Ad
Ad
Ad
Pages: « 1 2 [3] 4 5 »   Bottom of Page
Print
Author Topic: D3, 1DsMKIII, D300  (Read 34559 times)
Ray
Sr. Member
****
Offline Offline

Posts: 8908


« Reply #40 on: December 09, 2007, 07:39:11 AM »
ReplyReply

Quote
If what you're saying is that the camera at these settings just digitally amplifies the signal rather than amplifying in in the analogue domain, you might be right or partly right, but your use of the term 'underexposure' is not appropriate I believe.

I believe it is very appropriate in the sense that there is usually a qualitative improvement when using a higher ISO. The image has less noise than it would if one used the same exposure at a lower ISO. One is to some extent taking a risk in using a higher ISO. If one miscalculates and overexposes, the shot is ruined. However, if one gets it right, a good ETTR, one gets a better image.

But when using these false ISO's, the risk of overexposure is the same but the benefit regarding image quality and less shadow noise is zero. A correct exposure to the right, with the 5D at ISO 3200, produces the same result as using ISO 1600 at the same shutter speed and aperture. The only difference is in the appearance of the histogram and image on the camera's LCD.

Using ISO 1600 with the confidence one can underexpose a bit and preserve highlight detail without compromising image quality compared to using ISO 3200 is a real advantage. I'd describe it as being better that the latest feature of 'highlight tone priority' in Canon cameras, which is causing some confusion apparently

Quote
Furthermore, this issue is not new with these cameras as all cameras that I know off behave similarly in their respective uncalibrated high sensitivity settings.

That's true. It's not new. But Nikon have taken it a step further and given us 2 false ISO settings, and yours truly has taken it a few steps even further and produced an ISO 256,000 image with his 5D.  
Logged
Mark D Segal
Contributor
Sr. Member
*
Offline Offline

Posts: 6977


WWW
« Reply #41 on: December 09, 2007, 08:48:59 AM »
ReplyReply

Quote
I'd describe it as being better that the latest feature of 'highlight tone priority' in Canon cameras, which is causing some confusion apparently
[a href=\"index.php?act=findpost&pid=159436\"][{POST_SNAPBACK}][/a]

Hi Ray,

I'm not sure what you mean by "causing some confusion", because the description in the manual and the outcomes are quite consistent. To quote from the 1DsIII manual:

"Improves the highklight detail. The dynamic range is expanded from the standard 18% grey to bright highlights. The gradation between the greys and the highlights becomes smoother."

Then immediately under that cryptic description (yes, Canon still struggles with how to write a good manual), they do warn us: "With setting 1, noise in the shadow areas may be slightly more than usual."

My limited experience with it before I turned it off indicates that the manual is correct: it generates noise. Another Torontonian whose work I've seen a couple of times and respect has a 1DIII and he told me he turned it off permanently, so my experience has been replicated as the manual leads one to expect.

Perhaps there's some confusion about exactly how the "feature" operates, but not much confusion about its impact. People with more technical knowledge about how sensors work than I possess can probably reverse engineer an explanation in their own minds, because we certainly don't get it from Canon. That said, it seems to me there is only so much light hitting those receptors, hence perhaps the firmware is somehow allocating more of the available light to the part of the tonal range between 18% grey and white in order to improve tonal gradation in that part of the range, leaving less for the 3/4 tones and below, which are inherently relatively "starved" for light anyhow and therefore produce less S/N. Does this make any sense? Or am I just displaying the confusion you mention?  

Mark
Logged

Mark D Segal (formerly MarkDS)
Author: "Scanning Workflows with SilverFast 8....." http://www.luminous-landscape.com/reviews/film/scanning_workflows_with_silverfast_8.shtml
Graeme Nattress
Sr. Member
****
Offline Offline

Posts: 582



WWW
« Reply #42 on: December 09, 2007, 09:54:21 AM »
ReplyReply

As far as I understand the highlight mode just re-biases lattitude trading a stop or two below key, for a stop or two above key. To make the resulting image look "right" a tonal curve is used to brighten the image without crushing the highlights. This is something you can "do by hand" quite easily, but Canon have automated it for you.

Graeme
Logged

www.nattress.com - Plugins for Final Cut Pro and Color
www.red.com - Digital Cinema Cameras
Mark D Segal
Contributor
Sr. Member
*
Offline Offline

Posts: 6977


WWW
« Reply #43 on: December 09, 2007, 10:21:03 AM »
ReplyReply

Quote
As far as I understand the highlight mode just re-biases lattitude trading a stop or two below key, for a stop or two above key. To make the resulting image look "right" a tonal curve is used to brighten the image without crushing the highlights. This is something you can "do by hand" quite easily, but Canon have automated it for you.

Graeme
[a href=\"index.php?act=findpost&pid=159460\"][{POST_SNAPBACK}][/a]

Graeme, I'd appreciate if you could restate the first sentence using what Ben Willmore calls "a techno-babble decoder" so I can understand what you are saying  .  If you would kindly explain the meaning of the terms "re-biases lattitude" and "key" that would do it for me. Despite my difficulty with the first sentence I agree with the second sentence, because it occured to me as well that whatever Canon is doing in HTP one can most likely do by hand in Camera Raw. Then the final missing element is how all this may generate more noise.
Logged

Mark D Segal (formerly MarkDS)
Author: "Scanning Workflows with SilverFast 8....." http://www.luminous-landscape.com/reviews/film/scanning_workflows_with_silverfast_8.shtml
John Sheehy
Sr. Member
****
Offline Offline

Posts: 838


« Reply #44 on: December 09, 2007, 10:29:28 AM »
ReplyReply

Quote
One would certainly expect this to be the case, but often things are not what they seem to be. For example, the D3's ISO 12,800 and 25,600 settings are apparently bogus.
[a href=\"index.php?act=findpost&pid=159396\"][{POST_SNAPBACK}][/a]

Possibly true at some level, but "bogus" comes in different shades.  There isn't necessarily a visible difference in IQ between ISO 1600 pushed to 25,600 and actually having amplification 16x as strong as ISO 1600, if the RAW data clips below black, or exactly at black.  The only problem is if the data is clipped above black, in which case whatever is clipped is 4 stops bigger in ISO 1600 pushed to 25,600 than what "true" 25,600 might give if it clipped at the same ADU level.

As far as I can tell, I am the first person in the world of usenet and web photo forums to note that ISO 3200 and sometimes 1600 were achieved in a different manner than the lower ISOs on my 10D (and many other cameras too), and popularized the term "fake ISO" (some of the astrophotography folks may have noticed, too, but kept it to their astroworld).  That terminology was based on the context of the 10D, where, clearly, read noise in electrons dropped quickly from ISO 100 to 200, less so from 200 to 400, but still a good amount from 400 to 800.  The "real" ISOs, then were 100 to 800, which were achieved apparently through different amplifications *at* the photosites.  Upon examining other cameras, however, like the Nikons using Sony CCD chips, it became apparent that another level of fakeness existed, as all ISOs on these cameras have the same amplification at the initial read, and the differences of ISO were achieved only through amplifying the signal yet again before hitting the ADC.  There is no opportunity, however, for this second analog amplification to improve on the photosite read noise in electrons, as that read already occurs earlier in the chain, so the amplification basically only puts the signal at an advantage going into the ADC, with less resulting ADC noise in electrons at higher ISOs.  In the realm of high ISOs, ADC noise is so small, relatively, that there need be no major difference between amplifying and multiplying.  The differences are the kind you need to be stacking a dozen or more images to take advantage of.
Logged
John Sheehy
Sr. Member
****
Offline Offline

Posts: 838


« Reply #45 on: December 09, 2007, 10:43:37 AM »
ReplyReply

Quote
Despite my difficulty with the first sentence I agree with the second sentence, because it occured to me as well that whatever Canon is doing in HTP one can most likely do by hand in Camera Raw. Then the final missing element is how all this may generate more noise.
[a href=\"index.php?act=findpost&pid=159467\"][{POST_SNAPBACK}][/a]

You're then asking Camera Raw to pull down 1 stop more highlights into the image, which it may or may not handle gracefully.

Noise breaks down into two basic sources; shot noise, which comes from the actual exposure of the sensor (and has nothing to do with ISOs or modes, except as how they affect metering, and therefore, exposure), and read noise, which is a fixed blanket of electronic noise generated by the camera while reading the sensor and converting its signal to numbers for the RAW data.  The read noise is the only one that varies directly with ISO, and the HTP setting.  The read noise is usually about the same for ISO 100 and 200, being slightly higher for ISO 200 with modern Canon DSLRs.  This means that relative to your signal, using ISO 200 and HTP (which uses -1 EC and ISO 100 internally) has almost 2x the read noise of straight ISO 200, for the same absolute exposure.  The significance of read noise depends on what you are shooting, and how it is exposed.  Read noise is significantly visible only in the shadow areas, so if you shoot in controlled lighting, without deep shadows, then you won't have any tones swamped with read noise, and the loss is not significant.  If you are going to pull up highlights or have areas of slow gradients in near-blacks, however, the extra read noise from HTP can be significant.
« Last Edit: December 09, 2007, 11:05:42 AM by John Sheehy » Logged
Ray
Sr. Member
****
Offline Offline

Posts: 8908


« Reply #46 on: December 09, 2007, 10:56:45 AM »
ReplyReply

Quote
Perhaps there's some confusion about exactly how the "feature" operates, but not much confusion about its impact. People with more technical knowledge about how sensors work than I possess can probably reverse engineer an explanation in their own minds, because we certainly don't get it from Canon. That said, it seems to me there is only so much light hitting those receptors, hence perhaps the firmware is somehow allocating more of the available light to the part of the tonal range between 18% grey and white in order to improve tonal gradation in that part of the range, leaving less for the 3/4 tones and below, which are inherently relatively "starved" for light anyhow and therefore produce less S/N. Does this make any sense? Or am I just displaying the confusion you mention?   
[a href=\"index.php?act=findpost&pid=159446\"][{POST_SNAPBACK}][/a]

Mark,
I'm relying on people like John Sheehy for the explanations of these matters. But I have verified for myself, as probably you have also, that an underexposure at a low ISO produces a noisier image than the same exposure at a higher ISO. The effect was fairly marginal with early Canon DSLRs like the D60, so an ISO 100 shot, 2 stops underexposed, would have hardly more noise than the same exposure at ISO 400 (which in relation to the ISO 400 setting would be a correct exposure).

It's this principle at work which I believe is responsible for the noiser shadows with HTP enabled. The reverse of HTP would be to have a suitable shutter speed and aperture at say ISO 100, take an experimental shot and discover it was 1 stop underexposed, then take the shot again at the same aperture and shutter speed (on manual) but at ISO 200. The second shot would then be correctly exposed, along the lines of ETTR, and shadow noise would be less.

This probably sounds a bit complicated and convoluted, but it makes sense to me   .
Logged
m3photo
Newbie
*
Offline Offline

Posts: 3


« Reply #47 on: December 09, 2007, 11:10:27 AM »
ReplyReply

Just a word here for M. Reichmann with regard to Jay Maisel's close-up enlargements.
You say: "Possibly there's a bit more shadow detail in the Canon frame though (look at the iris). "
I think it's not the iris but just the reflection in his glasses which is positioned very slightly more to the left in the Canon shot thereby "drawing" what might seem to be detail from the eye rather than off the glasses themselves.
In any case, both wonderful machines and as always a refreshing article, thank you.
Logged
Mark D Segal
Contributor
Sr. Member
*
Offline Offline

Posts: 6977


WWW
« Reply #48 on: December 09, 2007, 11:39:13 AM »
ReplyReply

Quote
You're then asking Camera Raw to pull down 1 stop more highlights into the image, which it may or may not handle gracefully.

Noise breaks down into two basic sources; shot noise, which comes from the actual exposure of the sensor (and has nothing to do with ISOs or modes, except as how they affect metering, and therefore, exposure), and read noise, which is a fixed blanket of electronic noise generated by the camera while reading the sensor and converting its signal to numbers for the RAW data.  The read noise is the only one that varies directly with ISO, and the HTP setting.  The read noise is usually about the same for ISO 100 and 200, being slightly higher for ISO 200 with modern Canon DSLRs.  This means that relative to your signal, using ISO 200 and HTP (which uses -1 EC and ISO 100 internally) has almost 2x the read noise of straight ISO 200, for the same absolute exposure.  The significance of read noise depends on what you are shooting, and how it is exposed.  Read noise is significantly visible only in the shadow areas, so if you shoot in controlled lighting, without deep shadows, then you won't have any tones swamped with read noise, and the loss is not significant.  If you are going to pull up highlights or have areas of slow gradients in near-blacks, however, the extra read noise from HTP can be significant.
[a href=\"index.php?act=findpost&pid=159476\"][{POST_SNAPBACK}][/a]

John, thanks this is getting clearer as it continues. Where I noticed most of the noise on December 4th when I had HTP enabled was indeed in the dark areas of tall charcoal-coloured buildings in the TD Centre of Toronto. When I turned HTP off and returned there on December 5th to re-photograph those same buildings (intrusiveness from *security* notwithstanding) I obtained less noisy results. The interesting thing, though, is that these noise differences are much more apparent on a high resolution display (LaCie 321 at 1600*1200) than they are in a Premium Luster 13*19 inch print from an Epson 3800, where it hardly shows. Once this discussion moves from display to print (at least to 13*19 inches) I'm discovering that the issue's existence may be less significant than its impact.
Logged

Mark D Segal (formerly MarkDS)
Author: "Scanning Workflows with SilverFast 8....." http://www.luminous-landscape.com/reviews/film/scanning_workflows_with_silverfast_8.shtml
NikosR
Sr. Member
****
Offline Offline

Posts: 622


WWW
« Reply #49 on: December 09, 2007, 11:52:12 AM »
ReplyReply

One thing I would like to see discussed when judging the Nikon D3 high ISO quality or compare it to other (Canon) cameras is not only concetrating on noise but discuss the colour integrity of the results.

Colour integrity does not involve only saturation but fidelity and apparent 'depth' as well, things that cannot be easily restored through postprocessing.

From the examples I have seen it looks like the D3 performs much better than other cameras in this respect, managing to produce acceptable colour integrity at sensitivities where other cameras 'break down' so to speak.
Logged

Nikos
Mark D Segal
Contributor
Sr. Member
*
Offline Offline

Posts: 6977


WWW
« Reply #50 on: December 09, 2007, 12:15:50 PM »
ReplyReply

Quote
One thing I would like to see discussed when judging the Nikon D3 high ISO quality or compare it to other (Canon) cameras is not only concetrating on noise but discuss the colour integrity of the results.

Colour integrity does not involve only saturation but fidelity and apparent 'depth' as well, things that cannot be easily restored through postprocessing.

From the examples I have seen it looks like the D3 performs much better than other cameras in this respect, managing to produce acceptable colour integrity at sensitivities where other cameras 'break down' so to speak.
[a href=\"index.php?act=findpost&pid=159488\"][{POST_SNAPBACK}][/a]

"Colour integrity of the results" depends mainly on how a raw file is demosaiced and processed in the raw converter.
Logged

Mark D Segal (formerly MarkDS)
Author: "Scanning Workflows with SilverFast 8....." http://www.luminous-landscape.com/reviews/film/scanning_workflows_with_silverfast_8.shtml
John Sheehy
Sr. Member
****
Offline Offline

Posts: 838


« Reply #51 on: December 09, 2007, 12:41:25 PM »
ReplyReply

Quote
"Colour integrity of the results" depends mainly on how a raw file is demosaiced and processed in the raw converter.
[a href=\"index.php?act=findpost&pid=159498\"][{POST_SNAPBACK}][/a]

Other than what noise does to color, the only other camera-induced factor (assuming optimal software for conversion) is the response curves of the color filters, which determine how well subtle shades of hues can be differentiated without introducing extra chroma noise.
Logged
NikosR
Sr. Member
****
Offline Offline

Posts: 622


WWW
« Reply #52 on: December 09, 2007, 01:34:06 PM »
ReplyReply

While this is certainly true, in camera NR reduction methods (at whatever stage in the processing pipe these might exist) might well influence colour. So, yes in a sense colour fidelity deterioration is a result of noise and NR methods but, if one is interested in judging  final output I believe that colour should be judged as well as apparent noisiness.
Logged

Nikos
melgross
Newbie
*
Offline Offline

Posts: 46


« Reply #53 on: December 09, 2007, 03:29:51 PM »
ReplyReply

Quote
One would certainly expect this to be the case, but often things are not what they seem to be. For example, the D3's ISO 12,800 and 25,600 settings are apparently bogus. The purpose of having them is (presumably) to make assessing correct exposure in the histogram and the camera's LCD much easier. The jpeg image has been adjusted, in-camera, despite real and actual underexposure. Without such settings, one would be squinting at apparently underexposed shots in the camera's LCD and trying to judge if the shot was really too much underexposed or not.

I think also the purpose of these ultra high ISO settings relates to ISO bracketing. I'm not sure about the features on Nikon cameras, but I believe they've had ISO bracketing for a while. Of course you can't bracket an ISO which doesn't exist.

For example, if I take a shot with my 5D at ISO 3200 and the histogram and highlight flashing tell me I've overexposed, I've ruined the shot. If I need a particular combination of aperture (for DoF) and shutter speed (to freeze the action or camera shake), then autobracketing of exposure is not a good option.

Without ISO bracketing there can be a disadvantage in using an 'ersatz' ISO setting.

Since Nikon is now offering these 2 ultra-high settings which are really underexposures, it's quite likely they have built in a level of noise reduction to make them more acceptable. Once detail has been lost through in-camera noise reduction, it cannot be regained.

However, there is now a way of reducing noise, not only without destroying some degree of resolution, but with actual enhancement of resolution.

I'm suggesting here that using such stacking processes with ultra-high ISO shots, the D3 might not even equal the 5D. It's something which I think should be tested.
[a href=\"index.php?act=findpost&pid=159396\"][{POST_SNAPBACK}][/a]

I haven't used the D3 yet, so i don't know, but do you have evidence of this, or is it an assumption?

My 5D does have low noise levels, but 3200 makes a jump. More so than from 800 to 1600, so what you say could be true in regards to the 5D.

But, it seems to be quite a step to go one from stop further in underexpose, to two stops.

From what Michael has shown, and from what I've seen on some other sites, even 25,600 looks to be noisy, but usable. I haven't tried underexposing to get to 6,400, but somehow, I don't think the noise, and lack of shadow detail, would be as good as the Nikon at 12,800. But, now, after all of this talk, I will see if I have time tonight to try it.

The supersharp techniques seem to be interesting, but are not really useful under most conditions. It's too specialized, more so than the HDR tecniques I use.

No matter what we want to do, the capability of the camera itself is still the practical limiting factor. The 5D has the greatest dynamic range I've seen outside of the Leaf backs I test for Leaf. I assume other medium format backs also have great dynamic range. But, these backs rarely go above 400, and I've not tried to push them further.

It's an interesting topic, and so maybe I will try next week, with the Aptus. The problem pushing any camera beyond what the manufacturer specs, is that the RAW converters are set up to process these files only according to the limits set up by the manufacturers, and moving out of that parameter range might result in unexpected deterioration of the image.

No matter how we look at the 5D vs the D3 (and this is from a Canon user since 1969 when I went to Phokina and saw the new Canon "F".), the Nikon seems to have at least two "real" stops of ISO extension, and this is very significant. Canon will have to catch up. Hopefully, a 5D replacement will show up in late Feb, or March, and will make up one of those stops, with a "normal" range going to 3,200, and an extension to 6,400. This would satisfy the old Tri-X at 1200 with Accufine person in me quite well.
« Last Edit: December 09, 2007, 03:35:57 PM by melgross » Logged
John Sheehy
Sr. Member
****
Offline Offline

Posts: 838


« Reply #54 on: December 09, 2007, 03:53:41 PM »
ReplyReply

Quote
While this is certainly true, in camera NR reduction methods (at whatever stage in the processing pipe these might exist) might well influence colour. So, yes in a sense colour fidelity deterioration is a result of noise and NR methods but, if one is interested in judging  final output I believe that colour should be judged as well as apparent noisiness.
[a href=\"index.php?act=findpost&pid=159512\"][{POST_SNAPBACK}][/a]

No such processing is done to RAW data, in any camera, AFAIK.  The only doctoring of RAW data is to scale individual color channels (which has no effect on color that can't be  changed in the conversion), or individual lines of pixels, as a sort of calibration, and of course, clipping on the highlight end in all cameras, and clipping at, near, or below black, depending on the camera.  And things like reducing the numeric precision in the highlights, as Nikon does in their compressed NEFs.
Logged
melgross
Newbie
*
Offline Offline

Posts: 46


« Reply #55 on: December 09, 2007, 04:13:43 PM »
ReplyReply

Quote
No such processing is done to RAW data, in any camera, AFAIK. The only doctoring of RAW data is to scale individual color channels (which has no effect on color that can't be changed in the conversion), or individual lines of pixels, as a sort of calibration, and of course, clipping on the highlight end in all cameras, and clipping at, near, or below black, depending on the camera. And things like reducing the numeric precision in the highlights, as Nikon does in their compressed NEFs.
[a href=\"index.php?act=findpost&pid=159549\"][{POST_SNAPBACK}][/a]

This is an interesting question, and one the manuals don't make clear. For example, my 5D manual shows the menu to allow noise reduction to be turned on or off for long exposures, that is, exposures over 1 second. The camera can determine whether such noise reduction is needed, or you can further specify whether it should simply give the noise reduction for all 1 second, or longer, exposures.

It's been my opinion that as this noise reduction is done by taking a "dark" shot automatically, as far as I know, and removing noise using that as the "standard", that noise reduction would be in the RAW file as well. You're saying it would only end up in the jpeg? Again, this is something I've not made a comparison of. It's a good experiment.
« Last Edit: December 09, 2007, 04:15:46 PM by melgross » Logged
John Sheehy
Sr. Member
****
Offline Offline

Posts: 838


« Reply #56 on: December 09, 2007, 04:24:45 PM »
ReplyReply

Quote
It's been my opinion that as this noise reduction is done by taking a "dark" shot automatically, as far as I know, and removing noise using that as the "standard", that noise reduction would be in the RAW file as well. You're saying it would only end up in the jpeg? Again, this is something I've not made a comparison of. It's a good experiment.
[a href=\"index.php?act=findpost&pid=159554\"][{POST_SNAPBACK}][/a]

No, I wasn't talking about long exposures at all.  In any event, the dark frame subtraction is done before the RAW data is written to a file, or converted in-camera to JPEG.  But that does not qualify as something "other than noise" because it is noise (removal).
Logged
Leping
Jr. Member
**
Offline Offline

Posts: 87



WWW
« Reply #57 on: December 09, 2007, 10:33:34 PM »
ReplyReply

Quote
No, I wasn't talking about long exposures at all.  In any event, the dark frame subtraction is done before the RAW data is written to a file, or converted in-camera to JPEG.  But that does not qualify as something "other than noise" because it is noise (removal).
[{POST_SNAPBACK}][/a]

We need to watch the interesting discussions over the subject here, titled "RAW files are not RAW anymore?"

[a href=\"http://nikongear.com/smf/index.php?topic=6829.0]http://nikongear.com/smf/index.php?topic=6829.0[/url]
Logged

NikosR
Sr. Member
****
Offline Offline

Posts: 622


WWW
« Reply #58 on: December 09, 2007, 11:54:23 PM »
ReplyReply

Quote
No such processing is done to RAW data, in any camera, AFAIK.  The only doctoring of RAW data is to scale individual color channels (which has no effect on color that can't be  changed in the conversion), or individual lines of pixels, as a sort of calibration, and of course, clipping on the highlight end in all cameras, and clipping at, near, or below black, depending on the camera.  And things like reducing the numeric precision in the highlights, as Nikon does in their compressed NEFs.
[a href=\"index.php?act=findpost&pid=159549\"][{POST_SNAPBACK}][/a]


Yes, probably, until we are proven wrong by the manufacturers. But you're missing my point leading this discussion somewhere I had not intented to lead it.

My point is one and only. High ISO exhibit both grainyness and deterioration of colour quality. Now both of these might be the result of noise but when judging the final outcome (be that straight off the camera or off an external raw converter) both of these visual clues should be looked at. You can't judge (visually) the final outcome of a raw file without converting it, so your point is moot in the context of my question.
Logged

Nikos
melgross
Newbie
*
Offline Offline

Posts: 46


« Reply #59 on: December 10, 2007, 12:58:54 AM »
ReplyReply

Quote
No, I wasn't talking about long exposures at all.  In any event, the dark frame subtraction is done before the RAW data is written to a file, or converted in-camera to JPEG.  But that does not qualify as something "other than noise" because it is noise (removal).
[a href=\"index.php?act=findpost&pid=159556\"][{POST_SNAPBACK}][/a]

I realize that you weren't talking about that, though long exposure is being talked about here, where this will occur.

However, it does alter the data that would otherwise be recorded. First, the picture is taken, then the dark frame is taken (or the other way around, it doesn't matter), after which mathematical interpolation is done to the two files to come up with the de-noised file. That IS altering the RAW file.

 What results is no longer a RAW dump from the sensor. It has been modified. The question is how de-noising is done on shots other than the longer dark frame method. If they also modify the RAW file, then it also is no longer a straight dump.

This is important, because it may affect the way the converter handles the mosaic.
Logged
Pages: « 1 2 [3] 4 5 »   Top of Page
Print
Jump to:  

Ad
Ad
Ad