Kategorie: News, Blog photography

Nikon LS 9000 scanner – Gradual sharpness decrease during scanning

After purchasing new scanner Nikon Super Coolscan 9000 ED and performing several multipass scans with switched-on ICE cubed function I was shocked by the poor sharpness of the scanned film grain. 

During the course of many tests I have discovered the problem of gradual decreasing sharpness during scanning. Gradual decreasing of the sharpness is caused by overheating of some of the elements inside of the film scanner NIKON LS 9000. 

Follow the grain sharpness, please on following examples.

All the scans of the film grain are scanned in 4000 dpi and publicized in the 100% size. Particular swatches from the left to right matches position on the scanned slide:

0, 14, 28, 42 and 55 millimeters in the direction of the film moving. 

Test1:

This problem is bounded to the switched-on DIGITAL ICE function and includes both modes - normal and fine. 

For example:

4x superfine no ICE 

4x_superfine_no_ICE....... is trouble free! 

Scanner Nikon LS 9000 is equipped with the glass holder FH-869g. Focal plane of the holder (tested without appropriate plastic mask) is excellent – variation from the
ideal plane is within 3 – 4 focusing steps (focal sharpness tolerance is around
10 steps up-and-down). This problem is not affected by change of the focal plane. I have made number of scans with manually shifted focal plane +- 15 and +- 30 steps, however the effect was only respectively shifted.

The degradation is beginning to appear during second minute of scanning and gradually increases up to approx. 30th minute of continual scanning. During the course of scanning time longer then 30 minutes (8x superfine or 16x superfine) the reached unsharpness remains without change. Manual focus changes before scanning does not compensate this fault: 

1x_normal:

1x normal

1x_superfine:

1x superfine

2x_superfine:

2x superfine

4x_superfine:

4x superfine

In the situation that a next scan is started within a few seconds after completion of the previous scan, the following scan unsharp already from the beginning. 

Most of low contrast slides without deep shadows and bright highlights are scanned by the “slower mode” (6x6 cm on 4000dpi/4x superfine takes about 26 minutes) - this mode is fully affected by the problem of decreasing sharpness during scanning. It applies to all modes (1x .... 16x). Only small amount of normal density slides, scanned by the faster* mode (6x6 cm on 4000dpi/4x superfine takes about 14 minutes) is a little bit better (but not good). 

* This “Faster mode” in the case of scanning high density or contrast slides is illogical – it is an automatic choice of the scanner firmware that cannot be changed by the user! 

I discovered this problem on three machines (two scanners I tested myself), serial numbers 200473 and 201705 – both were absolutely new.
These unsatisfactory results cause each unmodified scanner to be practically unusable for any serious work with function of the “hardware” dust and scratches removal.

This problem was probably the cause of the wide-spread superstition that: “Digital ICE causes decreasing of the scan sharpness”.
Previously I have had Nikon LS 8000 scanner and during 3 years I never registered this problem.

Test 2: 

I discovered that NIKON SCAN program (version 3 and 4) has one unusual feature: holding the left mouse key interrupts scanning as long as the key is pressed. This feature allowed me to make the following test:

I have had prepared 4x-supefine scan (current scanning time is about 30 minutes). Every 4th minute of the scanning time I interrupted scanning temporarily by pressing and holding down the left mouse button for the following 4 minutes. Overall scanning time has been increased to 60 minutes! This experiment allowed me to achieve visibly better sharpness (approx 50% better, but not fair!) of the scan. I would called it the “Software Cooling”.

Test 3:

Opened scanner (the scanner case was dismounted) provides better results than closed, but still unusable.

Power_semiconductors_open.jpg

Odmontované víko skeneru - chlazení zajišťuje větráček

Gives results approaching a „90%" of final quality - the fan is too low-lying and is unable to reach the margins of the board, where are heat-sensitive components.

Final cooling.jpg

Účinné chlazení skeneru

- sharpness is now perfect at the whole scan area.
I think that failure caused by overheating is not problem of the LED driver power semiconductors, but it is caused by others elements on this board, subsequently heated by these power semiconductors.

“Overheating grade” (level of decreasing of sharpness) is also dependent on Digital ICE utilization = on the amount of “slide pollution”.

Final_cooling_4x_superfine.tif

Final cooling 4x superfine

HEPA filter protect scanner from dust scattered in the surrounding air. Effective cooling needs very intense air flow and relative cold air – maximally 23 degree of Celsius scale.

I think that this problem can be partially solved by firmware modification and will require replacement of some electronic components in the scanner. Adequate solution for better cooling of the scanner interior would be also helpful.

Prague, 23rd September 2004.

This publicized exploration of facts was given with the aid of the Czech Nikon representation to the Japan Nikon Corporation. Unfortunately this work was totally ignored and all other Nikon LS 9000 scanners are up to this day affected by the above-mentioned fault. I hope that my sophisticated solution will help to improve the functionality of many other Nikon LS 9000 scanners. 

Komentáře rss


, odpovědět

Few weeks ago I bought Nikon 9000 scanner, and you are right - when I use "nikon scan" software with switched on digital ICE, there is sharpnes decreasing. But I tryed to use ViewScan software, and with 4x sampling and switched on digital ICE (on level "Heavy") there is absolutely NO sharpnes decreasing. It seems, that viewscan drives the scanner in different manner. When you use "nikon scan" with digital ICE, the scanner first make 1 quick pass over the chosen frame(I suppose that this pass is for the Infra Red ), and then starts to scan slowly from the begining of the frame. With viewscan there is no such first quick pass. Have you ever tryed ViewScan ? If not, you can try it.

And I have one question, maybe here is not the exact place for it, but I'dont know where to post it:

Do you know, is there a big difference in therms of image quality between Distagon 50/4 CF and Distagon 50/4 CF FLE ? (CF FLE have the same optical design like CFi)

Zeiss sais, that FLE version is sharper in close distance, and much better in the corners, expesially wide open, but is it true ?

Best regards, Ivan

icon , odpovědět

This scanned slide (by Nikon 8000) is imperfectly sharpened – operator’s fault.

Physical resolution of Imacon/Hasselblad scanners is 6300/8000 DPI for 24x36 mm (35mm film) only! For medium format (60x 60 mm) is the maximum resolution 3200 DPI.

Yes, for 35 mm format is Imacon better then Nikon, but for medium format no.

, odpovědět

Nice approach:) Maybe you should enhnance the cooling system with a Peltier's cell ? I guess it would make the cooling system more effective however you'd have to attach the peltier cell with a radiator to the devices you want to cool. I'm not sure what's the temperature cotrol (if there is any) in Peltier's cell. I know that the difference of the temperature of two sides of the cell is 60 C.

And thanks for the technical tip. I'm eagerly waiting to read more of your articles!

, odpovědět

Seems nikon 9000 is not perfect as imacon, for example

http://www.filmscan.ru/imacon/test_ni.html...

"
, odpovědět

...and that's what they call perfectionism

great article, keep them coming please

icon , odpovědět

Hello Chris,

A Peltier's cell is not too useful in this case, because the overheating problem isn’t restricted to only one component. Intensive air flow is also helpful for other components like CCD chip (noise reduction).