White Dots  

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Revolution
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White Dots

by Revolution » Fri Mar 08, 2013 3:53 pm

Hello,

I just captured several more panos... and came across something interesting.

I think I know what's causing it - but I would appreciate the opinion of others
as well as ideas / suggestions as to avoid this.

The image provided is a reduced / crop.

Look at the white dots that appear in the image.

Thanks,

Pierre


Revolutiion Photography, AP Freelance Photographer
Nikon D3, D3x : Nikkor 16mm f/2.8, 14-24mm f/2.8, 24-70mm f/2.8, 70-200mm VR2 f/2.8, 105mm f/2 DC, 50mm G f/1.4, Nodal Ninja M1-L Ultimate / RD16, Win 7 16GB + Dual 24" Monitors, MacPro 16GB + Dual 36" Cinema Monitors, MacBook Pro 17" 8GB, MacBook Pro 15" 8GB, MacBook Pro 13 4GB, iPad 64GB 3G+Wifi, iPad II 64GB 3G+Wifi

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DrSlony
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by DrSlony » Fri Mar 08, 2013 4:51 pm

Take a photo of a uniform blank wall or page (anything large enough to fill the frame, you can zoom in), expose for the histogram to spike in the middle. Use a small aperture ( f11 or more). This will show you exactly where to clean your sensor. Check your lens for stains too. This type of photo is called a flat field. If you use RawTherapee you can use the flat field to automatically remove such things from all photos.

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by klausesser » Fri Mar 08, 2013 5:20 pm

Revolution wrote:Look at the white dots that appear in the image.

Hi Pierre!

Whet i see is you´re using PTGui. Can you try the same using APG?

best, Klaus
Simplicity is the keynote of all true elegance. Coco Chanel

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gkaefer
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by gkaefer » Fri Mar 08, 2013 6:01 pm

klausesser wrote:
Revolution wrote:Look at the white dots that appear in the image.

Hi Pierre!

Whet i see is you´re using PTGui. Can you try the same using APG?

best, Klaus

and why not removing the dust artefacts coming frm lens or sensor and stitching the cleaned Images?
Georg

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Revolution
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by Revolution » Fri Mar 08, 2013 7:53 pm

the white spots are not dust
Revolutiion Photography, AP Freelance Photographer
Nikon D3, D3x : Nikkor 16mm f/2.8, 14-24mm f/2.8, 24-70mm f/2.8, 70-200mm VR2 f/2.8, 105mm f/2 DC, 50mm G f/1.4, Nodal Ninja M1-L Ultimate / RD16, Win 7 16GB + Dual 24" Monitors, MacPro 16GB + Dual 36" Cinema Monitors, MacBook Pro 17" 8GB, MacBook Pro 15" 8GB, MacBook Pro 13 4GB, iPad 64GB 3G+Wifi, iPad II 64GB 3G+Wifi

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by gkaefer » Fri Mar 08, 2013 9:03 pm

the pattern is recurring... so it seems to be on each single Image on same Position. if ist not dust than maybe some sort of remains of a dried liquid (on sensor or on lens parts).
make a set you your Images available for download (best the originals, of some sort of resized jpgs...)
one is clear: apg does not add Patterns to the Images...

Georg
Last edited by gkaefer on Fri Mar 08, 2013 9:05 pm, edited 1 time in total.

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by Gund » Sun Mar 10, 2013 9:11 am

Just check every single image before stitching - if these dots are in the images than the software is not to blame. Looks like a spot on the lens or a flare or dust on the sensor.

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by Revolution » Sun Mar 10, 2013 7:36 pm

I appreciate all the comments. I really do.

This is a strange issue... but I can definately say
- it's not a software issue... apg and ptgui have worked flawlessly.

I thoroughly cleaned the camera and all my lens before the shoot.

I'm by far - not a pano expert... most of you guys here outclass me when it comes to panos
- but I do know how to clean a camera.

This specific pano was #3 of 5 panos I captured - all different rooms - one building.

None of the other panos had the white dots. Panos 1,2,4, and 5 are Ok... no dots.

I went back to reshoot this one pano with a 2nd (borrowed) Nikkor 16mm... after again cleaning everything.
- same body (Nikon D3)
- different lens but same model (Nikkor 16mm)
- same tripod (Manfrotto 055CXPRO4)
- same pano head (NN Ultimate RD-16)

I even went back at the same time... to try and duplicate the shooting environment.

Immediately after the capture - I flipped through the images
- and the white dots were there... but in a slightly different position on the images.

I moved my camera about 4 feet off-center... reshot the pano - and the white dots moved.

Then, I turn off all the lights and used ambient light coming in through the windows...
- and the white dots went away.
Revolutiion Photography, AP Freelance Photographer
Nikon D3, D3x : Nikkor 16mm f/2.8, 14-24mm f/2.8, 24-70mm f/2.8, 70-200mm VR2 f/2.8, 105mm f/2 DC, 50mm G f/1.4, Nodal Ninja M1-L Ultimate / RD16, Win 7 16GB + Dual 24" Monitors, MacPro 16GB + Dual 36" Cinema Monitors, MacBook Pro 17" 8GB, MacBook Pro 15" 8GB, MacBook Pro 13 4GB, iPad 64GB 3G+Wifi, iPad II 64GB 3G+Wifi

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gkaefer
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by gkaefer » Mon Mar 11, 2013 12:18 am

;-)
+ recurring Points on the Images
+ no dust on sensor nore on lens
+ no recurring light sources seen in pano that can cause the recurring Points
= if light placed directly above the lens/camera and is falling into the lens.

this seems for me the only logical solution for this puzzle.
playing Lotto gives you better Odds ro redo this Hattrick next on Scene...
Last edited by gkaefer on Mon Mar 11, 2013 12:19 am, edited 1 time in total.


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