View Full Version : Problem-Purple Halo
04-13-2002, 04:10 PM
I'm hoping Geckonia and Ron will see this message and perhaps have some input for me.
My new camera, the MVC-FD95 Sony, is doing something a little odd. (I know...Operator Error! :D -Probably!) I noticed this morning that I'm getting a violet "haze" in my pictures. Something akin to an outline or "halo". This is an example, unretouched.
Where do I start to find the culprit. I've noticed it mainly on the outdoor shots.
04-13-2002, 06:00 PM
Hey Julie, I found a review of the Mavica FD91, not quite the same number but of the same line:D Maybe this is related to your problem.
04-13-2002, 06:24 PM
I think you found the problem...now we need to find the "fix". I'm having ALL of the problems listed on that review page. My first digital camera was a Polaroid...it sucked rocks (Oops Sorry...but it's the truth!) Horrible grain-y photos with nothing "extra" to work with. SO when I got the first Sony, I was completely amazed at the difference in quality. Still couldn't match the results of the Minolta SLR, but certainly acceptible for general picture taking. (Notice I didn't say "photography!" :)
I have tried working with the white balance setting and managed to reduce the appearance of the purple halo. But the reviewer on that site made mention of the level of exposure. So that's what I'll try next.
One thing about this MVC-FD95, it has LOTS of things to PLAY with. (Did you hear Geckonia faint??? hehehehe)
04-13-2002, 06:48 PM
geckonia...having sniffing salts waved under her nose...Huh? What happened?
Julie, that does suck rocks! Nikons give a blue halo...I'd prefer purple myself!
04-13-2002, 06:54 PM
That is called "purple fringing" or a "halo" effect. Some cameras are much more guilty of creating them than others. Sony's seem to be a culprit.
Your photo with purple fringing...
Here are two ways I used to get rid of the fringing.
The second and by far the easiest is to use "hue/saturtion" and pick the "magenta" setting and go HIGH with the color and very low with the saturation slider controls (like +50 and -40). Use your eye to tell you when the fringing disappears. If you still see a different color fringe, chose that color and do the same thing... such as too much green or blue fringe left over.
The first was more involved using "channel mixer" and adding in green and cyan then taking it back out with "image adjust variations". Not a quick solution.
In addition, go to this URL and you will see some steps called "Useful techniques" about half way down that you can play with also.
04-13-2002, 07:04 PM
I am SOOOOOOOOO glad you two showed up!
Anne...I'm glad you recovered...at least enough to make a wise crack! ;) And it's awfully nice to know that "OE" isn't at the heart of THIS problem. :D
Ron, that correction you did looks fantastic. I'm going to go right now and put both routines through their paces. Maybe if I get this down, I can Buzz only when I WANT to.
I'm beginning to uderstand using the editing software for turning out fairly decent digital photos is the norm rather than the exception. (And here I thought I was cheating!) :cat:
Thanks again...ALL of you!:clap:
04-13-2002, 07:33 PM
I have VERY strong feelings about this "idea" of manipulating photos as being some form of cheating. This is quite a bit more common than I would have imagined among digital camera users. There is this one woman I know who actually takes wonderful photos, yet she absolutely refuses to alter them in any manner using photo editing software. (No, it isn't someone here in WetCanvas... ;) )
My point being she could be presenting beautiful photos either here online or when printing them instead of having "so-so" ones to show. The ingredients are there, but she won't give up the notion that the photo isnt "true" unless it is raw from the camera. I can't even think of photos I have taken that can't benefit from some tweaking of some kind.
Maybe all of this is due to the fact that I had my own darkroom back in my "film" days when I developed, processed and printed my own negatives. I actually felt I was a better printer than I was a photographer. It seemed there was more an artistic challenge in the darkroom after the image was made and this is where my interest lay.
The very best of photographers were and are master printers. I can assure everyone that if you gave the exact same perfectly exposed negative to 6 different master printers you would get 6 beautiful but different printed efforts. The manipulating of the image is just as an important part of the photographic process as is the making of the image itself.
So, I urge EVERYONE who may be reticent... please go and explore the use of digital darkrooms just as you would do in your basement with the black tape over the window, red lights glowing and water running in the wash trays. It's all about the final image not just about the snap of the shutter.
(Sorry, but I get a missionary zeal about this subject.)
04-13-2002, 07:45 PM
Ron, I'm with you 110%! If negatives could print themselves she'd have a point. How do you get a print that's raw anyway? There are so many varibles...paper, exposure time, toners, filters.... anyone who isn't interested in pulling everything they can out of each negative/digital image is missing the point of photography, imho. To be told you should keep your images raw is like telling a painter he should keep his colors in their tubes.
04-13-2002, 07:50 PM
Ne'er a truer word spoken.
04-13-2002, 08:05 PM
I ALWAYS keep my paint in the tubes. Am I not supposed to do that?
04-13-2002, 08:49 PM
Did anyone else rate this thread? Hint, hint. :D
04-13-2002, 09:10 PM
waving arms in the air and shouting hallelujah...
at one point I told people I would never digitally alter a photograph - but that was before I learned how to use photoshop. Now every picture I post has be digitally alerted if not for size, a tad of sharpening or a bit of contrast - take down that red and darken that photo (I like dark always have). That is what makes it a "MissMouse" Ansel Adams watch out here I come waving photoshop 7 in my grubby little paws." The second and by far the easiest is to use "hue/saturation" and pick the "magenta" setting and go HIGH with the color and very low with the saturation slider controls (like +50 and -40). Use your eye to tell you when the fringing disappears. If you still see a different color fringe, chose that color and do the same thing... such as too much green or blue fringe left over." quote Ron....I use this all the time and it works well for me.
Ps; On second thought I think Mr. Adams would like photoshop 7............
04-14-2002, 07:08 AM
BRAVO...I love soapboxes! Especially when the topic is one that I benefit from. :D
You all make great points for the digital darkroom, I guess I never thought about the process from that perspective before.
Ron, I tried your hue/saturation process and it worked VERY well. Thank you to everyone who has made a comment here.
(And for some reason, I can just picture MM running down the street with her PS7 in her hand...LOL But look who's right behind her...ME!!!;) )
04-15-2002, 06:32 PM
The technical term for this is 'chromatic aberration', and here's a SUPER-easy way to fix this (and, incidentally, remove the distracting CCD noise from long exposures):
1. Filter->Blur->Gaussian Blur, 5px. (Vary to suit AFTER going through the whole process at least a few times.)
2. PS 6: Edit->Fade, Color mode, 100%
PS 5.5 or lower: Filter->Fade, Color mode, 100%
If you've done a REALLY long exposure, here's a variant:
1. Filter->Noise->Dust 'n' Scratches, 1px, threshold 20.
2. Repeat as in above procedure, but with 12px instead of 5.
04-15-2002, 06:37 PM
Thanks for the "abberation" fix. I'll try right away. I did manage to "fix" one on my own this morning using PaintShop Pro...had a little trouble using the dialog "thingy" in the software, but the hue/saturation shifts really worked.
BTW...noticed you're up here in my neck of the woods...well, we're both NORTH, anyway.
Sure is nice to have you around....keep posting those great photos.
04-15-2002, 06:49 PM
sure thing :-)
not sure how well those instructions will work with PSP - I don't believe PSP has an equivalent to Photoshop's 'Fade' command. You could simulate it, though, by duplicating the entire photo on a new layer in the same document, filtering that layer, and setting the blending mode of the layer to 'Color'. Same difference, but less convenient.
Man, it's nice out today - eighty-five degrees, and I'm happier than a clam in the sea. or something. ;-)
04-15-2002, 07:03 PM
I don't know what the temperature is here...but it was supposed to be 88 and I think it made it! FANTASTIC DAY!!! Too bad it's not going to last very long. Big rains forecast for tomorrow here.
And as to using the PSP...I'm pretty good and making it work (even if I DON'T know what I'm doing...hehehehe) I'm going to get right on those instructions...if all else fails, I DO have a copy of PS 5 and a demo of PS6 (I can always print the screen and get the image into PSP to save. sneaky, eh? )
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