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Posted on 31/10/09 10:30:39 AM |
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dprangan@yahoo.co.in
* Posts: 24 Reply |
Scan Black & White Negatives
Have got a Epson Perfection V600 Photo. In scanning options are 48 bit colour, 24 bit colour and 16 bit greyscale. I have many old black and white negatives I want to scan now. What is the best resolution to be adopted from the three alternatives stated above. Tried scanning one image in all the three modes and could not come to a conclusion between 24 bit and 48 bit. I would request the Administrator and/or any viewer with experience i n this issue to give me a proper counsel to proceed. I will be extremely obliged. I have enough hard disc space to accommodate them. - Rangan D P |
Posted on 31/10/09 6:46:18 PM |
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GKB
Magical Montagist Posts: 4058 Reply  |
Scan Black & White Negatives
If your negatives are in perfect condition then scanning in greyscale will be perfectly ok however I normally scan B&W negatives in RGB. I may convert to greyscale later but often will just leave it as RGB. As far as I am aware there is no real point in scanning black and white negs in 48 bit so I would leave it as 24 bit (8 bits per channel) but I'm quite prepared to be corrected on that. If the negatives have some colour staining on them they can be easily repaired by removing the channel which has the most staining, hence scanning in RGB rather than greyscale. You would then remove one of the remaining channels to leave the best. Of course, you then end up with a greyscale image. The staining may come from age or inadequate fixing when developed. The downside to RGB as opposed to greyscale is that the file size will be three times the size. Hope this helps. Gordon _________________ Why is there only one body to investigate Monopolies ? |
Posted on 01/11/09 02:58:35 AM |
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dprangan@yahoo.co.in
* Posts: 24 Reply |
Re: Scan Black & White Negatives
Agree with you. File sizes are big. It does not matter. The images can be processed in photoshop and converted back into jpeg. Even then they are around 5 mb size. I tried viewing the image in Channel palette in each of the three colours separately. There is absolutely no difference in the image displayed. Further the scanner does not say RGB. Only 48 bit. Should I switch over to Colour negative and operate the B W negatives. Would it work. Surprisingly I find that B W negatives are well preserved even when they are 30 years old. Colour negatives have developed horrible green cast. Do not know how to remove them. |
Posted on 01/11/09 10:50:19 AM |
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GKB
Magical Montagist Posts: 4058 Reply |
Re: Scan Black & White Negatives
If you save as a jpg and have not converted to greyscale you will still have an RGB file with three channels. You may be confusing greyscale with de-saturating. De-saturating will still give you three channels; all identical. Greyscale reduces to a single channel. That will be why you still have a larger file size than you might expect. If your negatives are in good condition with no colour stains from age or poor processing then all three channels in an RGB file will look the same because there is no colour information in any of the channels. If, however, you have a stain on the neg then you can expect to see it in one or, possibly two, channels. By discarding these two channels you should get a good image from the third. You can try this by taking a surplus B&W PRINT (don't ruin a negative by doing this!) and writing on it with a red pen. Don't lean heavily with the pen as this will cause a scratch which may be picked up on the scan. Scan this image and you will see the writing in the red channel. If the ink has other un-noticed colour components you may well see it in another channel but there should be one channel where no ink can be seen or, at least it is quite faint. That is the one to keep. Scanning colour negatives can be awkward because of the orange overlay. If you are scanning a bunch of negatives which all display the same green cast it is probably better to scan them identically and then remove the green cast in Photoshop later. Set up an action to do this and then apply the action to the rest of the scans. If the casts vary from neg to neg then it's down to working on each individual negative to fix them. Your scanner software may have an ability to remove colour casts prior to the actual scan. By doing things this way you get something better to work with in Photoshop for the final tweaking. There are many different ways of removing the green cast. One quick and simple way is to try Image>Adjustment>Auto Colour and see if that fixes it. In many cases it will but if it doesn't then it's down to setting your own black points and white points with all the other photo retouching ability that Photoshop gives you. Katrin Eismann's book on photograph restoration and retouching in Photoshop is a very good starting point. Hope this helps. Gordon _________________ Why is there only one word for ‘Thesaurus’? |
Posted on 02/11/09 01:42:51 AM |
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dprangan@yahoo.co.in
* Posts: 24 Reply |
Re: Scan Black & White Negatives
Dear Gordon, Very grateful to you for the trouble you have taken. I will follow your valuable suggestion. I am a retired individual with a belated interest in photography and have plenty of time and resources. I have made photoshop mastery as the last mission in my life. Once again voicing my thanks and pray God to give you a long life and do this kind of good samaritan work. Rangan |