I've Joined The A-Lens Club!

As I mentioned in the projector forum, I've picked up a used Panamorph UH480 Anamorphic Lens, from another AVSforum member, and I'm all giddy. So I thought I'd share...and ask some questions.

As a dedicated "zoomer," why did I buy one?

As some here know, my system was deliberately designed as a Variable Image Size system, to use the projector's zoom with 4-way masking to vary the image size to my desire. I had bought the largest possible screen for my wall - larger even than could be accommodated by the throw distance (maximum zoomed out image size) of many projectors. And my throw distance is limited, so any projector ends up being placed within an inch or so of the back wall (actually, it's a bay window). So the mere depth/length measurement of a projector can add or subtract from my maximum image size. I have up to 124 or 125" or so available screen width, with my side masking fully retracted, that I want to be able to take advantage of.

My first Panasonic AE900 projector, being small, gave me the largest image size. My next, the JVC RS20 still gave a pretty big scope image, but not as wide. Now my new JVC RS55 projector, being even deeper, has limited the size of my 2:35:1 images even more. I was down to between 118" and 116" wide for scope. Only an A-lens would allow me to re-size scope images larger, in my room. And, I'm not one of those who is terribly worried and an A-lens affecting the image quality adversely (by putting more glass in the way) - every A-lens set up I've seen always struck me as looking great.

So, from the beginning, I designed my projector lift area to accommodate an anamorphic lens at some point. However, holding me back was the fact they are so darned expensive. Further holding me back is the fact I'm so happy zooming the image, including for scope, and it's not like I had a small image. An A-lens just gets me a few inches more, so it would have been hard to justify spending thousands of dollars on an A-lens given I don't use a strict CIH system, and that it would only be for those times when I wanted the widest image possible. But...a great deal I couldn't refuse came up so now it made sense and here I am. And, I know those last inches can really add impact - with an A-lens I'm back to about a 124" wide scope image again.

I'm at about a 1.8 throw ratio with the 16x9 image size, so I am told I can expect a bit of pincushion.

Pictures, and then first impressions and questions to follow...

Photos of the UH480 A-Lens with my RS55 projector. My projector sits on a lift that sits close to the floor, but telescopes up to about 6 feet or so. (The green tape is temporary for marking positions).

The member who sold me the UH480 had built is own cost effective lens sled, out of drawer slides, screwed to a black shelf board. He gave me that slide/shelf as well.
So for now I've just plopped the whole thing under my JVC RS55, which makes it easy for initial testing:



You can see how close the back of the projector is placed to the ledge of the window, hence maxing out my throw distance:



Projector Lift is up a bit: A-Lens in position:



A-Lens shifted out of light path:

First Impressions:

These are so preliminary as to be almost invalidated by the technical issues I ran into...but since some of them are positive I'll mention them anyway.

When my projector lift is fully raised, the Projector sits about 3" above the height of my largest 2:35:1 image on the screen.

The first issue is that I set my image size, switched my RS55's anamorphic processing on, and then slid the UH480 into place. Right off the bat (looking at the lens pattern) the geometry was crazy-off, warping all over the place. So I tilted the UH480 to try to try to compensate, and it got a bit better, but was still a mess. The other issue was about 1/3 of the bottom of the image was in shadow - it was missing. I realised later, especially from looking at A-lenses in the "2:35:1 Screen Picture Thread," that my UH480 is riding too high on the shelf. It's mounted to a 1" high wood block, which appears to put it up too high in front of the lens as you can see here:



So it looks like I'll have to fix that issue somehow, for now I'll put something under my projector to raise it up. But my question is: do I need the projector to be perfectly level with the lens? Or, because it's slightly higher than my screen, will the lens be best placed slightly lower down, angled slightly down toward the screen? (That's how many of the ceiling-mounted A-lens set ups look to me, from pictures).

Anyway...

I ended up lowering my projector lift to the point I could tilt the UH480 up just enough to eliminate the bottom shadow from the 2:35:1 image. However, the image geometry was still pretty awful - not just the fringes of the image, but there was warping on either 1/2 of the image as well. I can really use some advice as to how to best situate and dial in this lens.

All that said, I watched some movie scenes anyway, just to see them fill my screen.

It was awesome seeing that even-more-huge-and-cinematic impact of using most of my screen width. The bigger the image, the more cinematic it feels.
The Alien Blu-Ray scenes had me feeling I'd lost a bit of clarity (hopefully attributable to the current crappy lens set up) and perhaps a bit of contrast (black levels seemed a tad higher). But then as scenes went on, many exhibited quite nice contrast. I was happier as I continued to view...it was at least quite promising. Was it brighter? I don't know objectively, but my over all impression from everything I watched was "hey, this is quite bright, especially given it's an even bigger image size than the biggest I've watched in quite a while." I had my RS55's iris down most of the way, to about -12 and the image was vivid at 123 or 124" wide.

After that I watched some of The Fifth Element and The Island. Holy cow they looked fantastic! (Though I could spot the poor geometry, it was far less intrusive than the lens pattern would have led me to predict). I think this is where a projector like the RS55 really comes into play, with it's amazing contrast and the added clarity you can bring in with the E-shift/MPC settings. But the huge scope image was just gorgeously sharp and detailed, with tons of "pop" and contrast. It just looked better than it had any right to at that size. Once those two movies went on, I was just "wow...wow!" for the rest of the night. I put on 2001 Space Odyssey and it looked astonishingly good!
Better than I thought it could at that size. And of course, no film demands more immersion than that one.

I don't know yet if I can attribute the excellence of the image to adding an A-lens or not. Maybe, in allowing this image size at a smaller zoom setting, it's allowing for more contrast in the image. That's the feeling I was getting.
But I won't know better until I do some good zoom vs A lens comparisons.

But it was a very promising first look in terms of the image experience. I just hope I can lick the geometry problems.

Any advice would be much appreciated as to what type of angling I should aim for with the A-lens.

Thanks for reading....

Thank you HogPilot! Your quick reply is just what I need, as I'll be trying to address these issues tonight.

I did start with aligning my projector to the screen (in a quick and dirty way, as opposed to the very precise way I'd aligned it before I had to lift it off and place the lens shelf under it). Though, once I build the new shelf to accommodate the new lens, I'll be extra precise in re-aligning my projector to the screen again.

I am not using any horizontal lens shift. I am using a fair amount of vertical lens shift, to shift scope images downward to fit my screen. Given that: do I still want the A-lens perfectly aligned, level with my projector, and then I angle the A-lens more down toward the screen? Or...do I want the A-Lens to be mounted slightly down from the projector lens, to best accommodate the downward vertical lens shift? (It seems to me a number of ceiling mounted A-lens users have their A-Lens hanging a tiny bit lower than the projector lens).

Good point about making sure neither side of the A-lens is higher than the other. Though I have the A-lens slid down to the bottom of it's vertical position, so I think both sides must be level.

However, I did note that my A-lens was not perfectly parallel to my projector lens, being a little bit closer to one side. I'll correct that.



Especially at the price I paid for mine.

Much obliged!

Rich

Will do!

Also, one other issue was on my mind: When the lens is slid out of the light path it ends up in front of the left fan exhaust vent (there are two intakes on the back of the projector; 2 exhaust vents on the front, one to each side). You can see that in the last image of those first 4 I posted.

That has me curious if it would be a problem either with ventilation for the projector, or just vent heat flowing toward the lens.

It seems to me the slides other people have made, and also the slides offered by Panamorph, put the A-lens in essentially the same position when not used (in front of one side of a projector - hence likely in front of an exhaust vent). But I haven't heard any problems with this, nor did Mr.littlejeans (who sold me the UH480) seem to have an issue on his projector.

Thoughts, anyone?

Thanks mrlittlejeans, I'll check it out.

Highjinx, taffman...

I don't want to raise expectations unduly. I'm not able to be too technical about the comparison as I do not have a light meter. I'll just be eye-balling the difference between zoomed/A-lens to see what I think.

I'm finding the positioning of the A-lens even tougher than I thought it would be. Last night I raised my projector, maneuvered positions. Even though it seems to me the projector beam is centered through the A-lens I'm still getting nowhere near normal geometry. I still had to lower my lift a lot to get the geometry better. Still, watching more content through the lens at full size looked absolutely amazing last night. Also, pixel focus through the A-lens, at least near the center of the screen, is quite impressive. Without a quick A/B, I'm not sure I can tell any difference from no lens. So my hopes are somewhat up...

Thanks stranger89.

Right now the A-lens is slightly below my projector's lens, and tilted downward toward the screen. Since I'm still experiencing issues, it looks like I have to raise my projector even more. Or...and this is the question on my mind...would I want to also tilt my projector on a slightly downward angle toward the screen, so that both my projector and A-lens are tilted down toward the screen? (Off hand, I would have figured one would want the projector's lens as parallel to the screen surface as possible, hence no downward tilting).

Right now, when I bring my projector lift down half-way I can get geometry that, using the projector's lens pattern, has the top and bottom of the lens pattern line fairly straight along the top and bottom of my screen frame. But I see significant bowing on both the outer side vertical lines of the lens pattern AND bowing on the inner vertical lines - the ones that designate the 16:9 and 4:3 areas of the image.

I just wanted to say: thanks Mike, GetGray, stranger89 for the suggestions.

Boy, this is still proving to be challenging. I have to get back to trying to get that geometry straight tomorrow.

Well, silly lil' me...

See, I told you I was a newbie at this A-lens stuff.

As I've mentioned, I was trying to adjust the geometry with the A-lens in place, using the projector's lens pattern. With the A-lens in place and anamorphic stretch employed, I'd been wondering why no amount of fiddling with the A-lens could fix the obvious warping/stretching of the geometry lens pattern.

I only realised last night that the anamorphic stretch is automatically TURNED OFF when I switch to the projector's lens pattern. Whereas I'd presumed the anamorphic stretch had been applied to it, like the movie image. That obviously explains the un-fixible warped geometry: it was a regular 16x9 image that was being stretched wide by the A-lens!

Doh.

So I threw in the Spears and Munsil Blu-Ray for the geometry pattern and things looked much better. Still not perfect, there are challenges still to be met. But that explains why the image looked ok with movie material.

I'm still awestruck by how good the image looks this big.

Sort of.

I had such a heck of a time trying to figure out the best position for the A-lens that I threw in the towel for a while and just started using it. I have to get back to decide on it's final position, hopefully this week (and then have a proper shelf built). I've been busy with other things in the home theater, room upgrades, moved from an Oppo 83 to Oppo 93 blu-ray player and for some reason I'm now tracking down a lipsync issue.

I'm thrilled to finally own an A-lens, mostly for it's allowing me to finally use every inch of my screen real estate. I can now get that really massive feel for scope when I want it, so there is a sense of completion there.

I haven't done any strict zoom vs A-lens comparisons yet, but it looks tremendous with the A-lens. Probably because I just got the A-lens I've been viewing more scope films larger than before, though I'm still glad to have the option of varying the image size. Last night we opted to watch Kurosawa's '63 scope film High And Low at a smaller size, which preserved the image quality better of that older film.

Guests think the A-lens demos are neat, though altering the image size via zooming seems to get more of a "wow" out of them - it's that JVC lens pattern that looks to guests like the image has been replaced by a laser show, and then the image pops back on and its a new movie at a different size.

Once I get to re-adjusting my lens I'm going to be back here with a question or two. I'm very happy with my purchase as it is.