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Author Topic: P45+ Centerfold  (Read 16204 times)
stewarthemley
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« Reply #40 on: December 13, 2007, 07:08:53 AM »
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Continuing the digression... it's interesting, do photographers as a breed migrate much, I wonder? I'm from the UK, then to Australia then UK then Canada and now Japan. But maybe it's another thread. Trouble is, all the interesting stuff is in the Medium Format section!
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thsinar
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« Reply #41 on: December 13, 2007, 07:14:05 AM »
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Stewart,

I was having the same thoughts this morning, when reading this. I was wondering how many of us photographers are living/working abroad.
It seems to be a lot, when reading here.

Very interesting, IMO.

Best regards,
Thierry

Quote
Continuing the digression... it's interesting, do photographers as a breed migrate much, I wonder? I'm from the UK, then to Australia then UK then Canada and now Japan. But maybe it's another thread. Trouble is, all the interesting stuff is in the Medium Format section!
[a href=\"index.php?act=findpost&pid=160325\"][{POST_SNAPBACK}][/a]
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Thierry Hagenauer
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eronald
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« Reply #42 on: December 13, 2007, 03:54:20 PM »
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You all supported me, I owe you all a report.

The good news is that thanks to Espen Beck who is the product manager for digital backs at Phase one, and Olivier Percheron who is the technician at Prophot, I have a replacement new P45+ back which is a definite improvement on the first one.

The bad news is that I have adjusted my expectations of what one can expect of a P45+. It appears some degree of striation at high ISO is normal for this product.

Good news detail: When I got to Prophot, Olivier had already read the LL thread and had got some phone calls. He opened a new back, and did some comparison images of me wearing my dark grey wool sweater. The first images he took of me at ISO 800 immediately showed up the centerfold issue. I was offered the just-opened back as a warranty replacement and accepted this offer.

Bad news detail: We did some comparison tests with the old and new back at 800,400 and 200 ISO. The new back too shows some -a few-  striations in the shadows, although fewer than the old one,  and these bands are really apparent at ISO 800 and 400, and you can still see them at ISO 200 if you know what you are looking for. This is bad news because it appears to be a general characteristic of the product.

Olivier and I agree, that after comparing the old and new backs we can say that the old one was out of spec (centerfold), but that with respect to the new one I have to be prepared to adjust my expectations, and accept that shots above ISO 200, or underexposed shots at ISO 200 cannot be expected to be really completely clean. Olivier states the real native ISO of this product is ISO 50, and we would agree that it should be shot at or below ISO 200, with ISO 400 and 800 risking a need for some retouching in the shadows, although if lucky the pictures would be ok.

It also appears therefore, that the common advice of using the P30+ for low light shooting is probably justified because it should shoot ISO 400 without striations, if it has the same performance as the P45+ with one stop more due to microlenses.

In the end Phase did indeed deliver on its warranty - I do regret that my hopes of smooth albeit noisy Hi-ISO have been dashed for the time being, although one can always hope for future improvement. I will temper my expectations, and await your reports on competing backs at high ISO with great interest.

This has certainly been a learning experience, and I am glad it is resolved.  I would like to thank Espen Beck at Phase and Olivier Percheron at Prophot for their friendly help, my dealer Fabrice Michaux at Le Moyen Format for his solidarity, and everyone who contributed to this thread for their support and encouragement which certainly helped to get this problem solved.

Edmund
« Last Edit: December 13, 2007, 05:02:15 PM by eronald » Logged
Caracalla
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« Reply #43 on: December 13, 2007, 05:36:43 PM »
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It also appears therefore, that the common advice of using the P30+ for low light shooting is probably justified because it should shoot ISO 400 without striations, if it has the same performance as the P45+ with one stop more due to microlenses.

[a href=\"index.php?act=findpost&pid=160472\"][{POST_SNAPBACK}][/a]

Logically after I send you two Images P45+ ISO 400 & ISO 800 I decided to pick few of my friends P30+ and test the performance in underexposed condition. All I can tell you at ISO 400 it's funny but the striations/bending is obvious with P30+   perhaps to my surprise even more than on your P45+ files but no centrefold issue.

Next time when you are with your dealer pick one of his P30+ and see what is your experience. I know there are number of P30+ owners here, perhaps they can report on underexposed ISO 400/ISO 800 condition/performance.

Hopefully new P45+ will come with more charm  Anyway, all these products are good, I am just tired of getting the files ready for post processing and just the whole issue is a little technical regardless of you/us using Leaf, Sinar, Hasselblad, Phase, sooner or later we are all searching for answers etc.
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Ray
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« Reply #44 on: December 13, 2007, 06:51:41 PM »
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Bad news detail: We did some comparison tests with the old and new back at 800,400 and 200 ISO. The new back too shows some -a few-  striations in the shadows, although fewer than the old one,  and these bands are really apparent at ISO 800 and 400, and you can still see them at ISO 200 if you know what you are looking for. This is bad news because it appears to be a general characteristic of the product.

[a href=\"index.php?act=findpost&pid=160472\"][{POST_SNAPBACK}][/a]

Edmund,
I'd be interested to see a P45+ RAW image at ISO 400 which requires a -1 EC adjustment in ACR to recover highlight detail and which also shows striations in the shadows.

From what I've seen of your seriously underexposed ISO 400 & 800 shots, I find it difficult to believe there would be any problem in the shadows with a further 3 stops or so of exposure.
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eronald
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« Reply #45 on: December 13, 2007, 07:19:15 PM »
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Edmund,
I'd be interested to see a P45+ RAW image at ISO 400 which requires a -1 EC adjustment in ACR to recover highlight detail and which also shows striations in the shadows.

From what I've seen of your seriously underexposed ISO 400 & 800 shots, I find it difficult to believe there would be any problem in the shadows with a further 3 stops or so of exposure.
[a href=\"index.php?act=findpost&pid=160518\"][{POST_SNAPBACK}][/a]

Ray, although your comment is doubtless justified, I have an experiment for you. Take the piece of plexiglass that came with your back, put it in front of the lens, set your camera to full auto, at ISO 800, and shoot a frame with focus at infinity. Then look at the display on the back of the back, and the C1 preview and see what that looks like. Next develop the image and look what that looks like. My feeling is that the nicer the shot when unprocessed, the less work the software needs to do to correct, and the fewer the problems that make it into the processed file.

I'm going to take the new back, and the C1 3.7.8 beta which was recommended to me by Samuel and which I now got from the dealer too (found another in the VA package), and am going to go shooting at random for a couple of days to see how things go. Pixel peeping only makes me unhappy, and is only necessary anyway when one starts to have image issues. I just hope I won't have any image issues.


Edmund
« Last Edit: December 13, 2007, 07:25:45 PM by eronald » Logged
Ray
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« Reply #46 on: December 13, 2007, 08:59:38 PM »
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My feeling is that the nicer the shot when unprocessed, the less work the software needs to do to correct, and the fewer the problems that make it into the processed file.
[a href=\"index.php?act=findpost&pid=160528\"][{POST_SNAPBACK}][/a]

Edmund,
Although your comment is doubtless justified also, I think it's unreasonable to expect an image that has received 1/8th of the amount of light for full-well exposure in the highlights to be processed in the usual manner.

On the basis that the P45+ has a base ISO of 50, an exposure at ISO 400 represents just 1/8th the amount of light. Furthermore if such an exposure is 3 stops less than it could be with a full ETTR, that's another 1/8th less, a total of 1/64th the amount of light that a full ETTR exposure would get at ISO 50.

I just mention this to get things in perspective. I don't need to own and use a digital back to see these simple mathematical relationships, do I?
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Jonathan Wienke
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« Reply #47 on: December 13, 2007, 10:03:01 PM »
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My feeling is that the nicer the shot when unprocessed, the less work the software needs to do to correct, and the fewer the problems that make it into the processed file.

I agree, except for the observation that habitually underexposing by two stops does not generally make one's shots "nicer", especially at higher ISO settings. Your own posted images demonstrate this.
« Last Edit: December 13, 2007, 10:08:11 PM by Jonathan Wienke » Logged

bradleygibson
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« Reply #48 on: December 14, 2007, 12:11:58 AM »
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Glad to hear they took care of you, Edmund.

Best regards,
Brad
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rainer_v
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« Reply #49 on: December 14, 2007, 01:32:11 AM »
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i.m.o. its absolute nonsense that a back cannot be underexposed.
if the back works as iz should do the underexposed image has to be clean but darker.
and even if yu raise up after the levels of  this image there should not become visible any strivations or other artefacts ( except noise ). the "noise floor" of the sensor has to be much lowr, if its a bad sensor around 10stops under clipping level, if its a good one 11,5. this can show up in fine lines or "hair" structures in the worst case. in the best case there will not become even at this floor any image ununiformity visble, just noise.
if this stripes would be normal you never could make any HDR image, just for example. and if this should be brand or type specific i would hardly suggest not to buy this product.
its clear you cant underexpose three stops and push it up and expect great quality,- although this will result in worser images than the properly exposed ones. but in any case they should not be DESTROYED by unacceptable amounts of image defects, which are not caused by increased noise.
i think Edmund is right here from the beginning.
« Last Edit: December 14, 2007, 01:44:46 AM by rainer_v » Logged

rainer viertlböck
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« Reply #50 on: December 14, 2007, 01:50:32 AM »
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You are right Rainer, it should happen not but my experience (after quite a number of different backs) is, it does.

Sure you can make a HDR, if you underexpose for HDR you typically expose for highlights, which are not affected by the underexposure as the shadows are.

Anyway, I think you should consider yourself very lucky when you have a back that doesn't deliver some weird stuff in the dark parts when you underexpose. Most I have owned did, some were just less obvious than others.
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rainer_v
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« Reply #51 on: December 14, 2007, 02:15:40 AM »
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my two backs dont show things like this. one is perfect ( ofcourse it has "normal" noise floor ) and one shows very fine hair structures which become a little bit visible if i raise up shadows about 6 or 7! stops.

in general its really sad that tools as expensive as are this backs spread so wide in terms of quality. if i buy a sigma 12-24 lens i can understand this, sigma hardly can ask a price of 2000$, which they probably should ask for if they kick 4 out of 5 lenses to the rabbish where they belong to ( although same with many canon and nikon lenses ).
with the mf backs it seems to me that many of this defects are caused by tolerances of electronic parts which can be bought cheaper with higher tolerances. this are probably justsome 100 dollars if QC department would manage their business diferent, which they would do if the buyers would be more demanding. it would not be any problems if the backs would cost 1000 or 2000 $ dollar more and would deliver consistant quality, what they obviously dont do.
it shows much that so many photographers accept backs which are acting by far inferior to hi-end 35mm cameras just to have the feel to get (imaginative) 16bit files and subjectiv perceived 3-dimensionality.
ofcourse i am far away to bash mf backs here otherwise i would not
use them nearly exclusiv for my own work - with good reasons.
B.T.W. i use the sigma 12-24 lens too for ultrawide shots with my 5d,- but i kicked back to the shop 4 from the 5 samples i tried out,- bringing my pb with me in the shop. its not fun to sell this days equipment to me, but quite often i  cant live and work with the quality out of the box .

for me its not acceptable that edmund gets bashed here for doing something wrong which he obviously hasnt done.
the statements of the users who tell here that backs in general CANNOT be underexposed are wrong.
mf backs can be underexposed and this should be possible if they are working at its specs.

about HDR.
no,- with bandings as shown by edmund you cant stack images because these stripes are visible in the blacks for beeing the lightest parts there,- except you pull them down in postpro, so far that they become hided.
if i shoot for HDR i let all exposure and gradations linear and the results are amazing, this should not be possible with backs which act as edmunds.
« Last Edit: December 14, 2007, 02:42:49 AM by rainer_v » Logged

rainer viertlböck
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« Reply #52 on: December 14, 2007, 02:19:18 AM »
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Yeah..... you have got Sinar backs which are still on my list to own one somewhere in the future

My C-Most was horrible, the Valeos were so-so, the Aptus was not good, the H10 was really good, the CF39 seems to be really good and I cannot comment on the 384 yet since I don't own it that long (in multishot it is fantastic ).

No kidding, sure you can have one that doesn't and if it is indicative for the whole line that would be great. I have never touched a Sinar or handled a file of one.
« Last Edit: December 14, 2007, 02:24:57 AM by Dustbak » Logged
stewarthemley
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« Reply #53 on: December 14, 2007, 02:46:21 AM »
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The bad news is that I have adjusted my expectations of what one can expect of a P45+. It appears some degree of striation at high ISO is normal for this product.

Bad news detail: We did some comparison tests with the old and new back at 800,400 and 200 ISO. The new back too shows some -a few-  striations in the shadows, although fewer than the old one,  and these bands are really apparent at ISO 800 and 400, and you can still see them at ISO 200 if you know what you are looking for. This is bad news because it appears to be a general characteristic of the product.

- I do regret that my hopes of smooth albeit noisy Hi-ISO have been dashed for the time being, although one can always hope for future improvement. I will temper my expectations, and await your reports on competing backs at high ISO with great interest.
[a href=\"index.php?act=findpost&pid=160472\"][{POST_SNAPBACK}][/a]

My H3D39II arrives on Monday so I will do a few tests to see how it handles underexposure. It will be interesting as the sensor is the same. I have said before that I'm not defensive about gear (or my purchase decisions) so I'll tell it how it is. I'm not heavily into pixel peeping or charts, etc, so it will be a real-world test, like Edmund's. I tested an H3d39 mk1 for underexposure by accident, got the dials all wrong as I didn't know the camera and had 1.7 stops under on several shots but I didn't notice anything horrible lurking in the shadows. When I get time I'll look harder and will also be able to compare with my mk2. My starting point is that I agree with Rainer: it is nonsense that backs at this level cannot be underexposed.
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godtfred
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« Reply #54 on: December 14, 2007, 03:15:14 AM »
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i.m.o. its absolute nonsense that a back cannot be underexposed.
if the back works as iz should do the underexposed image has to be clean but darker.
and even if yu raise up after the levels of  this image there should not become visible any strivations or other artefacts ( except noise ). the "noise floor" of the sensor has to be much lowr, if its a bad sensor around 10stops under clipping level, if its a good one 11,5. this can show up in fine lines or "hair" structures in the worst case. in the best case there will not become even at this floor any image ununiformity visble, just noise.
if this stripes would be normal you never could make any HDR image, just for example. and if this should be brand or type specific i would hardly suggest not to buy this product.
its clear you cant underexpose three stops and push it up and expect great quality,- although this will result in worser images than the properly exposed ones. but in any case they should not be DESTROYED by unacceptable amounts of image defects, which are not caused by increased noise.
i think Edmund is right here from the beginning.
[a href=\"index.php?act=findpost&pid=160581\"][{POST_SNAPBACK}][/a]
+1

My thoughts exactly. No brand should be able to label their product with an ISO setting that produces anything other than an increase in noise. Artefacts, be it stripes, banding, miscolorations or otherwise, should not appear, and if it does, the product should not have been put out for sale with a label stating the ISO where the artefacts start to appear.
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Axel Bauer
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« Reply #55 on: December 14, 2007, 03:22:15 AM »
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my two backs dont show things like this. one is perfect ( ofcourse it has "normal" noise floor ) and one shows very fine hair structures which become a little bit visible if i raise up shadows about 6 or 7! stops.

in general its really sad that tools as expensive as are this backs spread so wide in terms of quality. if i buy a sigma 12-24 lens i can understand this, sigma hardly can ask a price of 2000$, which they probably should ask for if they kick 4 out of 5 lenses to the rabbish where they belong to ( although same with many canon and nikon lenses ).
with the mf backs it seems to me that many of this defects are caused by tolerances of electronic parts which can be bought cheaper with higher tolerances. this are probably justsome 100 dollars if QC department would manage their business diferent, which they would do if the buyers would be more demanding. it would not be any problems if the backs would cost 1000 or 2000 $ dollar more and would deliver consistant quality, what they obviously dont do.
it shows much that so many photographers accept backs which are acting by far inferior to hi-end 35mm cameras just to have the feel to get (imaginative) 16bit files and subjectiv perceived 3-dimensionality.
ofcourse i am far away to bash mf backs here otherwise i would not
use them nearly exclusiv for my own work - with good reasons.
B.T.W. i use the sigma 12-24 lens too for ultrawide shots with my 5d,- but i kicked back to the shop 4 from the 5 samples i tried out,- bringing my pb with me in the shop. its not fun to sell this days equipment to me, but quite often i  cant live and work with the quality out of the box .

for me its not acceptable that edmund gets bashed here for doing something wrong which he obviously hasnt done.
the statements of the users who tell here that backs in general CANNOT be underexposed are wrong.
mf backs can be underexposed and this should be possible if they are working at its specs.

about HDR.
no,- with bandings as shown by edmund you cant stack images because these stripes are visible in the blacks for beeing the lightest parts there,- except you pull them down in postpro, so far that they become hided.
if i shoot for HDR i let all exposure and gradations linear and the results are amazing, this should not be possible with backs which act as edmunds.
[a href=\"index.php?act=findpost&pid=160585\"][{POST_SNAPBACK}][/a]


You are right, if you let the stripes come through but these are very easy to mask out.

Anyway, I think we are in agreement here. It should not happen, you should be able to underexpose  at least to some degree without pulling up all sorts of misery. It is indeed sad the reality is not always at par with how it should be.

I had no idea Edmund got flamed?   At least that was never my intention if it came across like that. I must admit I also was sceptical in the beginning after the first files. After seeing more and seeing the centerfold appearing under circumstances it absolutely should not, I had no doubt his back was not what it should be.

I am glad it got resolved. (though he now has a back that does the same but to a lesser extend).

BTW, I never claimed MFDB cannot be underexposed. I have only experienced that you exponentially increase the likeliness of getting weird stuff when underexposing. To be frank I don't recall anyone saying you cannot underexpose because obviously you can (but against what price).

Again. I totally agree that you should be able to underexpose (to some degree) without pulling up all sorts of misery.
« Last Edit: December 14, 2007, 03:28:16 AM by Dustbak » Logged
godtfred
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« Reply #56 on: December 14, 2007, 03:28:54 AM »
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that doesn't deliver some weird stuff in the dark parts when you underexpose.
[a href=\"index.php?act=findpost&pid=160583\"][{POST_SNAPBACK}][/a]
This "truth" about underexposure has to stop, I provided ample evidence throught raw files that the histogram before my eyes in the examples I provided on the other thread, showed no underexposure, and where just short of clipping to the right. Yet the images still had visible artefacts in the dark parts of the images, even at ISO 400 (one stop short of the P45+ max iso range.) It does not show a lot, but it shows if your eye is tuned into what it should look for.

The fact that Panopeeper and others could find ample underexposure if using other software that the one supplied from the manufacturer should in this case not be of any significance. The software you have to use for tethered shooting, or the histogram on the screen of the back, should be the measurement for correct exposure, anything else is: "if you cut out your convenient, P1 approved workflow, an try this other more demanding workflow, then you may or may not see these artefacts. Of course you will not be able to trust your eyes to check for clipped highlights during a photoshoot unless you check and recheck the histogram every 5 minutes during the shoot in this second, non manufacurer provided, software." What if you are not shooting tethered, and cannot check your histogram in ACR like in Edmunds cases. How do you then determine correct exposure if you cannot trust the histogram on the back for an ETTR exposure?

-axel
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Axel Bauer
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« Reply #57 on: December 14, 2007, 03:44:44 AM »
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Not sure what you are currently quoting of me but I have never put anything down as the 'truth'. I always say stuff within the context of my own experiences.

The only thing you have supplied ample proof of is that your back delivers artefacts even when exposed properly.

I agree you should be able to trust your histogram but in case it is off it is not so hard to compensate through experience. If you have used your equipment for a while you should know how to handle it and how to compensate if necessary.

Sure, we should live in a perfect world where everything functions as advertised and flawless, unfortunately in my experience we are not. I would love to have it otherwise don't get me wrong, I envy those that have not experienced a single glitch, setback, etc..

I even recently received a recall of something that hadn't even arrived at my address!
« Last Edit: December 14, 2007, 03:56:56 AM by Dustbak » Logged
eronald
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« Reply #58 on: December 14, 2007, 03:55:31 AM »
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about HDR.
no,- with bandings as shown by edmund you cant stack images because these stripes are visible in the blacks for beeing the lightest parts there,- except you pull them down in postpro, so far that they become hided.
if i shoot for HDR i let all exposure and gradations linear and the results are amazing, this should not be possible with backs which act as edmunds.
[a href=\"index.php?act=findpost&pid=160585\"][{POST_SNAPBACK}][/a]


Rainer, Dustbak,

Exactly wiich back are you using ? How did you get a sample that doesn't band or stripe ?

I think Dustak has Hasselblad as posted above but I'd like to know more details about the 384 - I don't know what this is, and why he didn't get the CF39 converted to MS  ?

Note that one can actually do HDR -probably- with a back that stripes like the Phase, by going down to an ISO where it does not stripe. That means several images, obviously, one cannot do it just with the Raw developer.

Edmund
« Last Edit: December 14, 2007, 04:07:41 AM by eronald » Logged
Caracalla
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« Reply #59 on: December 14, 2007, 04:06:50 AM »
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about HDR.
no,- with bandings as shown by edmund you cant stack images because these stripes are visible in the blacks for beeing the lightest parts there,- except you pull them down in postpro, so far that they become hided.
if i shoot for HDR i let all exposure and gradations linear and the results are amazing, this should not be possible with backs which act as edmunds.
[a href=\"index.php?act=findpost&pid=160585\"][{POST_SNAPBACK}][/a]

Of course you can, I do it regularly but with ISO 100, ISO 200 very few with ISO400 because I use long exposure so I don't need to even go over ISO100
So HDR is definitely NOT a PROBLEM with PHASE ONE, in fact the results are excellent. Of course as you know I'm sure, you can't expect to please everyone!

To my surprise as I said before I tried two P30+ and when underexposed they show more striations/bending at ISO 400, ISO 800 than P45+, Other LL members/P30+ owners here can report on their results with underexposed ISO 400/ISO 800 condition/performance.

Let's hope the new version of C1 will fix the striations/bending problems.

Regarding Sinar Digital Back, I think they have a very nice product only my dollar goes to Sinar when they decide on at least 3" screen and I hope it happens very soon!
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