Q-Factor and max DPI for 35mm Slides

[seawolf]

I am confused by Q-factor when scanning 35mm slides. I have a Nikon Super Coolscan 5000 with a max optical scan resolution of 4000 dpi. I am scanning my slide collection for multipurpose archive. I want to scan at the max dpi without exceeding the 'True' (interpolation) resolution of the scanner. I print to a Epson 2400r inkjet printer, but also my slides are sometimes published in magazines. What Q-Factor should I use?

If I set a Q-Factor of 1, the max scan resolution is shown as 4000 dpi. If I set a Q-factor of 2 the max scan resolution is 8000 dpi and this would be beyond the optical cabablities of my scanner. Can somone please help me understand what Q-Factor would be best for my purposes. Again, I want the highest quality as a archive scan, I will just this 'digital negative' for individual purposes such as: printing to epson 2400 inkjet, magazine submission. What Q-factor should I use?

Thank you.

[RAG]

seawolf,

In addition to my previous response you should know that the scale you select will directly impact your scans in the following way.

If you leave the scale at 100% in conjunction with the previously mentioned settings your scanner will use "Optical" resolution, but if you increase the scale over 100% interpolation will come into play. The reason for this is that in order for your scanner to produce a larger image at the same resolution it is forced to add pixels to the image.

Information on this subject may also be found in the guide.

[seawolf]

My question is not about scaling. I am aware of the effects of scaling. I always have scaling set to 100% only. What I am confused about are the settings of Q-factor, Screen (lpi), and DPI.

You state that if I leave the settings as mentioned above (Q-factor 2, Screen (lpi) 4000, resulting in DPI of 8000), with scale set to 100% my scanner will use its 'Optical' resolution. I find this very hard to believe because the resutling image is almost twice the size (in pixels) of the stated max for resolution for the scanner (3946x5782).

[RAG]

You are missing the point of my question. Let me try and ask it in a different way. What is the difference between?

Q-factor of 2 and Screen (lpi) of 2000 which results in 4000 ppi image
VS.
Q-factor of 1 and Screen (lpi) of 4000 which results in a 4000 ppi image

Ok? My concerns are around the fact that if I set Q-Factor 2, Screen (lpi) 4000, I get a 8000 ppi image that is far above the 4000 optical capabilities of my scanner (yes scaling is at 100%).

I am trying to understand what should I use when scanning my 35mm slides for a digital negative archive (I want the best quality possible). My needs are to use print to an Epson Inkjet as well as digital submission to magazines (I will downsize the original scan appropriately).

The short answer is the formula (lpi X Q-Factor = ppi)

My question is not about scaling. I am aware of the effects of scaling. I always have scaling set to 100% only. What I am confused about are the settings of Q-factor, Screen (lpi), and DPI.

You state that if I leave the settings as mentioned above (Q-factor 2, Screen (lpi) 4000, resulting in DPI of 8000), with scale set to 100% my scanner will use its 'Optical' resolution. I find this very hard to believe because the resulting image is almost twice the size (in pixels) of the stated max for resolution for the scanner (3946x5782).

seawolf,

In addition to my previous response you should know that the scale you select will directly impact your scans in the following way.

If you leave the scale at 100% in conjunction with the previously mentioned settings your scanner will use "Optical" resolution, but if you increase the scale over 100% interpolation will come into play. The reason for this is that in order for your scanner to produce a larger image at the same resolution it is forced to add pixels to the image.

Information on this subject may also be found in the guide.

Sorry, I meant in conjunction with the previously mentioned settings by me, not you. If your LPI is 2000 with a Q-Factor of 2 then the resulting DPI/PPI will be 4000.

For archival purposes you should scan the image based on your most resolution demanding dimensions. By this I mean if the most you intend to do with an image is have an 8X10 printed at a print shop, then you should scale the image to 8X10 at an output resolution of 300dpi. I, for example, leave my Q-Factor set at 2 and then set my output resolution based on my desired print size at 240 dpi (one sixth the resolution of my printer).