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Author Topic: Can you tell anything about a lens from a flare? Mark J. Marshall Film God Posts: 3188 From: New Castle, DE, USA Registered: Aug 2002 posted 01-17-2008 12:32 PM                    Maybe this is a stupid question, and if so I'm ok with that. Since lens flares can look very different, I've often wondered if you can use them to tell anything about the lens. I've seen perfectly round flares, and octagonal looking flares, and even triangular flares. I've also seen one flare, two or three flares, or tons of flares all stacked up on top of each other. All of these while looking at a single light source. Can anything be learned about the lens by looking at the flares? If not, what can cause them to be different shapes? Thanks.  |  IP: Logged Ron Funderburg Jedi Master Film Handler Posts: 814 From: Chickasha, Oklahoma, USA Registered: Nov 2007 posted 01-17-2008 12:50 PM                        That is a good question and I have absolutely no idea but would love to read the answers. I do know that when you have lens flare on a scope film that it is often not complete stretched back out when it is projected. I use to do photography and of course you really don't want lens flare except for certain effects. Motion pictures started to use, lens flare or rather not worry about it, in the mid 1960's and it became a bit of an artistic statement! the directors of photography prior to (hum what was the film oh yes) Cool Hand Luke avoided the flare at all cost to maintain realism. The Director of photography in Cool Hand Luke thought you over sanitized the shot if you tried to avoid it and gave it a duller look. A quick look on the Internet shows that lens flare is covered all over it but I don't actually see anything that says what lens gives what kind of flare, now they even have software to create lens flare! So it could be that the software determines the shape of the flare rather than the lens. They now create lens flare where at one time they avoided it like a plague! Of course, this doesn't answer the question so um don't know!  |  IP: Logged Bobby Henderson "Ask me about Trajan." Posts: 10973 From: Lawton, OK, USA Registered: Apr 2001 posted 01-17-2008 01:26 PM                     quote: Mark J. Marshall Can anything be learned about the lens by looking at the flares? If not, what can cause them to be different shapes? Lots of different things influence how optical effects like lens flare and "bokeh" appear on the photographic image. Different lenses vary on how many blades make up the shutter. A less expensive lens with a five blade shutter may capture pentagon shaped "discs of light" from things like out of focus street lights, etc. You can get five pointed lens flare stars around light sources in long exposures. A more expensive lens with more blades (eight or more) may capture nearly perfectly round discs of light. Most lenses have numerous glass elements in them. Zoom lenses with image stabilization can have a lot of elements. If a strong light source, like the sun, is hitting the lens at a certain angle you'll see lots of different flare discs appear along that axis. Even lens hoods can change the shape of out of focus discs of light ("bokeh") at certain long zoomed focal lengths. This sometimes happens with rectangular hoods over movie camera lenses. The circles in the background get their tops and bottoms lopped off, and at a long enough focal length the bokeh just becomes a rectangle shape. I haven't seen this optical effect in recent movies, but it certain seemed common in a number of 1980's movies. Anamorphic lenses bring another layer of optical effects to images. It's usually pretty easy to spot when a movie has been filmed with anamorphic lenses. Circular lens flares get stretched horizontally. There's vertical football shaped bokeh in the background. I think those effects look pretty cool and make a movie look even more like a movie. Other people simply cannot stand those optical issues. quote: So it could be that the software determines the shape of the flare rather than the lens. They now create lens flare where at one time they avoided it like a plague! Most lens flares and other optical artifacts usually occur naturally when the image is photographed. More expensive lenses are typically better at controlling and/or suppressing problems like lens flare and worse problems like chromatic abberation. Artificial lens flare is available in Adobe Photoshop, certain 3D animation programs and various plug-ins for programs dealing with 3D, motion graphics or effects compositing. Generally speaking, such effects should be used vary rarely and with lots of tasteful restraint when doing so. Everyone who plays around in Photoshop will fart with that lens flare effect at least a few times. After awhile it only just seems to make any project look really cheesy.  |  IP: Logged Ron Funderburg Jedi Master Film Handler Posts: 814 From: Chickasha, Oklahoma, USA Registered: Nov 2007 posted 01-17-2008 01:35 PM                        Bobby I agree with you and like lens flare a lot in a film it does make it obviously a movie! The purist of the early days of Cinema avoided the lens flare for just that reason they were trying suspend disbelief and they felt that lens flare defeated that. When I see lens flare I think it is bigger than life! And that is what most movies are suppose to be! kudos on the information I'm sure when I was a shutter bug I knew these things but ones mind tends to forget that which isn't called to the front! I do remember working trying to get a lens flare in just he right place on shot so that we could not move the film and have it in just the right place on a double exposure! We did that double exposure 7 times and the first shot on the roll was the right one, who knew?  |  IP: Logged Bobby Henderson "Ask me about Trajan." Posts: 10973 From: Lawton, OK, USA Registered: Apr 2001 posted 01-17-2008 02:19 PM                     quote: Ron Funderburg The purist of the early days of Cinema avoided the lens flare for just that reason they were trying suspend disbelief and they felt that lens flare defeated that. I guess it all depends on the kind of movie that is being made. Liberal use of lens flare in imagery would seem out of place in a pretty serious drama. But for something like an escapist action movie, buddy cop action comedy or some other popcorn chewy stuff like that crazy lens flare is cool.  |  IP: Logged Ron Funderburg Jedi Master Film Handler Posts: 814 From: Chickasha, Oklahoma, USA Registered: Nov 2007 posted 01-17-2008 02:48 PM                        Cool Hand Luke had lens flare in the road work scenes the sun was low in the sky in the early morning shots and late evening and they didn't use any filters or hoods. The director came to the camera man after the dailies were looked at said "Did you know that you have lens flare in these shots?" To which the camera man said "So what is your point?" "Well we don't have lens flare in movies." The camera man was well experienced in the industry and answered "We can be the first, I like the effect." Now Cool Hand Luke was a Drama with comedy in it and the effect is you kind of believe these men are burning up doing this hard manual labor in chains. "What we have here is failure to communicate, you just can't reach some men." Sorry couldn't resist that one!!!  |  IP: Logged Brian Michael Weidemann Expert cat molester Posts: 944 From: Costa Mesa, CA United States Registered: Feb 2004 posted 01-17-2008 02:52 PM                        I always wondered why IMAX films' lens flare shows up as pentagons. I never noticed the pentagons in other films or photography, so I figured there was something special going on in the IMAX camera lens assembly.  |  IP: Logged Tim Reed Better Projection Pays Posts: 5246 From: Northampton, PA Registered: Sep 1999 posted 01-17-2008 03:03 PM                       Note that not all lens flares these days are real. I have several plug ins for After Effects that will put any kind of photo-realistic flare (even "anamorphics") into your shot. They'll also simulate flares at various focal lengths.  |  IP: Logged Ron Funderburg Jedi Master Film Handler Posts: 814 From: Chickasha, Oklahoma, USA Registered: Nov 2007 posted 01-17-2008 03:06 PM                        All I can find on Imax lenses is that they are Imax lenses it doesn't say spherical so not sure what it means but I would guess it has to do with the way in which the Imax lens works!  |  IP: Logged Mark J. Marshall Film God Posts: 3188 From: New Castle, DE, USA Registered: Aug 2002 posted 01-17-2008 03:15 PM                    Thanks for all of the quick responses. I'm not quite sure what this means though... quote: Bobby Henderson Different lenses vary on how many blades make up the shutter.  |  IP: Logged Kenneth Wuepper Phenomenal Film Handler Posts: 1026 From: Saginaw, MI, USA Registered: Feb 2002 posted 01-17-2008 03:15 PM                     Some of these oddly shaped images are caused by the blades of the IRIS inside the lens and the reflections of that image among the internal surfaces of the lens. Most common as seen with very bright point sources of light in the field of view. Almost always when photographing a scene including the sun. Five sided images from a five blade iris.  |  IP: Logged Mark J. Marshall Film God Posts: 3188 From: New Castle, DE, USA Registered: Aug 2002 posted 01-17-2008 03:22 PM                    Ah, I think I get it now.  |  IP: Logged Joe Redifer You need a beating today Posts: 12859 From: Denver, Colorado Registered: May 99 posted 01-17-2008 04:42 PM                        I haven't read everyone's replies, but you can certainly tell if a lens is anamorphic or not by the flare. In many programs I have which offer generated lens flares, you can choose the type of lens and whatnot and the flare changes accordingly, so I guess you can tell.  |  IP: Logged Bobby Henderson "Ask me about Trajan." Posts: 10973 From: Lawton, OK, USA Registered: Apr 2001 posted 01-17-2008 07:51 PM                     Uh...yeah. I think "iris" would have been a better term to use. Or even "aperture." The "shutter" is actually the mechanical thing inside the camera body behind the lens.  |  IP: Logged Wayne Keyser Master Film Handler Posts: 272 From: Arlington, Virginia, USA Registered: May 2004 posted 01-17-2008 10:34 PM                     Even the modest effects that come with Adobe Premiere Pro let you add lens flare to a shot.  |  IP: Logged

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