What resolution to scan at?

[Janet]

It's the eternal question that just isn't a cut and dried answer from what I've found. In the end, it comes down to what works for you. Period.

So, to start with take a look at this article that helps a bit with the complexities here, and WHY 300 ppi is 'the standard" for scanning. I still wrestle with understanding all of it. It is hard to get your mind around it. Lisa and Lauren have got such a great grasp on it and much I've learned has been from them, but also by doing my own experiementation and asking anyone who may have more info on the subject.

http://www.digitalscrapbookplace.com/university/articles/ppiexplained1.shtml

And (toward the bottom of this next one is about 300 ppi and why it's the standard).
http://www.digitalscrapbookplace.com/university/articles/ppi.shtml

So...once you've gone through those, THEN go onto the next post. :)

[Janet]

OK, so now that you get that 300 ppi is there to just cover the extremes, now you've got your box of images. What to do?

Decide the MAIN way you will use them. How large do you think you'll want to print them? What size are they NOW? A tiny slide or even smaller disc camera negative (remember those? Yeah, I've got some). Those are an inch across or smaller! Scanning it at 300 ppi and leaving it at that tiny size won't give you squat to work with.

So, let's say you would...usually at most want to print an 8x10. Then you have your answer. You can stick with 300 ppi at an output size (the final size of your scan) . Simple 8x10 at 300ppi. BUT...what if you think you'll want to crop out the acres of grass you have showing in the photo? (Yep, took a lot of those as a kid myself). You can crop with your scanner. OR, you can go even larger if there are things in the background that might come in handy as an accent photo in a layout. With those, I bump them up to 600 ppi.

One of the drawbacks of one of my scanners is that it's limited on how large I can go....or I don't want to deal with an image that's 2 feet across. The latest extreme I did was for my sister's brilliant idea: to get an image of my folks' for their 50th anniversary scanned well enough to create a lifesize image of them (turned out to be a few inches shorter due to the width of the dress my mom wore). The width of the printer was 40" and could be as long as needed. The image was 4" wide (handy for someone who can do, but doesn't like math). 40" x 300 ppi = 12,000 pixels wide. The end scan didn't need to be 40" wide, so I cut it in half and did 20". Cut that size in half, but doubled the ppi to 600. 20" x 600ppi = 12,000 pixels wide. Cool. I could do that. It came out to be almost a gig in size, but it came out just GREAT...AND was the hit of the party!

So, scanning depends a LOT on
1. What quality you want in the end product (keep in mind that article about what's needed for MOST printing)
2. How large you think you'll need to use the image and if you'll be using the entire image or if you think you'll be cropping

More to come...

[Janet]

http://www.digitalscrapbookplace.com/gallery/showphoto.php?photo=104143&nocache=1

Here's the (almost) life size version of the image my sister created & mounted on foam core. FUN to see everyone's reaction on this! :)

[Janet]

Oh! Another tidbit I've come across is that many museums scan in their collections of 35mm slides and negatives at 3000 ppi - and kept to the same original size (you can convert it to a large size at 300 ppi but it's still the same).

Often their collections are extensive to say the least (and some of us have comperable sized collections). They don't want to rescan endlessly as technology jumps. They want to digitize ONCE...and funny, so do I. :) So, I came at this more from an archiving side rather than a quality of print side. Our local historical society was wrestling with this issue which got me going on the archiving sites. From articles I've read over the past few years on those (I'd have to do some digging, but they're probably still online), it sounds like 35mm stuff scanned at 3000 ppi pretty much gets you to film grain. Professional photographers often bump that up to 4000 ppi (or convert to the same pixels at a size for 300 ppi) so they have the ability to crop a horizontal photo to a vertical one and still meet criteria for the extremes of printing (like large calendars or large, sofa sized art prints to hang on someone's wall).

Personally, I do most of our family's 35mm stuff at 2000ppi for scrapping purposes. Any of those jpgs (I also ALWAYS save as TIff's as my archive copy) uploaded to kodakeasyshare gallery says they print out at up to 20x30 (that average printing thing again). MORE than enough for me to do some serious cropping. :)

[Janet]

Someone PM'd me and asked wouldn't 200 ppi be fine? Isn't that what DSP uses?

YES. Give it a try. Look again at what the printing requirements are. Same as if you created an element at 200 ppi and then recreated the same element the same way at 300 ppi - scan the same image at the same output size. Once at at 200 ppi and once at 300 ppi. Then print.

I've just used 300 ppi because that's what the photo world uses as their standard, though I had to 'retrain' myself to use that - the archiving world uses 3000 as a 'standard' also for 35mm stuff. The difference is in the output size. The end file size is virtually the same.

Using 300ppi at 12x12 for scrapping is overkill in my book (recently HAD to, due to publisher requirements, create full page magazine layouts at 300ppi and even with 200ppi elements - used with permission - almost killed my computer -- but it did train me to save often!). And, my images from my camera are...200ppi at 10.26 x 15.42". And those uncompressed jpegs also say at my kodak gallery that they'll print at 20x30.

[Vallie]

Gosh Janet, my head is swimming!!!! Lots of great information though. I have heaps of 35mm slides that I never look at anymore and they are getting dusty and dotted with I think may be mildew even though they are stored in wooden slide boxes. So I guess that is another job to clean them before scanning. I would like to scan some of the better ones (a lot are probably lousy anyway). I have a HP scanner 3770 which has a slide mount in it. I did one slide but wasnt that happy with it as I really dont know what I am doing half the time. What dpi (ppi) should I scan the slides at to get a print good enough to scrap, I usually do 8x8 layouts. It probably has something about it in the scanners manual but of course I dont know where I put it. Also I had a thread in General Scrapbooking recently about cleaning the scanner, perhaps it could be moved to this area. I like the new arranging of the site, it is easier to find things. Thanks :)

[Janet]

Glad you like the rearrangement of the site - I like it better as well! I have moved some threads over here, and will continue to look for others. I think the one on cleaning scanners is here as well as the one on products to use to clean slides.

Understanding ppi (or in scanning they sometime refer to it as SPI - samples per inch) is tough! You're pretty safe scanning things in at 300 ppi with an output size of around 8"x10" (or whatever the proportions come out to). If you can't set the output size, and are scanning it to the size of the slide itself, then scanning 35 mm slides at about 1000 ppi should be around the same.

I do all of our family slides for scrapping at 2000ppi to allow me to crop heavily and still end up with the ability to stretch it out to fill a whole background on an 8x8 page at 300 ppi (which is the same as 12x12 at 200).

It does take time to learn what works for you as well as learning your scanner. Take some time and work on a slide at different resolutions settings and then try scrapping them. Also take time to really play with the settings your scanner has and find out what they do. :)

[Vallie]

Thanks Janet. I will have to fiddle around with it when I am not frazzled! I have so many slides to sort through. I am sorry now that I took slides instead of film as a lot of my good holiday stuff is on them and since my projector broke years ago they have been ignored. It was always a pain dragging out the old projector too anyway. Oh well .... one day! :)