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shaunm71
01-16-2007, 03:14 PM
I have a question that I am sure has been answered here, but I am still struggling with. I have an HP 3570c scanner that I use to scan kodachrome slides. I typically set it at 72 DPI re-size my image to 1024kb x 700 or so, and sharpen the slide using either the extreme or high setting. I seem to consistantly have two reasons for slide rejection. Bad Color: Not enough color depth or too much color saturation (what exactly does this mean and how do I identify it before I send it) or I have an image that still seems blurry. I have had slides that are accepted using the methods stated above. All are properly exposed and properly lit. I have to admit that the scanner is new to me and have so far resisted the gigital age. I feel a bit frustrated since I have been shooting slides for 20 years with great results but am unable to get a decent scan for posting. I am not looking for a print quality scan either. Any ideas? Thanks, Shaun McGinnis

scottychaos
01-16-2007, 03:56 PM
Slides need special color correcting to convert them to acceptable scans..
real slides, the ones you project, are actually quite dark and quite cyan/blue..they are that way on purpose, because they are meant to be projected in a dark room and the "dark and cyan" balance is needed so our eyes see them as "normal" in the dark room..
They look great when projected! We dont "see" them as too dark and too blue when projected, but its really there...so when they are scanned with no correcting, THEN we can see the dark and cyan balance, because we are no longer looking at the scan projected on a wall in a dark room.

Thats why you see a LOT of scans from slides that have a very cyan color cast..
they have not been corrected.
I got yelled at on this forum before for pointing that out! ;)

Did your scanner come with any photo editing software?
If so, it might have a prodedure for correcting slides..
I googled your scanner, and found a review:

http://www.ephotozine.com/equipment/tests/testdetail.cfm?test_id=159

notice the "Sample transparency scans" at the bottom of the page..
they look..yep..dark and blue!

That picture of the seagull is a perfect example of what im talking about..
the way that photo of the seagull looks on that webpage is the way the slide REALLY looks! the white of the seagull's feathers is really that dark and cyan on the actual slide, the white buildings in the background are really that dark and cyan on the slide..the scan posted on that webpage is an accurate depiction of what the slide really looks like!
but if you *project* that slide, with a slide projector, in a dark room, the seagull will be a nice, crisp, bright white! it wont *look* too dark and cyan..
our eyes adjust for the darkness of the room..slides need that "wrong" balance to "look right" in a dark room..
so slide *scans* need to be corrected to *remove* the dark and cyan balance to make the scan look "normal" again..

(all the above information comes directly from the Eastman Kodak Company, where I work as a research technician...its not a secret, slides have been balanced that way as long as slides have existed..its just not generally known.)

What kind of imaging software do you use? (what program for tweaking digital photos?)
if we know that, maybe there is a specific balance procedure for that program.

Scot

shaunm71
01-16-2007, 04:09 PM
Wow. Now I feel like a total newbie....... The only editing that I am doing is at the scanner. I do have a new laptop that has a Micrsoft editing program on it that I haven't used yet. Would I scan the slide and then edit the image later? I will check on the software tonight. Thanks for the help!

alan-crotty
01-16-2007, 04:17 PM
Hi Shaun,

In addition to Scots advice you may like to try scanning at a higher resolution, then reduing the size in, say photoshop or Elements.

I always find that it's better ti start off with more information than you need, then let your image editing software resize the image down to 1024x768 pixels (BTW you do not need to specify a DPI when sizing in Pixels), this way you are letting the resizing programme carryout the interpolation work.

Try scanning the slide as if you were going to make an A4ish size print at 300dpi that would be say a 3508 x 2408 pixel scan. About 23.5meg files size.

Now in you image editor resize (tick resample image) to 1024 x 681 pixels.

Once resized apply a little unsharp mask at say

Amount 50, Radius 1 and Threshold 0.

That should sort out the blurry image.

BTW carryout all your colour changing work and lightness/brightness work BEFORE you re size.

Something else to consider is that ICE dust removal can react badly with Kodachrome slides.

Hope this is helpful

Alan

scottychaos
01-16-2007, 04:19 PM
The way the slide itself actually looks, and the way a direct scan with no color or density correction looks, too dark and too cyan:

http://gold.mylargescale.com/Scottychaos/temp/seagull1.jpg



The way the slide looks to our eyes when projected in a dark room,
and when corrected in photoshop:

http://gold.mylargescale.com/Scottychaos/temp/seagull2.jpg

I lightened the image,
removed almost all of the overall cyan cast by desaturating the cyan channel only, for the whole image.
still a bit overall blue/cold cast, so added back in some yellow to warm it up.
sharpened slightly.
and removed some of the leftover blue from the seagull alone.

the seagull still has a bit of magenta cast in his feathers..it could be tweaked further..all the white areas of the seagull could have all color removed..desaturate all color completely..but I didnt do that.
(except for the red reflection on the bird's belly, you would want to keep that since that color is really there..)

Scot

JRMDC
01-16-2007, 05:36 PM
Scot, that's fascinating info, thanks.

BTW, is there any software that has an automatic correction function for slides? Or is there too much variation in the extent of imbalance for that to be feasible?

scottychaos
01-16-2007, 06:01 PM
Scot, that's fascinating info, thanks.

BTW, is there any software that has an automatic correction function for slides? Or is there too much variation in the extent of imbalance for that to be feasible?

Thanks,
yes, there are programs that offer automatic correction, I know they exist.
but its been about 6 years since I worked in an area that did anything with film scanners, so im out of touch with what is out there these days.

but this "problem" is nothing new, all the scanner makers are well aware of it, and any decent slide scanner should just have it built in somehow..either automatically at the time of scanning, or with a program that comes with the scanner.

and there shouldnt be much variation..the amount of "darkness and cyan-ness" applied to slides is fairly universal, so the correction should be fairly universal as well..

I dont work with scanners anymore, so im not sure what is out there there days in terms of "correcting software",
I just know why the dark and cyan thing happens, because its built into the slides, but I always just correct for it manually in photoshop..and create an "action" if many images need to be corrected all at once...photoshop is all I have ever used, so sorry, I cant really help with other programs.

I have scanned whole rolls of slides before, and I would do one correction in photoshop, get the image looking the way I want it (like with the seagull above), while I was making the corrections, I could set photoshop to "record" all those steps, (its called an "action" in photoshop), then you can "run the action" and photoshop will apply the exact same changes to every image..when I have done that, the changes for the first image resulted in good corrections for the whole roll, so thats why I think the corrections should be mostly universal.
but I have never used anything except photoshop to do this..

Scot

JRMDC
01-16-2007, 06:10 PM
Thanks. I was just curious. While I have some old slides (and negs), it hasn't been a big priority to scan them. Maybe that means it will never happen? :) I would have to rent a slide scanner.

scottychaos
01-16-2007, 06:23 PM
Thanks. I was just curious. While I have some old slides (and negs), it hasn't been a big priority to scan them. Maybe that means it will never happen? :) I would have to rent a slide scanner.

Any digital minilab should be able to scan slides for you.
(and pretty much ALL minilabs are digital minilabs these days)
shouldnt cost any more than having negs scanned and burned to a disk.

I would try a store that is more of a "camera store"..someplace that sells cameras and also has a lab in the store..they would be a lot more knowledgeable than the minilab at the drug store, grocery store or Walmart-type store..

Scot

WembYard
01-16-2007, 07:25 PM
Excellent thread - I have a Nikon Coolscan V ED and have noticed all of the problems mentioned.

I usually scan at the highest resolution possible and save as a psd file though am wondering whether it is really necessary to have a file that is about 50mb in size. So far I have only used the scans for the web, doing all further adjustments and re-sizing in Photoshop (Elements 5 in this case).

What resolution and size should I be aiming to save the psd file at? Bearing in mind that I do not wish to go back and re-scan thousands of slides and negatives in the future should I need to make, say, A3 prints at some stage.

Also what are the problems to be aware of when scanning colour negatives (have several thousand of those too!) - I have not started on those yet, but will do so at some stage. Most of them are Fuji of varying types though there are some Kodak ones around the late 1980s early 1990s mark).

The Coolscan appears to be happiest with Fuji slides, I have had mixed results with Kodak, despite using the special option for Kodachrome positives - for examples of scans see pre-2005 photos via RP link in my signature or HERE (http://www.railpictures.net/showphotos.php?userid=17294) for Mr WembYard's (which I administer for him) again, any post 2004 is a scanned slide.

a231pacific
01-17-2007, 05:05 AM
The HP 3570c is a flat bed scanner, designed for scanning prints rather than transparencies. There is a slide scanning adaptor, but the results will not be close to what you can get with a dedicated slide scanner.

Since a 35mm slide is a little over 1" wide, setting the scan at 72 dpi would mean only 72 pixels. I doubt if the scanner works at anything below it's maximum 1200 dpi rating when the slide adaptor is used. This is still pretty marginal for slide scanning. The least expensive dedicated scanners work at around 2400 dpi. Also dedicated slide scanners usually have included special software for eliminating dust and scratches as well as correcting color and reducing grain.

Depending on how many many slides you want to scan, you may want to buy a dedicated film scanner. $600 gets you a new Nikon coolscan V scanner, which scans up to 4000 dpi. $200-$300 will get you a good used Nikon LS-2000 on eBay that scans at 2700 dpi. You can pick up a Minolta Scan dual II on eBay for under $100, but Minolta is out of the scanner business and you are on your own for support. Nikon still supports the LS-2000 with software upgrades. Digital ICE comes with the LS-2000 and is terrific for getting rid of dust and scratches automatically.

Michael Allen

JRMDC
01-17-2007, 12:30 PM
If you live in the Washington DC area, you can go to the pro photo store, Penn Camera, and rent a film/slide scanner - either a Nikon Coolscan 5000ED or 9000ED. Try a pro photo shop in your town, I would think someone does this everywhere.

andy buckley
01-19-2007, 11:27 PM
This has been a most helpful thread :thumbsup:

many thanks to shaunm71 for asking the question and to all of you who added some very useful points.

I've just bought a Nikon IV ED on ebay so I'm hoping to start scanning my slides as soon as I've worked out how to do it.

alan-crotty - I didn't know Digital Ice 'reacted badly' with Kodachrome

Something else to consider is that ICE dust removal can react badly with Kodachrome slides.

Could you say a bit more as to what kind of reaction?

Are there any other formats that Digital Ice won't work with? - I have quite a few AGFA and Ektachrome slides and much of my earlier work is on B+W negatives...

andyb

alan-crotty
01-20-2007, 12:09 PM
Andy

Digital ICE can react badly to KChrome due to the structure of that film. If you look at a KChrome from the right angle you'll see that there are apparent ridges in the emulsion, this has something to do with the structure of the film. I am not a KChrome expert, I only used it for a short time and then exclusively used FujiChrome for years. I found the gen on KChrome in a magazine after I had had problems scanning some of my few KChromes. I have a Nikon Coolscan 3, A friend has a Coolscan 4, and that has a setting for KChrome, so you might have greater sucess than me.

I expect someone on this forum has experience of the Coolscan 4 and KChrome.

One thing to be aware of with the Nikon scanners, they do suffer from dust on the mirror system that makes up the light path between the tranny and the sensor. The problem shows up by producing a diffused image.

The fix is easy though, I did the complete job in about 45 mins, just follow the instruction

for coolscan 5

http://www.pearsonimaging.com/articles/howto/ls5000cleaning.html

fFor coolscan 3

http://www.vad1.com/photo/dirty-scanner/ls2000-cleaning/


These are for a Coolscan 3& 5, but yours is pretty much the same as a 3 I think.

Weather looks set fair for Monday and the Super D :D



Alan

TonytheTiger
01-20-2007, 05:13 PM
I usually scan at the highest resolution possible and save as a psd file though am wondering whether it is really necessary to have a file that is about 50mb in size. So far I have only used the scans for the web, doing all further adjustments and re-sizing in Photoshop (Elements 5 in this case).

What resolution and size should I be aiming to save the psd file at? Bearing in mind that I do not wish to go back and re-scan thousands of slides and negatives in the future should I need to make, say, A3 prints at some stage.

I only have a flatbed Epson scanner with a transparency adapter to use for my scanning at this time. I hope to upgrade to a Nikon CoolScan someday.

I scan all of my slides at the highest resolution possible. I initially save them as .tif files and do my adjustments at that resolution - then reduce them to 300dpi and 3600 pixels wide. I save them as a .jpg with compression set at 5 which results in a file around 3meg (about the same as a digital camera's Jpeg Fine setting). When I submit it, I reduce it to 1024 pixels wide, do some additional sharpening, and save it as a .jpg with compression at 1.

The ones I take to Wal-Mart to get prints made have been saved at exactly 4"x6" which results in around 600dpi, and makes excellent "post cards". I have successfully made good 13"x19" enlargements from my scans (which is around 190dpi).

Every scan I have made has needed to be lightened and color adjusted. One setting I use a lot is RGB [-10R, -3G, +10B]. I stopped using the "One Step Photo Fix" feature since it usually results in a "water color" overall effect with a loss in sharpness. One thing for sure - never use the automatic scratch removal feature of the scanner! It may be good for portriats and landscapes, but it will ruin a photo with the detail on a typical railroad photo. It almost always results in letters and numbers with openings having them filled in. I go on a scratch and dust hunt and remove them with the clone tool before I do my adjustments.

I'm sure that someday a book will be written about all of the ways to fix an old 35mm slide that has been scanned.