Need help / advice on a Xrite 820 Densitometer

[Koller01]

I purchased a used Xrite 820 and am having some trouble. I have a Stouffer TP 4x5 - 21 transmission step tablet. When I take readings of the first step with the black channel (Trans A with the color channels off) it is giving me a reading of 2.55? Shouldn't it be around .05 (the known density) It is giving really high readings and am not sure if I am missing something?

The unit looks clean and in good working order. Can it be that far out of calibration?

Also, doing a max black on just some RC paper in reflective mode it is reading 5.22? Any advice on this machine sure would be helpful.

Thanks!

 

[Chan Tran]

I purchased a used Xrite 820 and am having some trouble. I have a Stouffer TP 4x5 - 21 transmission step tablet. When I take readings of the first step with the black channel (Trans A with the color channels off) it is giving me a reading of 2.55? Shouldn't it be around .05 (the known density) It is giving really high readings and am not sure if I am missing something?

The unit looks clean and in good working order. Can it be that far out of calibration?

Also, doing a max black on just some RC paper in reflective mode it is reading 5.22? Any advice on this machine sure would be helpful.

Thanks!

You have to calibrate it. Xrite usually have the film and plate with the densitometer. Without them I think you could use your step wedge for transmission.

 

[Nicholas Lindan]

Sounds like it's either dramatically out of calibration or something is broke.

If it came with the calibration standards then go through the standard procedure. If you don't have the standards then you can use the Stouffer tablet for transmission calibration. An RC print will usually have a pure white ~0.1 and pure black of ~2.3 - varies slightly with the brand/type/surface/phase-of-the-moon. Calibrate the 810 to these values.

If everything looks OK now then the problem is, hopefully, solved.

If not, then the unit needs fixing.

 

[Chan Tran]

If it can't be calibrated perhaps need new bulb.

 

[nbagno]

These guys will calibrate it.

 

[Kino]

See page 55.

https://xritephoto.com/documents/manuals/en/820-64_820_Densitometer_Operation_Manual_en.pdf

 

[Koller01]

Thanks for the replies. I tried just calibrating it of a print with black and white with relative densities.... Seemed like it should of worked but still reads very high like before. The light was flickering a little while in the mode which seemed odd. I think something is off and might send it in to have it looked at. Not sure what else to do. Does anyone know of a source to buy the actual calibration targets?