Luminous Landscape Forum
Equipment & Techniques => Medium Format / Film / Digital Backs – and Large Sensor Photography => Topic started by: EricWHiss on December 17, 2007, 08:15:55 pm
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Just curious if anyone else got the e-mail from Phase that says "Best of both Worlds"
Here's what it says....
The P+ Digital Back
The P+ series generation digital backs from Phase One are now available for quick delivery on any model
• Higher ISO settings
• Low noise
• A dynamic range of 15 stops
• Improved Color accuracy
• Faster capture rate
• Live preview capable
I was surprised by the 15 stops - thought they only had 12? If its true then that's a reason to upgrade right there for me. But I'm thinking its a typo as the specs on their web page still say 12. But then again maybe they have improved it? Anyone know for sure?
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Just curious if anyone else got the e-mail from Phase that says "Best of both Worlds"
Here's what it says....
The P+ Digital Back
The P+ series generation digital backs from Phase One are now available for quick delivery on any model
• Higher ISO settings
• Low noise
• A dynamic range of 15 stops
• Improved Color accuracy
• Faster capture rate
• Live preview capable
I was surprised by the 15 stops - thought they only had 12? If its true then that's a reason to upgrade right there for me. But I'm thinking its a typo as the specs on their web page still say 12. But then again maybe they have improved it? Anyone know for sure?
[a href=\"index.php?act=findpost&pid=161342\"][{POST_SNAPBACK}][/a]
Erik, I own a "normal" P back. I could do the test but since there's a few here with the P+, maybe they can put a test for you. It can be done by taking a grey card under soft, diffuse light and placing it on zone V. Then opening and closing full stops until it clips on both sides. Is very easy to find out.
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Erik, I own a "normal" P back. I could do the test but since there's a few here with the P+, maybe they can put a test for you. It can be done by taking a grey card under soft, diffuse light and placing it on zone V. Then opening and closing full stops until it clips on both sides. Is very easy to find out.
[a href=\"index.php?act=findpost&pid=161343\"][{POST_SNAPBACK}][/a]
I've got a p20 and that looks like around 12 stops so no need to test yours but if someone with a + version wants to test that would be great!
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My guess is they're referring to results with Plus backs and Capture One 4, that has added range in shadows and highlights a la LightRoom. It's a guess only.
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That claim isn't even remotely plausible unless one of the following conditions is true:
Phase has managed to create a sensor, read circuitry, and A/D converter that keeps noise +/- 1 ADU all the way to the black point, which must be exactly zero, and you accept 4 levels as an acceptable number of tonal gradations for the 15th stop.
OR...
Phase has invented a sensor technology that does not have a linear relationship between photons striking a pixel and the ADU readout for that pixel.
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All of the sensors have between 70 and 72db of dynamic range according to Kodak spec sheets, 11.5 to 12 stops?
Marc
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All of the sensors have between 70 and 72db of dynamic range according to Kodak spec sheets, 11.5 to 12 stops?
Marc
[a href=\"index.php?act=findpost&pid=161385\"][{POST_SNAPBACK}][/a]
At which temperature ?
Edmund
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At which temperature ?
Edmund
[{POST_SNAPBACK}][/a] (http://index.php?act=findpost&pid=161421\")
40 deg C (I'm assuming sensor temp not ambient)
[a href=\"http://www.kodak.com/ezpres/business/ccd/global/plugins/acrobat/en/datasheet/fullframe/KAF-31600LongSpec.pdf]http://www.kodak.com/ezpres/business/ccd/g...600LongSpec.pdf[/url]
http://www.kodak.com/ezpres/business/ccd/g...000LongSpec.pdf (http://www.kodak.com/ezpres/business/ccd/global/plugins/acrobat/en/datasheet/fullframe/KAF-39000LongSpec.pdf)
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I have a P45+ back and, while I haven't done scientific tests, I don't think it has anywhere near 15 stops. More like 11 or 12 at iso 50, it's native sensitivity. Eleanor
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I can tell you that it only delivers 2.5 to 3 stops above midtone (Zone V) before it saturates. I've tested this myself. So if it really has 15 stops (which I doubt), it is almost all in the shadows below midtone.
This is a function of the tone curve they are using, so I'm not sure how meaningful my 2.5 to 3 stop number is, except that whenever I expose for brighter highlights, the midtones are almost always underexposed.
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That claim isn't even remotely plausible unless one of the following conditions is true:
[a href=\"index.php?act=findpost&pid=161367\"][{POST_SNAPBACK}][/a]
Jonathan,
It could be that someone in the Phase marketing department has been reading that thread on LL where I'm claiming 12 stops DR for the Canon 5D .
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My quick informal test agrees with the quote below. at between 2.5 and 3 stops overexposed above middle gray, I got warning that I was at 255 or above. eleanor
I can tell you that it only delivers 2.5 to 3 stops above midtone (Zone V) before it saturates. I've tested this myself. So if it really has 15 stops (which I doubt), it is almost all in the shadows below midtone.
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I was surprised by the 15 stops - thought they only had 12?
The issue is confused by the fact that "dynamic range" doesn't have a single, clear definition. Generally, it means the ratio of the highest signal that can be recorded vs the lowest usable signal. This can vary with the resolution of the sensor or the desired crop, what "usable" is; what the white balance is, etc. The limiting factor is noise, although, theoretically, with less noise, the bit depth could be a limiter of dynamic range.
15 stops is only likely with current technology if the standard is low; IOW, you are only interested in making out extremely coarse and well-defined details in the shadows.
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I have a P45+ back and, while I haven't done scientific tests, I don't think it has anywhere near 15 stops. More like 11 or 12 at iso 50, it's native sensitivity. Eleanor
[a href=\"index.php?act=findpost&pid=161481\"][{POST_SNAPBACK}][/a]
Do you feel the P45+ DR is an improvement over the original? If so, are you seeing the improvement in the highlights or in the shadows? I'm still getting used to the P25 and I do wish it had a bit more headroom above the mid-tones. I'm shooting -1/3 to -2/3 EC and then bring up the shadows in post, so it's not a big deal. But all things being equal, I'd rather not have shoot with the negative EC adjustment.
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Just curious if anyone else got the e-mail from Phase that says "Best of both Worlds"
Here's what it says....
The P+ Digital Back
The P+ series generation digital backs from Phase One are now available for quick delivery on any model
• Higher ISO settings
• Low noise
• A dynamic range of 15 stops
• Improved Color accuracy
• Faster capture rate
• Live preview capable
I was surprised by the 15 stops - thought they only had 12? If its true then that's a reason to upgrade right there for me. But I'm thinking its a typo as the specs on their web page still say 12. But then again maybe they have improved it? Anyone know for sure?
[a href=\"index.php?act=findpost&pid=161342\"][{POST_SNAPBACK}][/a]
I have a P45+ and reckon it gives me 12 stops on a perfect exposure. Certainly not 15!
Bill
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I just did a quick test with my p45+
About 12 stop when viewed in ACR with their P45+ profile.
I imagine that processed in C1 with the tonal curve set to linear the camera would probably yield one to two stops more. I will look at the test more closely when I have some time.