lensflare or problematic lens?


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afterdark

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Feb 4, 2005
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#1
hello all,

been fiddling with my pns powershot a75 for some months already happily without problems but some shots came out odd during my last session, such as this one



was doing long exposures of 4-8 seconds at f/8, and bright sources (the nearly full moon that night and near lampposts) caused lots of these hexagonal trails (shape of aperture?). didn't encounter these previously, or perhaps i haven't chanced into long exposures of very bright light sources. can i ask if these are normal expected lens flare, or is there a problem with my pns?

thanks!
 

#2
afterdark said:
hello all,

been fiddling with my pns powershot a75 for some months already happily without problems but some shots came out odd during my last session, such as this one



was doing long exposures of 4-8 seconds at f/8, and bright sources (the nearly full moon that night and near lampposts) caused lots of these hexagonal trails (shape of aperture?). didn't encounter these previously, or perhaps i haven't chanced into long exposures of very bright light sources. can i ask if these are normal expected lens flare, or is there a problem with my pns?

thanks!
For one things you get to see this more when you do night shoot is due to the dark skyline...so it makes it alot more easier to see lensflares. You get this during the day too but with a brighter scene or sky, it might masked it. Now how lens flare happen has to do with the angle by which a bright light source ( Sun or lamp post light ) hits your lens elements and at times internal reflection between glass elements. Good lens like those used by SLRs and DSLRs are usually better at handling the flare with the help of multicoating used to treat each lens elements. But even then....some form of flare will still show up. That is why some lens comes with lens hood to further minimise it or eliminate it if possible. Usually when you shoot a scene like the one you showed here, the the light from the lamp post, just out of sight from your camera view, usually at that angle, flares will appear more so with pns then with SLR lens. I would not say it a problem with your pns or pns in general. It is really about how you use your camera. There are some ways to avoid or minimise it though.

I could write more but it is 4am and I am getting sleepy :bsmilie: but maybe you would like to visit this link to learn more about it.

http://medfmt.8k.com/mf/flare.html
 

swhyge

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Apr 5, 2003
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#3
sammy888 said:
For one things you get to see this more when you do night shoot is due to the dark skyline...so it makes it alot more easier to see lensflares. You get this during the day too but with a brighter scene or sky, it might masked it. Now how lens flare happen has to do with the angle by which a bright light source ( Sun or lamp post light ) hits your lens elements and at times internal reflection between glass elements. Good lens like those used by SLRs and DSLRs are usually better at handling the flare with the help of multicoating used to treat each lens elements. But even then....some form of flare will still show up. That is why some lens comes with lens hood to further minimise it or eliminate it if possible. Usually when you shoot a scene like the one you showed here, the the light from the lamp post, just out of sight from your camera view, usually at that angle, flares will appear more so with pns then with SLR lens. I would not say it a problem with your pns or pns in general. It is really about how you use your camera. There are some ways to avoid or minimise it though.

I could write more but it is 4am and I am getting sleepy :bsmilie: but maybe you would like to visit this link to learn more about it.

http://medfmt.8k.com/mf/flare.html

Sound like Consultant talking...
 

afterdark

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Feb 4, 2005
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#4
thank you for the explanation and link, have a better idea now and will experiment again to get that bright light source in without flaring out my pics :)
 

#5
afterdark said:
hello all,

been fiddling with my pns powershot a75 for some months already happily without problems but some shots came out odd during my last session, such as this one



was doing long exposures of 4-8 seconds at f/8, and bright sources (the nearly full moon that night and near lampposts) caused lots of these hexagonal trails (shape of aperture?). didn't encounter these previously, or perhaps i haven't chanced into long exposures of very bright light sources. can i ask if these are normal expected lens flare, or is there a problem with my pns?

thanks!
Hmmm.... actually they look like water droplets to me. Was it drizzling while you were taking this shot? Check your lens.... I don't think it's lens flare.
 

afterdark

New Member
Feb 4, 2005
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#7
Hitman said:
Hmmm.... actually they look like water droplets to me. Was it drizzling while you were taking this shot? Check your lens.... I don't think it's lens flare.
thought it was moisture at first too but shorter exposures came out fine. and the hexagonal shaped lights should be a good indication that it's unwanted lens flare effects i guess.

to quote from the link sammy gave:

http://medfmt.8k.com/mf/flare.html said:
Ghosts

Where do those hexagonal lens diaphragm ghosts come from? Light bouncing off the reflective glass and metal (and film) surfaces reflects back through the hexagonal diaphragm opening. The light then reflects off the reflective glass surfaces beyond the diaphragm back into the lens towards the film. The result is a bright hexagonal diaphragm shaped blob of light on your film, especially where the background is darker.
 

yanyewkay

Senior Member
Sep 22, 2004
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Cons digger.
#8
it does look like water/dirt to me.. i haven't seen hexagonal flares scattered randomly like that. Flares on my lenses normally occur on a same line plane from the source of flare.
 

afterdark

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Feb 4, 2005
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#9
yanyewkay said:
it does look like water/dirt to me.. i haven't seen hexagonal flares scattered randomly like that. Flares on my lenses normally occur on a same line plane from the source of flare.
thanks for your opinion, think i shall just send it for checkup soon just to be doubly sure!
 

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