Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@y..., "jimhayes361" 
<jimhayes@j...> wrote:
> --- In DigitalBlackandWhiteThePrint@y..., Carolyn Frayn 
> <carolynfrayn@s...> wrote:
> <snip>

> > I was hoping that Jim would convert his same gamma2.2 file to 
> AdobeRGB
> > instead of the sRGB in both versions, run the prints and see if 
that 
> made a
> > difference to his output, kept them similair.
> 

The two prints done in Adobe 98 are only two hours dry but here is 
what it looks like it may be:

first, here are the values for the histos, with the same Paul's curve 
applied after conversion...


PS6/Adobe98: mean=47.87 SD=70.61 median=12
PS7/Adobe98: mean=47.83 SD=70.63 median=12
PS6/srgb:    mean=46.83 SD=71.55 median=10
PS7/srgb:    mean=45.57 SD=72.27 median=8

Puzzling that there is a difference using Adobe98, and I think there 
is only one version of the space on the computer.

Before I tell you what happened, I'm going to fill you all in on more 
of the history behind the image. It is a triple seamless montage of 
three hands, all shot with a Canon G2 during the same session. The 
background is dark, as is most of the image. I like it that way, but 
it started out as a misfiring of a flash that I didn't erase from the 
CF card. The background has been boosted up a little. The camera works 
in 10 bit mode, so I have a little headroom in pshop 16 bit to tune 
it. I also used Genuine Fractals to enlarge image to correct size from 
the native 4 mp CCD.

However, the camera like the Canon D30, has a habit of introducing 
banding in low key areas, and it gets worse with multiple shots , as 
camera warms. I was lucky to realize when I first printed this in 
Febuary with PS6/srgb, that the banding was barely visible, and 
certainly acceptable.

Okay, end of lecture. When I examine the four prints,

PS6/srgb: best print, no or little posterization. Good tones. Some 
banding can be seen if you know what to look for- my wife as impartial 
judge searched long and couldn't see any banding or cordury.

PS7/srgb: posterization, ugly. Shadow background a little darker than 
above. Wife can't see any cordury or banding. She sees the 
posterization- no problem, like an um, a sore thumb.

Ps6/Adobe98: Not bad really. The tones are off from the PS6/srgb 
print, but nothing that isn't within artistic interpretation or 
whatever you want to call it (darkroom fudge factor?). I rather like 
it except for two small areas where the transition is not as smooth as 
the PS6/srgb print and a tiny bit of posterization occurs- this takes 
a critical eye to spot. Wife sees no banding. I don't think she would 
have seen the posterization either.

PS7/Adobe98: Something odd. The print looks identical to the 
PS6/Adobe98 print except that in one area especially, microbanding 
shows up in a 3/4 tone area. I don't know if this is due to the camera 
noise or not, but it looks sharper and finer- more like microbanding 
than cordury. Lest you think I'm overly picky, I took all four print 
samples and layed them on a mat board, handed it to my wife who stood 
under a sunlit skylight with a sunny sky. After about 20 seconds  
without hinting she easily "labeled" the microbanding in ONLY the 
PS7/Adobe98 print in one area. Then I prodded her to find the 
cordury/banding in the other three images and in the noisiest areas of 
the all four, even pointing them out, but she couldn't see them.

I checked the images myself under my good old Vison saver Ott-lite and 
 I had to agree, although I could see all the banding- it was more 
prominent on the PS7/Adobe98 print in one 3/4 tone area. I don't know 
if the camera noise is masking the microbanding in other areas of the 
PS7/Adobe98 print or if the microbanding just occurs in one roughly 3 
x 3 inch area. 

In fact I saw it right out of the printer, and thinking something 
amiss with the inkflow, did an immediate nozzle check which came out 
perfect. So if it was due to a misfiring nozzle, it cleared up before 
print was done (could be I guess <shrug>).

I don't know if that helps, I think I am rather adding to the 
confusion. My computer seems to, in it's mind, want me to use PS6, 
whatever the profile.<g>
Jim H.