Luminous Landscape Forum

Raw & Post Processing, Printing => Digital Image Processing => Topic started by: feppe on September 24, 2007, 02:53:43 pm

Title: Strange flare(?)
Post by: feppe on September 24, 2007, 02:53:43 pm

I'm getting strange diagonal flare on this panorama (http://harrijahkola.exposuremanager.com/scripts/expman.pl?rm=view_photo&photo_id=spain-jumillalandscape-30d-master43&file=spain-jumillalandscape-30d-master_medium.jpg) (can't get the shot to show up here directly).

It's a stitched shot with Sigma 10-20mm, circular polarizer and Canon 30D. The flare is visible in the individual shots, but not as much as in this post-processed shot.

Does this look like flare from shooting head-on with a sub-par lens? Polarizer? Or is the harsh lighting too much for most lenses? Fortunately this is something that's fixable in post, but I'd like to avoid this in the future.

Title: Strange flare(?)
Post by: rdonson on September 25, 2007, 10:15:50 pm

Generally its a bad idea to use a polarizer when shooting multiple images for a stitch pano.  You can't keep the conditions constant across the series and it drives the stitch software nuts.

Title: Strange flare(?)
Post by: GerardK on September 26, 2007, 02:58:30 am

Quote

Generally its a bad idea to use a polarizer when shooting multiple images for a stitch pano.  You can't keep the conditions constant across the series and it drives the stitch software nuts.
[{POST_SNAPBACK}][/a] (http://index.php?act=findpost&pid=141869\")

Agreed. Also, are you doing the processing in 16bit? Because the diagonal bands look like 8bit posterization to me. If you work in 16bit for as long as possible it'll be less of a problem. Generally, you'll get better results if you use a longer focal length and take more shots, the software will have less perspective distortion to deal with. For instance, I'd rather take ten shots on 50 mm than 5 shots on 28 mm. I use PTAssembler, it'll let you do the whole workflow in 16bit and if you use the Enblend plugin (free), banding in the sky will be much less of a problem.


Gerard Kingma
[a href=\"http://www.kingma.nu]www.kingma.nu[/url]

Title: Strange flare(?)
Post by: sniper on September 26, 2007, 03:25:09 am

Quote

Agreed. Also, are you doing the processing in 16bit? Because the diagonal bands look like 8bit posterization to me. If you work in 16bit for as long as possible it'll be less of a problem. Generally, you'll get better results if you use a longer focal length and take more shots, the software will have less perspective distortion to deal with. For instance, I'd rather take ten shots on 50 mm than 5 shots on 28 mm. I use PTAssembler, it'll let you do the whole workflow in 16bit and if you use the Enblend plugin (free), banding in the sky will be much less of a problem.
Gerard Kingma
www.kingma.nu (http://www.kingma.nu)
[a href=\"index.php?act=findpost&pid=141887\"][{POST_SNAPBACK}][/a]

Tell me about it lol, I just spent a day stiching 18 images from a d2x with a 10mm lens taken indoors (360%), PS had a fit trying to work out all the distortion, but to be fare it did a really good job with just a few tweeks.  Wayne