice, just take off the filter.  * AR coating the back side of the filter doesn't help that much. Although I hope that Leica does coat the back side like Heliopan, it would be a decisive reason to pick one filter over another. You would think it would really help and it does but a lot less than theory would indicate.  * a curved rear filter surface would eliminate the problem. But in order for the filter to have zero optical power the front surface would have to have exactly the same curve. This would be very expensive. Only Canon with their high end long telephotos can afford to do this. In this cause the filter is a permanent part of the lens. However, if this approach was taken, a radial cyan correction coating could also be applied. Of course such a lens would be very $$$ and only usable on the M8. If your going to go that far, you mays as well make it specific for the 1.33X crop factor sensor. Perhaps an M8 specific, 21mm F2.0 would generate enough interest to sell but this is another thread. Link to post Share on other sites More sharing options...
arthury Posted February 10, 2007 Author Share #18 Â Posted February 10, 2007 Just OT: In actuality, good old Canon is not the only one using a meniscus glass because my Nikon 200/2 VR has it also. Â Anyway, for all we know, the Leica IR filters may not have this issue. I ask again ... if someone who has the new Leica-issued IR filters, could you try it out to let us know so we have our expectations adjusted correctly for this scenario. Link to post Share on other sites More sharing options...
sean_reid Posted February 10, 2007 Share #19  Posted February 10, 2007 No, it´s not! I had the same problem with my 35/1,4 Asph. without filter. Frank  An exclamation point no less...hmm See the post below - it was the filter. Sorry to hear that yours shows reflections even without a filter.  Sean Link to post Share on other sites More sharing options...
sean_reid Posted February 10, 2007 Share #20 Â Posted February 10, 2007 Â May be someone is kind enough to do a test with the 486 IR filters or the Leica-issued filters on the M8 with candle lights. Â That will be in the last test section of the IR filter comparison that is in my M8 updates article - candles, bright lights, etc. Filters are the (Leica) 486, B+W 486 and Heliopan Digital with a MC UV filter as a control comparison. I've already tested color rendering (daylight and studio tungsten) and cyan drift. Â Cheers, Â Sean Link to post Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.