alex_kas

Dear all,

I have the same trouble on three laptops (HP, HP and Acer, all under XP). I use Spyder 3 to calibrate the screens. It looks like "it is not a bug, it is a feature" ;) If it is a bug, then we should stick to the comment in this thread about color change rate and TFT elements response I guess. Some slow reaction if it takes place for laptop LCDs in blues will definitely drive any colorimeter crazy. All the rest is hidden in the profile connection transformations. I'm not common with in mathematical details but I assume there are general STANDARD ways which should give good mappings. Most likely LCD screens ARE NOT STANDARD in one or other way. Is it the matrix response or not: I guess not so many people know. What seems true is that changing the profile creation software will not cure the problem. If the hardware does not drive the colorimeter crazy, then, probably, one has to accept the LCD purple tint and try to find an LCD-specific profile mapping.

Technically: the blue angle of my monitor(s) profile(s) triangle is just above (the same x, bigger y) the blue angle of the sRGB on the xy-chromaticity chart. NO ONE known to me rendering intent would raise blue point straight up. Thus ... What the laptop users may expect?

Can people around recommend (or not maybe) the Dell 2408WFP? Is it a good piece for photos? I have an amazing 25% off deal right coming weeks?

With best regards,

Alex

Roger, I think, you opened my eyes. Just to repeat that I have got the point:

For negs: I scan the gap, this adjusts the exposure. Then I make a number of raws. Then, working with raws I assign as output my favorable profile, say AdobeRGB. Correct? (or alternatively use device RGB and then convert in PS)

May be I'm really stupid but I have not understood yet why the exposure, somehow set by scanner on the gap is correct? My worry is the following:

How can I be sure that the exposure set on the empty frame will not be too low (and will still give details in dark areas, which are light in negs) and will not be to high (and will still give details in highleighted areas, which are dark in negs)?

or may be the best way is a scan of a frame with highlights and the gap at once, so that scanner will find the best value.

I mean, empty space is just transparent. Suppose I shot on sunny sea with very bright water in the direction of sun. Most likely I'll have almost white close to the sun. It will be extremly ddark on negs. How I can be sure that exposure, set by transparent area will be enough to distinguish hues in the bright area?

Erik's method involves increasing of the gain which means increasing of noise. Also I do not see why changing the gain per channel in order to neutralize the base will not affect (at least slightly) main colors? Anyway, I have to write few formulae myself to see what is going on.

Slides: Is it correct to calibrate with targets, then assign the resultant profile as the scanner profile, set output to device colorspace and eventually convert it to the workflowprofile in PS?

I use film camera and then scan films using Nikon Coolscan 5000. Raw files, I mean raw files, produced by vuescan including infrared channel.

My questions are specific for vuescan, I would say. Other soft is either expensive or useless for me, I guess. My wish is to make raw files and then, in some time, say in few months process them through some workflow which I do not know now. I will dig in.

I'm not so stupid to understand that scanner exposure does affect raw.

However, it is a mystery for me how scanner adjust exposure scanning just a gap between frames and why the resulting value of exposure is correct?

Basic question about negatives: does "lock film base color" affect raw produced by vuescan or not? If not, this simplifies the current task which is scan of physical media.

Sorry, if I put questions not clear from the beginning

Dear Professionals,

I have few questions being new to the business.

Setup: I scan negs and slides using Nikon 5000, and want to use vuescan as an

afforadble soft.

1. Negs. I learned that I have to take an unexposed partion and scan it in order to

determine the exposure and base color (super-advanced workflow by Erik Krause

is a bit doubtful for me from the mathematical point of view, anyway, it is not

related to the question directly).

How do I know that the exposure got this way is the correct one?

2. I want to make raw files. Does "lock film base" color affect raws?

If not, I hopefully can scan them (raws) and set film base color later.

What does it mean "scanner color space" and "device RGB" output when I scan

from a raw file? Does raw file has any info what scanner was used and what is its

RGB?

3. Slides: How do I know what exposure should be set to scan rolls and calibrate

(I'll use velvia and provia targets). I mena, I inderstand I have to use the same

exposure for calibration and scanning. But how to set it correctly?

Thanks for your help and the time spent,

Alex