Railfan Technology > What causes this to happen when scanning film?

If you look at the building to the right of the Edmonton trolleybus you can see what my question is about. The building has vertical lines and for some reason the scanner has warped them in two attempts. This is being scanned from film and my guess is that because the film is bowed it caused the distortion. Would the only way to correct this is to flatten out the film and try again? It should be noted that the film was cut so that this and one other frame were together on this piece of film.

Jim

---

---

What kind of scanner and how is it being scanned, in a holder, straight on the glass, what? That looks like a Newton ring of some sort.

Epson V500 and using the holder.

Jim

I've seen this develop when film touches the glass or two pieces of glass come into contact, surface-to-surface. As the light passes through that microscopic space, it gets refracted, just as in a rainbow.

I'm thinking that is what is happening. If I push the film toward the end of the holder I can eliminate this effect on the shot on the end of the piece of film. For the pictures in the middle I can't do quite as well. Haven't had this happen before but for some reason this roll is really bowed out in the middle.

Jim

Google search "newton's rings film scanner" for all sorts of ways to deal with this.

Just a wild guess here. Occasionally you sometimes get some distortion of parallel lines when you look at a picture on your screen. If you blow the picture up slightly or reduce it, you can often get rid of the problem. My first thought would be to try a slightly different resolution when scanning. I've had a similar problem when scanning pictures or maybe magazine pictures. If the relation ship of the lines on the subject is just "real close but not the exact resolution" of your scanner, this happens. Try increasing or decreasing scan resolution by 15%.

It does have a similar property to the effect mentioned above. I'm not going to discount that possibility at all.

Just a thought. If you resolve it, let us know what you find.

John

F40PHR231 Wrote:
-------------------------------------------------------
> Google search "newton's rings film scanner" for
> all sorts of ways to deal with this.

I recall that this used to happen with film enlargers. Some film holders used glass plates to keep the negative flat.

If it is a Newton ring, there is a "anti Newton ring" glass insert available to fit the original V500 film holder that may be the ticket for you.

http://www.betterscanning.com/scanning/insert35.html

Alternatively, put the film emulsion side down on the scanner to do the scan. Then you invert the file 180 degrees for display or printing. This will eliminate the Newton Ring issue.

Posted from Windows Phone OS 7

Yup - do what fbe says.
My standard scanning method on an Epson is to scan emulsion side down. It is a Newton ring issue.

RWJ

fbe Wrote:
-------------------------------------------------------
> Alternatively, put the film emulsion side down on
> the scanner to do the scan. Then you invert the
> file 180 degrees for display or printing. This
> will eliminate the Newton Ring issue.
>
> Posted from Windows Phone OS 7

I don't see it at all..I have an ASUS laptop and the pixs look fine to me..Very sharp.. JACK...



M

Posted from Android

Jack T Charley
Clackamas, OR

Just fix it using the clone tool in photoshop. Pick a section of the building without the disortion, then clone over top the distorted section. You can also try de selecting the "unsharp mask" feature on the window for the scanner before scanning the image.

-Trevor

JackWA7VNN Wrote:
-------------------------------------------------------
> I don't see it at all..I have an ASUS laptop and
> the pixs look fine to me..Very sharp.. JACK...
>
>
>
> M
>
> Posted from Android

Interesting, I've had the issue on a few scans.
The area is here:

---