Aztek Premier 16 bits, really?

[onnect17]

In many sites I see the claim about the Aztek Premier scanner as a "16 bit" scanner. All I see in the board is a AD9220AR which is a 12 bits ADC, not a 16 bits. Any comments?

[ramon]

In many sites I see the claim about the Aztek Premier scanner as a "16 bit" scanner. All I see in the board is a AD9220AR which is a 12 bits ADC, not a 16 bits. Any comments?

Hi onnect17,

Thank you for sharing with us the ADC IC component.

I think that they say its a "48 bit workflow" scanner and that the "output" file is 16 bit RGB.

http://www.aztek.com/premier.html
http://aztek.net/Mailers/Feb%2007/Premier.pdf
http://www.prepressexpress.com/pages...k_Premier_Spec

Just add 4 zeros to a 12 bit value, and you have a "16-bit separate RGB output". ;-)

[Lenny Eiger]

Just checked in with Aztek, spoke to Haddon. They say the 4500 and lower is in fact 12 (36) bit, some of the larger ones (7500?) are 42 bit and the Premier is full 16 bit. As far as what chip is used, I have no idea.

I would call them and ask. They always pick up the phone..

Lenny

[onnect17]

A picture is worth 1000 words...

[ramon]

A picture is worth 1000 words...

True. Be carefull and turn off the flash when taking pics. And also be carefull when handling the board, those ICs are ESD (electrostatic discharge) sensitive devices.

Thank you for sharing this. Its quite interesting to see how it works internally, there is no such information on internet.

They use two logarithmic amplifiers (AD640). Both of them cost more than 8 times the ADC price. I cannot see from the board if they are cascaded to have a wider dynamic range. If so, maybe they could use "now" a single AD8310 and save more than $90 USD.

[onnect17]

The Field Service Guide is not available so I have to open it to get familiar with it. I wish howtek's way of holding the main board was less exposed to mechanical stress. I can see some users having troubles with temperatures changes or just simply moving the scanner.

[8x10 user]

The manual for the HR8000 shows a 12 bit DAC.

[onnect17]

The manual for the HR8000 shows a 12 bit DAC.

I guess you are referring to the ADC, not the DAC. I started to read the user guide for the Premier and I have to put it away. Too many errors/inconsistencies. Checked Aztek site and nothing there. Emailed Evan at Aztek thinking I was reading some beta version (revision B) and to my surprise his reply confirmed I was reading the latest version.

Then I downloaded the HR8000 user guide and realized most all the errors are dragged from the HR8000. Perhaps my expectations where set too high after reading many of the posts from Phil at the Yahoo group.

[Daniel Stone]

Well whatever it is(12bit, 14bit, or 16bit), my DPL8000(between Premier and HR8000) puts out marvelous scans on pretty much everything I throw at it. No complaints whatsoever in terms of file quality; but I do wish the drums could be a bit larger so mounting 8x10 film would be easier.

[8x10 user]

I think there was suppose to be something special about the way DPL works where it can bypass the ADC and go right to the log amps. Somehow information is uploaded into the scanner regarding each scans parameters so the scan is more optimized then a RAW scan approach. Supposedly this was part of the magic of Phils innovations and perhaps one of the scanners patents. It's been awhile since I researched this subject.

I used a DPL8000 and it did nice scans. It was a bit hard to mount an 8x10 on the drum and I ended up selling on this forum many years ago. While it is a nice scanner it was somewhat oversold in some regards. The 3 micron aperture for example is not useful for any color film types, kodakchrome works with 6 micron aperture but for most color films an aperture of 8-14 microns is ideal. When you go smaller then the grain clump size you start to you get grain-aliasing. Also the D-max of the all three lines is a strict 3.88 and some scanners are a bit better in the shadows of very dense film. So there might not be a real advantage quality wise between the Aztek and many other well-tuned high-end scanners for many large format scans. However for very thin black and white negatives and the sharpest of 35mm and medium format images, the smaller apertures selection optimized endpoints and curves would help bring faint details.

I did some some sample scans on Aztek plateau for Harvard medical of the thinnest and sharpest negs that I have ever seen. I think these were images of a virus shot with a gamma or electron microscopic film camera. The scans came out very good and my contact was excited when he saw structures that he said were 1 atom wide. They purchased the scanner, although I recommended a 3 micron drum scanner for their specific application. The plateau was faster and useful for them either way. The resolution is fixed on the plateau and you have to manually stitch the images for the highest resolution scans.

The Creo Supreme, I, II & Select, and IQ3 are three scanners that are known to have 16bit ADC.