Schneider or Isco iii ? - Page 3

I checked the specs of high end anamorphic lenses, and found out that the amount of available technical information is embarrassingly low.

The only data I could find about the focusability/sharpness and the sweet spot was Panamorph UH480. All other lenses including ISCO III did not give any data about the focusability throw range. If I have missed any data please fill it up. Above technical discussion indicates that even top end lenses (ISCO III and Schneider) with focus adjustment have a throw range for razor sharp focus. However, I couldn't find this data.

Panamorph focus ranges:
14.5' - 17.5' UH480 standard
17.5' - 20.5' UH480B
20.5' - 24.0' UH480C
24.0' - 29.0' UH480D
29.0' - 40.0' UH480E

I expect these different UH480 models have cylindrical lenses with different focal points to achieve sharp focus for the given ranges.

I couldn't find any focusability data for Prismasonic HD5000. It has single spherical lens to obtain sharp focus in contrast to multiple cylindrical lenses in UH480 to obtain multiple focus ranges.

If anyone could find focusability data on other high end lenses please post. Thanks.

I happened to be passing the Schneider booth at CEDIA and noticed that they were showing a new jumbo lens which they were calling the 1.33XL. They did not have any details at the time, but indicated it would be available in about 4 to 6 weeks. The diameter of the barrel was about 5 or 6 inches, so it should not have any trouble passing the light from larger projector lenses.

The other thing I learned while visiting their booth...Schneider has purchased ISCO (or is in the process of doing so). According to the Schneider guy it was not to acquire ISCO technology or to corner the market on high-performance lenses, but rather to acquire more production machinery of a highly specialized nature.

I'm glad someone else had searched the available literature and came up mostly with a blank, like I did.

I wrote a few posts about a year ago lamenting the dearth of performance information, but got nowhere.

Words like "excellent" and "brilliant" in web sites describing lens performance are hardly technical, or even really meaningful terms, especially when it seems that no matter what information you put into various "lens calculators" around the place these words pop up. How they are defined is literally left to the user's imagination.

A lot of this, I think, can be attributed to not wanting to confuse potential customers with details that disclose performance limitations.

There'll always be someone who doesn't understand what these "limitations" really mean (usually very little) and will buy the other lens that doesn't disclose any limitations at all.

Oh, I wonder if they have any waterfront property in Florida for sale too ...

Very good point. People should think twice before spending big dollars based on hype. It is a possibility that the ISCOIII and Schneider focusability range is weaker and limited in comparison to Panamorph UH480, although they are adjustable. Unless ISCO comes up with hard data, I think I could assume this is the case. "Adjustable" doesn't mean it is adjustable for any throw distance, there should be a range for the adjustability.

Oh crap. Someone to stoke AB's ire again on his anti-Isco/Schnieder campaign. My opinion FWIW, is that Isco's primary market isn't AVS enthusiasts who are looking to rationalize the purchase of a Prism based solution or provide comparison specs to those who make their own. So it isn't focusing much in the way of resources to meet these comparision desires. Yes, I have a biased viewpoint, but I basically announce in in my sig. I beleive there are some other unannounced biases going around these threads. But in any case, I think you are kidding yourself if you take limited specs published to the masses to mean the ground glass lenses are not of higher quality that the other solutions. AB's just ticked he can't judge his lens to their specs . And, as far as I know, everything AB reports about their presumed design and performance is hypothesis, and almost always negative. Last I checked they sure aren't releasing how they design their lenses. It took Schneider almost 2 years to bring the larger prototype to market, it's not as easy as AB makes it sound, apparently. So factor the input accordingly. My string pulled. Now back to work...

ISCO and Schneider may or may not produce a sharper image. However, how can it be proved that it is sharper, unless they publish hard technical data? Without data, unfortunately, it becomes perceptions of different people and also possibly hype.

I am probably biased since I use Panamorph UH480. I did my research before committing to it and obviously that was my choice based on my research and understanding. I factored in perceptions as well as available data when I made my decision to purchase the lens.

My sense is that "Perceptions" only come into play when two lenses are almost identical. The human eye can easily detect very slight differences in detail. You don't need specifications or measurements to judge the relative sharpness of two lenses. The UH380/480 -- as good as they are -- simply look softer in comparison to either an ISCO or Schneider. Whether the upcharge for the German optics is justified is a matter of perception.

Okay. If scientific/technical credibility is needed in relation to any measure regarding human perceptions, a scientifically controlled experiment should be conducted and results should be statistically analysed. This is not a trivial process as one may think. This is not to say that just A/B comparison will not work. It may indeed give valid results. However, such a comparison can be questioned and it will be hard to justify the results.

Nevertheless, I wish to hear from people done direct/simultaneous A/B comparisons on high-end lenses. Unfortunately, I did not have the opportunity to do this type of comparison.

However, I did lens on/off tests on Panamorph UH480 and I can assure that I couldn't see any sharpness decrease due to UH480 when coupled with vw60 for my installation. My throw distance is about 17.5' and it is on the edge of the focus range to obtain razor-sharp clarity for UH480 standard cylindrical lens (This cylindrical lens can be tailored for the throw distances from 14.5' to 40' at the time of purchase). Pixel structure was razor shcrp for both cases (lens on and off) except for the edge of the screen. On the edge of the screen. I could see some smoothness in the pixel structure in both lens on/off cases. This was the case with the vw60 lens, so I expect this is due to my throw ratio ~1.7. The difference in the distance to the middle and the edge of the screen from the lens will make it impossible to obtain 100% screen-wide consistent sharpness unless a correctly constructed curved screen is used especially for lower throw ratios. I was extremely impressed and so as my teenage children.

I really cannot imagine how ISCO III could improve the sharpness of the pixel structure (as well as the test pattern) at least for my installation. It is a possibility that the Sony vw60 primary lens is a limiting factor. But I doubt that is the case.

I have seen a notable sharpness increase when changed from UH380 to UH480 (together with brightness/contrast improvements). So, it is unfair to use UH380 in performance comparisons.

Never said that GG. Just said that the cylindrical designs are not rocket science and are therefore limited in scope (I made a pun). I believe I've levelled criticism at prismatic lenses too.


Apart from there being nothing wrong with that sentiment, nobody else can judge lenses against each other. That's the important point.



A nice counterbalance to all the positive fluff coming from certain quarters.


You're not asking hard enough. I simply wrote to one of them and they told me: "4-element" means "two doublets"... the simplest possible anamorphic design. As both companies describe their lenses in the same terminology, I'm assuming they're both basically similar in design strategy.

You correspond regularly with them. Why don't you ask?

Even the 2x stretch lens I have from a 16mm projector is just that - 2 doublets...

Mark

The 2-doublet design is good for long throws coupled with large throw ratios: simple in design and manufacture (only one air gap to adjust for focus).

Short throws, as in HT, need more elements to massage the light through the lens (not a technical term) for best performance, even at 1.33x enlargement.

The Orpheum cinema in Sydney, Australia's Cremorne (one of the most beautiful cinemas I've ever seen) has a 17'5" high by 41' wide anamorphic screen, with a throw of 95'. This is still a TR of over 4. It uses a 2-doublet anamorph.

http://www.orpheum.com.au/