Re: Digital negative novice needs help.

Sandy,

I don't understand the logic of trying to get a better final resolution then
our eye can resolve. Is there somekind of effect that gives us the
impression a print looks better at a higher resolution then our eyes can
see?

For example, we have say a 5x7 in camera neg resolving 40 lines and we
manage to get the best scan possible from this same negative. I think you
would agree with me that there is always some lost when you reproduce an
image, negative or positive. Let's say in this case we manage to get a
resolution of 35 lines. If the printer and medium we use to make our digital
negative results in a further loss as expected we may get down to only 30
lines. If I understand you correctly from what you wrote below, we shouldn't
be able to tell which was used even if printed on silver-gelatine paper?

That's what I would think also but then you basically say in cases where you
want some magnification that you try to get a final resolution of twice what
is considered by many to be what our eyes are capable of or about 5 lines on
average, I know, this is an average and it means that the number can and
will vary by a few lines on each side depending on who is looking. In other
words, if we target the final print resolution at 5 lines say 6 to be
conservative this should mean on average most people wouldn't see a
difference for any prints of higher resolution then 6 lines, keeping all
other factors constant of course.

I have a feeling you will tell me this is theory and in practice things are
lets say more complicated then that, right?

Regards
Yves

----- Original Message -----
From: "Sandy King" <sanking@clemson.edu>
To: <alt-photo-process-l@usask.ca>
Sent: Wednesday, April 19, 2006 10:55 PM
Subject: Re: Digital negative novice needs help.

> Matt,
>
> Etienne has a good response to your question and I agree almost
> completely with his observations. I will just add a couple of more.
>
> >
> >Would it be reasonable to think that I could get good enough scans
> >from my 5x7s on a good flatbed to make up to 12x17 negs, or do you
> >really need imacon/drum scans?
>
>
> In my opinion you do not need an Imacon or drum scan for 5X7
> negatives if print size is limited to about 3X the original. An Epson
> 4870 or 4900 scanner is capable of about 40 lppm, so at 3X
> magnification your are still at 10 lppm, which is beyond the
> resolution of Epson inkjet printers.
>
>
> >
> >What level of resolution and apparent sharpness can be achieved from
> >out putting on a high end epson ink-jet? Do the negs stand up well
> >when compared to analog enlarged negs in this respect?
>
> About 8-10 lppm. That is also about the limit of resolution of a
> Pt./Pd. print on most of the popular papers used with this process.
>
>
> >Any advice and description of people's process and equipment set-up
> >would be greatly appreciated. I would be interested to how and what
> >people are doing in this field.
>
>
> I scan 5X7" negative with an Epson 4870 scanner. The scan is done at
> 3200 dpi, and I then down size for storage to 1600 dpi, which gives
> an effective resolution of about 35 lppm. The maximum print size I
> make from these scans is about 2.5X, which keeps resolution at 14
> lppm or more, well beyond the threshold of resolution of the human
> eye at the optimum viewing distance of 10-12".
>
> Printing with Pt./Pd. digital negatives from the Epson 2200 give
> results that can not be distinguished from in-camera negatives with
> most papes. On some hard surface papers one might see a slight
> advantage to an in-camera negative.
>
> In contact printing with silver gelatin papers in-camera negatives
> are definitely superior in most cases to inkjet negatives. With
> carbon, it depends on the final surface, but on many papers an inkjet
> negative gives results as good as an in-camera negative.
>
> Sandy
Received on Thu Apr 20 05:48:26 2006