Q about 'macro' camera settings

4 Scale · 09-07-2015, 09:55 AM

Actually several posters have already provided excellent advice on controlling distortion AKA bent barrel, but I will be glad to recap. There are two easy ways:

1. Frame the pistol in the viewfinder. It's when the barrel is near the top or bottom of the frame that it seems to bend. Looking in the viewfinder keep the lens parallel to the gun but move the camera around until the barrel appears straight. As you move the camera to put the barrel near the top then bottom of the frame, you will actually see the barrel bend one way, then the other. You want the center position where it is in-between and shows no bend. Take the picture at that point, then crop and enlarge the image on your computer as needed to make it big enough.

2. Or, take the photo from farther away then crop and enlarge on your computer.

FWIW I just tested both these methods using my Canon G11 before responding, which verifies that the technique is correct but that the G11 does not automatically eliminate this type of distortion. Some better cameras actually do control distortion via software in the camera. There are also expensive cameras and lenses that optically eliminate distortion, used in studio or architectural photography but those are costly and complex. There is also image software for your computer that can eliminate distortion. But given your budget it might be best to stick with the two approaches above.

4 Scale · 09-07-2015, 10:29 AM

Here are some results. Please forgive the lighting, I'm just trying to show distortion correction method #1 from my previous post.

Actually the Luger pistol design tends to understate barrel distortion because the top silhouette of the pistol is very busy, broken up with receiver, toggle, toggle knobs etc. The barrel exhibits visible bend in the top photo, when shown at the top of the frame. In the second photo it is straighter. You can actually lay a ruler on the photos using three reference marks like the front sight and bottom of the toggle and safety lever, and measure less bend in the second photo. While the "straight" picture is not perfect, it actually illustrates another important technique - if you want one good photo, take many more (20?) from various positions, then pick the best. I just took just two pictures to make my point.

sheepherder · 09-07-2015, 10:44 AM

Quote:

Originally Posted by Dwight Gruber

The effect is called barrel distortion...

Quote:

Originally Posted by 4 Scale

Actually several posters have already provided excellent advice...There is also image software for your computer that can eliminate distortion...

Yes, my PSP 10.2 has this software function, but I didn't know the name of the effect to find the instructions...

But I was wondering if the camera itself had the ability to 'straighten out' the image before processing...

sheepherder · 09-07-2015, 10:55 AM

And here's a rough 'barrel distortion correction' of my original pic on pg 1, done with PSP 10.2...

Still a crappy pic, but now I have an idea of how to straighten the bend...

My Thanks! to Dwight, Olle, Ron, Norm, Greg, and all who commented...

09-07-2015, 10:29 AM	#2
4 Scale User Join Date: Nov 2014 Posts: 544 Thanks: 194 Thanked 490 Times in 251 Posts	Here are some results. Please forgive the lighting, I'm just trying to show distortion correction method #1 from my previous post. Actually the Luger pistol design tends to understate barrel distortion because the top silhouette of the pistol is very busy, broken up with receiver, toggle, toggle knobs etc. The barrel exhibits visible bend in the top photo, when shown at the top of the frame. In the second photo it is straighter. You can actually lay a ruler on the photos using three reference marks like the front sight and bottom of the toggle and safety lever, and measure less bend in the second photo. While the "straight" picture is not perfect, it actually illustrates another important technique - if you want one good photo, take many more (20?) from various positions, then pick the best. I just took just two pictures to make my point. Attached Thumbnails

09-07-2015, 10:55 AM	#4
sheepherder Lifer Lifetime Forum Patron Join Date: Feb 2009 Location: ...on the 'ol Erie Canal... Posts: 8,197 Thanks: 1,416 Thanked 4,462 Times in 2,336 Posts	And here's a rough 'barrel distortion correction' of my original pic on pg 1, done with PSP 10.2... Still a crappy pic, but now I have an idea of how to straighten the bend... My Thanks! to Dwight, Olle, Ron, Norm, Greg, and all who commented... Attached Thumbnails __________________ I like my coffee the way I like my women... ...Cold and bitter...

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09-07-2015, 09:55 AM	#1
4 Scale User Join Date: Nov 2014 Posts: 544 Thanks: 194 Thanked 490 Times in 251 Posts	Actually several posters have already provided excellent advice on controlling distortion AKA bent barrel, but I will be glad to recap. There are two easy ways: 1. Frame the pistol in the viewfinder. It's when the barrel is near the top or bottom of the frame that it seems to bend. Looking in the viewfinder keep the lens parallel to the gun but move the camera around until the barrel appears straight. As you move the camera to put the barrel near the top then bottom of the frame, you will actually see the barrel bend one way, then the other. You want the center position where it is in-between and shows no bend. Take the picture at that point, then crop and enlarge the image on your computer as needed to make it big enough. 2. Or, take the photo from farther away then crop and enlarge on your computer. FWIW I just tested both these methods using my Canon G11 before responding, which verifies that the technique is correct but that the G11 does not automatically eliminate this type of distortion. Some better cameras actually do control distortion via software in the camera. There are also expensive cameras and lenses that optically eliminate distortion, used in studio or architectural photography but those are costly and complex. There is also image software for your computer that can eliminate distortion. But given your budget it might be best to stick with the two approaches above. Last edited by 4 Scale; 09-07-2015 at 11:10 AM.