Posts Tagged ‘K20D

03
Aug
09

More experiments with film; scanning and stereo!

Some time ago my Dad gave me a Kodak Stereo Camera as a novelty from one of his antique store forays. I’d wondered if it still worked, so I took it to the Lethbridge airshow. With lots of aircraft on static display, it would be a good place to try it out. It has some very limited settings for aperture and shutter speed, and focus is by guesswork, using a distance scale; the viewfinder is actually the square window between the lenses, just above the green bubble level.

Kodak Stereo Camera

Kodak Stereo Camera

Originally slide film would have been sent to Kodak and they would have cut and mounted the left and right images in cardboard to make them easy to use.  Keep this in mind if you have one of these cameras and would like to try it out… starting with slide film will save you a TON of time later on. All the unused film I have handy is 35mm for prints; not slides… had I known how much hassle I was about to cause myself I would have sprung for a roll of slide film for sure.

For starters, the images from each lens are almost square, and quite small. They are interleaved 3:1 on the negative, and that was the first hurdle. The photo lab couldn’t print or scan them because of the non-standard size… the tech tried, but the spacing didn’t match the standard mask sizes.

That left me on my own; I could go to a pro lab and explain to them what I wanted, and it would have cost a fortune in labour… or I could buy my own film scanner – but still have the same problems with needing non-standard image masks and having to realign every frame. What I ended up doing – photographing the negatives – was far more work, but the end results are (almost) worth it. If you get close enough to the screen and let your eyes cross the images below should fuse to a single 3D image!

Final result: A left+right image pair. Click for a larger size.

Final result: A left+right image pair. Click for a larger size.

After some failed experiments simply photographing the negatives against window light, I mounted a flash on one end of a 4 foot long bit of wood, my trusty K20D with a Tamron 70-300mm macro on the other end. One thing I had read about photographing negatives is that the orange cast of the negative can be best dealt with by gelling the lightsource to blue/cyan. I picked a strong blue gel from my freebie pack of Lee filters, and my first guess was pretty good (I think it’s #200 – Double C.T. Blue). I also put four layers of a white plastic bag in front of the flash as diffuser.

I mounted the negative at roughly the minimum focus distance. I used a folding cardboard slide holder taped against the bottom of a shoebox, with an oversized hole cut in the box. The flash was a few inches back from this, firing into the box to limit light spill. The camera was set to ISO 100 and f/11. Because of the spacing of the flash and camera I used some cheap eBay triggers; to keep the sync right I set it to 1/30 second shutter. The hotshoe trigger also gave me a handy mount for the flash.

The steps of transforming the negative to positive required some trial and error. These links should help:

http://photo.net/digital-darkroom-forum/00NFyc

http://www.velocityreviews.com/forums/t248544-digital-slr-as-slidenegative-scanner.html (scroll down to Dave Martindale’s post)

http://www.pbase.com/sinoline/35mm_slide__film_copy

A negative, lit from behind with a blue gelled flash.

Starting from the image above, here are my steps using the GIMP (Photoshop should work too):

1. Switch to the color picker, and choose an area of neutral orange (the sprocket holes, for example) or something known to be grey (like a cargo plane).

2. Add a new layer using this new foreground color

3. Invert the new layer from orange-pink to blueish. I ended up editing this blue tint to be Red: 0, Blue:255, Green:175, after experimentation. A different filter on the flash will mean these values will change!

4. Set the new layer to ‘Overlay’ mode. This should improve the color range, but it’s still a negative image.

5. Merge the new layer down (you should have only one layer now)

6. Invert the layer; it won’t be quite right yet, but it should be close

7. Edit the curves for red, green and blue individually; I just selected the midpoint and dragged it up or down very slightly. Also edit the brightness and contrast to taste.

Hope this helps anyone looking to scan or copy old negatives with their digital camera. For the money a good flatbed scanner, with masks for 35mm film is going to save you a lot of time.

01
Aug
09

Alberta International Airshow

Last weekend we snuck down to the city of Lethbridge, Alberta, for the ‘Alberta International Airshow’. It’s not as big an affair as the old airshows at the old base at Namao (Edmonton), but the more relaxed atmosphere meant lots of space up at the fence to get close to the action… not that you needed to be very close with a unexpected treat like this old girl:

B-52

B-52 (in black and white, for a vintage feel)

All of these shots were done with the Pentax K10D and K20D.  The K10D pretty much had the 16-45mm lens on it all day; the K20D had either a 50-135mm f/2.8 or Tamron 70-300mm (sometimes with a 2x TC on it). By having two bodies with different focal lengths I was able to switch quickly, and by pairing the K20D with the tele’s I could use higher ISO’s that the Tamron needs (f/8 for best sharpness) without sacrificing shutter speed. The day was pretty warm and hazy; I’ve color corrected the sky in these back to a better shade of blue, and in some cases have done additional color treatments to bring out some extra pop in the shots.

Easily the most photogenic aircraft was this silver P-51 Mustang; the nearly chrome finish really makes it stand out. Turning up the ‘Clarity’ slider in Lightroom also added a whole lot of punch. I wish I had selected a slightly longer exposure time to let the prop blur more; the plane was actually turning in front of the crowd so I’ll have to settle for this:

P-51

P-51

This shot was chosen from several frames for the pleasing clouds and clean ground under it. The other shots had ground antennas, trucks, and ground crew visible. Ick!

P-51

P-51

And who can resist a nice sharp shot with no distractions?

P-51

P-51

The Mustang also flew a bit with a Harvard trainer. They trotted out a number of older planes to celebrate 2009 as ‘100 Years of Flight’ in Canada. This particular shot is a tight crop to isolate the aircraft, but also leave in a nice cloud in the distance.

Mustang and Harvard

Mustang and Harvard

A nice young lady from Montreal gave us a wing-walking show; she starts off by lying in the criss-crossed cables between the wings for take-off, then clambers up to the top wing for the show.  The sun wasn’t at a perfect angle for shooting most of the action, so the best shots were of the aircraft from crowd-left. For most of the of the show the sun was directly across the runway from the crowd fence, making for pretty uninspired shots; when a plane did a dive and was lit pleasingly the shots have much better color.

Wing Walker

Wing Walker

A pleasant suprise was the show from the ‘MiG Fury Fighters’, which was entertaining. They had an old T2 trainer, and did a simulated dogfight with a MiG 15 and MiG 17. Nice. They also did several ‘beauty passes’, so I’m sure there are a lot of folks with shots like this one:

MiG Fury Fighteres: T2, MiG-15, MiG-17

MiG Fury Fighters: T2, MiG-15, MiG-17

Another suprise is that they could afford to take a CF-18 and paint it up in non-combat colors for the airshow circuit this year. I honestly didn’t think we had enough of them to spare… but I’m not complaining… flat grey fighters are pretty boring! For this shot I wanted the water vapour that get squeezed out of the air during high-G manouvers.

CF-18

CF-18

Not as clear, here is a similar effect from another angle:

CF-18

CF-18

I also shot several rounds at 22 frames per second (the K20D has a super-duper burst mode that nobody seems to talk about much) so I could capture the Snowbirds doing their close-pass manouvers. Here is a particularly interesting 4 plane cross… I’d love to have shot this from the second seat of one of these planes… they used to be trainers, so they sit two-abreast.

Snowbirds

Snowbirds

All in all a great show; I think this is one I’ll do again next summer, although I’ll bring more water and more ice next time. In total I shot about 20GB of images; what you see is just the fraction that I’ve looked at so far.

For memory cards I had a 16GB SDHC card in the K20D. It meant less changing cards, although I still used a Hyperdrive Space for making backups, and dumping the 2GB card in the K10D (my 4GB cards had disappeared in my bag for the day!). I can’t rave enough about the Hyperdrive; I upgraded the hard disk from 40GB to 250GB; plenty for vacations or extended shoot assignments. The built-in battery is enough for about 40GB worth of backups, and you can buy or build an external battery pack for cheap. It also charges from USB or AC, and I’ve noticed a lot of USB power in airliners, rental cars, and hotel business centers, so power is never an issue.

13
Jul
09

A Tale of Three Umbrellas and a Gel

I was just reviewing some shots of Kasandra (one was poster earlier). She is a make up artist that did double-duty as model on a recent shoot, and what a gem she is:

Pentax K20D, ISO 400 ,f/9.5, 1/90 sec, 135 mm, smc Pentax 50-135mm f/2.8

I had been experimenting with white umbrellas (reflective, not shoot through), and found I really prefer the light over a harder reflective material, like silver.

This shoot would be a chance to try out a lighting arrangement that normally would need a bunch of reflector cards, softboxes, and such, but since we were shooting on location I wanted to pack a bit lighter, and keep the setup time down to a minimum.

What I decided on was a variation of butterfly lighting. I knew she would be sitting, and these would be head-and-shouler shots to show off a necklace, so I placed a chair about 6′ from a scrap of seamless background paper. The room was too narrow for a a full 10′ wide roll of seamless, so I put up the portable background stands with only two lengths in the horizontal crossbar, instead of all three.

For light, I put two umbrellas up high and in front of the model, pointing about 45° down. In these shots the light stands are just barely out-of-frame to the left and right. I found that the shadow under her chin was too dark, and a small 2′ x 3′ white foamcore didn’t help enough.

To give a more even light I put my most controllable light, an Alien Bees ABR-800 (that’s right, a ringflash), on it’s umbrealla adapter (which is a curse and should be redesigned…), and put this third white umbrella on the floor, pointing up. No stand, just a pile of black scrim fabric under it, to give it the right angle. Which by no coincidence was 45° up. It was so close to her that she could touch it with her feet.

The main light in the first umbrella (on image-right) was an old hot-shoe flash on full power. It’s an old Sunpak auto 28, but for whatever reason it has a really short recycle time, making it perfect for ‘strobist’ style use.

For the fill umbrella on image-left, a second hotshoe flash, I chose my new Pentax 360. It has good manual control, so I turned it down to about 1/4 to nearly match the main, but not quite, to give some shape to her face.

The Alien Bees is quite a powerful light, so I kept it down to 1/32 – 1/16 territorry. All of these lights were fired from ebay style radio triggers, which aren’t bad for this kind of close range work. And the new ones use AAA batteries in the receivers, so rechargables are now an option.

The resulting image (above) was pretty darn good, in terms of matching my vision. It could be developed has high-key with more juice, but really I was going for a slightly lower tone and DR in the main colors to make it more suitable for print. If you look at the exposure data you’ll notice this was done at ISO 400; this is because the main was already at full power, and couldn’t pump out more light.  I could have set up a heavier stand and put the ABR-800 up in the air as the main, but balancing the output of that monster of a light with a puny little hotshoe flash would mean I would have just turned it down anyway. I could also have opened up from f/9.5 to f/8, but if you look closely enough you’ll see that at f/8 I would have to start making trade-offs in focus; the back of her pony-tail is already starting to blur; and my focus point was either the corner of her eye or her hairline around her ear.

On and off throughout the shoot I added a fourth light, right behind her head; it was sometimes pointed forward, to give her a nice rim light, but that also showed too many fine / stray hairs. Toward the end of the shoot I decided to gel this strobe and point it at the background; I think this color was a Lee Filter ‘Bastard Pink’, and the resulting images from the last 10 minutes really came to life:

Pentax K20D, ISO 400 ,f/11, 1/90 sec, 108 mm, smc Pentax 50-135mm f/2.8

The effect of the gel on the white background paper is remarkable; and the hue of the light is very close to her lipstick shade. I think when I looked in the LCD after this shot I told her she looked like the color of a sorbet!

I hope this inspires you to play around more with inexpensive lighting; I could have substituted a cheaper light for the under-fill and claimed this was done for $200 in gear (three $20 lights, three $20 umbrellas, two $20  stands with hotshoe/umbrella brackets, and two pairs of $20 ebay trigger sets.).

Maybe I should change my tagline to ‘the $20 strobist’…

12
Jul
09

High Dynamic Range – Tripod -vs- Software

I used to have a quiet chuckle to myself when I saw someone hiking with a tripod lashed to their backpack.

Well, turns out there still IS a place for that archaic camera support… the HDR (and maybe Panoramas… next post…)

Well, maybe.

It took me nearly an hour of cropping, rotating, tweaking, and otherwise fiddling to get three exposures to line up to produce this small sample shot, using an older version of Photomatix (2.3.2):

2000203876

Pentax K20D, ISO 200, f/8, 50mm, 3 images @ 1/90, 1/180 and 1/350 combined.

Not bad; I was using really low resolution jpegs just to get a feel for the process, so it’s not as sharp as it could be. But all the tweaking to get the images to line up really bugged me, so I checked for a newer version of Photomatix.

Turns out the new version is really pretty good, and even has an alignment mode that works on matching common features. I chose another image set to see how long it would take, and how well it would align:

Behind Chester LakePentax K20D, ISO 200, f/22 (I know… I know…), 16mm (smc Pentax 16-45 F4 ED AL), @ 1/30, 1/15 and 1/8 sec

This image took the new version of Photomatix seconds to process. I spent a few minutes fiddling with various slider controls that adjust the various tone mapping parameters, but Holy Cow, the alignment is perfect. I did spend a minute in the GIMP to clean up a couple of dust spots in the sky, but from start to finish the results are as good as you could hope for, even with a tripod.

And one more little plug for Pentax Shake Reduction… look at the exposure info again… the brightest shot was at 1/8 second, resting on the top of a trekking pole. Nice. I should have opened it up to f/11; I thought it was f/16 but I think my thumb slipped when I was balancing the camera on the top of the handgrip of the pole and it got cranked up a notch.

Perhaps if the only goal of the hike was to make perfect images – then I’d take the tripod, but for casual use like this… Photomatix is the way to go.




Afterexposure has moved!

Click here for the new page!

Tweets