Pages: [1]   Go Down

Author Topic: Roundshot review  (Read 3566 times)

David Mantripp

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 826
    • :: snowhenge dot net ::
Roundshot review
« on: July 06, 2007, 01:57:33 pm »

Wow. A film camera review! Just collecting my jaw bone from the floor. Thanks for an excellent and interesting article, Michael.  Both the sections on the camera, and on scanners and scanning, are fascinating and very interesting. In particular the comments on scan resolution are a timely reminder.  However, I have a small question:  taking as read that there is no point in scanning film at a higher res than around 3200 dpi, in your opinion is there nevertheless any advantage to scanning at a higher resolution (my Minolta goes to 4800 dpi optical) and immediately subsampling prior to any further work ? I can convince myself that I see some advantage in terms of definition from Xpan scans treated in this way.

--David
Logged
--
David Mantripp

michael

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 5084
Roundshot review
« Reply #1 on: July 06, 2007, 02:33:40 pm »

If the scanners native resolution is 4800, then I would use it. That should be the rule of thumb – the highest optical resolution that the scanner offers.

Michael
Logged

Mark D Segal

  • Contributor
  • Sr. Member
  • *
  • Offline Offline
  • Posts: 12512
    • http://www.markdsegal.com
Roundshot review
« Reply #2 on: July 07, 2007, 08:32:03 am »

Quote
If the scanners native resolution is 4800, then I would use it. That should be the rule of thumb – the highest optical resolution that the scanner offers.

Michael
[a href=\"index.php?act=findpost&pid=126872\"][{POST_SNAPBACK}][/a]

Michael, what you are saying is clearly the safest approach in terms of preserving maximum resolution, but there is a question about whether it is necessary - and this depends on expected output. From the work I've done and written-up, I've found it perfectly satisfactory to work back from the largest intended print size (not today but *forever*), and calculate the required scan resolution such that the largest print size will still have resolution within the range of 240 to 360 ppi. For clarity: e.g. largest print dimension 10 inches, desired ppi 360 per inch, scanning resolution required is 10*360 or 3600. The advantages of this is approach are shorter scan times, smaller file sizes, and no resampling - granted the latest resampling algorithms are very good, but I think still better not to use them if avoidable.  On this point, there is a view that downsampling helps to mitigate film grain; if true it also says something about loss of resolution from downsampling; here my experience indicates that film grain is well-controlled using noise reduction software giving one flexibility to adjust the balance between grain reduction and fine detail retention.
Logged
Mark D Segal (formerly MarkDS)
Author: "Scanning Workflows with SilverFast 8....."

Jonathan Wienke

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 5829
    • http://visual-vacations.com/
Roundshot review
« Reply #3 on: July 07, 2007, 04:08:46 pm »

Scanning at highest optical resolution and downsizing as needed reduces noise from the scanner, as well as extracts a bit more detail than scanning directly at the lower resolution.
Logged

Mark D Segal

  • Contributor
  • Sr. Member
  • *
  • Offline Offline
  • Posts: 12512
    • http://www.markdsegal.com
Roundshot review
« Reply #4 on: July 07, 2007, 04:29:42 pm »

Quote
Scanning at highest optical resolution and downsizing as needed reduces noise from the scanner, as well as extracts a bit more detail than scanning directly at the lower resolution.
[a href=\"index.php?act=findpost&pid=127022\"][{POST_SNAPBACK}][/a]

My experience using a Minolta Dimage ScanElite 5400 and making prints at A3 size from 35mm colour negative film doesn't reveal this kind of difference on paper (Epson Enhanced Matte at that time in an Epson 4000).
Logged
Mark D Segal (formerly MarkDS)
Author: "Scanning Workflows with SilverFast 8....."

Rob C

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 24074
Roundshot review
« Reply #5 on: July 08, 2007, 07:26:16 am »

Not an expert on scanners and probably never will be, but there is another thing to be borne in mind and that is that final size of print is never really known.

Some years ago I bought myself a CanoScan FS4000US and I had it tied up to my laptop which was connected to a basic Epson printer. I fell into the habit of ´scanning to fit´ the A4 printer and that, in turn, tied me in to a rather rigid habit of always printing vertically on the sheet. This resulted in largish vertical images but smaller horizontal ones across the vertical sheet. This was entirely self-imposed and the stupidity of not scanning at the maximum available resolution is now very irritatingly obvious to me as I find myself re-doing work that need only have been done once, had I but known and had higher expectations. (Today, the laptop lies in a breaker´s dump and the cheap Epson gets to do nothing more serious than print letters.)

I did like the idea of a horizontal image across a vertical sheet and still do; the problem seems to lie in the matter of scale: what looked all right at A4 does not always work when repeated at A3 - somehow, the larger blank white distracts rather than frames.

I should say that nearly all of my scanning has been of people shots on Kodachrome with a little Velvia for the odd landscape and some black/white negative too. Contrary to what many people report, Kodachrome 64 Pro has worked very well with the scanner. I do not use any scratch elimination functions and all corrections or changes are done later in Photoshop.

My one and only venture into digital capture is with my current D200 and I have to admit that though the colours look beautiful to me, I think film works better when going to black/white. Now this might be entirely subjective, not least of all because I have no people shots on digital, only the occasional scenic of one kind or another and my interest is much stronger in the people zone.

But in any case, I have no doubt that scanning as large as the equipment permits is the way to go. Whether it takes a little longer is not all that important to me - I´d still rather have to do it only once!

Ciao - Rob C

Mark D Segal

  • Contributor
  • Sr. Member
  • *
  • Offline Offline
  • Posts: 12512
    • http://www.markdsegal.com
Roundshot review
« Reply #6 on: July 08, 2007, 08:52:25 am »

Quote
Not an expert on scanners and probably never will be, but there is another thing to be borne in mind and that is that final size of print is never really known.
.......................................

But in any case, I have no doubt that scanning as large as the equipment permits is the way to go. Whether it takes a little longer is not all that important to me - I´d still rather have to do it only once!

Ciao - Rob C
[a href=\"index.php?act=findpost&pid=127097\"][{POST_SNAPBACK}][/a]

While they say "never say never", there are circumstances when one has a high degree of confidence that never is never.

In those circumstances, I also have no doubt that scanning at maximum resolution is NOT always the way to go because I've tested it within the parameters I've mentioned. Have you?
Logged
Mark D Segal (formerly MarkDS)
Author: "Scanning Workflows with SilverFast 8....."

David Mantripp

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 826
    • :: snowhenge dot net ::
Roundshot review
« Reply #7 on: July 08, 2007, 03:59:25 pm »

Quote
Scanning at highest optical resolution and downsizing as needed reduces noise from the scanner, as well as extracts a bit more detail than scanning directly at the lower resolution.
[a href=\"index.php?act=findpost&pid=127022\"][{POST_SNAPBACK}][/a]

I want to believe this but I'm not sure why it would be the case.  Surely if I reduce scanning noise by resampling down, I also can't avoid reducing detail ?  The frequency distribution of the noise must overlap with the frequency distribution of resolvable objects...
Logged
--
David Mantripp
Pages: [1]   Go Up