How does Better Light calculate MP count?

[sanking]

Megapixels aren't everything, even though it's far from state of the art, my Phase One Studio kit with it's lowly 9mp images still look amazing printed double truck.

What does "printed double truck" mean?

Sandy King

[jkuska]

Many people naively make this mistake without being familiar with Better Light systems and thoroughly thinking it through. The equation is not merely 8000x10660, it's 3x8000x10660 in normal mode and 3x8000x15990 in enhanced mode. You are not simply taking one picture every time you make a scan, you are taking 3 pictures. There are not just 8000 sensors scanning the scene, there are 24,000 sensors, three rows of 8000 sensors each, one row for each primary color, RGB. This is why Better Light provide superior results over instant capture cameras which only record 1/3 of the color data for each point in the scene and then have to interpolate every image up 300% before it can be displayed or printed. Better Light captures the true RGB value for every point in the scene with no interpolation (& no sharpening, no compression, no anti-moire or anti-aliasing algorithms either - just pure, clean accurate, high information density captures).

Since Better Light captures 3 pictures simultaneously (1 each for red, green & blue – RGB), each measuring 8000x10600 in normal mode then this becomes 3x8000x10600=254.4 megapixels per capture in NORMAL mode.

And then in enhanced mode this becomes 3x8000x15990=383.76 megapixels per capture.

Now in enhanced mode to maintain the correct proportion in the scene Better Light has to interpolate those 8000 sensors (pixels) up to 12000, which becomes a 150% interpolation in the final image, only half the interpolation as used in all instant capture and only in the one axis of the image. Thus even the ENHANCED images are still far superior to any instant capture image and superior to any resizing up that could be done in Photoshop. Only the fussiest of archivist, scholars or academicians object to this modest degree of interpolation and most folks agree it is undetectable.

I hope the proceeding is clear but in any case it is all restated here on Better Lights website as the first topic:
http://www.betterlight.com/faq_sales.html

[jkuska]

What does "printed double truck" mean?

Sandy King

2 pages up, a double spread, not just 8½x11 but 11x17

[Gordon Moat]

That makes sense.

In the BL literature it is noted that at a print size of 20" X 26.7" the resolution would be 300 spi. Since the sensor size is 72mm X 96mm (2.8" X 3.78") a print that size represents about a 7X magnification, which suggests effective resolution of around 2000 ppi, which would only be about 40 lp/mm. That sounds low to me.

Sandy King

It might help to know their pixel cell site dimension, and then that might equate better to the optical resolution (not file sizes). Some of the Better Light literature reminds me of Foveon for some reason. Also, somewhat related, here is an article I ran across recently the discusses pixel sizes and optical resolutions:

http://www.vision-systems.com/displa...es-and-Sensors

I do think the lack of Bayer patterning could improve that, though light transmittance is still affected by colour filtration over each pixel cell site. The other factor would be the dead zone between pixel cell sites, though determining that on the Better Light scan backs is difficult.

Ciao!

Gordon Moat Photography

[jkuska]

There was some discussion in another thread today about Better Light scanning backs. Never having used one of these I looked at the product line and came away confused about how total MP count is determined...

...Question, how do you get 144 MP and 216 MP from a scan of 6000X8000 pixels? I would have calculated this as 48 MP for both backs. Are the higher figures interpolated resolution?

Sandy King

Many people naively make this mistake without being familiar with Better Light systems and thoroughly thinking it through. The equation is not merely 8000x10660, it's 3x8000x10660 in normal mode and 3x8000x15990 in enhanced mode for the Super 8. You are not simply taking one picture every time you make a scan, you are taking 3 pictures. There are not just 8000 sensors scanning the scene, there are 24,000 sensors, three rows of 8000 sensors each, one row for each primary color, RGB. This is why BL provides superior results over instant capture cameras which only record 1/3 of the color data for each point in the scene and then have to interpolate every image up 300% before it can be displayed or printed - not to mention all the other algorithms at work reprocessing and stepping on all the data in so many ways. BL captures the true RGB value for every point in the scene with no interpolation (and no compression, no sharpening, no anti-moire, no anti-aliasing algorithms either - just pure, clean, accurate, high information density files).

Since BL captures 3 pictures simultaneously (1 each for red, green & blue – RGB), each measuring 8000x10600 in normal mode then this becomes 3x8000x10600=254.4 megapixels per capture in NORMAL mode. Then in enhanced mode this becomes 3x8000x15990=383.76 megapixels per capture.

Now in enhanced mode to maintain the correct proportion in the scene BL does have to interpolate those 8000 sensors (pixels) up to 12000, which becomes a 150% interpolation in the final image, only half the interpolation as used in all instant capture and only in the one axis of the image. Thus even ENHANCED images are still far superior to any instant capture image and superior to any resizing up that could be done in Photoshop. Only the fussiest of archivist, scholars or academicians don't care for any enhancement but nobody ever really detects this relatively low level.

For the Super 6 this becomes 3x6000x8000=144mp in normal mode or 3x6000x12000=216mp in enhanced mode.

I hope the proceeding is clear but in any case it is restated here on the BL website as the first topic:
http://www.betterlight.com/faq_sales.html

[jkuska]

Seriously... A flatbed scan of a negative could get near that at a substantially lower cost, and you could use an instantaneous exposure! Step up to a drum scan and there's no comparison. Especially at 8x10.

BL backs are effectively flatbed scanners that have been redesigned to fit into a form factor similar to the Polaroid 545 back so that they may be used in basically any 4x5 view camera ;-)

[jkuska]

It might help to know their pixel cell site dimension, and then that might equate better to the optical resolution (not file sizes). Some of the Better Light literature reminds me of Foveon for some reason. Also, somewhat related, here is an article I ran across recently the discusses pixel sizes and optical resolutions:

http://www.vision-systems.com/displa...es-and-Sensors

I do think the lack of Bayer patterning could improve that, though light transmittance is still affected by colour filtration over each pixel cell site. The other factor would be the dead zone between pixel cell sites, though determining that on the Better Light scan backs is difficult.

Ciao!

Gordon Moat Photography

72mm/6000=a 12 micon sensor size for the 6K and 72mm/8000=a 9 micron sensor size for the 8K systems. At a 1:1 repro ratio (life size on the imaging plane) with the Super 6K this equals 2116 ppi or 1058 line pairs per inch or about 42 line pairs per mm and with the Super 8K this equals 2822 ppi or 1411 line pairs per inch or about 56 line pairs per mm. It should be noted that LF lenses use a LOT of glass and project a very large image circle to cover all possible camera movements and consequently large format have only diminishing returns to be gained through redesign. Smaller format lenses mostly only cover a fixed and small image area using much less glass so could realize greater gains through redesign. If BL made, for instance, a Super 14K, there is no LF lens that could deliver that level of detail at the imaging plane so while you would have more pixels you would NOT have more detail.

[jkuska]

They're pulling the same marketing BS as Sigma did with their Foveon sensors, and tripling the effective MP count since each photosite location samples R, G, and B. But you're not going to get 3x the resolution from one of these backs as you would from a Bayer sensor with the same number of photosite locations. The real world gain is in the 25-50% range.

It's is NOT BS, it is the industry standard and it is REAL.

[jkuska]

What does "printed double truck" mean?

Sandy King

PS... Hi Sandy... it's Jerry the carbon printer and former owner of the long defunct Limited Edition Photographics

[Ben Syverson]

BL backs are effectively flatbed scanners that have been redesigned to fit into a form factor similar to the Polaroid 545 back so that they may be used in basically any 4x5 view camera ;-)

Right, but if they're only getting 40 lp/mm, then there's no image quality advantage to using them, and many many workflow disadvantages.

You know what else can be used in basically any 4x5 view camera? Sheet film.