Re: Newton rings on scanned 8x10" negatives
Quote:
Originally Posted by
DannyTreacy
Hi all,
I have read this thread with great interest and toady attempted my first wet scan using an Epson V850.
I followed all of the hints and tips I could find and used all of the correct materials, the scan seemed to go fine, no issues with bubbles or streaks. I thought I'd do a test on 120 neg (Kodak Portra 160), one using the film holder, one wet scanned straight onto the glass using Kami fluid and Mylar on top, the issue is that on close inspection the scan with the holder actually seems sharper. Both were scanned at the same dpi, 2400.
I also tried changing the setting 'film area guide' to 'with film holder' when wet scanning as I thought perhaps the lower res lens might be causing an issue but both versions wet scanned still produced 'less sharp' initial scans.
I'm using Epson scan software, is that right? I did install Silverfast 8 and had a go with that but I find the software very cumbersome and not at all intuitive and the resulting scan was awful when wet scanned.
Any info or advice most welcome!
Hello Danny,
Presently I also scan wth V850.
Software:
Your Silverfast 8 bundled software has a very interesting feature that EPSON soft do lack: Multi-Exposure. You have a little button at left of image area that you can activate.
Multi-Exposure is a must for negatives that have high densities, this is deep shadows with slides and highlights with negative film.
http://www.silverfast.com/highlights...posure/es.html
If you know PS well then it's good advice to avoid most other image enhancing at the scanning stage and leave sharpenning and color management for PS, etc.
Remember to scan 16bits per channel, and save it as TIFF to conserve that, edit and save it for you 16 bit. If you are to make a web posting version then convert to 8 bits/channel, resize to the final display size, but remember to set "Bicubic, ideal for reductions" (it's not the default) in the image size dialog bottom (Photoshop).
Holder vs glass:
The wider lens covers well 8" (with area guide) and it has a theoric resolution of 4800 dpi, with an optical performance (USAF 1951) well under 2000dpi, but this is a lot for 8x10". I guess this lens has the glass top in focus.
The other lens has a narrower field of view and can see 5.9" wide, this is to scan a couple of strips at the same time, focus it is placed a few mm over the glass, note that V850 holders have adjustable height in order you can place film in perfect focus, you can use a negative with fine detail to adjust it. Native resolution with this lens is 6400, true optical (1951) performance may be 2800 to 2300 depending on the axis. To obtain that resolution you need to scan higher, perhaps 4800.
Obtaining a sharp look from a sharp negative will depend mostly on your post-process. For example a portrait should use different sharpenning settings for the eyes or hair than for the rest of the face, also image reduction algorithm you select it is critical, compression... and remember that webs/browsers do nasty things when resizing. Also "structure" enhancing software (like instagram one) is useful.
A Full HD monitor/TV has only 2 megapixels, but a true 60mpix image can look not well sharp in the TV because post-process. Digital post process can be oriented to make a 2 mpix image look sharp, and this is what all digital bugs are trying to do all day long.
Re: Newton rings on scanned 8x10" negatives
Thanks for the info Peter and Pere, lots to think about!!
Re: Newton rings on scanned 8x10" negatives
>>the issue is that on close inspection the scan with the holder actually seems sharper. <<
The holder image could be sharper because your lens' optimal focus point and film holder height happen to match. Just like the lens for film holders, the lens for scanning off the glass can have variability too. If the lens is not focused right at the glass bed level, it will affect sharpness. The ability to use the better lens and variable height are why it is preferable to use a film holder or mounting station when possible, like with the 120 format film you tested.
Doug