Spectrascan 650 Manual
Tom thank you for the feedback. The Photo Research Inc. Page does indicate the 'The PR-650 SpectraScan Colorimeter is no longer available. Check out the new PR-655 SpectraScan Spectroradiometer.' The new PR-655 looks pretty interesting, it has a color touch screen display, and slew of nice features including bluetooth.
I also noticed that the PR-655 is capable of going to much darker levels (.1fl or.3 cd/m2) than the PR-650. You mentioned that the PR-650 has a 8nm resolution, the specification on the Photo research site state a spectral resolution of 4nm for the PR-650. Am i missing something? Thanks again for your feedback. Originally Posted by socalAV1 You mentioned that the PR-650 has a 8nm resolution, the specification on the Photo research site state a spectral resolution of 4nm for the PR-650. Am i missing something? Here's the PR spec sheet for the PR-650.
The relevant spec is what they refer to as 'Spectral bandwidth.' This is the interval at which the instrument is capable of sampling the spectrum. 380-780 in 5nm intervals is the desired performance. Here's the comparison sheet for PR spectros. They all come standard with 8 nm resolution, but are upgradable to 5 nm at extra cost.
The PR-655 would be a better-though considerably more expensive-choice. However, you can get an Orb Optronics SP-100 5 nm spectro new for under $10K.
Please look at the specifications on the PhotoResearch website for the sytem options which is where they bury the real specifications for the instruments performance at 8nm and 5nm. As you can see they specify that at 8nm the PR655 measures to 1.0 fL whereas at 5nm it is able to read to only 2.0 fL which is nowhere near the.2 fL low light level specified in the luminance range spec that most people believe the piece is able to accuratley measure to!
Spectrascan 650 Manual 2016
This piece is really not adequate to perform a complete calibration on a video display with the low light performance being what it is. You would need to spend a lot more money for a PR-670 to get the low light level performance which is needed on current displays. You could also look into the Progressive Labs MicroSpec spectroradiometer which costs less then any competing model and provides 5nm bandwidth with 1nm reporting increments from 380nm-780nm and measures to.25 fL with exceptionally fast integration times. The price is $8K including software. Originally Posted by socalAV1 You mentioned that the PR-650 has a 8nm resolution, the specification on the Photo research site state a spectral resolution of 4nm for the PR-650.
Am i missing something? A good spectro will oversample the 'slices' of bandwidth for which it reports readings (the so-called 'full width, half max', or spectral bandwidth as Tom indicates). Simplistically, light is split by a prism or a tightly-spaced grating into a 'rainbow'. The various slices of this rainbow then fall across one or more 'cells' on a CCD chip (typically several hundred or several thousand cells arranged in a line).
The software aggregates the readings from one or more cells, and reports this as the reading for the particular slice of bandwidth to which it has been assigned. For a given spectral bandwidth, as you add cells, you usually get increased low light sensitivity. Conversely, you can also maintain the same sensitivity, and increase the resolution. As with most things, there isn't a free lunch here. Based upon the above information, the implication here is that the PR-650 is using a 2x oversampling (2 'cells' per reported measurement). This would help to explain the mediocre black level. The spectral resolution of the PR-650/655 is calculated as follows: the wavelength range measured from 380nm to 780 nm which is a range of 400nm divided by the number of pixels on the detector which is 128 equals 3.125nm/pixel.
The data is reported to the user in 4.0 nm increments or 100 data points. This resolution is not fine enough for some display technologies which produce very 'spikey' spectral light output. Higher spectral resolution instruments are available from PhotoResearch and others which can resolve to 1.0nm/pixel increments or better due to higher pixel count detectors being used. This provides 400 data points to plot a graph with much better precision. It is also important to understand that as bandwidth is increased ie going from 8nm to 5nm the light which is available to the detector is cut in half!
This is why most instruments are typically sold as 8nm or 10nm devices so that they are able to read to a lower light level by sacrificing resolution. This methodology can introduce errors in many cases as the instrument is not able to discern small differences which lie closer then the sampling interval of the instrument. You mentioned that the PR-650 has a 8nm resolution, the specification on the Photo research site state a spectral resolution of 4nm for the PR-650. Am i missing something?
Thanks again for your feedback. The 4.0 nm value given in the specification is the Spectral Resolution. The spectral resolution of the PR-650/655 is calculated as follows: the wavelength range measured from 380nm to 780 nm which is a range of 400nm divided by the number of pixels on the detector which is 128 equals 3.125nm/pixel. The data is reported to the user in 4.0 nm increments or 100 data points. This is not to be confused with the bandwidth of the instrument which is typically 8nm/pixel unless the option for 5nm/pixel has been specified at an additional cost which is several thousand dollars! The improvement in the bandwidth to 5.0nm/pixel reduces the low light sensitivity of the instrument so that it is able to measure to only 2.0 fL instead of 1.0 fL which the 8.0nm instrument is capable of. Neither of these low light level values are particularly impressive given that less expensive products are able to measure to far lower light levels.
Spectrascan 650 Manual
Used PR-650 with several accessories regularly sell for between $5K and $6K. I have had three of them and sold my last one on Ebay 4 months ago with the rapid charger, battery eliminator, and spare battery for $6,500.00.
These included accessories alone sell for over $1600.00 dollars. Also note that from the serial number 60981903 which includes the date code when the item was built, this piece was made in 1998 (eleven years old).
Spectrascan Inc
As several of the parts on this instrument are no longer available even though it comes with a six month warranty it is not a very comforting feeling to be told that your unit is not serviceable as the parts are not available a year or two down the road. Look at the trade in value of the PR-650 provided by the factory: The piece is valued at $1,000.00 for a 1998 instrument which they may only need to inspect and recalibrate before offering it for sale! For anyone that has a PR-650/655/670 I have several accessories available at an extremely attractive price if you are interested.
Please inquire regarding prices for individual items or a package price for the entire group of items. The standard battery supplied with the PR-650 uses 800 maH Nicad cells good for 2 hours per charge. The supplied charger which is a wall wart ac/dc charger requires an overnight charge to restore the battery to working condition. AC-650-1 AC-Adaptor (Used with DC-600) $270.00 (List Price) IFC-600 RS-232 Interface Cable 6650-0009-10 $215.00 (List Price) Used for SpectraWin, Remote Mode software and SAVE/RESTORE functions. 25 pin sub-D female connector on Host (PC) side.
Standard equipment with the PR-650. Ptogressive Labs CA-6X software package also provides support for the PR-650 and can be supplied with this item if desired at additional cost. FP-650/ FP-670 2 Foot Flexible Probe 6650-0008-02 $1,700.00 L9ist Price) same as 6670-0008-12. 2 foot (60.9 cm) long probe designed for contact measurements of luminance and radiance. Probe tip is 0.125' (3.18 mm) diameter.
Replaces the MS-75 during use. CR-650/ CR-670 Cosine Receptor 6650-0008-00 $1,405.00 (List Price) same as 6670-0008-10.
For cosine corrected illuminance/irradiance measurements. Replaces the MS-75 lens during use. BP-650 Rechargeable Batteries $215.00 ea. (List Price) Spare battery for PR-650. Up to 2 hours continuous operation.
Standard equipment with the PR-650. Will also provide an upgraded NiMH batter pack for use in the BP-650 housing made with 2300 maH cells providing close to triple the amount of time as the standard battery pack. MS-2.5X MicroSpectar™ Lens 6650-0008-08 $2,170.00 (List Price) same as 6670-0008-18.
2.5X magnification, fixed focus lens for luminance/radiance measurements. Provides 0.020' (0.51 mm) field coverage at a 1.81' (46 mm) working distance. Replaces the MS-75 during use. Send an email if interested in any of the items which are all in as new condition.