Monday, December 29, 2008

Humans see faces


I always tell the photographers I work with at the airshow, there is a face in everything, even airplanes. Find it and you're one step closer to connecting to the audience. But in smoke? This photo was taken at the Exploratorium in San Francisco on Dec 28, 2007.

Sunday, December 21, 2008

Maximum printing resolution


So how big is the maximum print size for an 8 Megapixel image? The reason I pondered this was two experiences. Someone I know flew around the world in a small plane, a home-built Vans RV aircraft. I took a photo of him getting out of the plane with my Canon Digital Rebel XT. I then blew that photo up to 36x24 inches as a poster. It looked really good. (around 100 DPI)

Recently, I enlarged a photo I took of the Pigeon Point Lighthouse similar to the one to the left, but from the ocean side. I blew it up to 22x28 inches (around 200 DPI) and I really could not see any problems.

I knew I had to blow the image up fairly large or the detail would get lost. It looked great. And it only cost 25.00 at a photo shop.

So I'm not so sure that the standard of 300 DPI is valid anymore. Yes, that gets you a gret resolution, but at what advantage?

You can see the larger image here

Friday, November 21, 2008

Radical changes.

So Canon released the new 5D mark II and the 50D cameras. The 5D is a full-frame SLR using the Digic-4 chip, and the 50D uses an APS-C sized sensor, and the Digic-4 chip. And yet, the 5D mark II also provides 1080P quicktime movie capabilities, which is really cool.

I got to listen to Vincent LaForet talk about using the new 5D mark II to create a short movie (see it on his web site.) The exciting thing was that he was able to use all of his regular lenses to record to an image the size of 35mm film. That means he can really play with the capabilities of the lenses, light gathering, depth of field, etc, rather than having to learn a completely different system. His opinion is that this will change how photographers work, how they shoot professionally.

I agree, and I'm waiting for the software upgrades to the 50D so it can do high-def video as well. I hope it doesn't require the larger buffer sizes the 5D mark II has over the 50D...

Sunday, October 26, 2008

Uncomfortable views


Occasionally, luck favors the prepared. This shot of the cement ship, the SS Palo Alto can be seen in the upper right corner of the photo. This shot was taken without looking through the camera lens, I held the camera up and shot continuously while the pilot rolled the airplane.

This is an example where I wanted the extra buffering of using JPEG, but the extra depth of RAW. I went with RAW knowing I probably would have enough buffer to get me through 3/4 of the roll.

Saturday, October 11, 2008

Hand-holding and digital cameras


Something I've been playing around with in my head is the standard rule of how slow you can hand-hold a camera before you get too blurry. The standard rule is 1 over the length of the lens, though Doug Criner suggests twice that. With an image stabilizing lens, the idea is you can get two stops of help, so 1 over 1/4 the length of the lens. For a 100-400 mm zoom, at 400mm, you can hand-hold at 1/100th of a second.

However, that only applies for 35mm film. And for many years I shot with film with this lens on a Canon Elan IIe. I purchased a Canon Digital Rebel XT when they came out, and started playing around with it, and had bad luck. I realized that with the APS-C sized sensor, I could no longer use the old method, I had to adapt it for the new "film" size.

The actual formula should be 1 over 1.6*lens length. Since the original rule comes out of 35mm land, the new formula has to be put back into 35mm land, thus the 1.6 times. That appears to be the consensus at a couple of different sites. Doing a Google search shows some good information.

Of course see my earlier post on monopods to help out.

And because I think conservatories need as much help as possible, visit Bolsa Chica when you're in Southern California...

Tuesday, August 26, 2008

Cool "Lens" technology

Origami Lens

I was at SIGGraph recently, and I ran across the Origami Lens people, actually a graduate student from U.C. San Diego. The basic technology is the same as a Newtonian telescope, where parabolic mirrors are used to bend light rather than refraction through a lens. This technology uses a specially cut mirror on one side of a crystal lens, and a flat mirror on the other. The light enters the outside portion of the lens, gets reflected several times and enters the device from the center.

The quality is so much better than a standard small lens like one would find in a cell-phone camera. The weight and size is also drastically changed. While the lens has to be larger in diameter for a given f.stop (which depends on the area of the light coming through the lens), it can be much shallower and thinner.

This is the future for fixed focal length lenses. I'll be watching to see how they handle zoom lenses.

Sunday, March 30, 2008

Think, Think, Think

Unlike what I did. I do aerial photography from a 1946 Stinson 108, and I went out on the 22nd to take some photos. I decided to try for maximum sharpness by setting the ISO high (with enough light, you don't get as much noise), and then setting the camera to use maximum aperture. This was all shot with the Tamron 18-250 mm lens (
review here)

What I didn't think about was the f.16 rule which put the shutter speed beyond what my camera can handle. Everything was over-exposed, and my camera locked up. Turning it off and then back on fixed that. I then went to a standard mode and was able to salvage some shots...

Wednesday, February 27, 2008

More on the monopod


I had a chance to roam around Golden Gate Park with my camera setup. That would be the Digital Rebel Xt, 100-400m IS zoom, and a 1.4 x teleconverter. This was all mounted on the monopod. I found an egret and started taking photos. I have had a hard time taking hand-held photos with the 540 mm lens (35mm equivalent of 896 mm )

However, with the monopod, it was much easier, even with the higher speed. I think part of it was being able to focus better (have to manually focus at this length) There was no cropping for this image...

EXIF data is 1/2500 sec at f.9, ISO 1600. IS off.

Sunday, February 3, 2008

New Digital Canon

I am amazed at what Canon is putting out these days in digital SLRs. The new Canon Rebel XSi Looks fantastic. It has a great pixel resolution, news advances in the Digic processing, and what appears to be a good fps given 12 megapixels.

I'll stick with my Digital Rebel Xt right now, but for someone getting into the under 1000.00 digital SLR, this looks like a great camera.

Monday, January 21, 2008

Monopods


One of the problems I've had with the longer lenses (100-400mm is with 1.4 teleconverter) is hand-holding the lens and getting a good shot. I decided that a monopod would help quite a bit, and be much easier than the Bogen 3021 tripod I have. I bought it when I had much heavier camera gear.

I purchased a Manfroto 676B monopod and a 3229 head. According to my calculations, it should just hold the 100-400 mm zoom, camera, flash, and 1.4 teleconverter I have.

To test it out, I took some photographs in my living room, with the 100-400 mm lens. The photograph shown (with some odd white-balance) was taken at 400 mm, 1/13th of a second, f 5.6

It is way beyond what I could do hand-held, and I look forward to using this in the field.

In case you're interested, that thing I took a photo of is a weather station in the shape of an old satellite.

Sunday, January 13, 2008

New lens


With careful hinting, I was given a Tamron 18-250 mm Zoom lens for my Canon Digital Rebel XT. So far I have been impressed with it. It has a massive range for a zoom, and produces some pretty good shots. The bird shown was taken at Lake Merced in San Francisco

The photo was only slightly cropped.

My reasoning for this lens was I kept finding myself switching between the 18-70 mm Zoom I had with the Rebel Xt kit and the 28-105 mm zoom from my Elan IIe. Now I have a lens that covers both areas, and more. I won't stop using my 100-400 mm IS zoom, but it will make a great lens to carry around on short trips.