Slide scans -jpeg or TIF?

Hello Everyone

I have a mountaineering friend who has used an pentax film slr for many years and has a huge collection of colour slides taken in many exotic locations.

To archive these he wants to have them all professionally scanned. He has an option to pay slightly more for the output to be saved as TIF files rather than the standard jpeg service.

What do folk think about this - would TIF be a more versatile or more detailed digital image if he then wants to do any further editing on his PC?

Does anyone have any comments about professional slide scanning services?

Thanks

Geoff

Good slide scanning is either expensive or, if done ourselves, both expensive and time consuming.

12 months ago I would have said TIFF, but things are moving along and I'd try JPEG as well and see what you think.

Over the last few months I've been scanning my old negs from my Pentax film camera. I'm saving them as uncompressed TIFs. Why are TIFs more expensive than JPGs? The only difference is the filesize.

TIFF file sizes are larger for a reason. A JPEG is a lossy compression (which means that some info is discarded at file compression stage) - crucially this includes colours.
JPEG will be 8 bit colour depth (images made up of 256 colours)
TIFF will be 12 or 16 bit (the latter being over 60,000 colours)
To eek this extra data out would take longer & hence be more expensive.

In answer to the OP, TIFF's can be pushed further in post process without causing artefacts, but if your friend thinks that the editing will be just a few "minor tweaks" then I can't see why using JPG should be an issue.

I'm in the process of archiving all my slides and negs from years past.

My scanner is a Minolta Dimage Scan Dual IV with Vuescan software. I'm saving as compressed TIFF. Each image file size is about 30Mb and a rack of 4 slides takes around 10 minutes to scan.

My intention is to PP these in Lightroom and output them as JPG's for distribution to other family members, mainly to embarrass them .

Rob, I agree with what you said, but your numbers are misleading (or incorrect)
JPEGs are 8 bits per RGB channel - 256 levels of grey (tones) per RGB channel - 24 bit in total. or 16 million colour permutations.
TIFFs can hold 16 bits per channel but you would normally finish editing and save in 8 bit mode so potentially the same amount of colours as a JPEG but JPEG compression makes assumptions about visual perception and groups or discards data as it sees fit.
Always save as TIFF if you have space and bandwidth on your network or you intend to do further editing.
If you compress your TIFF as JPEG then you will probably have the worst of both worlds!

I would suggest TIFF as more detail will be retained.

He can then get a suitable editing application and use a batch mode process to convert all of the TIFFs to JPG at a medium level of compression so he has versions that can be quickly called up and shown.

If printing of an image is required it can be taken from the TIFF or a low compression high quality JPG.

Thanks Darkmunk for expanding on my explanations. My disclaimer id that it was rather early when I was typing that.

Tiff is better but as there is cost to consider I would probably choose jpeg if there was a decent cost saving.

Thanks Guys, I'll suggest he gets a few done as TIFFs and we see if the extra flexibility for editing is important to him or if he just wants the security of having a digital copy of his amazing slide collection.

I am certainly interested to see the comparison between the digital scans and the projected image in terms of richness/gradation of colours for which i still feel slides have something going for them. But then I still prefer to hear LPs than CDs!

Cheers all
Geoff

In theory the slides should be superior, but in reality next to digital projection they look very dull.

At ADAPS we tried running competitions that included real 35mm slides and also digital files projected, and the digital ones were brighter, clearer, more vibrant in every way.

Why? Probably because of the resolution and perception of the eye which sees a 72ppi image at several feet away as full of detail. As a print, viewed close, it would look awful.

It will be interesting to see what you think.

Digital images may well look better post processing, but how would they compare with a slide if viewed straight from the camera?

As for scanning I dont think you'll ever get the quality from a scan that would match the original, not yet at least

The slide is the finished product usually, so what you take is what you get. All the adjustment is done in advance, in terms of composition, use of filters, choice of film, etc.

With digital the adjustment is done mainly after the image is shot, as we are now quite familiar with.

So I don't really think you can compare fairly one or the other by excluding the processing stage for that option.

Thanks all

I will be very interested to gauge his reactions. He'll doubtless want to get into post-processing and enhancement in order that the images do justice to his memories.

Seems he can now have the TIFF files at the same price as jpegs so this should give the better platform for post processing.

I will let you all know when we get to see side by side images.

Thanks again
Geoff

yup

How do you mean eek the extra data out? You don't scan compressed, you choose to compress the data as a JPG after scanning ( within the scanner if a compressed file is the chosen output file of course )

Perhaps it's more expensive because more discs are needed to burn the larger file sizes, which also takes longer.