What causes this effect?

[tnguyen600]

"The problem is caused by the strong reflection from the mirror-finished sensor (and its filter pack). Film was not so reflective. Light bounces off the sensor, strikes the rear element, and reflects directly back to the sensor--maintaining the image of the light source.

Multicoating the rear element allows the reflected light to continue back through the front of the lens." (RDKirk, POTN)

"The dynamic range of that scene exceeds the capabilities of the sensor. Only way to do it is to set your ambient exposure (ISO/f-stop/shutter speed) to properly expose the window. Just doing that will obviously make the room quite dark, so that's when you add flash. E-TTL is generally smart enough to output just enough flash power to light the room (especially if you bounce a hotshoe flash off the ceiling). So the flash lights the room, and the "regular" exposure exposes the window. Flash pictures are really two separate exposures. Ambient is determined by ISO/shutter speed/f-stop, and the flash exposure is determined by ISO/f-stop/flash power." (egordon99, POTN)

 

[Zero-Defect]

"The problem is caused by...determined by ISO/f-stop/flash power." (egordon99, POTN)

Wow, my mind just went on strike after trying to comprehend that all lol. But I agree with everyone. I wouldn't be using UV unless the situation really called for it (weather for example)

 

[ryan s]

first...yes...i have lenses that will reflect (cause circular spots) on a digital sensor without a filter mounted.

second...the second quote is true because if youre using fill flash for a back-lit subject...you pretty much average the standard pic and the flash pic to get one thats properly exposed...

 

[trevendous03]

Promaster makes quality filters... you just have to use them right like everyone is saying.

 

[finch13]

Promaster makes quality filters... you just have to use them right like everyone is saying.

For a beginner filter, yes. I have 3 or 4 promasters and they're okay, nothing too special. If you want quality, Hoya or B&W is where it's at and expect to shell out ~$100+

 

[trevendous03]

filters really aren't important enough to warrant spending that much. haha I hardly ever use mine. post-processing can get you the same effect.

 

[xluben]

I always have a UV filter on for protection.

 

[tnguyen600]

a multicoated filter wont cause the reflections

 

[d1blet]

You can probably get Hoya HMC UV filters for a pretty decent price. They are pretty inexpensive multi-coated filters and do the job just fine. I'm actually asking myself why I shelled out the extra bucks for Hoya Pros when I could have just gotten HMC filters.

But everyone has their own shooting style and what not. Experiment and decide what's best for you. I would only slap on a UV filter when I know the weather is windy/inclimate or if theres going to be something that's going to want to poke my lens.

 

[xluben]

I would only slap on a UV filter when I know the weather is windy/inclimate or if theres going to be something that's going to want to poke my lens.