quality of scan from a professional lab

[Rowan Crowe]

These are three 1:1 crops from a 2614x1772 scan done by a professional
lab. The media is Velvia 100F on a slide mount. I am interested in
your feedback on the quality of the scan.

(Sorry about the 300-400k filesize of these samples, but I needed to
save them in lossless format for obvious reasons)

http://media.sensationcontent.com/rowan/scancrop1.png
- note the diagonal staircasing on the trunks and the general
"oversharp" look.

http://media.sensationcontent.com/rowan/scancrop2.png
- this is the bottom left of the frame, I'm not sure if this is a lens
limitation or a noisy scan.

http://media.sensationcontent.com/rowan/scancrop3.png
- again... camera/lens/film or a noisy scan?

To my amateur eyes this scan looks way too "digital" - too sharp and
noisy. The 8x10" Pegasus print that it was done for looks a little
washed out and a little low in contrast, which I suspect is because of
the oversharpening showing up the edges. The colour also looks quite a
bit less vibrant than my slide viewer.

For this scan the output resolution was 250dpi, which requires just
under 2400dpi optical resolution... nothing too major for a
professional scanner. A scan on my own 2400dpi flatbed (Canon 5000F)
looks fairly muddy when viewed 1:1 on the screen (see
http://media.sensationcontent.com/rowan/flatbedcrop1.png ), however
the print from the cheapie scanner ends up looking more aesthetically
pleasing than the professionally scanned one!

The scan + Pegasus print cost $44. Am I being too fussy for that price
or do you think I am right to feel unsatisfied with the quality of
this scan?

I am going to get an optical 8x10" enlargement done elsewhere to
compare the results.

Thanks for any comments...

 

[Bart van der Wolf]

These are three 1:1 crops from a 2614x1772 scan

SNIP

That is a very small output for an intended 8x10 print, so depending on the
scanner and (if at all) downsampling method used, you can't expect too much.

The quality could have undoubtedly been much better if they had scanned
large and used a proper downsampling method to reach the native resolution
of the printer. Then a mild sharpening (depending on the intended use) would
have given 'perfect' quality. However, that is a time consuming procedure,
and that cuts into their margin. So I suspect they've cut a few corners.

IMO you had to pay too much for the quality offered.

Bart

 

[RSD99]

"Rowan Crowe" posted:
"...
These are three 1:1 crops from a 2614x1772 scan done by a professional
lab.
...."

And Bart's comment:
"... That is a very small output for an intended 8x10 print, ..."

Essentially I agree with everything Bart van der Wolf posted, and add that the last time I
looked, 300 dpi was an appropriate minimum file size for a print. That would be

2400 pixels by 3000 pixels

I also question the designation of "professional lab." WHAT do you/they mean when you/they
say "professional lab" ... do they mean an outfit that is "professional" as in actually
being in business as a "photo lab" (as opposed to someone doing it "at home") or do they
mean a photo lab that caters primarily (if not exclusively) to imaging professionals and
professional photographers. There is a VERY BIG difference.

As for the quality of the scan? From Velvia 100F I would expect better. The scans are
visibly over-sharpened and appear to be quire noisy; however the color balance seems OK.


As for your statement/question "... The colour also looks quite a bit less vibrant than my
slide viewer. ..." Looking at any given image on a slide viewer will always be "more
vibrant" than looking at the best possible print that can be made from that slide. This is
because you are not looking at the same thing. Remember that a slide (or transparency) is
viewed by transmitted light and a print is viewed by reflected light. They are VERY
different, and a valid direct comparison really cannot be made.

 

[Rowan Crowe]

SNIP

That is a very small output for an intended 8x10 print, so depending on the
scanner and (if at all) downsampling method used, you can't expect too much.

The quality could have undoubtedly been much better if they had scanned
large and used a proper downsampling method to reach the native resolution
of the printer. Then a mild sharpening (depending on the intended use) would
have given 'perfect' quality. However, that is a time consuming procedure,
and that cuts into their margin. So I suspect they've cut a few corners.

IMO you had to pay too much for the quality offered.

One thing I forgot to add: the currency of the charge! It was $AUD44
(about $USD30) which may make some difference to your "pay too much"
opinion.

I also expected that the scan would be at a higher resolution and then
downsampled. I'm disappointed at how digitally sharp it looks; I
naturally assumed that the quality would be similar to a chemical
enlargement, perhaps a little sharper. When you say time consuming, do
you mean that the scan takes longer at a higher resolution, or that
the operator needs to spend more time adjusting the scan? According to
their web site, each image is scanned and retouched individually.

RSD99: By "professional" I do mean that they cater predominantly to
professionals. It's not a minilab tucked away at the back of a
supermarket.

Here's what the company has to say about the service that I ordered:

http://www.cpldigital.com.au/pegasus.html

I'll contact them now with my concerns, I was just a little unsure as
to whether I was expecting too much.

 

[Aaron Queenan]

} These are three 1:1 crops from a 2614x1772 scan done by a professional
} lab. The media is Velvia 100F on a slide mount. I am interested in
} your feedback on the quality of the scan.
}
} <snip>
}
} For this scan the output resolution was 250dpi, which requires just
} under 2400dpi optical resolution... nothing too major for a
} professional scanner. A scan on my own 2400dpi flatbed (Canon 5000F)
} looks fairly muddy when viewed 1:1 on the screen (see
} http://media.sensationcontent.com/rowan/flatbedcrop1.png ), however
} the print from the cheapie scanner ends up looking more aesthetically
} pleasing than the professionally scanned one!
}
} The scan + Pegasus print cost $44. Am I being too fussy for that price
} or do you think I am right to feel unsatisfied with the quality of
} this scan?


Was this their "Hi End / Drum Scanning" or one of the other services? See
http://www.cpldigital.com.au/scanning.html.

Regards,
Aaron Queenan.

 

[Rowan Crowe]

Was this their "Hi End / Drum Scanning" or one of the other services? See
http://www.cpldigital.com.au/scanning.html.

The only reference I can find to 250dpi scanning on that page is "Set
up for Peg. / RGB 250dpi" under the heading "Digital Scanning Price
Scale." There isn't any mention of this heading in the descriptions on
the right-hand side of that page.

I did ask in my email which method/device they used for scanning the
slide...

 

[Bart van der Wolf]

SNIP

One thing I forgot to add: the currency of the charge! It was
$AUD44 (about $USD30) which may make some difference
to your "pay too much" opinion.

That's a bit better value for money, but it must be possible to get a better
quality, and certainly a bigger file if it needs to be printed at 8x10in. At
250ppi (if that's the Pegasus' native resolution), a 2000x2500pixel file is
needed.

I also expected that the scan would be at a higher resolution
and then downsampled. I'm disappointed at how digitally sharp it looks;

On screen (pixel for pixel) it may look oversharpened, in print it may be
okay.

I naturally assumed that the quality would be similar to a
chemical enlargement, perhaps a little sharper. When you say
time consuming, do you mean that the scan takes longer at a
higher resolution, or that the operator needs to spend more time
adjusting the scan?

Scan time.

According to their web site, each image is scanned and retouched

individually.

Makes sense.

SNIP

Here's what the company has to say about the service that I ordered:

http://www.cpldigital.com.au/pegasus.html

I see that the scan comes as an AUD 11.00 option to the printing process,
that seems fair enough, but then the print is rather expensive ;-). The
benefit is also a color managed scanner+printer and monitor for color
balancing workflow.

Bart

 

[Rowan Crowe]

SNIP

That's a bit better value for money, but it must be possible to get a better
quality, and certainly a bigger file if it needs to be printed at 8x10in. At
250ppi (if that's the Pegasus' native resolution), a 2000x2500pixel file is
needed.

The scan was from a 35mm frame so rather than cropping I opted for
vertical whitespace, which is why the shorter side of the scan is not
in proportion to the print. The longer side is 10" @250dpi = 2500px,
which the scan covers. 2614px actually exceeds that number and the
print has a border on all sides which further reduces the required
pixels, so the Pegasus machine appears to have internally downsampled
the image by about 9-10%. I guess that would offer a slight
improvement in final print quality. BTW, I can't see the diagonal
staircasing on the print unless I look REALLY closely, but viewed
normally the whole thing still looks way too sharp. I did a Gaussian
blur on that scan and the print looks a lot better.

I hope to be making 20x30" prints of my slides one day, so that's why
I am bringing up this problem with the test print...

 

[JD]

Hi Rowan

I'm a pro-photographer in Melbourne that set up a scanning service to fill
in the down-time between shoots...I do a lot of work for people who aren't
too happy with CPL (price and performance).

I hope you won't consider this spam, but have a look at
http://www.imagesciencescanning.com.au

We're very affordable and our goal is to work with our clients to get them
the best possible results.

If you just want to do a test scan so you can see the difference and show
CPL, I'd be happy to help (free of course).

Cheers

--
Jeremy Daalder
Australian Landscape Photography

http://www.jeremydaalder.com

Digital Services - Affordable Hi-res Scanning and Printer Profiling

http://www.imagesciencescanning.com.au

 

[Philip Homburg]

I hope to be making 20x30" prints of my slides one day, so that's why
I am bringing up this problem with the test print...

I think that if you want to play with the digital image yourself it is best
to get an uncorrected scan (preferably with an ICC profile of the scanner).

Sharpening for prints (what they did) should be the last step in the
whole process. The scan you got is basically only good printing.

The next thing is trying to get 16-bit/ch output.