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New to LF Journal 3: processing

Erik DeBill

New member
Saturday everyone went to my parent's house to help them put up Christmas lights. Naturally, I took my camera, which let me practice taking long exposures and thinking about reciprocity failure.

Once I developed the film, it meant I had several shots to scan and work with on the computer. Before, I'd never had more than one negative to scan and process at a time. What's more, 2/3 of those negatives were from polaroids, which aren't quite as big as 4x5 negatives. That little bit of extra size makes a big difference. Like the difference between 2G of RAM being fairly comfortable and it being painfully slow.

The slow pace of processing these large files made what seemed like it should be a 30 minute job turn into a several hour ordeal, waiting for progress meters to complete. Saving the files afterwards was painfully slow, too. I'm either going to have to spend a lot on upgrades or learn to be more efficient when I'm processing files on the computer.

I'd seen recommendations to always scan at a resolution based on your intended output, rather than always going for the maximum. That makes a lot more sense in the context of overloading my computer. There is so much information in a 4x5 negative that unless I'm going to print it truly huge, I may be better off backing down on the scan resolution. I'd already gone from 4800 to 2400 dpi. Next time I'll start with 1200. I might even try scanning at both 600dpi and 2400dpi, then processing the 600dpi image, saving a template and then applying it to the 2400dpi scan all in one go.


LF000003-christmas_lights-pad.jpg
 

Don Lashier

New member
Great shot Erik,

Your experience here along with digging up my old negs for the "rangefinder" thread has me thinking about doing some b/w film again also, but maybe 2-1/4 rather than 4x5 - was good enough for most of my needs and roll handling is a lot less work than sheet film. NOTHING DIGITAL yet compares with film for b/w. Time to check ebay ;)

- DL
 

Asher Kelman

OPF Owner/Editor-in-Chief
Erik,

It's impressive! Now I'm thinking of my olive tree!

You are doing a great job and making the creative juices start to flow towards B&W film!

Asher
 
Erik DeBill said:
I'd seen recommendations to always scan at a resolution based on your intended output, rather than always going for the maximum. That makes a lot more sense in the context of overloading my computer. There is so much information in a 4x5 negative that unless I'm going to print it truly huge, I may be better off backing down on the scan resolution.

"Always" and "never" are words to be used with caution, especially when scanning.

In general I'd recommend scanning at native scanner resolution, to reduce grain-aliasing as much as possible. In the case of web-publishing one might get away with scanning at a few times higher ppi than output resolution, followed by proper down-sampling. You might want to try 4x over-sampling for the output ppi needed.

When scanning, I generally use VueScan Pro, I use native resolution scanning for a Raw scan. From there it is rather fast to read the Raw scan and re-purpose the output for the intended use, while avoiding the need to physically handle the original again. VueScan allows to "bin/average" the data for reduced (say 4x) output size, to be further processed by a proper down-sampling application, if necessary.

Bart
 

Erik DeBill

New member
Bart_van_der_Wolf said:
When scanning, I generally use VueScan Pro, I use native resolution scanning for a Raw scan. From there it is rather fast to read the Raw scan and re-purpose the output for the intended use, while avoiding the need to physically handle the original again. VueScan allows to "bin/average" the data for reduced (say 4x) output size, to be further processed by a proper down-sampling application, if necessary.

This is pretty much what I've settled on at this point. I'm using VueScan Pro scanning at the max optical resolution of my scanner (4800 dpi) and having it simultaneously save a RAW and a 4x downsampled version which I then process and further downsample for web or print. My printer only goes up to 13" wide, and I have not yet made an image I like enough to try a print large enough to need something bigger than that 1200dpi scan (which needs downsampling to print at 12x15").

My original attempts with using lower resolution scans to create templates for application to larger scans weren't producing enough of a speed boost to make it worthwhile when the larger images were only 1200dpi. I still plan to revisit that when I make a print that needs higher dpi.
 

Asher Kelman

OPF Owner/Editor-in-Chief
Erik,

Are you using ImageMagick for the 4X downsampling as Bart suggests? I'm especially interested in the Unix version to have a Mac OS X derivative we could use without knowing about command line instructions.

Anyway, it's great to follow your progress in this revival of your film work!

Congratulations!

Asher
 

Erik DeBill

New member
Asher Kelman said:
Erik,

Are you using ImageMagick for the 4X downsampling as Bart suggests? I'm especially interested in the Unix version to have a Mac OS X derivative we could use without knowing about command line instructions.

I'm afraid I'm letting VueScan do the downsample for me. Even using ISO 400 film I haven't noticed a lot of problems with grain, except when scanning at 600dpi. I chose XTOL as a developer based on recommendations that it helped with grain when scanning :)

Being a former Unix junkie my natural inclination would be to use ImageMagick from the command line. I used to use a combination of ImageMagick and dcraw to do my RAW processing (RAW -> RGB, whitebalance, light curves adjustment and input sharpening) before going to a graphical tool. I only really stopped when I upgraded cameras and the 20D had a weaker antialiasing filter that dcraw didn't play nice with (all my fine detail like twigs and grass had bands of aliased colors).
 

Asher Kelman

OPF Owner/Editor-in-Chief
Well great that you are not Unix challenged like some of the rest of us! Is there a version for OS X that is more user friendly or could someone prepare it?

Asher
 

Erik DeBill

New member
Asher Kelman said:
Well great that you are not Unix challenged like some of the rest of us! Is there a version for OS X that is more user friendly or could someone prepare it?

Even on the Linux side, where people like to wrap complicated command line programs in pretty GUIs I've never heard of such a thing.

There is a binary distribution for OS X here, but I'm afraid it's the normal CLI version.

It's fairly easy to use, though.

Code:
convert scan.tif -filter Lanczos -resize 3000x2400 smaller.tif

I suspect that someone with a modicum of OS X programming experience could make a nice icon that wrapped that, so you could drop an image on it and it'd pop up a dialog asking for what size and giving a dropdown to choose resizing filters. Unfortunately, I'm not that programmer :(
 
D

Deleted member 55

Guest
Problems with grain on 8x10 Polaroid?

Even using ISO 400 film I haven't noticed a lot of problems with grain

Hello Erik,

I have been getting good results with ISO 800 8x10 Polaroid (hi key) scanned at 2400 DPI.


Now you have me thinking to try a low key long exp.
 

Erik DeBill

New member
I have been getting good results with ISO 800 8x10 Polaroid (hi key) scanned at 2400 DPI.


Now you have me thinking to try a low key long exp.

All my long exposure problems have been pilot error. I don't get the feeling that grain increases on long exposures (I haven't gone much more than a minute or so). So with digital you can avoid reciprocity, with film you don't get long exposure noise.

What model polaroid are you using? I've been using type 55, which is ISO 50 (but gives a very high definition negative to go with the positive).
 
D

Deleted member 55

Guest
4x5 Polaroid to proof 8x10 Polaroid!

What model polaroid are you using? I've been using type 55, which is ISO 50 (but gives a very high definition negative to go with the positive).

Type 803 ISO 800 8x10 and for the the test shot I use type 53 ISO 800 4x5.

Kind of ironic I use 4x5 Polaroid to proof my 8x10 Polaroid.
 
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