Google Street View car drove down my street today

This was a lucky shot – lucky that I had gotten a glance “of something” going down my street and on a hutch, sprinted for my camera, ran back, saw what it was, and got this shot.

This is the second time I have captured their car on my camera. The other time, I was bicycling on an off road bike trail and encountered the Google bike taking pictures.

The Google vehicle scarfs up photos, laser measurements to create a 3D world model, Wi-Fi access points and MAC addresses, and in the past, also stored any private email you might have been sending over Wi-Fi as they drove past. Now I need to change my router ID and create a new fake MAC address for it.

File this under “Cameras” because, well, it is!

Enhanced by Zemanta

Reducing image noise in the Canon XH A1

English: Canon Xh-A1 HDV camcorder
English: Canon Xh-A1 HDV camcorder (Photo credit: Wikipedia)

The Canon XH A1 is not very old, but it is tape-based, which today seems quaint and dated!

However, the camera shoots excellent images and its 20x zoom lens remains amazing.  Even at 1440×1080 HDV, it shoots sharper and lower noise images than most of the consumer 1920×1080 camcorders.

But when comparing to my Lumix GH-2 in daylight, the XH-A1 has some image noise that resembles film graininess. Some people actually like that – I do not. I like clean and smooth images and prefer clean over sharp.

Some tips that I have discovered may be helpful to others.

If you shoot using the default camera options, the camera applies no noise reduction strategies “out of the box”. Not surprisingly, there will be some image noise.  While each scene is going to be different, I have found that by configuring the custom presets with some noise reduction options, I get very clean imagery.

I am using the following as a starting point:

  • SHP set to -3
  • Sky Detail to set to smooth/soft
  • NR2 set to “Low”.
  • Coring set to +9

Noise reduction can be improved a bit more by setting NR2 to its medium setting, or reducing the sharpness setting a bit more. These modest changes make a very large and noticeable reduction in noise. The NR1 noise reduction option only works on imagery that is not moving or barely moving, otherwise you get “ghost trails” in the video.

You can also manually set the lowest gain setting to -3db (instead of 0 db). For DSLR shooters, the video gain setting on a video camera is the same idea as setting the ISO level. More gain is the same as higher ISO, which also implies, more noise.

I remain unconvinced that the -3db setting makes any difference in noise. It does buy an addition 2x neutral density equivalent, which can be useful in broad daylight.

For maximum sharpness, I have found (as have others) that the sharpest images occur at an aperture of around f/4.0 plus or minus.

I shoot virtually everything in manual modes, usually shutter priority Tv mode, which means I adjust the neutral density filter settings and the shutter speed to get close to around f/4.0. Much above f/5.6 and sharpness starts to degrade.  You can manually set the aperture to f/9.5 and the camera’s automatic features will go as high as f/22! Images at those aperture settings produce garbage! Incredibly soft, grainy and ugly looking – don’t do that! This is the cause of widely reported and unexplained “grainy” footage captured with the XH A1 – using far too high an f-stop for the lens and sensor. The solution is to use ND filters and shutter speed to keep the f-stop in a low range.

Using these tips you can produce some very clean and very sharp video on the XH A1. I recently did some shooting using both the XH A1 and the Lumix GH-2. If you tweak your XH A1 well, it is very difficult to tell the difference between the XH A1 and the GH-2, unless you have a gigantic HDTV. The XH-A1 shoots at 1440×1080 while the GH-2 can shoot at 1920×1080/24p and /30p, or also 1280×720/60p.

  • 1080/24p is 49,766,600 pixels per second.
  • 720/60p is 55,296,000 pixels per second.

Because of how our eyes process images over time, the higher resolution image might not appear as high to our eyes. Weird, huh?

Finally, if you have noisy images already on tape that you would like to clean up, get Neat Video (http://neatvideo.com). This product is fantastic. On my quad core processor, it can take nearly one hour to clean up a minute or two of HD video, but the results are stunning. (I think they just released a new version that may drop the time to 20 to 30 minutes per minute of HD video on my configuration but I have not installed the update yet.)

Enhanced by Zemanta

DSLRs and rolling shutter

Rolling shutter” is a video image distortion that commonly appears when using modern CMOS-based DSLRs – and also CMOS-based consumer camcorders. It manifests as a wobbly or skewed image. In the simple case, a fast pan left or right causes vertical lines to become slanted and bent. In a more typical case, portions of the image can appear wobbly if the camera – or the subject – are moving left or right.

I’ve elevated the following to its own blog post; it first appeared within the following post about the new Canon SX40IS. I also wrote about rolling shutter before.

I’ve been discovering some issues with rolling shutter on my Lumix GH-2 when using long telephoto settings that are, for me, more problematic than fast pans. Specifically, if I use the 45-200mm zoom at the 200mm setting (think 400mm full frame equivalent lens), and then switch into the ETC extended digital teleconverter mode where it isolates just 1920×1080 pixels (multiply by 2.6 times) giving a 1040mm (full frame) effective lens, the very slightest motion produces skew and wobble in the image.

Last week I shot a scene using this feature – since a 1040mm equivalent lens is compressing a huge amount of atmosphere, the thermal refraction occurring in the image made the image wobble. And sure enough, that resulted in rolling shutter issues even though the camera was locked down securely on a tripod!

Some day … an electronic global shutter will be added to CMOS sensors, I suppose. Until then, for long range video shooting, I prefer CCD imagers.

Is rolling shutter a problem? Some claim its not if you merely plan your images in advance. For those who can plan their images, this strategy may work fine.

But I shoot a lot of live events that I do not control and or which there can be only minimal planning. I am finding that DSLRs are great for shooting video:

  • For wide angle views, including handheld shots
  • For producing narrow depth of field
  • For convenience and small size (relative to a prosumer camcorder like the XH A1 or HMC-150)
  • Where you do not need real time audio monitoring and audio controls
  • Where you do not need a motor controlled zoom
  • For excellent low noise video images (especially at low ISOs)

For long telephoto shots, I find myself fighting rolling shutter far too often. I cannot control the wind. I cannot control the air temperature that causes thermals and refractions, making the image move around. As you can see in the linked articles, below, some people like all the wobbliness! I don’t!

Real video cameras have the following advantages:

  • CCD imaging (hopefully!) and no rolling shutter
  • Audio controls without adding on extras (I use a Beachtek audio mixer and external mics with my Lumix GH-2)
  • Motorized zoom control
  • Better auto focus. The GH-2 tends to hunt when shooting video so I end up using manual focus.

DSLRs (although not the GH-2) tend to suffer from false image artifacts created by aliasing and moire patterns in the images

On a typical modest screen HDTV (mine is 42 inches) it is very difficult to tell the difference between GH-2 video and XH A1 (once the A1’s noise issues are addressed – I’ll add that item to another post).

DSLRs are a fantastic tool for video, but they are not yet the be-all solution for video. But they are a wonderful additional tool to have for video shooting.

Enhanced by Zemanta

Canon SX40 HS has much improved video

One my cameras is a Canon SX1IS that I bought used. This model is probably 2 1/2 years old now. But once I figured out how to really use it (think RAW!), I get great results. I really like using this camera for stills – I don’t have to carry a bag for lenses. Sure, its not a gaziggle pixel camera with the world’s sharpest lens, but I am not shooting professionally. Instead, it provides a lot of capability in a convenient package.

But the SX1 video has been a disappointment. It’s 1920×1080 is decent for relatively non-moving scenes, but once things have motion, the video codec gets blotching, and then there’s always the SX1’s image noise issues at higher ISOs. Since ISO selection is automatic in video mode, the video is nearly unusable in anything other than shooting video outdoors.

The Canon SX40 appears to have greatly improved the video codec, as seen in the sample video clips in this YouTube video – watch in 1080p, if you can:

 

No idea how the new model handles low light as that was not demo’d in that otherwise great video sample. Sony is also coming out with several new cameras that might compete with this, and I have been impressed with their low light capabilities. By next year, I suspect everyone will have full 1080p cameras at the low to mid range, and I have seen indications of 1080p60 – that’s 60 progressive frames per second, full size, coming next year too.

The video demo, above, also includes the required rolling shutter test, panning the camera quickly left and right on a vertical fence. While effective for showing what rolling shutter is, that is not a common scenario. I’ve been discovering some issues with rolling shutter on my Lumix GH-2 at long telephoto settings that are more problematic than fast pans. Specifically, if I use the 45-200mm zoom at the 200mm setting (think 400mm full frame equivalent lens), and then switch into the ETC extended digital teleconverter mode where it isolates just 1920×1080 pixels (multiply by 2.6 times) giving a 1040mm (full frame) effective lens, the very slightest motion produces skew and wobble in the image.

Last week I shot a scene using this feature – since a 1040mm equivalent lens is compressing a huge amount of atmosphere, the thermal refraction occurring in the image made the image wobble. And sure enough, that resulted in rolling shutter issues even though the camera was locked down securely on a tripod!

Some day … an electronic global shutter will be added to CMOS sensors, I suppose. Until then, for long range video shooting, I prefer CCD imagers.

Update: October 10, 2011: I previously labeled the camera the SX40IS but it is the SX40 HS. I corrected that in the title of this post. A lot of us made that mistake as the older cameras it replaces were “IS”.

Enhanced by Zemanta

Home made wind suppressing blimp for microphones

Photo taken in the Yellowstone area.
Image via Wikipedia

After dealing with wind one too many times, and especially in Yellowstone, I decided to build my own blimp. I assembled what you see in this photo:

After I built this, I discovered plans on the Internet for this same idea, even using the same components!

The tube is made from two inexpensive bird feeders, purchased at Home Depot. The sections are glued together using epoxy putty. Home Depot said they didn’t have any, but Lowe’s across the street, had Loctite, which is the same thing. I used two packages of Locktite on this.

The handle is a $1.68 paint roller handle, picked up at Lowe’s.

The end caps were made from two wire mesh sink drain covers, trimmed around and glued onto remnants of the bird feeder caps using more epoxy putty. The original bird feeder caps were drilled and then cut out with a jigsaw, leaving the rims.

I originally planned to weld the metal pieces together, but the bird feeder seems to be an aluminum alloy or something and was not weldable with my wire feed welder.

I still have to head to a fabric store to buy some fake fur to sew up a cover. That should happen within the next few days. I’ll try to post a followup picture of the final version.

Pros: Cheap, should work quite well. Can be mounted on any standard paint pole, as well as my 16 foot aluminum window washing pole.

Cons: the handle is not adjustable.

Enhanced by Zemanta

Firmware update for the lens?

It seems odd, even to me, a software engineer, to be updating the firmware in my camera lens – but its for real. Panasonic released firmware updates for several of their camera lenses, including the standard 14-42mm kit lens: 43 Rumors | Blog | Panasonic firmware update for four m43 lenses!.

The improvement is said to improve auto-focusing, image stabilization, and reduce potential focus noise when recording video. I have installed the update on my 14-42mm lens via the camera today, without any problems.