Storing TIFF files of scanned MF negatives

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Anil Kalagatla

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Hi:

I just started shooting MF (in the 6x6 format using a Mamiya 6) and scanned my first roll at 400 dpi. I knew the files would be large, but yikes! They are ~430MB each. In addition to the disk space, they also take forever to develop in LR4 (even from an SSD).

I'd appreciate any thoughts on how folks save these images for later processing. I thought I'd check before I destructively modify them and delete the originals.

Anil
 
I scan both 6x6 and 6x7 in MF at 4000dpi saved as TIFF - and your right about the size; 6x7 in colour ~550MB, B&W ~185MB, 6x6 colour ~470MB, B&W ~157MB. So for storage, everything sits on a 2GB RAID 1 NAS and I pull it across the network when I want it. As for processing them, I used to have computer performance issues where my approach was:
  • ensure the original was an even pixel count in both directions
  • set black and white points
  • maybe an initial global contrast adjustment
  • then save a copy
  • next down size the image to 50% which is only 25% of the original size
  • now do everything in layers
  • when completed, increase image size to 200%
  • open original saved version
  • place a copy of it just above the lowest background
  • flatten image

Now having said that, I have upgraded my computer to the latest Mac Mini with a Core i7, SSD and 16GB or RAM and working directly on the large TIFFs is no issue; basically instantaneous
 
Save them as .psd files, that format makes MUCH smaller layered files and allows you to store fullres files without reducing their resolution to save on disk space. I also save a flattened tiff version alongside the layered psd in case the Photoshop .psd format ever becomes obsolete.
 
I do down sample most of my scans conservatively. I find that while viewing 100% or 200% I see a fair amount of blur and scanner artifacts. Reducing a 4000dpi scan to 3000dpi retains all image information in a very clean file, and halves the file size. In print tests I can see a slightly more pronounced grain when printing very large (above 120dpi).
I also convert files to dng (you can do this from within LR). This applies a lossless compression which reduces files by about 30%.
 
Thanks for the suggestions!

Craig: With your current configuration, are you able to open the large files from your NAS over the network? I have my main storage on a NAS as well, but opening even 80MB files in Light Room and then editing them is rather slow. I haven't even tried to open a 400GB file over the LAN (it's gigabit)! It's possible that my bottleneck is my PC (a somewhat wimpy Intel Core 2 Quad proc with 6GB RAM).

I might try converting the files to DNG as well, thanks.

Anil
 
Although my scanner is rather humble (Epson V500) I ran into this problem too. It might not be the answer you are looking for, but I quickly optimize the .TIFFs so that exposure and color look about right. Usually this takes all of 15 seconds. Then I save as high quality jpeg. Minor adjustments can still be done on those (if you don't do it on successive copies that is). Works for me.
 
Scanners always get better every year, so I would only scan the negs at the quality that I need at the moment. So if I just want web size scans, I only scan at 1600dpi. If I need a better quality in the future, I will simply rescan it with a much improved scanner at higher dpi.
 
I scan my Negatives at 3600 to 4800DPI save the Master TIF on a server and using batch conversion tool I resize all scans to a lower resolution Din A3 at 300DPI and save them to another folder on the server these are my working TIFs. I never touch the original scans I only work on the resized Tif.

Dominik
 
TIFF is more universally supported comparing to psd files.
I scan 8bit TIFF and also save the layered psd filies.
They take up a lot of spaces
 
Araakii said:
Scanners always get better every year, so I would only scan the negs at the quality that I need at the moment. So if I just want web size scans, I only scan at 1600dpi. If I need a better quality in the future, I will simply rescan it with a much improved scanner at higher dpi.
Click to expand...


Not sure if they have been getting better every year, given that the best consumer scanners currently available (mostly on ebay) are from several years ago (Nikon Coolscan 9000, Dimage Multi Pro etc). Though this might hopefully change with the much anticipated Plustek 120.

All in all, given the hassle of scanning (especially medium format, where you have to worry about film curl etc), I'd rather scan at the highest quality possible just once. Also, one of my goals is to print very large prints, so this is important as well. Given the responses so far, it looks like the only way I can deal with this is by some sort of lossy conversion which I didn't want to do. Since I'm fairly new to digital image processing, I want to keep my files in a non-destructive form. I will do some experimenting to determine my bottlenecks and deal with them. Fortunately, since I'm using film for this and given that I end up culling a large number of shots anyways, it's not like I will have thousands of 450MB files :)

BTW, after my earlier post, as an experiment, I went ahead and copied one of the 450MB files to my NAS and opened it in Lightroom over the LAN. It took about 45sec to open it in the Develop module, but once open, it was not too bad: I was able to make various changes fairly quickly. Now I just need to figure out how to reduce this 45sec waiting time.

Anil
 
Anil Kalagatla said:
Thanks for the suggestions!

Craig: With your current configuration, are you able to open the large files from your NAS over the network? I have my main storage on a NAS as well, but opening even 80MB files in Light Room and then editing them is rather slow. I haven't even tried to open a 400GB file over the LAN (it's gigabit)! It's possible that my bottleneck is my PC (a somewhat wimpy Intel Core 2 Quad proc with 6GB RAM).
Click to expand...

Anil,

My NAS connection is GigEth through a switch and I have just been running a few rudimentary tests opening 157MB 6x6 B&W TIFF scans as well as converting one to RGB (440MB) and trying again. Starting point was PS CS5 already open - although with the SSD it hardly matters - and ensuring that the particular drive in the NAS isn't asleep; 157MB, as a guess is less than 4 seconds to open across the network and 440MB is under 10 seconds. Most actions on the 440MB image - ie curves, etc - is just short of instantaneous. My previous machine was a Apple G5, which in comparison to the Core i7 is night and day. As well, with images this big; RAM, RAM and then some more RAM is better. Saving a file back, however, can be a little slower
 
craygc said:
Anil,

My NAS connection is GigEth through a switch and I have just been running a few rudimentary tests opening 157MB 6x6 B&W TIFF scans as well as converting one to RGB (440MB) and trying again. Starting point was PS CS5 already open - although with the SSD it hardly matters - and ensuring that the particular drive in the NAS isn't asleep; 157MB, as a guess is less than 4 seconds to open across the network and 440MB is under 10 seconds. Most actions on the 440MB image - ie curves, etc - is just short of instantaneous. My previous machine was a Apple G5, which in comparison to the Core i7 is night and day. As well, with images this big; RAM, RAM and then some more RAM is better. Saving a file back, however, can be a little slower
Click to expand...

Thanks Craig, very helpful!
 
I've been wondering about the same thing since I recently started scanning MF but even 35mm negatives with my V700. I was surprised that there is no equivalent to DNG images with similar file sizes to digital camera files in the scanning software. I see that Vuescan allows for DNG images, but the ones I tried to create (admittedly I still need to better find my way around Vuescan) weren't exactly small and some programmes seemed to have problems opening them. Is there any way to convert TIFF images to "compressed" DNG files?

Best,
George
 
Convert them to DNG with adobes DNG converter. Auto compression, no loss in quality. If you use lightroom you can do it automatically on import.
 
Many thanks for the quick reply - I'll try that. The thing that puzzles me though is that as far as I gather from CNNY the files are still quite large if only reduced by 30% - how come the images are so much larger than say a 18 MP digial camera file? (Sorry if it's a newbie question!)

Best,
George
 
You can also save TIFF with lossless compression in a program like Photoshop. LZW or ZIP - try the different combos and see what the resulting files sizes are. Try to avoid layers - they really bump up the total. You can also select compression schemes for the layers.

If you must have layers, you might be better off saving the edited file as a PSD, turning off 'maximize compatibility' (or whatever it's called, and turning on all the compression options you can. The 'maximize compatibility' option saves an additional copy of the fully merged image in the file so other programs can access, but as you can imagine, it bumps up the size quite a bit. With just adjustment layers, you can get the sizes somewhat reasonable.

As an example, when I go balls out with a 35mm scan, my files are 180 megs. I open that up and dust it then save it. Then I do a 'save as' as a PSD with max compat turned off. Add in all my adjustment layers, do edits, etc. The file size drops down to 110 megs. For comparison, the same file saved as a TIFF (with adjustment layers) was 233 megs (layers ZIP compressed). When I changed the layer compression to RLE (default) it was 518 megs. Obviously, depending on what you put on your layers can dramatically inflate the size, i.e. if you put image data and not just adjustments on the layers.
 
As to why the file is bigger than a digi cam file - TIFF files have 3 bits of data for each pixel: R, G, and B. RAW files from cameras (99.9% of the time) have only one color per pixel: R, G, or B. So the files are roughly 1/3 of the size of a TIFF file of the same dimensions and bit depth. Throw in the fact that some RAW files are losslessly compressed AND they might only be 12 or 14 bit instead of 16 bit, and you get even more space savings.
 
Thank you for all the great answers! I hadn't thought about the sensor array only being in one color!

Unfortunately the conversion via Lightroom does not seem to work, as it gives me the error message that only camera raw files are converted to DNG - so it just makes identical TIFF copies... Is there a setting one has to change for it to do the conversion from TIFF to DNG?

I haven't invested in Photoshop (although am playing with the beta at the moment) since I can't yet justify the expense but I fear I might have to bite the bullet one of these days.
 
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