Veterans Day

Veterans Day in Peachtree Corners

The new Veterans Memorial at the Peachtree Corners Town Center saw its first Veterans Day ceremony. Here is a selection of photos from this event.

 

 


.:. © 2019 Ludwig Keck

Crowd Panos

Photographing Concerts and their Audiences

 

For as long as I can remember, I have always enjoyed showing the audience when photographing concerts. Invariably there is no way to step back far enough to capture the expansive crowd. Nor do I have a wide angle lens that can take it all in. My solution has been to make a panoramic image by stitching together overlapping views. Like this:

Evening Concert – PC Town Center  —  CLICK picture – with luck your browser will show it bigger

Sadly I can no longer link to a viewer that shows panos well, but with luck your browser will do a reasonable job.

The image here was stitched from eight separate exposures. Here are four of them.

Take a closer look at these four. You can see that stitching them faces some interesting obstacles. Yes, The photos show lots of noise. These photos were taken in the evening, night might be a better word. All at f/5.6 and 1/250s with the camera allowed to adjust the sensitivity (auto-ISO). My old camera doesn’t do so well at ISO 5000 to 25600.  On the left end the light evening sky tricked the camera into underexposing the people and I had to boost the shadows – always bad for noise. On the right end the camera reached ISO 25600 and all the noise that comes with that. I do use some noise removal app for these, but that is another story.

In the minute or so that it took to get this set people moved around quite a bit. Some people even walked along in front. That is one huge problem for stitching. Another is more subtle. Look at the lamp post. In one image it is quite bent, straight in the last. That tells you my lens produces a good about of barrel distortion. These problems, and even exposure nonuniformities are easily solved my my stitching program, Microsoft Image Composite Editor, ICE.

On the bottom it says: Camera motion: rotating motion. Stitched 8 of 8 images. Spans 169.3° horizontally, 48.7° vertically. You can see how the program ballooned the images to correct for distortion, moved them up and down for best alignment and found were to cut  from one to the next. Oh, there are stitching artifacts. In a crowd with everybody moving not even the best AI, for that matter nt even old-fashioned human intelligence, could get it perfect. ICE offers a number of different projections as you can see. For this I stayed with the default cylindrical projection.

The four steps at the top describe the major functions, Import, Stitch, Crop, and Export. In the cropping function it even offers to fill the areas around the edges with “context matching fill”. I did not make use of that for this pano.

The final step is to export. Sadly the Deep Zoom and Photosynth options are no longer of use. Time has marched on and Microsoft has given up on those tools. Even ICE is pretty much orphaned, although still available for download from Microsoft. I chose to export a full quality (100%) JPG image. You can see that it is 18098 pixels wide. That makes for a 98.78 megapixel image. I did go back and trimmed top and bottom, see first image above. The file size still came out as 99.6 MB. Yes, I did scale it down for this post.

Here is another pano. This one is made up of just two images. I am using this as the “featured image” so WordPress does not have to choke on the wide panorama.

Evening Concert – PC Town Center

Now for some other photos from this first Concert on the Green at the Peachtree Corners Town Center with the band Sister Hazel. The lead singer is Ken Block

 

.:.

© 2019 Ludwig Keck

Shadows in flash pictures

Bring out what’s hiding in the shadows

Pictures taken indoors with on-camera-flash usually have dingy, dark backgrounds. There is little that can be done about the behavior of light. An object at twice the distance from the flash will get only a quarter as much light. That means it will be darker in the picture.

There is no need to live with that problem. Post-processing, just a little bit of adjustments, can substantially enhance such photos. That is what the Shadows slider in Photo Gallery can correct substantially. With some judicious use of the Hightlights slider, and maybe a bit of adjustments with the others, a flash photo can be made to look quite good.

Here are a couple of screen shots to illustrate what can be done with a flash picture.

Shadows-01

This is the oroginal photograph, just the way it came from the camera. It looks like what you expect from a flash picture, the objects close to the camera, the table and chairs here, are properly exposed, things farther away look progressively darker.

Next the picture with some enhancements.

shadows-06

The Shadows slider was moved all the way to the right to make darker areas of the photo lighter. Sometimes such a drastic adjustment may turn out to be way too much, but for this picture it worked well. The Highlights slider is moved a little to the left to make the lightes areas a bit darker. The Contrast slider was also moved to the right jut a little bit to increase contrast.  Note how much lighter the far wall is, it looks almost normal they way you would see it.

Other photo editors have similar tools. Sometimes they have different names. In Picasa the Fill Light slider brings the details out of the shadows. The Shadows slider makes intermediate toned areas darker. Careful use and a little trial and error will help you get the best pictures out of your flash photos.

shadows-05

.:.

© 2016 Ludwig Keck

Photography makes news

photokina-logoThe great photo equipment show, Photokina, once again has introduced a lot of new photo gear.

C/net has a nice overview article about what is happening:

How camera makers are getting their design groove on

Pop Photo has a gallery of innovations at:

Photokina 2012: The Best New Gear

20120919_Leica_S_001_610x526Samsung-NX

 

Sony-RX1

Enjoy the articles and start saving your pennies!

.:.

© 2012 Ludwig Keck

LiveWriter-credit-360

Aperture is not what it used to be

In the olden days, as they say – that’s way back last century, photographers were taught to stop down the lens for best sharpness and depth of field. With 35mm cameras that was modified a little – apertures no longer went all the way to f/64. LJK_3724-640Smallest apertures were only f/16 on some lenses as seen in my photo here of a fifty year old lens.

Still, stopping down remained a good rule. Lenses sported aperture scales with the f-numbers, distance scales that were pretty accurate, and depth-of-field marks, as seen here, that made the relationship between aperture and depth of field pretty clear. In the photo here, the lens is set to the hyper-focal distance for f/16, about 8 feet. You can tell that the scale shows that objects from 4 feet to infinity would be sharp.

That brings us to “sharp”. The “sharpness” of objects in a photograph are always dependent on a number of different things. The resolution capability of the recording medium being just one factor. How a photo is reproduced and viewed is another. What looks tack sharp in a small print might be unacceptably fuzzy in a wall-sized enlargement.

LJK_3720 (3872x2592)Film for a long time was a limiting item, especially as cameras moved to smaller formats. One big problem lurking in the background always was “diffraction”. Yes, camera lenses are diffraction limited optics at the smaller aperture sizes. The aperture is that “hole” through which the light reaches the recording medium, nowadays, the sensor.

The distance from that aperture to where the light bundle converges to a point for an infinitely far object on the other side, is called the “focal length”. The focal length divided by the diameter of the aperture is called the “f-number”. The light actually never “converges to a point”. This is where the laws of physics wag a big finger. Diffraction happens, it is the cantankerous, ornery, way of light bending slightly around corners instead of proceeding in a straight line. The smaller the light bundle, the more light won’t converge to a point. We will let the physicists worry about “Airy disks”, the point here is that light is smeared out and small detail becomes fuzzy, the larger the f-number, the worse it gets.

As digital cameras get ever smaller, this problem becomes more bothersome. The individual sensor elements, “pixels” to all of us, are already smaller that what the optics can resolve. As the aperture is set to a smaller hole, the “spread” of the light increases. So the minimum aperture for some camera lenses is limited. I have seen f/11 as the smallest aperture on some cameras. Smartphones, which have absolutely tiny sensors, go to the extreme: No stopping down of the lens. They work at full aperture all the time.

I ran an interesting experiment. file-sizes-NEFI mounted my camera firmly on a tripod a good distance from my subject. This subject was a barren tree some two hundred feet from the camera. I was careful to exclude any foreground. I turned off auto-focus and vibration reduction. Then I took a series of photos at apertures from the widest, f/5.6, to the smallest, my camera goes to f/36. The first indication of how image quality is affected can be seen from the file sizes of the images. The seven images were taken at f/5.6, f/8, f11, f/16, f/22, f/32, and f/36. I let the camera choose the shutter speed.

file-sizes-JPGNotice that file size gets larger, reaches a maximum for f/11, then declines. When the raw images were translated to JPG format (at 100% quality), the differences became even more noticeable. Photo file formats reduce the file size by eliminating repeating values. The simplest way to explain this is to say that when a pixel has the same value as the previous one, instead of recording that value, a “ditto” is recorded. So if three pixels have the same value, the file says effectively “three times xxx”. As a consequence photos with less detail produce smaller file sizes since there are fewer different values. This is a gross oversimplification, of course.

Can you tell the difference in the pictures? You sure can!

comp

Here are small cutouts from the images. These cutouts are from the JPG images since this is how most photos get distributed and viewed.

Here, in a larger view the extremes, the f/5.6 image, the f/11, and the f/36:

comp3

I was far enough from the tree so that the small twigs were narrower in the image than the pixels of the camera sensor. The first couple of photos show improvement in the image as the lens aberrations decrease as the lens is stopped down. Then, after f/11 (third image in the top row, center image of the larger views) diffraction and some other effects take over.

The moral of this story is this: For best image quality, do not go to small apertures, large f-numbers.

For my camera the deterioration in this test starts at about f/11. This is a DX format Nikon D-60. For full-size sensor cameras, the sensors, and the pixel elements are larger thus the diffraction effects will be less. For smaller cameras, especially the point-and-shoot pocket cameras, image quality will decline starting at even larger apertures.

To give you an idea of the size of the areas shown above, here is the full image with the section indicated.

LJK_3707-Fm640

Camera manufacturers either help out, or cover up, depending on your point of view. You don’t see aperture scales on lenses any more. Distance scales are only on professional lenses. Cameras are programmed to do the best they can, and this means working at the largest aperture possible, not the smallest one.

.:.

© 2011 Ludwig Keck