Tease, new Prismasonic cylindrical lens and remote motorized sled. - Page 18

so adding physical stops to the down ..in.. position wont hurt anything?

While we're redesigning the lift... I had a minor issue with the lens that's worth passing along. The shipping bar/plate that is affixed to the bottom of the large (outer) lens, and that the shipping screw is attached to, fell off the lens last night. No harm was done to the lens. After discussing with Anssi I'm passing along the following: 1) the plate can come off if the shipping screw is tightened instead of loosened during unpacking/setup, 2) the plate is there for cosmetic reasons only after it performs its shipping function (to stabilize the lens), 3) it can be reattached with glue (or left off). If glue is used, use a flexible glue rather than a super glue. I went with a silicone sealant - basically a caulk used for aquariums - that stays pliable after it clots. Anssi said that they are looking at an alternative shipping arrangement to avoid this. He also said, after I expressed some concern, that the adhesive used for the upper lens attach point (focus adjust) is much stronger (i.e. the lens itself shouldn't fall out.

When driving the lens up (OUT POSITION) towards the physical stop, the electronics of receiver board shuts down the drive current of motor, but as always there is a slight time delay. That is why it is not recommended constantly drive up towards the stop.

Driving the lens down (IN POSITION) towards to physical stop should be pretty safe, because the spring coils loosen and the motors keep running. However I cannot recommend it because our stress tests for the lift has not yet covered this kind of operation.

At some point, we'll design a new receiver board as an update, which has a user defined travel to the lift.


The pulling adhesive is the same for both upper and lower bars (equals around 50 kg direct pulling weight). However, the torqued force of screw threads combined with the torqued force of L-wrench generates easily that large pulling force, which no set glue cannot resist if the lock screw is tightened against the bottom plate, and the threads are on the lens holder bar. To avoid this accident the threads should be on a bottom plate hole not on a lens holder bar, and this small change has already been made to next batch of lenses. I still point out that NO HARM is happening if the delivery lock screw is just opened and removed from the bottom.

Thanks for the correction regarding glue strength; my misunderstanding. (However, in my defense, I did not tighten instead of loosen; over tightening must have occurred during assembly.)
My concern in mentioning all this was that a loose lens holder bar might damage the front lens, as mine might have done, if the installer was mounting the lens to a lift, sled or pj mount. Mine dropped out of the lens case and almost hit me on the head.

My apologies, I did not mean to blame you for the accident. In all cases we are responsible for this. I just tried to warn that it is easy to loose the holder bar by accident due to design of locking screw mechanism. The lens may have got a hit during the delivery as well.?

No worries! The shipping bar was apparently loose from but not off the lens before I removed the screw. Only later, when I was holding the lens in front of the pj, did it come off completely. It was like the adhesive lost its stick. Anyway, no harm to the lens.
I was thinking that a better way to ship the lens would be to fill the case cavity with a preformed foam pad that cradles the lens(es). Then it could be removed by removing the lower cover. Not sure if that is cheaper or more effective than the shipping bar/plate and associated screw (and cap) though.

I am currently using a 1400 with the HE front lens upgrade and a RS20 projector. I use a Radiance XS for scaling. I will most likely upgrade the projector eventually, but just having seen anything offered yet to make me want to move from the RS20.

I am considering buying one of these lenses hoping for a substantial improvement in picture quality and overall improved focus (current focus method is a compromise from center of screen to sides of screen). I hate spending money on these "upgrades" to only be disappointed.

Can anyone tell me if this proposed "upgrade" will yield substantial improvements? What would the improvements be?

I'm also a bit confused on the mounting options for the manual version. Can this be mounted with the lens hanging from a ceiling mount? Some of the comments indicate otherwise.

Well, I finally got my, now fully working, lens hung tonight and spent some time dialing it in. After careful set up I must say that it offers a stunning picture... I'm a really happy camper.

I'm by no means an expert but here is my story.

My setup:
Screen: 54" CIH DIY curved screen (to a 41' radius) with Seymour AV Center Stage XD fabric.
Screen build thread
Projector: JVC RS-40
Throw: 18' (Throw Ratio = 2.25)

Setting up the projector and lens
1. The first step was to ensure the projector was mounted completely level front to back and level relative to the screen right to left (which is also level btw ).
2. Next I zoomed and offset the 16:9 image to over scan slightly the height of the screen. You can see in the pics below that the geometry distortion I was seeing was limited to barreling on the bottom edge. The top edge was flat and the side were very slightly trapezoid (wider at the bottom). I put this down to the offset optics of the JVS lens itself.
3. I made sure that the image was exactly centered on my screen.
4. After carefully setting the projector focus I brought the HD-6000 lens into the path and noticed that the now stretched image was projecting slightly to one side. I tweaked my lens ceiling mounting so that the lens was square to the projector lens -- if off even slightly, one side of the expanded image would be closer to the edge of the screen than the other side which results in subsequent distortion. Note that my custom ceiling mount was not connected to the projector mount so it is possible to be out of alignment hence the need for this step.
5. After the lens mount was square I tilted the actual a-lens on its pivot to ensure I had even distortion along the top and bottom edges of the image. In my case (and I guess I did something right calculating screen radius) because I was able to end up with an image with zero (honestly less that 1/8") distortion -- no barrel, no pincushion at all! The only distortion was was present was an emphasized trapezoid distortion on the sides particularly in the lower corner. I presume that the a-lens is amplifying the projector lens error(?) Maybe it is introducing so additional distortion but frankly this is the easiest type of distortion to mask off.
6. I went back to step 1 and did everything again with very minor tweaks.

Focus:
There have been reports that the focus of the HD-6000 differs from the center to the edges. With my curved screen I could not detect this at all. I've tried to provide some photos but its hard with my pocket digital camera. I did find the focus adjustment on the HD-6000 is on a very fine thread. It takes a turn or two to see any notable effect and there seems quite a range over which it is hard to discern any difference. The strategy I used was to get my wife to turn the focus so it was clearly degrading the image, then turn about 8 turns the other way until again it was clearly degrading. Then winding back to roughly the center between these points. This seemed to work fine, but honestly I could have turned the focus an entire turn in either direction without any noticeable change.

After this procedure I must say that I was very impressed. Some screen shots follow but I was hard pressed to see much of a difference in any part of the image. There was a small, but noticeable softening of the image (which I imagine would be a positive for a DLP projector). I took screen shots at the left/center edge and true center so you can judge for yourselves. Again, note that my camera quality is not the best.

Vignette
There is absolutely no trace of any vignette effects. My lux measurements between the center and corners of the screen proved that there was no measurable additive effect of the lens. I presume this is because the lens is quite a bit larger than needed at my TR.

Geometric Distortion
My curved screen was designed to eliminate distortion at a throw distance of 18'. Clearly this has worked out perfectly to compensate for the pincushion on the upper and lower edges. The only distortion I can see is the exaggerated trapezoid in the lower section of the sides.

Brightness
I need to check my results again because I was rushed, but I only measured a 1% reduction in brightness caused by the lens. The image is noticeably brighter that when I was zooming.. Given the less than marketed brightness of the JVC projectors this is great news. I am still able to get a bright enough image without resorting to high-lamp (although the iris is max open).

CA
I would say that it is almost unseen to the eye if it exists at all. I don't know how to properly test this and separate the effect from the slight convergence error in the projector...

Overall
Fantastic. Whether through my care in setup or just a great lens I know my widescreen image in my humble little theater is substantially better than what I've viewed in demo rooms at my local so called "high-end" AV stores.

Is the initial discounted prices still available? If so, my recommendation is to jump on this lens!

I'll have an update on my lift automation solution soon.

The pics:

Barrel distortion on lower edge with 16:9 and no anamorphic lens (as a result of my curved screen):


The same barrel distortion can be seen here:


With a-lens, the distortion has gone, but the trapezoid distortion is more apparent in the lower corners:


Focus, first without the a-lens, then with (darker because I reduced the exposure):


Center of screen, first without the a-lens, then with (camera location moved slightly):


Without lens, then with (far left of screen):


Geometry tests:



CA:


Eye Candy (without, then with lens):




Final note. The HD-6000 does indeed scale by x1.35, however my screen is built as a native 2.4:1 (with adjustable masking) so it worked out perfectly.

Those of you following this forum will know I was one of the first (if not the first) to receive a lens. Unfortunately I did wrestle with some problems. First the remote was broken, second, after a couple of lifts one of the motors stripped a thread. I needed to send the lens back to Anssi in Finland to fix. I will say that he is extremely attentive and promised (and delivered) on a very fast turn around time.

Everything is working now, but I'm the kind of "get it right then forget about it kind of guy" so I spent a little time crafting a solution to the in/out stop problem (which is particularly problematic when trying to automate) to hopefully ensure that I won't have future problems with the lift motors. In doing so I can also avoid the problem of the lens bottoming out and altering the critical tilt position.

Here are the additions I've made:

1. Ceiling mount
One problem with this lift is that it does not have an option to attach to the ceiling. The optional projector mount attachment is not ready yet and in any case I really wanted to put the weight on the lens on the ceiling and not the projector mount.

To solve this (and I posted this before), I folded some aluminum plate into a 'Z' shape and mounted it under the top of the round columns. In an OCD moment I decided to sand blast the mounts to match the texture of the lens, but then couldn't be bothered to paint



2. IN stops
Whilst it would be easy to stop the lens in the right stop when moving it manually (there really is a large window for the IN position) I wanted to automate the lift and needed to ensure that the lens would never accidentally bottom out. Doing so runs the risk of bumping the lens tilt adjustment. Since my lens is buried in my hush box I didn't want to risk this.
I'm fortunate to have a small lathe/mill and so fabricated these stops out of Delrin. I don't see a reason why these couldn't be made in a vise with just a drill. One thing to be careful of is to fix these so they are exactly aligned in height: if the lens rests on them it needs to be picked up evenly on both sides and this will only happen if the stops are level. Note that the drive mechanism on the lift uses a spooled metal strip similar to a tape measure so if the motor continues to rotate at the bottom of travel it won't damage the mechanism. BTW when I automated this (timed travel) I actually avoid hitting these stops -- I added them as a precaution, in case I accidentally sent the "IN' control more than once.



3. OUT stops
Similar to the IN stops I machined up some rings for the top of travel. However, given my past experience I wasn't prepared to rely on the motor overload circuit to stop the travel (it is suppose to stop power to the motors if the mechanism stalls). The extra step I took was to replicate a mechanism I originally built for my home mill. Specifically I mounted a couple of micro switches to the stops (made a flat mounting section) and wired the normally closed switches in line with the motor circuit. It is also necessary to flatten the other side of the stop so that it doesn't interfere with the "tape" lift mechanism.

When the lift hits the switches the motors will turn off. So far so good. Now the problem is that you still have to allow for the motors to run in the reverse direction. This can be achieved by inserting a rectifier diode in parallel which the switch so current can still flow to allow for down travel. In not going to explain this any further for fear of creating support work for Prismasonic -- but if you understand the approach I'm sure you can figure out which direction to orient the diode
BTW there are two convenient holes in the metal plate housing the control electronics through which to run the switch wires.




4. Automation
I use iRule on the iPad for automation. To achieve a single button IN / OUT movement I simply programmed a repeat on the IR code learned from the original remote. I slowly increased the number of repeats until the IN button would bring the lens into position without hitting the lower stops. The OUT button was similar although the speed of upward movement is slower than down, so some additional repeats are necessary. Once I had this number I added a couple for good measure so that the lift always hits my OUT stops. This is a nice and safe way to reset the position for the next IN movement.

Summary
In Summary I think Prismasonic have created an awesome lens. However, I don't think the lift is up to the same quality. I certainly like the vertical movement (which avoids getting in front of most projector fans) but I feel as though there might be some reliability issues with the mechanism as it stands. My modifications were to hopefully avoid future issues. With these modifications I'm now also delighted with my lens lift and automation. I hope Anssi takes these suggestions as positive. I have no desire to see folks mess with their lifts without the confidence to do it right but conversely I think these fixes are necessary.

And there she is happy in her new home:


And now I'm going to enjoy a BIG screen movie

Moggie, great write-ups! And I love the work you've done with the lift. (I'm going in a different direction, literally. Working on a sled (horizontal) for a HD-6000F, as I have little or no head room for the lift style.) Anyway, I love the setup description and pix; they'll be helpful to future lens purchasers I'm sure. (Suggest you edit your write-up to include your TR (I calc at 2.25?), since there has been several comments regarding optimum TRs for this lens.)

We recently received an HD6000F lens from Anssi for use at the UK CEDIA show. Whilst we were all exceptionally pleased with the build quality of the unit, we were limited to the briefest possible testing at the show where we ended up using the "electronic zoom method" in our demos.

My company is the residential distributor for Digital Projection right across the UK and Europe and so last week one of my colleagues took the chance to visit the factory in Manchester to perform some side by side testingof the HD6000F and the ISCO III.

The guys were able to spend quite a number of hours testing this lens on the full range of models from DP, from single chip DLP to the highest of high end 3chip DLP projectors. They found that in almost all categories it was impossible to differentiate the performance of the 6000 from the ISCO. The only area where they felt that a small advantage lay with the ISCO was in sharpness in the extreme corners but given the relative price difference in products this is a more than acceptable compromise.

There is no doubt that you can see the cost of the engineering in the ISCO product but for a one time setup item like an anamorphic lens we were more than happy with the Prismasonic setup.

We are excited about the opportunities this lens finally offers for constant height setup and in Europe in particular it makes a very compelling purchase when priced against any competing products.

Neil

Any updates on this lens? Any more reviews?

I'm particularly interested in any info on the mount and when it might be available.

Thanks.

Can the Cineslide be adapted to use this lens?

CB-500 mount parts are now in the surface treatment process, and should be back latest in 1.5 weeks. The user manual for the mount is ready some day in in next week. I'll inform the link for that here then.

Deliveries will start in about 2 weeks from now.

Yes, the stand for this lens is Cineslide friendly.

-Sean

Thanks for the response...........

Now to determine if the Isco III or IV is worth the added cost.......

Guys: Although I understand the lens has been made with CineSlide-compatible mounting holes, the manufacturer has not had the opportunity to evaluate it for compatibility. When the CineSlide was designed, it was done so with the large Isco lenses in mind, the heaviest availabl eat that time. Both Prismasonic's lens as well as others are apparently now considerably heavier than the Isco IIIL. Becasue of that, I'll have to evaluate any such lens before it is approved for use. In a ceiling mount orientation, in particular, one must not overload a consumer CineSlide. We do make an industrialized version of the CineSlide that is used with Isco DLP Cinema lenses and can make one of those on a one-off basis as requested. However they are substantially more expensive, eating away at the savings that may have drove you to get a particular lens in the first place.

Anyway, in summary, the Prisimasonic lens has not been evaluated and approved for use on a CineSlide at this time. Happy to evaluate if someone wants to send it.

What is the maximum weight allowed per specs? I searched on your site and read the manual but all I could find was 200lb pull out strength for the cineslide unit itself. No spec for lens weight. Certainly a published weight is more practical than certifying any and every lens individually.

Unfortunately it is more complicated than that. When a lens is moved it is accellerated. Acceleration casues force. In this case, a rotational moment perpindicular to the travel. Depending on how far the lens can be adjusted in height/altitude, the amount of that particular rotational torque changes. That torque is affected by the lens mass and (very important) the len's center of gravity, and the distance from the bearing where it can be adjusted in a worst case situation. I've found end users to be quite creative in acheiving worst case installations .

Next, whether or not the lens is balanced about the axis of travel is critical. Precision linear bearings like the one in the CineSlide are not designed to take a lot of torque in this direction. A properly balanced lens casues zero torque in that direction. A lens that is either off balance to start with, or can be adjusted off balance (e.g. via integral lens element movements) can be the equivilant of a little pry bar pulling to derail the bearing full time.

Next is the simple case you mention, the static load pulling (or pushing in the case of an upright lens situation) on the bearing when at rest.

And, while not usually a problem due to symetric designs, the lens has to be balanced on the bearing in the axis of travel, otherwise the torque induced at move time is different in one direction than the other.

These, along with some other variables have to be run through some complex bearing life and load limit calculations to ensure the operation is within a proper operational envelope with some safety factor.

So, it's just not as simple as checking weight when you are dealing with a precision, optimized and properly engineered design. I used to say it could do any lens within a certain weight limit. But that was before people started making their own mounts. With others making the mounts we have no way to know how the mount is designed, what forces can be generated, and whether or not the limits can be exceeded. We have no way to measure or test a len's CG without having one. And frankly the work and time to certify one isn't trivial so sales potential becomes a factor. And finally we do not vet anything just becasue it will sell one. We would like our unit to remain paired with units that have a high degree of quality engneering and construction, from my perspective. I'd like it to be compatible with everything for obvious reasons. But that does not mean that it is.

Cheers,
Scott

Thanks Scott. While the engineering is occasionally over my head, it shows the time you have put into your product.

I am hoping you get a sample of this new lens to test so there are even more options to use with the cineslide, and even more options for mounting this new lens.

L

This is not correct. I just weighed the Isco IIIL/Schneider XL lens I own, and it was as much as 6.4 kg. The weight of HD-6000F is 4.3 kg, which is around 30% less than that.

FWIW, the Isco IIIL and Schneiderder XL are considerably different in weight. Yours is apparently the heavy cased version of the Schneider XL, not the Isco IIIL. Unless you have an early model with the really big case, it sounds like a heavy measurment to me. I don't have a Schneider case sitting around but I do have a Cinema DLP 1.25x which is a very heavy lens, it is right at 18lbs. The Isco 4XL is about 10 lbs (4.5kg), the Isco IIIL was about 8 lbs (3.6kg). Your 4.3kg =~ 9.5lbs.

Anyway, re your weight, good to know, but as I said, it's not just about weight (mass). In this case, it's more complicated than that, unfortunately.

Cheers,
Scott

I believe Prismasonic owes you some marketing revenue after that photo spread.

Just expressing an opinion I will say again that Anssi (Prismasonic) was very responsive in helping me get a working setup. A setup that I'm now enjoying several times a week...

Is this adaptable for use with a Isco 3L? In my case a CineSlide won't work as I would have to move the projector out. A vertical slide may work though.

Judging by the images, I'd say an ISCO III L is too large.

A long shot I know but can anyone tell me whether 7" clearance between the ceiling and the top of the projector is enough to mount the Motorized Lift for the HD-6000 Anamorphic Lens. I measure 9.5" from the ceiling to the center of the projectors lens.

I have the HD-6000R on order but would like to know if I need to fit an extension to drop the ceiling mount down a few inches before the lift and lens arrive.

Epson 8700UB, 120", 2.40:1 screen

Thanks

Check THIS for dimensions. (You can see this by clicking on the image of the lens/lift on the lens specs page.) Looks like from top of lift to bottom of lens mount "shelf" is 337.5 mm or ~13-1/4". You may have to do a side view drawing of the pj and the lens/lift to determine if it will fit.

Question for Anssi or any of the cyl lens wizards, And this may only apply to the non-"purely cylindricals" (i.e. not totally round) like the Prismasonic. How significant is the horizontal proj lens to A-lens center alignment? I'm using a custom built (i.e. DIY) sled instead of the lift, due to ceiling clearance among other things. The A-lens does not quite sit center to the proj lens. I had no problem with alignment, focus, etc. and no apparent pincushion or other distortion. This is a big mouth lens - plenty of a-lens real estate to shoot light through. But I wonder if this horizontally off-center position introduces any non-linearity. I have not seen any but have not measured from vert line to line on a test pattern.

If you want true corner to corner, centering of the beam is of the utmost importance. I've done this using a DIY slide, and it quite easy.