If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#12
|
|||
|
|||
(Mendel Leisk) wrote in message . com...
[snip] Lorenzo, your first jpeg link appears to be to a maliscous site... Any idea why this should be??? No. Which link are you referring to? In case I've mispelled something, the working links are http://ljl.150m.com/slide_clean.jpg http://ljl.150m.com/slide_clean_b.jpg http://ljl.150m.com/slide_original.jpg http://ljl.150m.com/slide_map.png http://ljl.150m.com/slide_nmap.png All they do here is load the respective pictures, with JavaScript both enabled and disabled. I've noticed that 150m.com *sometimes* opens a pop-up window, but usually not. If that popup window contains malicious code, I don't know. I see it connects to 0catch.com when it has to show a 404. Anyway, 150m.com is just one of those free web providers that filling your mailbox with spam when you sign for an account, whose policies are dubious at least. If I could host the files on my own machine, I would, but I can't - I don't even have a public IP address. Please avoid using your browser to load those pictures, and just use wget or your favorite downloader to avoid unpleasant surprises. If the pictures don't load, try later - the files *are* there and the links I posted (at least the ones in this article) are correct. Sorry for any inconvenience, I just don't have a better way to publish files on the net. by LjL |
#13
|
|||
|
|||
On Tue, 26 Oct 2004 13:53:15 GMT, Gadgets wrote:
Interesting idea, but you'd need your object to be in the exact same place when you lifted the lid. Maybe it could work if you put glass over your orig. The film holder bundled with my scanner looks just about firm enough. On the other hand, putting glass over the film is something I, too, was thinking of... not only to keep the film better in place, but for a much more compelling reason: focus. As I understand it, my scanner has focus fixed on the glass. However, the film holder keeps the film something like half a millimeter above the glass surface, and unless I'm missing something, this would definitely compromise (compromit?) correct focus. Besides, films from one-hour photo development often comes back less than flat, with the section looking like this: _ _ __ __ ____ ____ ________ ________ ________________ (although the effect in ASCII art is definitely exaggerated). I bet focus doesn't benefit from this. However, putting glass on the film means that the film comes in contact with both the scanner glass and the newly added glass; I'm afraid friction could cause scratches on the film as soon as there is a dust particle moving... so I'm not sure this would be a good idea, at least for the film's health. by LjL |
#14
|
|||
|
|||
|
#15
|
|||
|
|||
In article , Don
writes On 29 Oct 2004 05:40:02 -0700, (Lorenzo J. Lucchini) wrote: By the way, a fluorescent lamp like you find them in scanners doesn't emit much infrared, right? If it did, I suppose one could place an infrared-pass filtering material between the lamp and the film, thereby doing the same thing Digital ICE does. That's assuming a scanner's CCD is sensitive to infrared light, and it looks like mine is (I scanned a remote control's emitter with a button pressed - definitely seems to pick up infrared). I don't know the spectral characteristics of a garden variety flatbed lamp or CDD response but I wouldn't be surprised if some IR data is picked up. The problem is separating this IR data from the rest because that's what you need to perform dust removal. This may be possible by applying Fast Fourier Transformation to extract only certain (i.e., IR) frequencies but that's only a wild guess and way over my head... "No FT - no comment!" ;-) (For those unaware, the FT in that instance was Financial Times!) Seriously though, there is no need to FT to achieve this, just an IR filter - although I doubt that much IR is emitted from the light source. I had hoped to check this for you, but having looked in my filter box I seem to have mislaid my Kodak No.87 - and since I haven't used it for years, I probably won't bother replacing it. In any case, with an IR filter in place you will probably get some response in all colours, so just make a grey mask. -- Kennedy Yes, Socrates himself is particularly missed; A lovely little thinker, but a bugger when he's ****ed. Python Philosophers (replace 'nospam' with 'kennedym' when replying) |
#16
|
|||
|
|||
Lorenzo J. Lucchini wrote:
As I understand it, my scanner has focus fixed on the glass. However, the film holder keeps the film something like half a millimeter above the glass surface, and unless I'm missing something, this would definitely compromise correct focus. PMFBI, and I haven't posted here before, but ... two things: 1) Parallax may enter into the equation, if one scan is reflected from one side of the film, and the other is "through." Although tiny, there may be a noticeable difference in scanned image size -- depending on pixel density, possibly enough to affect your final result beyond the intended effect. 2) Often, there is crud under the scanner glass which is difficult to clean. Every couple of years, I take my scanners apart to clean off dust which has gotten inside the works, and most especially the plasticizer residue sublimated off the wiring and electronics. While out of the focal plane, probably enough not to matter, it's something to consider when you're getting down to the (admirable!) level of detail you're chasing. BTW, all of the scanners I have require breaking of seals or use of Torx drivers and so on to get into the case. You also have to be very careful of ribbon cables, tiny boards, optics, plugs, etc. Not for the faint-hearted, but IMHO worth the time and risk to end up with a pristine imaging path. (I've never damaged a scanner doing this, but I have experience in this kind of thing.) |
#17
|
|||
|
|||
On Fri, 29 Oct 2004 17:57:51 +0100, Kennedy McEwen
wrote: I don't know the spectral characteristics of a garden variety flatbed lamp or CDD response but I wouldn't be surprised if some IR data is picked up. The problem is separating this IR data from the rest because that's what you need to perform dust removal. This may be possible by applying Fast Fourier Transformation to extract only certain (i.e., IR) frequencies but that's only a wild guess and way over my head... "No FT - no comment!" ;-) (For those unaware, the FT in that instance was Financial Times!) Seriously though, there is no need to FT to achieve this, just an IR filter - although I doubt that much IR is emitted from the light source. I had hoped to check this for you, but having looked in my filter box I seem to have mislaid my Kodak No.87 - and since I haven't used it for years, I probably won't bother replacing it. That's a good idea, although he'd then have to lift the lid in order to insert the filter thereby causing misalignment problems as the slide is bound to move. I guess a gelatinous IR filter (if such a thing exists) would be even better in practical terms. So, using Financial Times ;o) to extract only the IR component may be easier in the end. Don. |
#18
|
|||
|
|||
On Fri, 29 Oct 2004 17:57:51 +0100, Kennedy McEwen
wrote: I don't know the spectral characteristics of a garden variety flatbed lamp or CDD response but I wouldn't be surprised if some IR data is picked up. The problem is separating this IR data from the rest because that's what you need to perform dust removal. This may be possible by applying Fast Fourier Transformation to extract only certain (i.e., IR) frequencies but that's only a wild guess and way over my head... "No FT - no comment!" ;-) (For those unaware, the FT in that instance was Financial Times!) Seriously though, there is no need to FT to achieve this, just an IR filter - although I doubt that much IR is emitted from the light source. I had hoped to check this for you, but having looked in my filter box I seem to have mislaid my Kodak No.87 - and since I haven't used it for years, I probably won't bother replacing it. That's a good idea, although he'd then have to lift the lid in order to insert the filter thereby causing misalignment problems as the slide is bound to move. I guess a gelatinous IR filter (if such a thing exists) would be even better in practical terms. So, using Financial Times ;o) to extract only the IR component may be easier in the end. Don. |
#19
|
|||
|
|||
On Fri, 29 Oct 2004 18:38:23 -0500, "Tetractys"
wrote: As I understand it, my scanner has focus fixed on the glass. However, the film holder keeps the film something like half a millimeter above the glass surface, and unless I'm missing something, this would definitely compromise correct focus. PMFBI, and I haven't posted here before, but ... two things: Not at all! The more the merrier! 1) Parallax may enter into the equation, if one scan is reflected from one side of the film, and the other is "through." Although tiny, there may be a noticeable difference in scanned image size -- depending on pixel density, possibly enough to affect your final result beyond the intended effect. That's a very good point. Parallax is bound to contribute to his misalignment problems. 2) Often, there is crud under the scanner glass which is difficult to clean. Every couple of years, I take my scanners apart to clean off dust which has gotten inside the works, and most especially the plasticizer residue sublimated off the wiring and electronics. While out of the focal plane, probably enough not to matter, it's something to consider when you're getting down to the (admirable!) level of detail you're chasing. BTW, all of the scanners I have require breaking of seals or use of Torx drivers and so on to get into the case. You also have to be very careful of ribbon cables, tiny boards, optics, plugs, etc. Not for the faint-hearted, but IMHO worth the time and risk to end up with a pristine imaging path. (I've never damaged a scanner doing this, but I have experience in this kind of thing.) I recently did this on my flatbed which is only months old but I already noticed the residue on the underside of the glass. In my case no seals needed breaking I just lifted two plastic screw protectors alongside the lid hinge to reveal the screws (took a while to figure it out!). I then lifted the back and the front just slid out. Furthermore, the lid came off together with the glass making it much easier to handle. I just turn the whole assembly over. All the electronics as well as the lamp assembly stay in the base which is very handy. Ever since, I've been doing this every couple of weeks because the residue keeps building up. The longer the scanner is on the more apparent it gets as, presumably, the temperature rises and evaporation increases. BTW, what do you use to clean the glass? I use lens cleaner and lens paper but this still seems to leave a thin film/smudges behind no matter how thorough I am. I even tried to polish this off using a microfiber cloth but just can't seem to get it all off. I'm starting to get the feeling I'm just redistributing it. Don. |
#20
|
|||
|
|||
On Fri, 29 Oct 2004 18:38:23 -0500, "Tetractys"
wrote: As I understand it, my scanner has focus fixed on the glass. However, the film holder keeps the film something like half a millimeter above the glass surface, and unless I'm missing something, this would definitely compromise correct focus. PMFBI, and I haven't posted here before, but ... two things: Not at all! The more the merrier! 1) Parallax may enter into the equation, if one scan is reflected from one side of the film, and the other is "through." Although tiny, there may be a noticeable difference in scanned image size -- depending on pixel density, possibly enough to affect your final result beyond the intended effect. That's a very good point. Parallax is bound to contribute to his misalignment problems. 2) Often, there is crud under the scanner glass which is difficult to clean. Every couple of years, I take my scanners apart to clean off dust which has gotten inside the works, and most especially the plasticizer residue sublimated off the wiring and electronics. While out of the focal plane, probably enough not to matter, it's something to consider when you're getting down to the (admirable!) level of detail you're chasing. BTW, all of the scanners I have require breaking of seals or use of Torx drivers and so on to get into the case. You also have to be very careful of ribbon cables, tiny boards, optics, plugs, etc. Not for the faint-hearted, but IMHO worth the time and risk to end up with a pristine imaging path. (I've never damaged a scanner doing this, but I have experience in this kind of thing.) I recently did this on my flatbed which is only months old but I already noticed the residue on the underside of the glass. In my case no seals needed breaking I just lifted two plastic screw protectors alongside the lid hinge to reveal the screws (took a while to figure it out!). I then lifted the back and the front just slid out. Furthermore, the lid came off together with the glass making it much easier to handle. I just turn the whole assembly over. All the electronics as well as the lamp assembly stay in the base which is very handy. Ever since, I've been doing this every couple of weeks because the residue keeps building up. The longer the scanner is on the more apparent it gets as, presumably, the temperature rises and evaporation increases. BTW, what do you use to clean the glass? I use lens cleaner and lens paper but this still seems to leave a thin film/smudges behind no matter how thorough I am. I even tried to polish this off using a microfiber cloth but just can't seem to get it all off. I'm starting to get the feeling I'm just redistributing it. Don. |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Why digital is not photographic | Tom Phillips | In The Darkroom | 35 | October 16th 04 08:16 PM |
Top photographers condemn digital age | DM | In The Darkroom | 111 | October 10th 04 04:08 AM |
Sad news for film-based photography | Ronald Shu | 35mm Photo Equipment | 200 | October 6th 04 12:07 AM |
Which is better? digital cameras or older crappy cameras thatuse film? | Michael Weinstein, M.D. | In The Darkroom | 13 | January 24th 04 09:51 PM |