Full-frame v. DX Viewfinder Brightness

July 7th, 2012

On a photography forum somewhere (I’m sorry, I’ve lost track of it), I saw the following comment:

“In this regard, once again, your f/2.8 lens is “slow” in that it cannot illuminate a viewfinder as large as a FF viewfinder as brightly.”

This seems highly suspicious to me. The physics of optics uses f/ values as estimated measures of light-gathering capability. To a first approximation, they also serve as highly correlated measures of light transmittance. (Lots of elements in a lens design will factor in a reduction in transmittance, and thus the T-stop for critical exposure and reproduction work.) The amount of light transmitted per unit area in the focal plane is exactly the same for the same f/2.8 lens mounted on a DX camera, on an FX camera, or even on an oatmeal box, and will be quite similar even for different lenses of maximum f/2.8 aperture. Modulo some minor concerns about light fall-off with a larger image circle, the absolute amount of light per unit area in the viewfinder remains a constant for any lens shared between DX and FX bodies.

The expectation, in fact, would be that DX bodies will have apparently dimmer viewfinders, or if equally bright, that the DX viewfinder image will subtend a smaller apparent angle. Magnifying the smaller DX viewfinder image area to subtend the same apparent angle of view as the FX viewfinder image area will necessarily deliver a smaller amount of light per unit area to the retina (assuming the viewfinders are constructed using the same materials in each case and differ only in the optics).

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Canon Loyalty Program

March 16th, 2011

I have owned several Canon digital cameras in the point-and-shoot through prosumer range. Something Canon has offered for a long time is the Canon Loyalty Program. This allows one to obtain a refurbished Canon digital camera at a discounted price when one trades in a Canon digital camera. Unfortunately, I’ve never had much luck finding current offerings via Canon’s website. So a little while ago, I asked on the phone what refurbished cameras are currently available and at what price. I will provide the list in a table. I wanted to collect all the ancillary information, but my life is still pretty hectic now, so I’ll put up what I have and add to it as I get time (if I get time).

Camera model Price Remarks
SD1200 $87 CanonDirect price = $125.99, 10.0 MP, Image stabilization, 35-105mm (35mm equiv.), CHDK ready
SX120 $120 10.0 MP, 36-360mm (35mm equiv.),
G11 $260 Amazon price: $548.99, CHDK beta only
XS $320 w/18-55mm lens
7D $1088
T1i $480 w/18-55mm lens
T2i $576$511 (per comment) w/18-55mm lens
50D $665.99 w/28-85mm lens (not positive about the end of the zoom range)

To take advantage of the program, call Canon at 866-443-8002.

(Originally posted at the Austringer.)

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College Football — from the Stands

September 15th, 2010

Here’s a bit of a challenge… get the best shots I can from up in the stands at a college football game. Football has moments of quick action with periods of nothing much going on, which is pretty much perfect for digital image bursts and subsequent writing to media. The action helps keep me on my toes for getting timing right. The fact that the action is happening 30 to 100 yards away from my seat means practice with a longer lens.

Back in the days when I worked for the Independent Florida Alligator and before that doing yearbook photography at high school football games, I was able to work on the sidelines. I just don’t have that access at the moment.

So here are a couple of the better images I’ve captured over the past two weekends of attending the startlingly hot University of Florida Gator home games. I used my Nikon D2Xs and two lenses, a Nikkor 70-300m G and a Nikkor 70-200mm f/2.8 G VR. The 70-200mm produces cleaner images, which it should: it costs about twelve or thirteen times as much as the 70-300mm. The drawback is the smaller total size on sensor of the image when working at the maximum focal length, as I did. I also needed to use an aperture of f/9 or so on the 70-300mm to keep various lens faults in check, which meant bumping up the ISO on the camera to keep the shutter speed around 1/1000th of a second, and that introduces some issues in the image of its own. With the extra speed and better correction of the 70-200mm lens, I was able to shoot at ISOs between 200 and 400 using f/5 and f/5.6, and still have high very high shutter speeds.

With the 70-200mm VR lens:

With the 70-300mm G lens:

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Pelican in St. Petersburg

September 1st, 2010

Pelican in St. Pete

I really haven’t done that much to this image, but it looks almost like some of the work the grad student teaching under Wallace Wilson back in 1980 used to do. I can’t remember his name offhand, but I think his initials were “R.R.”. He would work on photos with a marker to outline regions of similar tone.

My process for this image was “crop”, “levels”, “curves”, “unsharp mask”, “scale”, and a small boost to “hue/saturation”.

Update: By request, the image as it appeared originally. The only thing I’ve done to it is “scale” via GIMP (Sinc/Lanczos). If I recall correctly, the gear was a Nikon D2Xs with a Tamron 17-50mm f/2.8 lens. It didn’t really need a whole lot of intervention, primarily the cropping to limit the visual elements.

Pelican in St. Pete

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Nikon D3s

October 16th, 2009

Nikon announced a new professional DSLR model, the D3s. This is a full-frame (FX) sensor with 12 megapixel resolution. It will take those at 9 frames per second. It will take 5.1 megapixel photos in “crop” mode at 11 frames per second. It has live view and will take HD video in 24 fps 720p format.

But the stunning difference is in sensor sensitivity. The standard ISO range goes from 200 to 12,800. In boost mode, it can go as low as 100, but on the high end it ends three stops of sensitivity, with an incredible high end of a bit over 100,000 ISO. The sample photos on the Nikon site show the results of up to 12,800 ISO, and it looks great. The noise does not look distracting at all.

Yeah, I want one. If anyone feels moved to drop one on me, just let me know. They are being initially offered at a retail price of about $5,200.

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A Couple of Stick Insects

October 16th, 2009

Stick insects in close formation.

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Theme Work

July 13th, 2009

I switched from a fixed-width theme to the Sancta Simplicitas (SS) theme. The primary reason is that I can use a larger photo size for inclusion in a post.

I picked SS as the theme for another reason: it is based on the Yahoo! YUI Grids CSS package.

Out of the box, it used a 240 pixel sidebar on the right. That wasn’t so hot for the reason that if you reduced the size of your browser, an image could be truncated by the right sidebar.

Changing the sidebar width and layout is as simple as changing a tag in the header.php file in the theme. Unfortunately, Yahoo! YUI Grids CSS doesn’t come with a 240 pixel left sidebar option. 180 pixels on the left is too small for the calendar view, and 300 pixels on the left is just too big. Fortunately, it has been extended by a web developer who likes symmetry in code, and that allowed me to set the layout to have a 240 pixel sidebar on the left. Now, if your browser window is too small, it will present a scrollbar to view the complete image as posted.

I doubt that I will have time to do much more with the theme until September.

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“Devil In Dover” Book Cover Photo

July 8th, 2009

Tammy Kitzmiller in press scrum after trial, 2005/11/04

This was one of the photos I took while attending the 2005 Kitzmiller et al. v. Dover Area School District trial in Harrisburg, Pennsylvania. In the middle of the press scrum, Tammy Kitzmiller (in the salmon sweater), the lead plaintiff, watches as her daughters answer a question from the reporters.

Lauri Lebo, a reporter for the York Daily Record, wrote a book, The Devil in Dover, about the case and her own experiences in reporting on it. Lauri had a philosophical difference of opinion with the management at the York Daily Record, and by the time the book was published, she was no longer working there. She had originally planned to use a photograph taken by a York Daily Record photographer the showed most of the press scrum on the courthouse steps. I’m pretty sure that the picture was taken by the fellow on the ladder:

KvD photographer who planned ahead.

The York Daily Record refused Lauri’s request for use of the photo for her book cover. Given that the print date was just a couple of weeks away, this put Lauri in a tight spot to come up with cover art on short notice. Lauri contacted Glenn Branch at NCSE, and Glenn reminded Lauri that I had a bunch of photos from the trial myself. Lauri and her editors picked the photo at the top to go on the dust jacket for the book.

The gear I used for the photos was a Fuji S2 Pro DSLR with a Tokina 12-24mm f/4 zoom lens. I went pretty light to the trial, with just the one lens, camera, and a flash.

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Gallery 21 Shot

June 24th, 2009

Laurie Hitzig framed

From 1982 to 1983, I worked at Media Image Photography in Gainesville, Florida. Randy Batista ran Media Image, and the space was shared with Gallery 21, run by Laurie Hitzig. Gallery 21 sold fine art poster prints and had shows of original works by North Florida artists. I had often done time exposure work, and I have a series of photos done in and around the Gallery 21 space. The one above features Laurie Hitzig in the frame, as it were.

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Gator Guard Photo

June 15th, 2009

UF Gator Guard 1981/01/27

The negative sleeve reads, “Gator Guard, 1/27/81″. I have stacks of negatives in glassine sleeves as a legacy from my job in college, which was as a staff photographer for the Independent Florida Alligator, the newspaper serving the University of Florida campus.

I recall doing my share of grip-and-grin pics and photos of visiting scholars and celebrities. But one thing that was consistently being provided by other staff photographers was “feature art”, the picture splashed on the page for no other reason than that it made people look at the paper twice. I remember just after lunch that day when the photo editor, Kim Kulish, caught me upstairs in the hall outside the darkroom and told me bluntly, “You will have feature art by 5.” OK, so he knew how to give people incentive. That still didn’t make it simple to actually deliver. Fortune favors the prepared, and I got over to campus.

Gator Guard is a drill team made up of ROTC students, and they happened to be out practicing. I have three negatives on the strip in the sleeve, the first an uninspired and uninspiring long shot down the line of students. As I recall, they did some fairly typical march maneuvers, but then they ended up in a rough circle around the drill leader, suddenly flipping their bayonet-tipped drill rifles inward, stopping just a few inches from the drill leader’s face. That was different, and I got a photo, but the angle was such that I could only see about three of the bayonets. I got a better angle on the group as they repeated the drill, and got the third photo, the one shown above. So I did actually have something for Kim when I got back to the Alligator, and they ran the shot and put it out on the AP Wire, making it the first photo of mine to get broad distribution.

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