This is what happens when you point the F3 at tight detail

All I have to say is wow. Thats just amazing, can't wait to get some of our testing going
 
Can you post a high res stil?

Since the video's not moving or anything.

300MB is a lot to download for two seconds of still footage.
 
Well I figured I didn't want anyone whining about compression skewing results. ;)

I'll put up the still tommorow.
 
Well I figured I didn't want anyone whining about compression skewing results. ;)

I'll put up the still tommorow.
 
10K posts Timur how do you find time to shoot?

DL'd the source file -

What the?? ISO800? That is one grainless image! I'm imagining you could mush out that ultra-fine aliasing with a bottom'd out detail setting, similar to the EX3? I'll read your blog post again.
 
I seem to remember if you drop detail too low on the ex1 it starts to actively blur the image. I set the F3 to about -20 to -30
 
Can some one give some more info on the chart I am not able to read what each circle is, Thank you.
 
The last circle thats clear is 31lines per mm. Thhis is used to test the sharpness of lenses, but since we kow the lens is sharp its just a torture test for the sensor and codec. i think they did well.
 
TimurCivan said:
The last circle thats clear is 31lines per mm. Thhis is used to test the sharpness of lenses, but since we kow the lens is sharp its just a torture test for the sensor and codec. i think they did well.
Click to expand...

The Putora chart was developed in the 60's for film mostly. There are better ways to test the contemporary solid state imagers, but let's stick to Ivan Putora.
The circles represent DS-degrees of sharpness. The imager should be placed 60 (actually 62) f-lengths from the chart. Side lighting and good focus. If we assume the last visible circle is DS5, it represents 31.3 lp/mm. Lp/mm is line pairs per milimeter in the center of the film frame (here sensor). The F3 imager is 23.6mm x 13.3mm. 31.3 lpmm x 13.3mm=416lp OR 832TVL (TV lines) or resolution. Let's be magnanimous though and allow half DS for the faintly visible DS6, this is allowed by the methodology of Putora Chart. That makes 36lpmm x 13.3mm=480lp or 960 TVL. Theoretical maximum for a 1080 pixels tall progressive solid state imager is ca 970TVL (1080 nyquist limit x 0.9 Kell factor).
960 TVL means a near perfect resolution in the real world. Perfect lens and excellent processing, close to the theoretical limit.*

*This way of measuring resolution says pretty much nothing of the image quality. We need to know the contrast of details to appraise the final look. Humans actually judge good contrast on less detail as a better picture than the other way round. For that kind of test we need good MTF (modulation transfer function) methodologies and equipment.
From the Putora way we can say that fully visible DS5 is maybe equivalemt to 50% contrast, so the MTF50 resolution of F3 is ca 830 TVL. The almost invisible DS6 corresponds to MTF10, 10% contrast,pretty much irrelevant. That's why the chart says use "half of DS", that would supposedly correspond to 30% contrast or MTF30, the traditional way of measuring photographic B&W resolution.But when you look on MTFs of modern lenses, the success line is way above MTF50. The great contrast is 90%, good one at 70%. Really good picture is above 40-50 lp/mm with a 70% contrast acros the frame. I would say Zeiss Master level. Of course Masters can resolve more (100lp/mm on best stock in Arri research), but with a much lower contrast.
 
Last edited:
You must log in or register to reply here.
Back
Top