Betterlight scanning back shot, low light exposure

A few threads back, there were some questions about using the Betterlight in low light. I was out at Alcatraz for an evening photo workshop. The light had faded to the point I switched to film at around 5:30. The sun was setting about 6:15 and I thought, what the heck, I'd try a low-light exposure with the scanning back. Because it is so finely detailed, you need to view at least a 2000 pixel wide jpeg to even begin to get an idea of how good the 36" wide print is, so below is a link to a 2000 pixel jpeg. To put the print detail in perspective, there are two American flags on top of buildings just slightly left of center and in the 36" print, you can clearly see the stripes and blue patch for the stars (but not the stars themselves). Of course in the print, the lighted "Ghiardelli" sign is crisp:

http://jack.cameraphile.org/gallery/view_photo.php?full=1&set_albumName=album10&id=sunsetskyline2

Comments welcome,

Very impressive.

I wonder whether you could keep scanning and overlay your images to decrease noise, increase resolution and DR?

Asher

Very cool, Jack. How long did the scan take?

Aligning multiple 6000x8000 pixel, 16-bit images is probelmatic even with a really high-end computer with lots of ram. The other thing is the light is changing so rapidly as the sun is setting that it probably is not practical for this type of shot anyway. (As it is, I probably lost half a stop of light from right to left as this scan was being done -- it does not show since the nature of the scan itself renders that loss over the width of the image as a smooth gradient.)

As for DR, the Betterlight can capture 11 stops. The software has a live histogram and in this image there was only about 5 stops total usable DR to begin with, so nothing to increase by using multiple scans. And 5 stops in a large colorspace is not going to stress image data

The "better" solution for me would have been to set up my pano adapter and have scanned this with a 300mm lens instead of doing the straight shot with my 120mm lens. By so doing, I would have gained a huge amount of resolution -- probably on the order of 20,000 pixels wide instead of the 8,000 in this image -- while keeping the overall aspect ratio constant. The truth is I did not think this image would turn out so I did not even consider setting up the pano head for it, though I had it with me. The other issue is a 20,000 pixel wide image would have taken 2.5x as long to scan, also a problem as the sun is setting.

Cheers,

Andy Biggs said:

Very cool, Jack. How long did the scan take?

Click to expand...

Thanks Andy! Total scan time was about 90 seconds using f8 and ISO 2000.

FWIW, the other significant issue I faced is the wind was blowing about 30 MPH during this shot. I had to hover over the camera with my jacket spread wide and act as a wind-break for the camera during the scan

Jack_Flesher said:

Thanks Andy! Total scan time was about 90 seconds using f8 and ISO 2000.

FWIW, the other significant issue I faced is the wind was blowing about 30 MPH during this shot. I had to hover over the camera with my jacket spread wide and act as a wind-break for the camera during the scan

Click to expand...

Simply amazing. I wish I could use this type of equipment in Africa, but too many moving objects in the frame prevent me from doing so.

How about the new Seitz scanning back will do that in 2 seconds!

So what if a few animals move! That will look good, The other animals won't!

Asher

P.S. Do you want me to send it UPS or FedEx?

that will work, but I didn't hear good things about the sample prints from Germany a few weeks ago. I hope it will have good image quality!!

Any camera that can scan that much linear pixel spread that fast HAS to use short line times and thus extremely high ISO to make it happen. That in turn means extreme noise which in turn means extreme noise reduction algorithms, which in turn generally mean loss of detail. That being said, the loss of detail may only take that Seitz scan down to the quality of say MF film, which still isn't too shabby. But the Bettelright scan is closer to what one can obtain when shooting 8x10 film and drum-scanning, and certainly better than what can be obtained when scanning 4x5 film.

Cheers,