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May 28th, 2011, 06:50 PM | #1 |
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Notice any halo effect using Ex. Tele Conv?
I shot a wedding today and set up and extra GH2 with a 28-105 vivitar and adapter. I wanted to try out the 105 with Ex Tele Conv down the center of a Catholic church with a really long isle. I was able to get a extremely closeup shot that was perfectly in focus, but it had a weird halo effect almost like I used some type of ethereal filter or something. I didn't notice it with EX Tele off, the footage looked really good. Anyone running in to this? Could it be that its not a proper lens and using an adapter?
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May 28th, 2011, 09:36 PM | #2 |
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Re: Notice any halo effect using Ex. Tele Conv?
I'm not an experienced photographer, so I'm just spit-balling here, but I would suspect one of two things.
1. It might be a thing with the lens. Maybe it's related to light fall-off? My "new" Vivitar Series One 28-90mm f/2.8-3.5 - Questions - Photo.net Nikon Forum 2. If you're using a UV filter, especially a less expensive one, maybe that is the cause? I've heard of halo effects, but can't remember what causes it. You might google the lens model with halo in the phrase and see what comes up.
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May 28th, 2011, 10:02 PM | #3 |
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Re: Notice any halo effect using Ex. Tele Conv?
Its really weird thats for sure. I am going to post a still pic in the morning so you can see what I am talking about. There are no UV filters on it.
Thanks, I am going to read that link. |
May 29th, 2011, 07:50 AM | #4 |
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Re: Notice any halo effect using Ex. Tele Conv?
Here are 2 samples with a little background. Long middle isle with both sides of the church lined with both blue and yellow staind glass windows shot in the day. One shot with Ex Tele off and second with Ex Tele on, using a Vivitar 2.8 28-105mm. What I am curious about is the bluish halo/glow around the light colored objects, is this because of over exposure or something with the lighting or lens?
Just fyi, I was just testing this camera and lens combo so I have several other cams rolling for the ceremony. |
May 29th, 2011, 06:27 PM | #5 |
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Re: Notice any halo effect using Ex. Tele Conv?
Steve, your grabs look fine to me. There is a phenomenon called light falloff with lenses, and I think that is what you are seeing. It is exacerbated when an area on the edges of your frame are darker than the middle. If you read the thread I pointed you too the Vivitar, according to the folks there, say it goes away about about F/8 or so.
I wouldn't give it a thought, there's nothing you can do in church about it, because you cannot close down your iris anyway. There's another name for what your seeing, but i forget what it is. I don't see it in your images, they look fine. I would suggest to forget about it. A more expensive lens may have less of it, I don't know. Keep in mind the telextender thingy is not ideal in low light situations also, so never assume you can use it with the best of results. In other words, you cannot count on it.
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May 29th, 2011, 11:48 PM | #6 |
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Re: Notice any halo effect using Ex. Tele Conv?
I was talking about the bluish glow around the alter, priest's robe, and the candle light glow. That is called falloff? I read the article and thought he was talking about a vignette effect and not lighter objects glowing hazeiness. I am going to read it again.
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May 30th, 2011, 05:11 AM | #7 |
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Re: Notice any halo effect using Ex. Tele Conv?
After looking at the second photo again, I see what you're talking about, sorry, didnt' catch it first time.
You are seeing effect of the telephoto, for sure. Sometimes it's great, sometimes it's not. Looks pretty bad in this case. I did't look at the photo or something the first time through, and I do apologize. Telextender shot is lacking in detail, and that is as bothersome as the halo effect you see. I would avoid it in church, if it were me. As an aside may I suggest you upload jpegs rather than bmp files? Bmps are a bit unweildy and way oversized. Jpg would have been 10% of the size and looked just as good.
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May 30th, 2011, 06:06 AM | #8 |
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Re: Notice any halo effect using Ex. Tele Conv?
That lens is not quite happy on the GH2 or it has some hazing of the glass elements. I had the same problem with a pro wide angle converter that was made for an old TV camera when I put it on a new HD camera. That didn't work because the glass wasn't manufactured to a high enough standard.
The ETC mode on the GH2 can bring out problems in low light situations such as ISO noise and in your situation blooming. In well lit situations, ETC is a fine tool. As long as you don't use ETC in low light the Vivitar lens seems fine for video.
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May 30th, 2011, 10:11 PM | #9 |
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Re: Notice any halo effect using Ex. Tele Conv?
Thanks Jeff and William. When I use the Vivatar I'm going to stick with normal mode without ETC. I uploaded just the bmp files that exported directly from the video, I should have compressed them.
I am going to make some tests with my other lenses this weekend. Thanks! |
May 30th, 2011, 11:42 PM | #10 |
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Re: Notice any halo effect using Ex. Tele Conv?
You'll be better off following that plan in church for sure. I used the tele-extender thing outdoors Saturday and it looked perfect, but those scenarios where it will look right are too rare for my paid shoots. Easier to use the right lens.
Here's a sample with the feature being used indoors pretty effectively. It's in two shots, the closeup of the hand and the closeup of the jeweler welding. I am aware the footage is too warm, it's kind of yucky, but the ETC worked great!
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"The horror of what I saw on the timeline cannot be described." Last edited by Jeff Harper; May 31st, 2011 at 04:57 AM. |
May 31st, 2011, 04:40 AM | #11 |
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Re: Notice any halo effect using Ex. Tele Conv?
Martyn (Chris) indicated his post for this thread hasn't shown up, but I'll reply anyway. He says he has trouble getting the look above with the ETC using his camera.
The key is the lens as well as lighting, I think. I found the Jewerlry store footage too warm for my taste, and I find indoors this is a commons scenario using the 20mm. It tends to run warm. But I find it is easier in post to cool footage off than warm it up. I personally find the lens selection to be more important than camera choice. That's one of the reasons I wouldn't mind shooing with most anything as long as I had a nice lens. Camera settings are useful, but I haven't learned to use them yet, such as smooth, etc. I personally find it easier to choose the lens I need than to fiddle with the camera settings. Now if I were shooting high end stuff, as some of you guys do, I would probably need to make adjustments, etc. but right now I'm just trying to focus on getting exposure and focus right.
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June 1st, 2011, 02:26 PM | #12 |
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Re: Notice any halo effect using Ex. Tele Conv?
I would suspect chromatic aberrations, which can be minimized by stopping the lens down.
When shooting with my 600D and Sigma 50-500, I need to stop down to f8 for good results. With some of these older zoom lenses, I don't think they have enough resolution for crop mode. |
June 1st, 2011, 03:06 PM | #13 |
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Re: Notice any halo effect using Ex. Tele Conv?
The problem in the OPs case is he likely cannot stop lens down much in his situation, but I think yes, you are right probably; if it were stopped down it would be less.
Better solution would be to run a different zoom with longer reach, IMO. Just by turning off the ETC feature problem also disappears, but he already understands that, now.
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June 2nd, 2011, 01:40 PM | #14 |
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Re: Notice any halo effect using Ex. Tele Conv?
Yes, I am trying to learn all of the GH2 limitations and work around them. I have a lot to learn yet! ;-)
That shot was wide open inside, Jeff is right, I couldn't stop down unless I bumped up the iso. I might give it some tests because I really like the lens and it would be handy with the ETC mode. But as far as now is concerned, I am staying away from that mode entirely unless outside. |
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