New arrivals - Amber Raytheon Radiance 1 camera and DIOP 75/250mm DFOV lens

[Bill W]

Raw materials and polishing materials and methods are two more things that are early on the learning curve industry wide.  Even when using materials that are potentially compatible with mass production such as molding, the processes are in their infancy.  The high indexes of many materials put them in sparsely explored territory for optical design.  Every where you turn the lens maker is exploring new territory.

I would say it depends who and where you are looking.  There are enough well experienced suppliers of pure Ge lenses about who have someone who knows how to run the design software, while spherical polishing goes back to Galilieo !.
Moulded chalcogenides are fairly new but again several companies have been at it long enough to get quite competent and to get the best out of the lens design options.

Equally there are a few 'chancers' about who do not know how to run the software (beyond school level optics anyway), do not understand tolerances or centering and think a 10.6um laser is a test bench for 7-14 optics.
With them the MTF of your '75% MTF' lens becomes closer to a lottery number predictor (for a lottery that only goes to no. 49).

You will understand I am not naming any names !

Bill

[Fraser]

Ultrapurple,

I just checked the lens FOV for a full moon disk from Earth and it is around 0.5 of a Degree to fill the scene.

My DIOP lens in 250mm mode will provide a Moon disk occupying 0.25 of the thermal image width. With my 320x 240 pixels that means only 80 pixels across the Moons width.

I NEED A BIGGER THERMAL TELESCOPE   

[Ultrapurple]

Ultrapurple,
I NEED A BIGGER THERMAL TELESCOPE   

No, just a *really tall* tripod

[CatalinaWOW]

Raw materials and polishing materials and methods are two more things that are early on the learning curve industry wide.  Even when using materials that are potentially compatible with mass production such as molding, the processes are in their infancy.  The high indexes of many materials put them in sparsely explored territory for optical design.  Every where you turn the lens maker is exploring new territory.

I would say it depends who and where you are looking.  There are enough well experienced suppliers of pure Ge lenses about who have someone who knows how to run the design software, while spherical polishing goes back to Galilieo !.
Moulded chalcogenides are fairly new but again several companies have been at it long enough to get quite competent and to get the best out of the lens design options.

Equally there are a few 'chancers' about who do not know how to run the software (beyond school level optics anyway), do not understand tolerances or centering and think a 10.6um laser is a test bench for 7-14 optics.
With them the MTF of your '75% MTF' lens becomes closer to a lottery number predictor (for a lottery that only goes to no. 49).

You will understand I am not naming any names !

Bill

Agree there are some quality folks in the business.  But we are really saying the same thing.  Those experienced designers exist, but their efforts are amortized over hundreds or thousands of lenses instead of of hundreds of thousands or millions.  And while software has speeded the process tremendously there is not the centuries of experience with finding designs in visible materials that don't have quite the sensitivity to manufacturing tolerances that others do.  The visible legacy only partly translates into the IR.  That experience base is much smaller in the IR, and has also been fragmented by the unique requirements of the applications.  Most, until the last couple of decades have been driven by military needs, which often pushed strange parts of the design envelope, providing a limited experience base in "mass" produced designs like the current pro-sumer products.

Spherical polishing has been around for centuries, but most of those centuries were optimising grits and other process parameters for two kinds of glass.  There are subtle differences and that experience base is much smaller.  As you say some have it better than others, and they are a little wary of sharing their secrets. 

My experience with optical materials is getting dated, but when last meaningfully involved materials were much less stable than visible materials.  Dispersion and other critical properties varied from batch to batch and vendors came and went with regularity.  These are issues that the good houses you mention can deal with, but it again requires time and expertise that is amortized over small runs.

Again, I think we fundamentally agree.  There are many, many reasons why IR lenses are very expensive relative to seemingly comparable visible lenses.  They all contribute some element to the cost, often not too large individually, but it adds up rapidly.

[Bill W]

Or more smaller pixels...

A 250mm lens coupled to a sensor with 12 or 10um pixels gets a lot better though, comes out at around 200 pixels wide.

Bill

[Fraser]

Bill,

I just tested the DIOP MWIR lens with a 12um pixel size LWIR core. Sadly, as expected, the lens is mono-band 3-5um AR coated so I cannot use it with any of my LWIR cores. Inframetrics used to produce dual band telescopes but the DIOP unit has been optimised for just one. A LWIR version of the DIOP lens was made for a NASA development version of the Radiance 1 that used a Quantum Well IR FPA but that was obviously a special order job.

I will need to look at the FPA specification of my SC4000 to see if it uses smaller pixels than the earlier Radiance 1 FPA.

Fraser

[Bill W]

My experience with optical materials is getting dated, but when last meaningfully involved materials were much less stable than visible materials.  Dispersion and other critical properties varied from batch to batch and vendors came and went with regularity.  These are issues that the good houses you mention can deal with, but it again requires time and expertise that is amortized over small runs.

Again, I think we fundamentally agree.  There are many, many reasons why IR lenses are very expensive relative to seemingly comparable visible lenses.  They all contribute some element to the cost, often not too large individually, but it adds up rapidly.

Indeed, and while 'pure Ge' is going to be reliable,  ZnS / ZnSe may be similar but I do not know them enough.  In contrast the various 'flavours' of Chalcogenide come and go. Unless (or even if ?) dealing with a totally integrated supplier (say Umicore) there is an obsolescence risk that could force design tweaks on a long lived design as new and better mixes keep coming along.

Bill

[Fraser]

The situation with lens prices vs production numbers is well demonstrated by the Nikon UV lens that Ultrapurple sought, and eventually found. That Nikon lens appears pretty ‘normal’ to the uneducated (my) eyes but it it has optical properties at the UV end of the spectrum that make it ‘special’. That UV lens is clearly intended for a niche market and so production numbers were far lower than the conventional lenses. The result is a very high original retail cost and a healthy second hand value.

https://www.nikon.com/products/industrial-lenses/lineup/uv/

You can have a lovely brand new example for just £12K !

https://shop.graysofwestminster.co.uk/product/105mm-f-4-5-uv-nikkor-ais/

The UV lens in use…….

https://www.mir.com.my/rb/photography/companies/nikon/nikkoresources/special/105UVmm.htm

You have to really need such a lens to justify such a high price tag !


On the DIOP DFOV lens front, I have just ordered a suitable power supply to power it  I will be carefully removing the Fischer 8 pin connector from the lens and replacing it with a nice new LEMO 10 pin socket for which I have plenty of plugs That is preferable to buying the Fischer connectors at their crazy high prices. The substitution operation appears relatively simple and is low risk to the lens. It may also be easily reversed if I ever find the correct Fischer plugs at a sensible price. I will also download and share the lens controllers firmware for future analysis.

There will not be any invasive work on the lens structure itself as I consider such to be ‘off limits’ unless repair is required. Messing around with a well designed high quality lens assembly carries risk and offers little by way of ‘enlightenment’ as we already know what resides inside the lens barrel.

I will tidy the wiring loom in the lens controller area. In days gone by, my mentors would have had a fit if they had seen cable ties securing the loom  I was taught to lace wiring looms as cable ties were considered ugly abominations and the work of the Devil  I have to agree that a well laced wiring loom does look nice if it can be seen, such as in a rack installation. Will I lace the loom in this lens ? Well I am thinking about it 

As an aside, our older techs were our mentors and many were very strict. They would carry a lace spacing gauge and check your lacing quality. If the spacing was not precisely 10mm and straight they would cut the lacing off with a knife and make you do it all again ! It was very much about self discipline and pride in your work back in the 1980’s and 90’s. These days, companies go for speed and cable ties are the norm. I miss seeing nicely laced looms though.

Fraser

[Fraser]

A tiny update on the faulty Radiance 1 camera.

The Fault: Stirling Cooler runs and reaches operating temperature but the camera displays no LED indicators on its keyboard and no power to the Electronic Viewfinder. Apart from the cooler, it is basically dead. The cooler is a closed loop control system that likely operates independently of the cameras image processing and control systems. As such it starts working as soon as it receives power and drops into its ‘maintain’ state once the cold finger reaches 77K (-196C). Cooling takes 6 minutes which shows excellent cooler condition. The camera is missing its firmware as the Linear Flash PCMCIA card that holds such is missing. That would stop the camera booting.

I sourced a Series 1 Linear Flash PCMCIA card and cloned my working cameras firmware on to it. Upon checking the clone copy it works in my original camera so the clone process did work. Installing the clone card into the faulty Radiance 1 sadly did not cure the fault. Whilst the cooler starts and behaves normally, the camera is otherwise dead. I suspect a power supply fault within the camera. The Radiance 1 uses an external DC to DC converter so I tried the one from my good camera in the faulty unit. No change. The fault lies within the main camera head.

I was already intending to carry out a careful disassembly of the faulty Radiance 1 camera so no great drama or disappointment about the firmware not curing the ‘no boot’ fault. I will document the disassembly on the forum. I will not be dismantling the cooler or associated FPA vacuum Dewar for obvious reasons. I hope to get this camera working again but even if that is not possible, I can use its good cooled sensor array assembly in my other Radiance 1 camera should the need arise.

I have my good camera as a reference against which to compare voltages etc. so my work is made simpler and less reverse engineering will be required.

For anyone wondering why the firmware PCMCIA card was missing from the camera, there could be many reasons but it is not uncommon for organisations to remove storage devices at the time of disposal in case sensitive data is held on them. The “better to be safe than sorry” policy applies. It could be that the camera developed its ‘no start’ fault whilst in service and that lead to its decommissioning. Another possibility is that the previous owner suspected a firmware fault and removed the PCMCIA card to look at the data on it. Replacement firmware was not, and is not, available so that may have marked the end of the investigation for its new owner.

Fraser

[Fraser]

I used a Dianyang Technology CA-10 thermal PCBA analyzer to image the main PCBA's of my good Radiance 1 camera and the faulty unit. I was looking to see how much of the faulty camera was active. This was not a detailed examination and was for interest as much as anything. The test did reveal that the faulty Radiance 1 camera has a processor that is dormant and not accessing the SDRAM memory. I also noted one IC on the processor board that is running warmer than that on the known good unit. I will investigate that IC in due course to see whether it is being stressed, or is faulty.

Pictures follow: The first image in each pair is the known good unit and the second image is the faulty unit.

[Ultrapurple]

Very interesting, Fraser - a fascinating comparison and I wish you well with your repair endeavours.

One thing that caught my eye was where the thermals are presented as a pseudo-3D. I've never seen that presentation before, but I could immediately see how effective it is.



(I invite anyone interested in a larger version to click on Fraser's originals, above, rather than this one).

[Fraser]

I must say I find the virtual 3D display mode very useful as my eyes quickly spot ‘peaks’ and it is great for comparing PCBA’s, as in this case. I asked DYT to enable image capture for this mode but they do not think it is needed as no measurement points are present. They do provide a video recording option in this mode though. I thought the virtual 3D display modes found on some other software products to be a bit of a gimmick but in this usage scenario it has proven to be very useful 

[Ultrapurple]

I'm with you on screen capture, even if no actual measurements are shown.

As a general rule, if the software can display something then I think it ought to be possible to save a copy in that form. Even with limitations.

But then, I'm firmly from the 'pretty pictures' end of things...

[Fraser]

As a side note on the Radiance 1 ‘fault’. I confirmed that the Radiance 1 camera will not show its keyboard LED’s or power the EVF if the processor fails to complete the boot sequence. I did this simple test by removing the firmware PCMCIA card from my good Radiance 1 unit and it failed to boot (as expected) This fact expands the fault possibilities beyond just hardware as I am using a firmware in the ‘faulty’ Radiance 1 from another camera. I cannot be certain that the firmware does not contain camera specific checks and so may not work in another camera. Food fir thought but I will continue my investigation into the hardware fir the time being.

With regard to the thermal analysis of the PCBA, I was looking for components that appeared to be in thermal distress or ones that should be active, and were not. There was also the possibility of components that were not in distress, but were unexpectedly perational or generating slightly higher levels of thermal energy. There are a few points on the faulty Radiance 1 processor PCBA that are warmer than those on the reference PCBA and these could point to a owner or processor state anomaly.

All good fun. I  am now in the habit of inspecting ‘dead’ PCBA’s in the thermal domain as well as the visible light domain as much can be learnt from ‘visual inspection’. It can give the repair tech a helpful steer towards the cause of a problem….. including a processor being held in a HALT or RESET state.

[IR_Geek]

Totally agree with both you guys (Ultrapurple and Fraser):  that 3D image is very useful to rapidly draw your eye to different areas.  Good way to quickly tell if you are saturated, have blinkers, or maybe even a focus check.

Thermal inspection is the way to go for troubleshooting.  Sometimes it's hard to tell where a circuit card has gone crazy if you were not there when the 'magic smoke' was accidentally released.   

[Bill W]

Thermal inspection is the way to go for troubleshooting.  Sometimes it's hard to tell where a circuit card has gone crazy if you were not there when the 'magic smoke' was accidentally released.

In some cases I find that being alerted by a current limit and then being able to check thermally can stop the magic smoke from ever appearing.

Even a second is enough to show thermally that power is going where it should not.

Bill

[Fraser]

Apologies for the lack of progress reports on the camera and lens. I continued my search for a suitable power supply for the lens as the one I ordered turned out to be unsuitable. I found a nice new XP Power open chassis power supply today that is perfect. 3V3 @6A, +12V @ 3A and -12V @ 0.8A. I will fit a load resistor to the 3V3 output that is unused to ensure stability. At £18 delivered from within the UK it was the right spec at the right price 

It is my intention to build a power supply unit that provides the lens power plus the RS232 port for remote control.

The camera will need careful diagnostic work to establish what is causing the failed boot process.

It has been too hot to work on the kit this week so I await cooler temperatures…. Dripping salt laden sweat from your forehead into delicate electronics and optics is not a good idea 

Fraser

[Fraser]

DIOP DFOV lens Firmware :

In case it is of use to anyone in the future, here is the content of the ST M27C512-15 PLCC32 OTP PROM used on the DIOP 75-250 lens controller.

[Fraser]

I have removed the power input board from the DIOP lens for inspection and modification. I will be removing the 8 pin Fischer socket and fitting a 10 pin LEMO socket in its place. The two centre contacts of the LEMO socket will be left unpopulated. The 8 outer pins match the positions of the Fischer socket so this should be a simple modification and the result will maintain the high quality of connector, whilst using a far more easily obtained make of connector.

Upon removing the power input PCB, I inspected it for any issues. I have previously commented that some specialist thermal imaging equipment can appear to have been hand made on a kitchen table as small production runs were often hand made or used 'cottage industry' production techniques. The DIOP DFOV lens power input PCB is a good example of this ! I personally would not have allowed this PCB design to leave the factory door as it is far from perfect and really needed a redesign to take account of errors made in the original layout. I attach many pictures to show the PCB and its issues.

My thoughts on this PCB design....

1. When I have seen a PCB hanging off of the rear of a connector, it is usually just a breakout PCB for ease of soldering wires or a ribbon cable connector. I do not like to see a larger PCB accomodating a relatively large power converter hanging off of the rear of a connector using only the connector pins for support. The power converter could easily have been mounted in the spare space on the control modules lid. This would have aided cooling and is a more appropriate location.

2. The soldering of the power input PCB is less than great. The soldering of the connectors pins to the PCB has a very dull appearance and poor application. Some of the tantalum capacitors have almost no solder fillet on the end contact, though the joints are nice and shiny.

3. The PCB component layout did not take account of some components physical needs, such a clearance height and avoiding other solder joints. The Varistor adjacent to the Fischer socket does not sit on its PCB pads due to height interferance so it has been soldered at an angle in an unprofessional manner. The Power Trends 5V switching regulator module uses a metal bracket at its top end. On the PCB layout, this bracket would short across the two thermistor bias supplies ! The solution used in production was to roughly distort the bracket and in doing so push the whole module in the direction of the three I/O pins, resulting in them becoming bent and the module casing interfering with the wiring landing pads for RS232 link to the controller PCB. Quite frankly, a bit of a botch and a mess.

4. The PTFE insulated wires connecting to the PCB broke off very easily, suggesting either previous flexing or poor insulation removal technique causing cutting of strands. All wires will be reterminated using a hot bar insulation remover.

5. The PCB had a lot of Rosin Flux redidue on it. It is clear that it was not leaned after soldering of the wires and Fischer connector.

There is an old saying that "you cannot make a silk purse out of a Sows ear" and this applies to the power input PCB. There is only so much that I can do to remedy the poor design without major alterations to the input power system layout. I will rectify the poor soldering, remove and modify the 5V switching Regulator to avoid its bracket being so distorted and to correctly position it on the PCB. The new LEMO socket has a different, smaller diameter, rear design and may provide greater clearance for the Varistor so that it may be placed on its PCB pads instead of hanging off of them on solder bridges.

This was a $35K science grade product ! I think it is pretty clear that DIOP may have been an excellent optics manufacturer, but their PCB design team left something to be desired ! The controller PCB is not without its issues either but I will leave that well alone as "if it is not broken.... do not fix it" applies 

Fraser

[Fraser]

In case anyone needs the PCB track detail, or is just interested, I attach pictures of the power input PCB with its 5V switching regulator and varistor 2 removed. I also include a picture of the 5V switching regulator PCB.

Removing both the Switching regulator and the Fischer connector was made harder by the PCB holes being an interferance fit ! DIOP could not even get the PCB hole sizes right on this PCB design. I resorted to Quickchip low melt solder to remove them and it  worked but a lot of effort was still needed to slide the pins out of the holes  The PCB holes were then wicked, cleaned, re-tinned and re-wicked to remove the Quickchip residue. For those unaware, you need to get rid of the low melt solder to prevent contamination of the new leaded solder when re-assembling. Note that the PCB mask around the Fischer connector pins was already scratched ... I have no idea how.... maybe they soldered it with a hot spoon or something similar

I am still considering whether to reinstall the 5V switching regulator on this PCB or whether to mount it in the lens casing. I need to look at its needs in terms of bypass capacitors etc.

Fraser

[Fraser]

The DIOP lens power input PCB is now reassembled. I decided to leave the design 'as-is' as it has lasted this long 

The new LEMO socket uses separate pins and I soldered 0.7mm TCW extensions to them for attaching to the PCB.

The varistor is now in its correct location and all solder joints that looked poor were reflowed.

[Fraser]

This is really an information post, rather than an update on the lens work.

The DIOP lens is using PTFE insulated cables, as is quite common in professional equipment. These cables can present a challenge to some techs when it comes to stripping them for soldering. One method uses a scalpel to cut the insultation off of the silver plated conductors, but this does risk conductor damage if not done with great care. Such damage can cause failure of outer strands in the cable. I use a hot bar type cutter for removing insulation from PTFE cables. This techique does not damage the conductors and easily strips PTFE insulation. PACE used to make one of these cable strippers but I could not find a used one so elected to buy the Kinetics-Teledyne "Stripall" and import it from the USA. Mine is 117V so I bought a compact 100VA 230V to 110V transformer for it. I also managed to buy several new sets of the stripping bars, but do not expect to need them any time soon. The stripping bars come in two types, flat, or notched. Flat is used for smaller diameter cables and that is what I use most.

You do need to use some common sense when using one of these heated bar type strippers.... you are heating insulation to the point that it melts... that can release gases that are toxic so you should ventilate the work area. The "Stripall" units can strip most flexible insulation types, as the name suggests, but obviously not high temperature fire rated types !

I mention this tool here only because it made my life so much easier on this DIOP lens job. Some readers may not be aware that such a tool exists. If stripping many wires, or specialist insulations, the Stripall is definitely worth consideration. It is far better than a knife or the tip of your soldering iron ! How hot does it get ? Well the bard glow red when operating  It was possible to buy a crude temperature controller as an accessory that reduces the operating temperature (this was just a simple lamp dimmer type circuit) but I have not needed such since buying the Stripall some years ago.

Fraser

[Fraser]

Job done... the DIOP DFOV lens is reassembled and ready for use 

For anyone wondering what tool I used to tighen the LEMO socket front castellated nut, I employed my heavy duty flat blade lens wrench. I attach a picture. Lens and watch back wrenches can be very useful tools for all manner of tasks for which they were not intended 

I include the old Fischer socket in the pictures as well as the two choices of LEMO connector that I can now use...straight of right angled. As can be seen, the Fischer and LEMO sockets look very similar. The mounting hole for the Fischer is almost 1mm larger than that needed for the LEMO socket though  I overcame this small issue with a strip of 0.5 mm thick ABS plasticard cut to the required 2mm width to perfectly fit the hole as a liner with, no overhang. The hole liner worked a treat and the LEMO socket was a nice tight fit in the case hole. Nut tightened... job done 

Now to sort out the power supply unit and revisit the Radiance 1 camera.

[Fraser]

The results of current draw tests on the DIOP DFOV lens

Dual rail lab PSU settings
Supply Voltages +12V & -12V
Current Limit set to 2.3A on each power rail


Quiescent Current after boot and self check competed

+12V @ 385mA
-12V @    85mA

Focus Adjustment motor active

+12V @ 480mA Maximum
-12V @    85mA Maximum

WFOV to NFOV or NFOV to WFOV change motor active

+12V @ 536mA Maximum
-12V @    85mA Maximum

Filter Wheel motor active

+12V @ 508mA Maximum
-12V @   85mA Maximum


As can be seen, the originally supplied 12V@3A / -12V@0.7A SMPSU is a little over rated for driving this lens ! The quiescent state current draw on the +12V rail only just meets the 10% minimum load requirements of many SMPSU's for accurate voltage regulation.

I thought the -12V rail was used as part of the motor drive circuit but this is not the case. It is used to power part of the position sensor circuit. Without the presence of the -12V rail, the lens complains of a Filter home position error and the focus system does not work.

I am now re-thinking my power supply design as I was using 3A rated SMPSU's

Fraser

[Fraser]

Just to confirm the connector pinout on this lens in case anyone needs it......

Pin 1 RS232 RCV (RX)
Pin 2 RS232 Gnd (Data 0V)
Pin 3 -15V @ <100mA
Pin 4 G- (0V for Minus Rail)
Pin 5 G+ (0V for Positive Rail)
Pin 6 +15V @ <600mA
Pin 7 Spare (Available on Power Input PCB but not connected to Processor PCB.
Pin 8 RS232 TXM (TX)

This information was taken from the silk screen of the Power input Board and agrees with my LEMO connector standard pin numbering.

Fraser