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Old Dec 9, 2006, 10:27 AM   #1
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Today is a bright sunny, but very cold day. There is a small moth, probably about 1" across that is stuck (probably frozen as it was 12º last night) to my window.

I was trying to get a shot through the window of him, but just can't get anything but a blob of color.

I am using my 18-55 lens at 55mm, on macro mode, without flash, anywhere from 1" to 12" away from it and the camera just won't focus on it. It's not that translucent, but it's like it can't see the "solid" wings.

I also tried in manual mode at both ends of the fstop. Also, manual focusing.

Can someone give me some direction on how I should be shooting this? I also have a 50-200 zoom lens. But, no macro dedicated lenses or filters.
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Old Dec 9, 2006, 11:00 AM   #2
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if you're using the Canon 18-55 kit lens, it should focus at about 11". what camera are you using?
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Old Dec 9, 2006, 11:10 AM   #3
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Using the Pentax K100D. I also played around with my old Olympus D550Z, but it has no macro mode.
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Old Dec 9, 2006, 11:30 AM   #4
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The problem is that the autofocus system needs some kind of texture to focus on and is probably not getting enough. Also, the view that close to the window is probably quite bright and the autofocus can't distinguish the moth from the background.

Check to see if you camera has a spot focus or manual focus mode and try those if available. Generally, autofocus does not work too well with macro shots.

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Old Dec 9, 2006, 11:08 PM   #5
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Thanks for the tips, Cal. I tried earlier today with the camera on spot metering. Hadn't realized I had changed it to overall. Might have helped me with the light bulb shot, too.

I did eventually get a somewhat focused shot, but not good enough to post here. The morning shots were taken about 9 a.m. with the sun on the other side of the house. The ones that were coming out later were with the sun shining in the window through the moth at an angle.

I was also about 10" away from the window when it would focus correctly. Why is it that sometimes I can photograph something and be 2" from it and sometimes I need to be farther away? The shot of the light bulb I was probably about 3" away.
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Old Dec 9, 2006, 11:35 PM   #6
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Some autofocus systems can be very finnicky! With your closeup of the light bulb, the focus system had some strong lines and patterns to work with. Shooting the moth in the window, this is probably not the case. My wife used to have an Olympus Centurian APS camera. The autofocus in that camera failed more than it succeeded and there was no manual focus option. There was one trick that worked when all else failed. If the focus would not lock, she would rotate the camera 90 degrees, lock the focus, rotate the camera back to the desired orientation and click the shutter. It seems that the focus system in that camera liked to find horizontal lines and would not work if there were none. However turning the camera 90 degrees would usually find some lines that could be used.

I hope this makes sense.

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Old Dec 10, 2006, 12:15 AM   #7
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most AF systems do require either sharp edges or some form of contrast to focus on. a dark blob won't do it, neither will, for instance, a sheet of plain paper. no edges, no contrast, no focus. if youuse center spot focus (which i recommend at all times, as a general rule - it's usually the fastest and most accurate point in the typical multi-point AF system), try moving the focal point designator to a subject with sharp contrast or texture, and see if it will focus on that. it doesn't much matter with modern AF systems whether the contrasting lines or edges are oriented one partucular way or another, as long as they're present. vary the distance to the subject to see where your lens will lock on. it should be somewhere between 10" and 14", unless your lens has an exceptionally good macro function. if you simply cannot get a consistent focus lock, there could be a problem with the lens; try a different one to see if it will focus consistently, even if the focal distance is different for that lens. if it locks on properly at about the same distance every time, the problem is with your 18-55 lens. if it exhibits the same problem, you may have something wrong with the AF system in the camera.

regardless, you should still be able to focus manually. the best thing to try at this point is to manually focus the lens on an object in good light. pick something with contrasting lines or texture, give it good light, and find out the closest distance at which you can actually get a clear focus. that's your minimum focal distance. i'd be amazed if an 18-55mm kit lens could focus at 2-3"; most have a minimum of 10-14". which specific lens are you using?
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Old Dec 10, 2006, 12:24 AM   #8
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Put your camera on a tripod, point it at the moth on the window, if it won't focus on that, get a black marker and a piece of paper, draw a thick X on the paper and tape it to the window, focus lock on that, remove paper and take a picture of your dead critter and post her on Steves, live happilt ever after...:blah:
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Old Dec 10, 2006, 7:46 AM   #9
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I had to do that when trying to take a picture of a milk drop-splash. I put an ink pen point where I wanted to focus, pressed the shutter button half way down to focus, removed the pen still holding the button down and then dropped the milk and shot. I have to do that too if the camera can't find a focus point....works well.
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Old Dec 10, 2006, 9:24 AM   #10
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Thanks for the tips, guys.

Iwill have to go back and look, but I don't think it is the lens as the photo of the impeller I'm pretty sure I took with the same lens (Pentax 18-55mm) and I'm pretty sure I was only 2-3" away from it. I'll have to recreate the scene. That one was taken under a very bright fluorescent light, though. And, the moth was through the glass with the woods in the background. But, I had made sure that it was the green pine needles, not the bark that was behind it.

The moth must be frozen dead as it is still there this morning. So, I get some more attempts now that I have a little more time today.

I know with an old p&s I had I would have to do as someone mentioned and focus on something else in the same field plane and then reposition the lens. But, I still have not mastered the button on this one to be able to do that. It is so touchy. I'll get it half way down and when I move the camera I press the button. Guess I could use the delay, I just keep forgetting.

I'll have to experiment with this. The lens manual says the minimum focus distance is 0.25m (0.82 ft) or 9.84". I know when experimenting when I first got the camera I was trying to focus on a dragonfly and I swear I was right on top of the thing before it would focus on the body of it.

I'm attaching the fullimage photo of the dragonfly. It's not crystal clear because the camera had been left on ISO 3200 and I hadn't realized it. But, this was taken hand held at probably 1-2" from the bug with the 18-55 mm. I just kept getting closer and closer to fill the frame and managed to get this.
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