Hi,
Has anyone else using a fisheye lens discovered rings (most evident on blue sky backgrounds) on their outside panoramas? The photos were shot with a canon 5D, set to small jpg, as the camera has a full frame CMOS the individual photo file sizes are 1664x2496 and 2mb approx. Even when rendered out as a TIFF the rings are present.
I'm using a Mac and Realviz Stitcher 5.5.4. The rings are evident on the spherical image output by stitcher before any adjustments are made. I've tried rendering with the following variables:
- JPG at 100% - resultant panorama is around 6000 x 3000 (4.6mb).
- TIFF at 100% - resultant panorama is around 6000 x 3000 (62.6mb).
Any ideas?
Chuck

Can you post some examples online for us to see?

Hi Badders,
 
I've found an online example of what I'm talking about. If you go to the following address, scroll down and click on the 'York Minster 360':
 
http://www.screenyorkshire.co.uk/f [...] 633dbad1ca
 
This pano in particular, was shot with a Canon 5D and a Canon 15mm Fisheye lens. It was shot on small jpeg, stitched with Realviz Stitcher on a Mac and rendered out as a jpeg at 100%.
Subsequent tests show that the rings are still there when shot on large jpeg and raw, and even when rendered out as a tiff at 100%!
The rings aren't present in the photos before being stitched, which is leading me to think it might be something in the rendering process perhaps?
It appears, from looking at other pano's, that the rings are present all over the tour, but more prevalent in the Zenith area and particularly when outside.
 
Any thoughts?
 
Chuck

Chuck
Are you talking about the color "banding" that radiates out from the sun? How the blue of the sky doesn't fade away from the sun evenly?

What are you rendering to? Spherical, Cubical or what? Can you post a screen grab of the render settings you are using?

It looks more like a compression setting issue than something that is likely endemic to the camera or lens; if I'mseeing in the blue of the sky the banding you're talking about thats straight up jpg compression issues where it can't support a smooth transition.  I'd look at points where converting from RAW or into your TIFs where something is adding jpg artifacts.  The equipment you're talking about is certainly capable of capturing a blue sky...rendering it into an image however can be trickier.

Hi Chuck!
 
I second radialstudios - JPEG compression artifacts.
 
BTW: Why are you shooting images with one of the most exquisite cameras ever created in small JPEG? If the images are too big then consider a fisheye.
 
Post edit note:
======================
Just re-read this post in full length.
You are shooting a fisheye (I'll be "Chief of Detectives" in no time!).
So even more puzzling - why the JPEG?

i've had similar issues with some sky shots as well. i shoot everything in RAW, and have found that converting the RAWs to 16bit (rather than 8bit) TIFFs is a good way of resolving this issue. it takes longer to render a 16bit image from stitcher, but by doing so and then converting down to  8bit afterwards you should avoid these kind of problems. i recommend shooting RAWs wherever possible: you have complete control over the white point and greater scope to 'develop' the image like you would a negative. it's an extra step in the workflow (and larger source files), but the added benefit of shooting in a native 12bit format then upsampling to 16bit for TIFF outputs allows for much more flexibility.