> Is there much image degradation if I were to use a gel (rather than glass filter) over my lens? I happened to settled upon a Roscoe Pink (4830) for my D80. After evaluating a sample set of Roscoe swatches alongside UniWB. I found that the Pink resulted in the least amount of Red and Blue WB adjustment for the D80 with flash as the light source.
When using flash as the only light source I always place the filter in front of the flash, not in front of the lens. This way no image degradation occurs.
If I need to use colour gel filters outdoors then I prefer Lee filters. When used with a deep compendium they cause image degradation on par with a regular protection filter.
LibRaw is based on dcraw sources. In turn, dcraw uses RGB-XYZ tables from Adobe (DNG converter? Or camera raw?). So, do not expect to get good color on digikam/LibRaw until dcraw and-or Adobe converter arrives
The problem is with Adobe slow release of releases. And I bet this will remain a problem every year after photokina. New cameras will be available in the market and Adobe will pick and choose which one to support when.
An open source alternative to get to DNG would be very helpful.
Right now, I have Panasonic LX3 and its not supported. The same goes for G10 and I am sure there are lot more.
And unfortunately, a lot of ppl( including me) are tied to Adobe Photoshop.
Any help to get digiKam running on windows would be appreciated.
thanks for your reply. I have more general questions, if I may pick your brain for more info...
Is there much image degradation if I were to use a gel (rather than glass filter) over my lens? I happened to settled upon a Roscoe Pink (4830) for my D80. After evaluating a sample set of Roscoe swatches alongside UniWB. I found that the Pink resulted in the least amount of Red and Blue WB adjustment for the D80 with flash as the light source. I never really use the filter, but I was so intrigued by all the posts that I read on dpreview that I had to try it out for myself as an academic exercise.
At the moment, I'm using NX 2.1 for raw conversion; I finally decided to give it a shot after using NX 1.3 for a while. The workflow of NX 2 still isn't very good, but I like the auto color aberration capability, and I just noticed that the WB problem (aka FixNEF) is now resolved.
As a side note, I don't have a Mac... otherwise I would use RPP. I was able to load OSX on my PC, but I had a weird issue with OSX changing my system clock such that it was 12 hours off. Anyway, RPP seemed very nice (evaluated 3 months ago), but I was getting some weird demosaicing artifacts (zig zags, if I recall, with AHD). I noticed that there is new multiprocessor capability with the latest version of RPP, so I may have to give it a shot again.
Very useful. Exceptional noise handling does not mean the exposure can be wrong and the result will be the same as with the correct exposure. I also prefer to know when one channel is truly blown out. I rarely use D3 at base ISO (most of the exceptions are wide angle shots); but when I do I use a gel to balance the sensitivity of the channels if shooting conditions permit. It never hurts to get the per channel exposure correct at the time of shooting instead of postprocessing for correct colour and exposure ;)
How useful is UniWB with the D3? Considering that the D3 is supposed to have exceptional noise handling, do you use UniWB in conjunction with a colored filter (over flash or over lens)? Or do you just use UniWB for histogram evaluation only?
The point in using magenta filter is to achieve better exposure of red and blue channels by allowing less light to hit the sensors under the green filters of sensor CFA. This is physical, pre-capture filtration; and as such it can't be reproduced by tuning the camera or through post-processing.
what if a manual WB is chosen and a -magenta is entered (i don't think most of calibrated in CC)? will this give a similar result?
for example, Sony will allow such a compensation. i have already, through my raw processing, set this as my standard, as i shot at one temperature with -magenta, and then adjust the proper temperature during raw processing.
Interesting you mentioned 'better rawnalyse'. Our feeling is that raw analysis tools are at least as important as raw converters. They help both photographers and developers. You can expect various tools there, not just a raw histogram.
Have you checked Rawnalyze with D40 files converted to DNG?
Were these produced from spectral data, from measured or published LAB values, or from RGB data in a known colorspace and whitepoint? What is the illuminant used?
Thanks for the explanation. If people are somehow reading "The simple lesson to be learned from this is to bias your exposures so that the histogram is snugged up to the right" to mean "bias your exposure so the histogram is snugged u to the left" then they are (sorry to be blunt) clueless, espacially given the two histograms labelled
"Normal Exposure
Centered Histogram"
and
"Histogram to the Right
For Maximim S/N Ratio"
which visually and clearly indicate exposing to the right.
On the other hand, his glib "not to the point that the highlights are blown" is inaccurate. Firstly, some hilights are always blown in a real world scene; its a question of how badly. Secondly, ETTR trades of more blown hilights for less shadow noise. His article should make that more clear.
> Is there much image degradation if I were to use a gel (rather than glass filter) over my lens? I happened to settled upon a Roscoe Pink (4830) for my D80. After evaluating a sample set of Roscoe swatches alongside UniWB. I found that the Pink resulted in the least amount of Red and Blue WB adjustment for the D80 with flash as the light source.
When using flash as the only light source I always place the filter in front of the flash, not in front of the lens. This way no image degradation occurs.
If I need to use colour gel filters outdoors then I prefer Lee filters. When used with a deep compendium they cause image degradation on par with a regular protection filter.
LibRaw is based on dcraw sources. In turn, dcraw uses RGB-XYZ tables from Adobe (DNG converter? Or camera raw?). So, do not expect to get good color on digikam/LibRaw until dcraw and-or Adobe converter arrives
The problem is with Adobe slow release of releases. And I bet this will remain a problem every year after photokina. New cameras will be available in the market and Adobe will pick and choose which one to support when.
An open source alternative to get to DNG would be very helpful.
Right now, I have Panasonic LX3 and its not supported. The same goes for G10 and I am sure there are lot more.
And unfortunately, a lot of ppl( including me) are tied to Adobe Photoshop.
Any help to get digiKam running on windows would be appreciated.
Thanks
Do you really want DNG converter under Windows? AFAIK, Adobe DNG Converter is free...
I have been trying to find a windows port of digikam and it seems like it's not there.
Is it possible to get digiKam install for windows.
Are there any other applications that user LibRaw to convert Raw files to DNG?
Thanks
There is free/opensource DNG converter, based on LibRaw:
http://www.digikam.org/drupal/node/373
Hi there,
Will it be possible for you to provide some pointers on how to use LibRaw to get a DNG output.
Raw documentation is very sparse and its very hard to understand anything from DCRaw code.
Thanks,
thanks for your reply. I have more general questions, if I may pick your brain for more info...
Is there much image degradation if I were to use a gel (rather than glass filter) over my lens? I happened to settled upon a Roscoe Pink (4830) for my D80. After evaluating a sample set of Roscoe swatches alongside UniWB. I found that the Pink resulted in the least amount of Red and Blue WB adjustment for the D80 with flash as the light source. I never really use the filter, but I was so intrigued by all the posts that I read on dpreview that I had to try it out for myself as an academic exercise.
At the moment, I'm using NX 2.1 for raw conversion; I finally decided to give it a shot after using NX 1.3 for a while. The workflow of NX 2 still isn't very good, but I like the auto color aberration capability, and I just noticed that the WB problem (aka FixNEF) is now resolved.
As a side note, I don't have a Mac... otherwise I would use RPP. I was able to load OSX on my PC, but I had a weird issue with OSX changing my system clock such that it was 12 hours off. Anyway, RPP seemed very nice (evaluated 3 months ago), but I was getting some weird demosaicing artifacts (zig zags, if I recall, with AHD). I noticed that there is new multiprocessor capability with the latest version of RPP, so I may have to give it a shot again.
regards / roy
Very useful. Exceptional noise handling does not mean the exposure can be wrong and the result will be the same as with the correct exposure. I also prefer to know when one channel is truly blown out. I rarely use D3 at base ISO (most of the exceptions are wide angle shots); but when I do I use a gel to balance the sensitivity of the channels if shooting conditions permit. It never hurts to get the per channel exposure correct at the time of shooting instead of postprocessing for correct colour and exposure ;)
How useful is UniWB with the D3? Considering that the D3 is supposed to have exceptional noise handling, do you use UniWB in conjunction with a colored filter (over flash or over lens)? Or do you just use UniWB for histogram evaluation only?
regards / roy
both mk2
Which teleconverters were used? Canon EF? Mk I or II?
The point in using magenta filter is to achieve better exposure of red and blue channels by allowing less light to hit the sensors under the green filters of sensor CFA. This is physical, pre-capture filtration; and as such it can't be reproduced by tuning the camera or through post-processing.
what if a manual WB is chosen and a -magenta is entered (i don't think most of calibrated in CC)? will this give a similar result?
for example, Sony will allow such a compensation. i have already, through my raw processing, set this as my standard, as i shot at one temperature with -magenta, and then adjust the proper temperature during raw processing.
To convert, you can use free ColorLab utility
http://www.xrite.com/product_overview.aspx?ID=1071&Action=support&Softwa...
You should be able to convert spectral measurement data using the program above.
thanks for these files
i am using an e1io(uv)and have a delta E of about 3 to the GM spectrolino data
is the program you used to convert the GB measured text lab values to an image available? you would be welcome to my i1 results
thanks
david morrell
by email and comment
Take a look at EMVA 1288
http://www.emva.org/standard1288/standard_for_measurement_and_presentati...
Thanks once again!
I agree that analysis tools help both photographers and developers.
I will try converting to Adobe DNG meanwhile.
It was D50, 3 of CC24 averaged (last batch), 2 SG and 2 DC. Device used was Gretag Spectrolino.
Okay, good. That will produce the best results. What illuminant was used - D65? D50?
Dear Chris,
Interesting you mentioned 'better rawnalyse'. Our feeling is that raw analysis tools are at least as important as raw converters. They help both photographers and developers. You can expect various tools there, not just a raw histogram.
Have you checked Rawnalyze with D40 files converted to DNG?
These were produced from spectral data.
Were these produced from spectral data, from measured or published LAB values, or from RGB data in a known colorspace and whitepoint? What is the illuminant used?
Thanks for the explanation. If people are somehow reading "The simple lesson to be learned from this is to bias your exposures so that the histogram is snugged up to the right" to mean "bias your exposure so the histogram is snugged u to the left" then they are (sorry to be blunt) clueless, espacially given the two histograms labelled
"Normal Exposure
Centered Histogram"
and
"Histogram to the Right
For Maximim S/N Ratio"
which visually and clearly indicate exposing to the right.
On the other hand, his glib "not to the point that the highlights are blown" is inaccurate. Firstly, some hilights are always blown in a real world scene; its a question of how badly. Secondly, ETTR trades of more blown hilights for less shadow noise. His article should make that more clear.
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