Large Format vs Medium Format Digital

[timparkin]

Well thanks to everyone who helped with the planning and analysis of the testing. All of the results and analysis are now up at

http://www.landscapegb.com/issues/lgb-0028/

The bottom line? 8x10 rules the roost and the challenge is really 4x5 vs IQ180 - personally I think the 4x5 wins but it's close..

Tim

p.s some interesting conclusions about differences between 10x8 and 4x5 in my report bit (i.e. almost no difference in resolution once you stop down to an equivalent depth of field of f/32 on 4x5).

[Leigh]

(i.e. almost no difference in resolution once you stop down to an equivalent depth of field of f/32 on 4x5).

What constitutes an "equivalent" DoF?

DoF calculations include a fudge factor called the Circle of Confusion, which changes with negative size, getting bigger with larger formats.

- Leigh

[timparkin]

What constitutes an "equivalent" DoF?

DoF calculations include a fudge factor called the Circle of Confusion, which changes with negative size, getting bigger with larger formats.

- Leigh

I've worked it out based on the same visible depth of field in the image - i.e. so all of the images look the same. (so CoC will scale with sensor size).

[dsim]

Wow Tim, a lot of testing obviously, your efforts are appreciated by all. The use of the 80x stereo microscope was helpful with showing absolute film resolution and I'm sure us 8x10 and other Large Format photogs are not surprised.

[timparkin]

Thanks Dsim!

[Bill_1856]

I don't understand any of this!
Can you see any difference between any of these in a 16x20/24 print?

[timparkin]

I don't understand any of this!
Can you see any difference between any of these in a 16x20/24 print?

Just look at the pretty pictures then ;-) I've talked about print assessment in my editors conclusions. And yes you can tell a difference.

[Bill_1856]

. And yes you can tell a difference.

What is the difference (are the differences)?

[timparkin]

What is the difference (are the differences)?

Well at 20x24 I could see a crispness of texture that was different between the P45 an Sony A900 and then the IQ180 and large format. The smaller formats had a look that was almost like a dabbed on oil paint. The strokes looked obvious. Whereas the larger formats looked more photorealistic. It was subtle but I asked a few people on an area that had similar colour (i.e. so that they wouldn't be influenced by tonality) and most people chose the larger formats as looking more 'real' but occasionally some would choose the smaller formats and say they looked sharper. This seems to be because of a spike in the frequency near the limit of the sensor resolution, hence creating larger contrast around that frequency. Hence, for people who's eyesight wasn't quite as good their limit of resolution corresponded to this frequency. For some people, they also chose the IQ180 over the film because of it's lack of grain. However, as many people chose the 8x10 over the IQ180 'because it looked more real' - this was at very large enlargements though, 50x70 ish. The sample size isn't great, only about 8 people so far, but most chose the IQ or LF out of the selection that included P45 and Sony A900. They also chose the 8x10 over the 4x5 (which surprised me).

[PhiloFarmer]

THANK YOU, Tim & Team...for all your hard work...your planning...your considerations...your execution...your analysis. Wonderful! We will all, in our own ways, use your work as a reference...and hopefully build an even more creative world together.

Let's do a similar comparison in five-years...Yes??

Cheers!