purple dot in picture

[cristian_a]

<p>I was in the mountains this weekend and i was trying to do some pictures while there, but somehow in a few of them appears a purple dot right in the middle, at first i thought it is because the viewfinder wasn't covered and light was getting in through there like in long exposure at night, but then i covered it with something and it still showed and at 1/80s i think it shouldn't show anyway... i'll attach 2 pics to see what i'm blabering about http://img836.imageshack.us/img836/8788/085.jpg http://img842.imageshack.us/img842/6162/130w.jpg<br>

So any ideas why they came out like that? </p>

[Matt Laur]

<p>This is not unusual with the 50/1.8 lens you were using, especially when you have it stopped down all the way to f/22. Open up a couple of stops, and get that shutter speed above 1/30th ... the combination will definitely be sharper!<br /><br />On your D90, try to avoid much past f/11 or f/16, so that you don't actually lose clarity to diffraction (it's a basic laws of physics thing - nothing to be done about it on these smaller sensors. The purple dot is caused by a double-reflection off of the sensor and the rear element of the lens.</p>

[daverhaas]

<p>simple - lens flare. Caused by a reflection or stray light entering the lens at an angle and showing on the sensor.</p>

<p>Solutions - lens hood or a hand or peice of cardbard held over the lens to prevent stray sun from coming in.</p>

<p>Dave</p>

 

[CvhKaar]

<p>mmm Christian, did you have an UV filter or something similar attached ( an older one , or a not so high quality one espacially ) ?<br>

This looks more like "Sensor Reflection" rather than lens flare to me... , more compact lenses like 35mm and 50mm primes are more sensetive to this because a filter is realy close to the sensor ...<br>

I only like to put those on if realy realy needed, and then still take pics without and with them filters...</p>

[ramon_v__california_]

<p>i will echo matt because this happened to me when i first got my 50mm f/1.8 and played with it on both extremes of aperture and shutter. i showed to a friend who teaches and i got the sae explanation as matt's.</p>

[wpahnelas]

<p>you wouldn't happen to mean something like this?</p><div></div>

[tom_mann1]

<p>Ach, mein Gott ... sightings of these luminous orbs are becoming more and more frequent as 2012 approaches !!!</p>

<p>;-)</p>

<p>Tom M.</p>

<p>PS - Do some comparison shots with and without any filters, with and without your hand blocking the sun, etc. as suggested above. Have the camera on a tripod for these tests because a change in position or direction by just a few degrees can have a profound effect on these sorts of reflections.</p>

[CvhKaar]

<p>William, that's a nice one !! :-)<br>

How did you get that one ???</p>

[cristian_a]

<p>C.P.M. van het Kaar as a matter of fact i did have a uv filter on...<br>

matt thanks for the insight, i'll take it into consideration next time.</p>

 

[alex_lofquist]

<p>This is a case for the Flying Purple Pupil Eater!</p>

[CvhKaar]

<p>Christian,<br>

There are filters that eliminate much of this problem ( but not all of it..) especially for digital, but they don't come cheap at all in my xperience..<br>

@Alex: indeed, the big freigthening one from jupiter ........</p>

[simon_hickie1]

<p>My 50mm f1.8 does the same at f11 upwards even when shooting with the sun over my shoulder. Perhaps a filter is worth a try before I *bay it as faulty.</p>