what the hell is causing this?

P

Paradox

New member
freakinacage said:
taking some quick photos with my iphone to email and these bands move across the screen. they are there when i take a still photos:
http://www.youtube.com/watch?v=ZmLE9Klg8og
two of these being used:
http://www.argos.co.uk/static/Product/partNumber/4308148/Trail/searchtext>DESK+LAMP.htm

any ideas? lost my charger form my canon and don't have the energy to look properly atm
Click to expand...

Those lamps are probably flickering at the frequency of the power supply. (50 or 60 Hz is common)
Your iphone updates its screen at some other frequency. I can't tell you exactly how those lines appear, but I bet it's related to those frequencies being close but not the same.

Edit:
Wait... two of those lamps?... Maybe they're causing interference? Try it with only one.
 
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J

Jericho

Consummate Brushlicker
I'm pretty sure it has to do with refresh rates/frequency of the lights. I lack the technical knowledge to properly explain what's going on though.

Back in the day before we had the wonders of LCD technology, you would get bars like that when you filmed/took photos of a CRT TV/computer screen due to the way the electron gun drew the image (using interlacing). Progressive scan technology removed most of these visual artifacts (denoted by the p in 480p/720p/1080p). This requires I think double the bandwidth, however, which makes it harder/more expensive to do properly. It's become pretty much standard though.

I bet it has something to do with interlacing or another "optical illusion" that technology can suffer from.
 
PegaZus

PegaZus

Stealth Freak
They are florescent lamps, and so you're capturing that flicker. If you've got an old CRT style TV, you see something similar. And I did confirm this. Took my iPhone and pointed it at the single florescent lamp here and got the lines. Took it to the incandescent, and no lines. So it's your lamps, and I'm not sure how to get around that.
 
freakinacage

freakinacage

Well-known member
I managed to take two photos before it started. Which is weird. I figured it was a refresh thing too but it would be all the time surely?

it does it with just one on as well
 
J

Jericho

Consummate Brushlicker
The flicker of fluorescent lamps can change when they warm up. One of my old lamps would have flicker for the first little bit once turned on, then it would go away.
 
richrockster

richrockster

New member
You could also check where they're plugged in. I remember reading about loops, Hifi and PC equipment can suffer from it, a bit of a techy explanation :

http://www.epanorama.net/documents/groundloop/

May or may not help solve the problem, but in my experience, eliminating one possibility helps you get closer to finding the source of the problem.
 
Orki

Orki

New member
freakinacage said:
any ideas? lost my charger form my canon and don't have the energy to look properly atm
Click to expand...

Freak, dig out the charger man! My older shite cam picks up phasing if I add my incandescent bulb to the mix, but my newer Fuji is fine. I'm guessing you never had this prob with the Canon?

I have two of the same lamps as you also. No probs with either and/or both of them.
 
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obsidianpainting

obsidianpainting

New member
Hey,

I encounter the same thing with my set-up. I did figure out how to get around it though. I found that using a darker background eliminated the flicker, and also, i have another lamp that uses a screw in bulb, and i bought a daylight bulb, and use it in conjunction with my flourescent bulbs, and this also helps.
 
freakinacage

freakinacage

Well-known member
well i use another lamp that doesn't flicker with the camera but it's too dull to use it alone. tried the different source technique, same result. had a look for the charger, gonna have to buy a new one i think...
 
freakinacage

freakinacage

Well-known member
both. i thought it would just be a viewer thing though. oh well. have found my battery charger now!! now for some scary big pics (note to self, out of focus makes the painting look better!)
 
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