CalArti

There are few places I’d rather be than on the Oak Savanna when the coreopsis is blooming. For a few days, maybe even a week, the sandy barrens seem to be adorned with gold.

Those June days seem far off, sitting here on a cold, damp, March 31 – but they will be here before you know it.

This is another shot from the archives, taken last June. Im not entirely sure why I passed it by while editing photos last summer. I am sure that a the time this immature Blue Dasher dragonfly was, metaphorically, sitting in butter.

I continue to go over RAW files from last summer, looking for interesting shots that I may have missed. There’s a lot of files to go through!

This image was set aside because I didn’t want to post it till I identified the subject. OK - I give up. I have no idea what this little creature is. They were quite abundant along the edge of my favorite seasonal marsh in late June and early July. The insect or spider was about 1/4th of inch tall. This one is on a wild raspberry leaf.

I’m not even sure if those are 8 legs or 6 poking out of that shell. If you can offer a clue as to the ID, please send a feedback!

UPDATE - April 1, 2009: The intrepid naturalists at the Kalamazoo Nature Center, with a little help from an MSU entomologist, identified this as a casebearer beetle – family Chrysomelidae, sub family Cryptocephalinae. Mystery solved!

The really big piles of snow may still be melting, but spring is definitely in the air. And with spring comes the wildflowers. The counties in the very southwest corner of Michigan – Cass, Berrien, and St. Joseph – are home to some of the finest spring woodland wildflowers. On Sunday, I made a quick exploratory trip to the Dowagiac woods, to see how things are progressing.

The late March woods were still pretty bleak. A few sprigs of wild garlic poked through the brown leaves that carpeted the ground. In some places, Harbinger of Spring had started to bloom – tiny white flowers. Here and there hepatica leaves were starting to appear.

That was 4 days ago – my guess is that in a week or so, depending on the weather, the hepatica should be coming out in full force.

Despite recent flood warnings due to heavy rain combined with snow melt, the woods were fairly dry. The Dowagiac River runs along the east edge of the woods, behind a short levee. The levee has cuts in it to allow high water to flood into the woods. On the day I was there water was draining out of the flooded areas and back into the river. While a lot of the ground was muck, the trail and the areas nearby were pretty firm.

One pleasant surprise was to hear a great cacophony of frogs near the flood ponds. Frogs are such a rarity anymore; it’s encouraging to hear large numbers of them singing.

I took the old Kodak Retina 1a camera that I try to keep in my coat pocket along for the walk, and here’s a snap of the flood area:

I think that place is “Crescent Pond” - I’d have to chck the maps to be sure, but it looks like a crescent.

This shot was taken on my very last expired roll of 35mm Plus-X (the “old” version). Since the Retina has no focusing aid and no built in meter, focus and exposure were determined by dead reckoning. The film was processed in Rodinal, 1:50, which really makes the Plus-X grain sing.

The traditional (for me) honey bee in a crocus shot. Rather late this year, coming in the last week of March…

Two years ago I put together a little comparison of image quality between a medium format film scan and a capture form a digital SLR. (You can see that original comparison here.)

Since then I’ve upgraded both my digital SLR and my film scanner, so it seems like it’s time to perform the comparison again. In 2006 I was shooting with a 6 megapixel DSLR (Pentax *ist-D), these days I’m shooting with a 10 megapixel K10D. Back then I scanned medium format film at 3200 dpi with and Epson 3200, these days I scan at 6400 dpi with an Epson V500.

To facilitate this comparison, I shot the same scene with both a digital SLR and medium format camera, and then processed the respective images.

The medium format camera was a venerable Pentax 6x7 with an SMC 67 55mm f4 wide angle lens. The film used was Kodak Portra VC, 160 ISO. The negative was scanned on an Epson V500 - a mid-range consumer flatbed scanner. Digital ICE was on while scanning, to take care of dust. (This may have some impact on sharpness and detail in the scan.)

The digital capture was taken with a ten megapixel Pentax K10d with a 16-45mm SMC-ED DA zoom lens. Both shots were taken at f16. The camera ISO was 400. There is a slight difference in the angle of view and framing between the two shots, which is the result of setting up to separate tripods and not lining things up perfectly. The images were taken last fall – I’m just now getting around to looking at this.

So let’s take a look at a scene taken with the two platforms, and see how they compare…

First, let’s consider the size of the image. Scanning a 6x7 cm negative at 6400 dpi produces a really huge digital file. Here’s an image that illustrates that:

This illustration shows the relative size of a 6400 dpi medium format scan, compared to a 10 megapixel digital capture (the smaller inset box) and the same digital capture opened to 25.3 megapixels in Adobe Camera Raw. Yes – these is a very substantial difference in size!

The film scan is roughly 17,500 x 13,700 pixels in size – just under 240 megapixels in total. At 300 dpi, the full sized film scan would print at 58 x 45 inches. By comparison, the larger of the digital captures – which, of course, has been up-sampled in Adobe Camera Raw – is 6,114 x 4,113 pixels. That’s just over 25 megapixels and at 300 dpi would print at 20 x 14 inches.

So without a doubt, the medium format scans are larger. But how much more information is in that larger image? After all, digital gets a real boost due to its superior ability to produce sharp edges (acutance) and much lower noise / grain levels.

Comparing detail, and showing it on the web, poses a bit of a challenge. I decided to take two approaches. In one case I up-sampled the digital image to make it equivalent to the film scan. This is a bit unfair to the digital image, since it pushes it to sizes never intended for it. In the other case I down-sampled the medium format scan to make it the same size as the digital capture. This is a bit unfair to the film scan, since it basically discards and ignores one of it’s main advantages – the huge image size that it supports.

Here are the two comparisons. In this case, I up-sampled the digital image to be the same size as the film scan. To do this, I first opened the image at the 25.3 megapixel size in Adobe Camera Raw version 5.3. I then up-sampled the image in Photoshop, using the Bicubic smoother option.

Here is an “actual pixel” sample from the medium format film scan:

Here’s the same portion of the image, at actual pixels of the up-sampled digital capture:

Here’s a second example – film first:

Now digital –

What can we conclude form this? Clearly, the medium format scans hold a lot more detail. In fact, disregarding comparisons, there is simply an impressive amount of detail in the medium format film scan. There’s no doubt that if you want to print large, going with medium format is a much better choice.

Now here is a comparison of a down-sampled film scan and a 25.3 megapixel digital capture. The digital capture has still been up-sampled within camera RAW, since comes from a 10 megapixel sensor. The film image was down-sampled using the Bicubic sharper method. First the film sample:

Now digital:

The differences here are less pronounced. There is clearly superior detail in the film scan, especially in the brambly branches and twigs towards the middle bottom of the frame, but the difference is not as marked. A bit of noise from the grain is evident in the film sample. To my eye, the leaves in the film capture have a much more realistic look to them, due to the better level of detail. But I’m not sure that much difference would be apparent in a print.

I think the images speak for themselves, and you can draw your own conclusions. One thing that I cannot demonstrate on the computer screen is the advantage that medium format gains by being able to print at a higher resolution. I’ve made a few 16 x 22 inch prints of this image from the medium format scan. The native scan is so large I print it at 720 dpi, and even then need to down-sample the image by 15% to get it to fit. The 720 dpi print really captures the great detail in this shot, and makes for a ver high quality print.

As I’ve noted in earlier essays - like Stuff Per Pixel and Film Vs. Digital Photography – digital has a long way to go before it can achieve the level of resolution and detail that film offers. As I’ve also noted before, a lot of subjects do not have a high level of visual detail in them. For things like close-ups, architectural shots, portraits, etc., the advantages of digital probably outweigh the superior detail and resolution that medium format can deliver.

But when detail is important, medium format really shines. Digital conitnually advances, and in time I’m sure someday I’ll give up on film. But for now, medium format film, even when scanned on a modest scanner, still outperforms digital for detail-rich shots of scrubby, brushy, woods.

Several weeks ago I was wandering around eBay, looking for bargains in 120 roll film. I didn’t find any, but the search led me to look at cameras, and of course that led to trouble…

A particular type of camera really caught my fancy – antique (or classic) folding medium format rangefinders. A couple of years ago a friend gave me an old Kodak Retina-A folding rangefinder, and I really fell in love with it. The only interesting shot that I’ve managed to take with it is this one from Chicago’s Millennium Park:

The idea of packing a medium format camera that, once folded up, was only a little larger than the Retina A was just too compelling. Thanks to the Retina A I’m accustomed to zone focusing, so even working with that constraint is acceptable.

After a few weeks of searching and researching, a great camera came along on eBay – an Agfa Isolette III.

The specimen I bought looked like a beauty. The bellows looked to be pristine (turns out they aren’t) and the lens and camera overall looked very clean (which they are.) The lens focusing mechanism works perfectly.

Shortly after the Isolette arrived, I hightailed it the graveyard across the way to see how it worked. The graveyard is my honored testing ground for new cameras and lenses – the square stones give a good sense of how rectilinear the lens may be, and the rolling hills and trees give abundant opportunity to test a lens under different circumstances.

A roll of Agfa APX 400 was used for this test. The first frame was sacrificed to test the bellows – I just advanced the film, opened up the camera, and held it out in the sunlight for a while. After that I just wandered around a bit, and shot whatever seemed interesting.

Getting home, I souped the APX 400 in Rodinal 1:50. Pulling the film out of the tank, I was disappointed to see that the first frame was not blank I hoped. Despite appearances, the bellows is indeed fraught with pinhole leaks. I later examined the bellows in a dark closet with a very bright flashlight, and confirmed this myself – the leaks are pinholes, but definitely there.

Despite the light leaks, the images I took were not ruined. In fact, the ones where the film was quickly advanced shoe very little impact from the pinhole leaks. Studying these shots reveals a very sharp and contrasty 6 x 6 cm negative – which works for me.

So, the camera will have to go off to get re-bellowed. But when it’s refurbished it will be a great addition to my digital camera bag. I’ve tried carrying TLR’s with me, but they take up too much space in the camera bag. The folding rangefinder and a couple of rolls of film will fit comfortably into my digital camera bag, and it will be great to be able to switch over to MF film at any time.

Here’s one shot from the cemetery – yah, I played around with the curves to give it a bit of a solarized feel:

After a bit of dawdling, I finally got around to downloading Photoshop CS4. Part of my reason for procrastinating with this upgrade is that I had heard about problems and limitations of running CS4 on 64 bit Windows XP Pro (the x64 edition.)

In my case, the rumors turned out to be completely wrong. I downloaded a trial version this morning and applied the registry tweak described on Adobes’s site (here). I then checked the “Enable OpenGL Drawing” box, found within Photoshop under the Preferences -> Performance tab. And voila – the zoom and rotate tools work like a charm. I can’t say that these tools are going to change my life, but the bird’s eye zoom looks like it will be very handy when doing detailed adjustments.

I was particularly happy to see that the GPU features worked on my x64 machine. It’s just my subjective impression, but CS4 actually seems to be a bit faster than CS3 – which is nice. FWIW – my rather aging PC is an Athlon 64 x2 4200 with 4 gigs of ram and a GeForce 7600gt video card. Definitely not a powerhouse.

I went back to a couple of RAW files I had passed over last summer, and ran them through the CS4 camera raw. It would be easy to not even notice the adjustment brush and the gradient filter tucked into Camera Raw – but they are worthwhile enhancements.

The interface is somewhat different – I can’t say that it strikes me as particularly better or worse. All morning I have been accidentally closing the whole application when I want to just close out a file… “Oh – the little ‘x’ is over there now, not up here…” But heck, it’s only been a few hours and by tomorrow the new interface will be old already.

Overall this was a worthwile upgrade and after a couple of hours of playing around I bought a serial number from Adobe. Here’s one of the shots from last summer, processed in CS4:

Update, March 12, 2009: After a few days of running it through its paces, I’m happy to say that 64 bit Photoshop is still working fine on Win Xp x64. The opengl effects are a lot of fun, and they’ve been working flawlessly – in the 64 bit version of the program. More important – the 64 bit version of Photoshop really sails through tasks. Even with large files, it is very quick and responsive – and I’m only giving it 2.75 gigs to work with.

The same I not true with the 32 bit version of Photoshop CS4. Here images break up, go blank in spaces, and even come together all akimbo after successive zooms and rotations. The situation is made much worse when a lot of images are loaded. As an experiment I loaded 6 different images, all in the 200 – 250 megabyte size - and ran them through a series of simple zooms, flips, and rotations. Everything worked flawlessly in the 64 bit version of PS, but in the 32 bit version the images quickly looked like a mess, with mis-rotated parts and blank areas. I should emphasize “looked like” a mess because the images themselves proved to be fine – only the display was garbled. I assume this must be a bug in the 32 bit video drivers for my video card.

Since I plan to work in the 64 bit version most of the time, this isn’t a major issue. I stumbled into it while scanning some prints today – the scanner drivers only work in the 32 bit version of the program.

I heard a bird sing this morning, an hour or so before dawn. That is a sure sign that spring is coming. Of course, the days are longer and the snow banks are steadily shrinking. Another season of snow crystal photography is drawing to a close.

A few new shots taken in late February are up in the Photoblog. In past years I’ve gotten one or twp snow crystal shots as late as early April – and the weather is certainly getting unpredictable so who knows. But early March is usually the end of the season.