film to DVD scan

[clcapope]

I have just started using film again and last week had 2 lots of film processed and just scanned to disk, rather than getting prints and disk.

The images on the disk were grainy and I was unable to zoom on any of them without getting rubbish.

Previous scans were much better quality

The scans from last week were done at 600dpi and the previous ones were 72 dpi

I don't know enough about the scanning to be able to ask the photo shop to do anything specific

What should I ask for, what is the best resolution to use ?
Thank you

[geck]

I've never had negatives scanned by a lab but I've been reading a bit about it on Flickr, and the general consensus is to ask them to scan at the optimum resolution for the scanner - some will say they go up to like 6400 dpi or whatever, but the optimal balance for quality and noise could be say 4800... I've bought a cheap neg scanner from Crazy Clark's which produces a (roughly) 5MP image at 200dpi - image size is 2592*1680. Looking at the images at full size, there is a bit of blurriness, but I wouldn't say they are rubbish. Can you post one of the images for us to have a look at, as well as a full sized crop of an area?

The best thing though could be to just have a chat with the people doing the scanning, tell them the problem and see what they say. Have you tried printing one of the images off the cd? Can I ask where you're getting the film developed too? I know that some places can be a bit... lax with staff training and quality control with regards to film these days.

[ameerat42]

^^I'd have to

[brewster]

Hi, I think I'm missing something here. Are you saying that your original negative was scanned at a resolution of 600 dpi, and you previously had negatives scanned at 72 dpi? Those resolutions may be appropriate to a scan of a print, but are totally inadequate for a negative (or slide). Even scanning a print at 72 dpi seems very low - I usually use 300 dpi on a flatbed scanner to scan a printed photo. To scan slides/negs, I use a dedicated film scanner (Nikon) at 4000 dpi.
I suggest that you check with your lab to see what equipment they are using to scan your negs, and ask them to scan at a higher resolution. Any scan of a neg should be (must!) at least 2800 dpi, and preferably done on a dedicated film scanner, rather than a flatbed scanner. If the lab can't scan at that resolution (preferably higher) and you want to stick with film, I think that you either need to find another lab to do the scanning, or invest in a good flatbed scanner with a good film scanning attachment (eg Epson, Canon).
Regards, Bruce

[clcapope]

Thank you for this advice Bruce. I am really in the dark about appropriate resolutions.

It was the local Kodak shop that did the scanning and I have since found a professional imaging group who talked about 2 different types of scanning techniques and they are happy to do a sample scan using both techniques so I can see the difference

At least now I have some additional knowledge
Cheers
CC

[Big Pix]

72dpi is regarded as screen resolution, just for viewing,...... 300 to 600 for reproduction....

yes you can do prints at 72dpi but small

[brewster]

I think I should clarify my previous post a bit further. 72 dpi (or 96 dpi) is often used as an output resolution for computer displays, as it keeps file sizes small and is therefore easy to send via email etc. For printing, an output resolution from 300 to 600 dpi is common. For scanning printed photos, an 'input' resolution of 300 to 600 is common. I use 300 dpi for scanning photos as the final image quality doesn't differ very much between 300 and 600 dpi, the files are much smaller, and the scan takes a much shorter time. For scanning negatives or slides, resolutions of 2800, 3200, 4000 and higher are common, and are needed because of the small size of what is being scanned.
Consider the size of 35mm film, at approx 1" x 1 1/2". If you scan this negative or slide at 600 dpi, you have a scanned result of approx 540,000 'dots', which will be similar in resolution to an image taken with a half-megapixel camera! How often would you take photos with a half-magapixel camera? However, if you scan the neg at 2800 dpi, your result will be similar in resolution to a 12 megapixel camera (2800 x 4200 = 11,760,000), although you may have lost some clarity due to the scanning process. I scaned my old slides and negs at the limit of my scanner (4000 dpi), so that I only had to scan them once, and then stored them away. 4000 dpi is similar to 24 megapixel resolution.
I hope this helps.