grain as a resolution limiting factor?

<p>Hello !<br>

The fine grain of the Velvia 50 is said to provide somewhere around 12-15 MP . But a grainier film ( ISO 100 ,200 and 400), like those that I currently find and shoot ? Is the grain a limiting and resolution downsizing factor?<br>

If so, does it worth investing in a high resolution scanner if I shoot mainly 200 and 400 , or should I prefere something providing around 7-10 MP ?</p>

<p>Grain is not the limiting factor, but it does degrade sharpness. The best objective measure for subjective sharpness is the signal-to-noise ratio. As the grain goes up, the sharpness goes down, but this doesn't necessarily affect the resolution. It does reduce the contrast in the higher frequencies. The simple version of this measure is to divide the MTF response (wavelength by wavelength) by the Wiener power spectrum (which is the granularity wavelength by wavelength). If you really want to dive into the technical details, go to the library and check out a 1962 Journal of the Optical Society of America: (E. C. Doerner, J. Opt. Soc. Am. 52, 669 (1962).)</p>

<p>Grain does in fact limit resolution. If not for the grain clobs, you could enlarge much more...for the most resolution I shoot with a 21mp DSLR...but I prefer film for it's wider dynamic range, and smoother tonalities. I have countless color negatives that I wish I could enlarge bigger, except for the grain...it's the limiting factor.</p>

<p>35mm FujiFilm Superia ISO 400</p><div></div>

<p>What Ron said.<br>

But in terms of scanning grainier films, the general advice is to use the highest resolution you can get. There's a problem called "grain aliasing" in which 2000 ppi and 2800 ppi scanners can make a horrendous mess from ISO 200 and 400 negative films. This is ameliorated by higher resolution scans (most 4000 ppi scanners are fine). You can then apply noise reduction and downsample the scans to a more reasonable size for final sharpening and printing, if you are printing smaller than 12x18.</p>

<p> </p>

<p>I agree that grain may limit the overall quality of a photograph, but that wasn't the question. If we are strictly talking about resolution, grain has a minor effect. For a very sharp film like Velvia 50 or Ektar 100, the limiting factor is often the lens in the camera.</p>

<p>Thank you Ron , Dan , David !<br>

Beautiful bokeh and colours , Dan !</p>

 

<p>Thanks Dan....I love Sedona.....and enjoyed a few cold ones there while spending two weeks photographing in the region.</p>

<p>There is more than resolution that comes with a decent scanner. Speed, color accuracy, DMAX and noise among other.<br>

A Nikon Coolscan is probably the minimum investment needed for film you intend to print for display.<br>

Even then, Velvia and TMAX 400 both resolve finer detail than what the Coolscan can retrieve.</p>

<p>This topic is so old that all the beer is gone; and Nikon, Canon, Polaroid, Minolta, Kodak etc do not even make film scanners anymore!</p>

<p>Well Kelly, the topic started yesterday. It's in a film forum. If you don't like it, you can always move on.</p>

<p>As to Nikon not making scanners....maybe nobody has told them:</p>

<p><a href="http://imaging.nikon.com/products/imaging/lineup/scanner/index.htm">http://imaging.nikon.com/products/imaging/lineup/scanner/index.htm</a></p>

<p>There's also scanner from a number of companies....Plustek for starters. Then Hassey, Epson, etc, etc. But what do I know...I only use them for a living.</p>

<p>Mauro, the Nikon 9000 is indeed a solid performer. It makes scans from my RB67 that are incredible. When I need a big enlargement from a film like Pro 160S for a large group portrait, I have an Imacon 848 scan done. Beautiful 32x40 prints on photorag. At least with prints, there really are "dots."</p>

<p>Anyone who uses B&W film (e.g., Kodak Tri-X) knows that grain does not necessarily impair sharpness or resolution. Grain tends to clump along edge detail, and local depletion of chemicals in the emulsion can enhance edge contrast with an effect similar to unsharp mask sharpening. Tri-X often looks sharper than slower film like Panatomic-X, even though the latter has much higher resolution.</p>

<p>You see this effect to a lesser extent when using negative color film. The dye clouds are small and well defined, and I don't find the grain obtrusive except in blue sky or large areas without details, and then only with USM sharpening. Masking areas to be sharpened should be done routinely.</p>

<p>Reversal film has much larger and relatively indistinct dye clouds. You don't see grain, but there are often other artifacts that look like grain. I'm convinced that Velvia shows high resolution with resolution targets because it has such high contrast - 4x that of a typical negative film. Low contrast subjects like tree foliage look no sharper (and perhaps less so) with Velvia than with Reala or Ektar 100.</p>

<p>I agree grain can make a photo look sharper when printed at normal size. What you see on screen @ 100% is not what you see in print. And that grain for me adds a sense of gritty reality that my digital stuff can't match. Here's a wagon I found in a doorway.</p>

<p>woops. ok here's the shot.</p><div></div>

<p>And here is a 100% crop. DP review would say the "noise" at 400 is almost unusable. LOL. This is not a high end scan but I doubt there is a lot of info left. When you hit the grain you hit the grain.</p><div></div>