Posted by Chris Whitted on April 26, 2006 at 11:12 PM
A couple of questions:
1) To be a participant in CNP, you merely have to post on the forum, but to be a member you have to pay the fee to NPN, correct?
2) There seem to be an awful lot of old postings in the Classifieds thread. Is there a reason people don't delete their posts when the items have sold or after x amount of time?
3) I went on a weekend warrior run to Moab this last, and learned a lot about when to and not to use a polarizer. Unfortunately, I learned by screwing up most of my shots of the sunset at Delicate. I think I know what's happening in the following photo, but I want to confirm it.
I'm pointed about 90 to the sun, and I figure I'm using such a wide angle that I got the entire polarize effect zone plus it fading off to either side. Is that right? I'm used to it doing something more akin to vignetting or just one side, but then I've not used a polarizer with this wide of a lens before. I'm also not used to the effect zone being so narrow, and I'm wondering if that's because of the relatively low angle of the sun. Nat's recent sunrise shot sure didn't have this issue, though it looked a lot narrower. What's the max focal length you would recommend using a polarizer with?
Photo is an unedited 20D small jpg lowest quality (what I use with RAWs) about 267kb, taken with a 17-40 at 17. A sample Oops.
As for the kudos, the first night there I picked up the little 'things to do in Moab' guide and was a little surprised to recognize a few names on some of the images - Brent Dozerman, Bret Edge, and Nat Coalson. And of course they were very nice shots!
Also, thanks to Adam for that Dunes contest opportunity. I'm looking forward to trying my hand, though given the company I'm in and having only been there once, I know it's a long shot.
Thanks any and all for your responses.
Posted by Brent Murphy on April 26, 2006 at 11:55 PM
1. You are correct. There really is no official "membership" in CNP, although for contests we prefer to only allow people who have been contributors, and not just lurkers. Participation in all the NPN forums is free, but there are some benefits to paid membership, which you can read about at the link at the top of the forum pages.
2. You're right about the Classifieds postings. Our rules indicate that items should be removed when they are no longer available. Rick and I can look into this to make sure the postings are still current.
3. I don't know about a maximum focal length for using a polarizer, but the situation you describe is one of the reasons I have cut down on my polarizer use, especially with wide angles. It seems when I was starting in photography, I used my polarizer on almost every shot, to get some dramatic skies. But over time, I started to notice the effect you have in your shot, with the variable sky color across the image, and have mostly stopped using the polarizer for that effect. I now only really use my polarizer to help remove reflections off water, and to punch out the colors a little bit in some of my intimate landscape shots, especially under softer lighting. While typing this response, I took a look at my web site, which has a lot of my favorite shots, and realized that maybe only 1 or 2 photos show the use of a polarizer on the skies. I suppose that means that in the long run, the polarized sky shots just didn't make the cut.
I agree with Brent on the use of a polarizer. I almost never use one for wide angle images involving sky for this very reason. Like you, I learned the hard way. I would bet that you cranked the polarizer to max effect (or very near) for these images. You might try the polarizer at about 1/4 strength to bring out a little definition between sky and clouds and/or darken the blue sky w/o creating such a dramatically polarized sky. Even w/o a polarizer at right angles to the sun you will find that the "sun" side of the sky is a bit lighter than the other side, which is natural.
Oh...and thanks for the kudos on the image in the Guest Guide. Brent and Nat, you guys have some great stuff in this edition!
From experience, I avoid the use of polarizers on lenses wider than 28mm. The angle to the sun also makes quite a difference. In addition, it seems that at our higher altitudes, the use of a polarizer (for skies) is unnecessary. On the other hand, polarizers cut reflections from vegetation very well and I try to use them consistently - but only with minimal, or no, sky showing.
Ken
Posted by Jesse Speer on April 27, 2006 at 1:01 AM
Re: polarizer effect
I too learned this the hard way. I don't know the exact science behind this, but I concur with everyone else. It will happen anytime you have a large area of blue sky in your frame ... obviously mostly with wide angle. Early and late. High altitude. All factors. I now rely on Photoshop if I need that contrast boost, and get more natural color as well (as the polarizer can alter that magic light). Even just a simple Levels/Curves adjustment can do the job.
We do have a CNP "Members" page at the top. It's more or less an unofficial membership list since, as Brent mentioned, there are no fees. Some folks are paid NPN Members, but not everyone is. If you want to be listed, you just have to send some basic information like what you see for the other members - name, brief description, website, optional picture, etc.
Yeah, we probably need to clean that up.
Ditto the others on the polarizer. I rarely use mine for wide scenics; more for telephoto work or more intimate shots.
Brent, Bret and Nat... congrats fellas!
Posted by Nat Coalson on April 27, 2006 at 11:10 AM
Thanks guys!
Re: polarizer - the raw capture of my recent Garden of the Gods shot did show a bit too much polarization in the sky; I knocked it back in Photoshop, just at the top left corner, very slightly... just to the point where it appears "natural".
I use a polarizer more often that it sounds like others might, although not always at full strength.
On that Garden of the Gods shot, I was more concerned about reducing the sunlight reflection on the rocks and the tree trunk than I was about the sky, so I used the polarizer to increase saturation, constrast and detail on the foreground elements and let the sky fall where it may.
Posted by Chris Whitted on April 28, 2006 at 9:13 PM
Oops, that should have said min focal length. Thanks to the mods for looking at the classifieds, and everyone else for responses.
This was my first time out with a wide lens and polarizer. Previously I'd only had a 28mm with one and never had any issues. The 17-40, even on a 1.6 like the 20D, was quite a jump. Strangely enough, I didn't have a problem with some shots while others were trashed. I'm looking at them more closely to try and learn the patterns (portrait shots, angle covered/from the sun, etc.). Actually, being the first time out with it I did a number of comparison shots (full strength vs 'off') for that very reason. Time and practice will tell.
Discussion
7 replies1) To be a participant in CNP, you merely have to post on the forum, but to be a member you have to pay the fee to NPN, correct?
2) There seem to be an awful lot of old postings in the Classifieds thread. Is there a reason people don't delete their posts when the items have sold or after x amount of time?
3) I went on a weekend warrior run to Moab this last, and learned a lot about when to and not to use a polarizer. Unfortunately, I learned by screwing up most of my shots of the sunset at Delicate. I think I know what's happening in the following photo, but I want to confirm it.
I'm pointed about 90 to the sun, and I figure I'm using such a wide angle that I got the entire polarize effect zone plus it fading off to either side. Is that right? I'm used to it doing something more akin to vignetting or just one side, but then I've not used a polarizer with this wide of a lens before. I'm also not used to the effect zone being so narrow, and I'm wondering if that's because of the relatively low angle of the sun. Nat's recent sunrise shot sure didn't have this issue, though it looked a lot narrower. What's the max focal length you would recommend using a polarizer with?
Photo is an unedited 20D small jpg lowest quality (what I use with RAWs) about 267kb, taken with a 17-40 at 17. A sample Oops.
As for the kudos, the first night there I picked up the little 'things to do in Moab' guide and was a little surprised to recognize a few names on some of the images - Brent Dozerman, Bret Edge, and Nat Coalson. And of course they were very nice shots!
Also, thanks to Adam for that Dunes contest opportunity. I'm looking forward to trying my hand, though given the company I'm in and having only been there once, I know it's a long shot.
Thanks any and all for your responses.
2. You're right about the Classifieds postings. Our rules indicate that items should be removed when they are no longer available. Rick and I can look into this to make sure the postings are still current.
3. I don't know about a maximum focal length for using a polarizer, but the situation you describe is one of the reasons I have cut down on my polarizer use, especially with wide angles. It seems when I was starting in photography, I used my polarizer on almost every shot, to get some dramatic skies. But over time, I started to notice the effect you have in your shot, with the variable sky color across the image, and have mostly stopped using the polarizer for that effect. I now only really use my polarizer to help remove reflections off water, and to punch out the colors a little bit in some of my intimate landscape shots, especially under softer lighting. While typing this response, I took a look at my web site, which has a lot of my favorite shots, and realized that maybe only 1 or 2 photos show the use of a polarizer on the skies. I suppose that means that in the long run, the polarized sky shots just didn't make the cut.
Oh...and thanks for the kudos on the image in the Guest Guide. Brent and Nat, you guys have some great stuff in this edition!
Ken
I too learned this the hard way. I don't know the exact science behind this, but I concur with everyone else. It will happen anytime you have a large area of blue sky in your frame ... obviously mostly with wide angle. Early and late. High altitude. All factors. I now rely on Photoshop if I need that contrast boost, and get more natural color as well (as the polarizer can alter that magic light). Even just a simple Levels/Curves adjustment can do the job.
Yeah, we probably need to clean that up.
Ditto the others on the polarizer. I rarely use mine for wide scenics; more for telephoto work or more intimate shots.
Brent, Bret and Nat... congrats fellas!
Re: polarizer - the raw capture of my recent Garden of the Gods shot did show a bit too much polarization in the sky; I knocked it back in Photoshop, just at the top left corner, very slightly... just to the point where it appears "natural".
I use a polarizer more often that it sounds like others might, although not always at full strength.
On that Garden of the Gods shot, I was more concerned about reducing the sunlight reflection on the rocks and the tree trunk than I was about the sky, so I used the polarizer to increase saturation, constrast and detail on the foreground elements and let the sky fall where it may.
This was my first time out with a wide lens and polarizer. Previously I'd only had a 28mm with one and never had any issues. The 17-40, even on a 1.6 like the 20D, was quite a jump. Strangely enough, I didn't have a problem with some shots while others were trashed. I'm looking at them more closely to try and learn the patterns (portrait shots, angle covered/from the sun, etc.). Actually, being the first time out with it I did a number of comparison shots (full strength vs 'off') for that very reason. Time and practice will tell.