Zoom versus lens Screenshots - Page 7

The term refers to those who hold the position that zooming is flat out superior to using an anamorphic lens without any real (let alone objective) firsthand knowledge or experience with a quality lens-based setup. Since the comparison is being made between the two methods, such experience is required to answer the question. Yet there are people here who are compelled to answer it without that experience, even when their statements contradict those with experience. And yes, there are actual people here who fall into that category - they're not exactly subtle about it either.

It's great that zooming allows people with certain setup or budget constraints achieve 'scope theaters. I know how much I loved mine (it was lens-based, but that's neither here nor there) for the "wow" factor and impact that it brought to my theather. I already admitted to LilGator that I can definitely see certain scenarios - seating distances, screen sizes, etc - in which using an anamorphic lens wouldn't yeild a noticable difference in PQ. However, there are conversely plenty of scnearios in which using a lens definitely does (again, speaking from experience) yeild a noticable PQ difference.

Screenshots are useful for illustrating specific properties (i.e. CA and pixel density) that are or are not imparted by a lens. They are not useful for judging overall PQ, which is something that can only be properly experienced in person.

I look forward to hearing your in-person anamorhpic lens impressions at whatever point in the future you finally attain some.

Like cream on a cake, you have to have a cake first. So in its most simple form, (for me) a quality lens is any lens with addional correction elements which includes both prismatic and cylindrical.

The ultimate lens (fully corrected cylindrical) is a lens with continiously adjustible astigmatism correction which allows both horizontal and vertical lines to be brought into focus at the same time. This adjustment is made after the projectors primary lens is focues as best as possible and when the cylindrcial lens is also adjusted, the only real difference between lens in and lens out will be geometry.

However, unless you have seen this for yourself, it is hard to fully comprehend and may cause a sense dis-belief when just reading someone's post.

This is exactly what I've seen as well. Personally I'd like to see us get away from all the zoom vs. lens threads and start talking about what type of setups are likely to achieve significant improvements using a lens and what setups are likely to be better off sticking with zooming. Sorting through all the variables involved is a real challenge. I'll use my recent experiences as an example:

My last setup was an 8ft wide scope screen zooming(and later shrinking) my RS1 at the absolute min throw possible. Seating distance was 8ft and neither it nor the throw could move back any. On a new bulb the image was too bright but responded well to calibration. I could occasionally see some pixel structure, but most of the time the image still seemed smooth and film-like. I certainly didn't need the extra brightness from using a lens. I would have benefitted from less pixel structure, but at the throw I was at, pincushion would surely have bothered me too much. It would also have presented logistical problems setting one up in that small of a room. Seemed like a no-brainer to stick with zooming/shrinking.

My new setup is a 125" wide screen from about a 17.5 ft throw which significantly increased my throw ratio. I settled on a 12ft main viewing distance which has increased my viewing ratio from 1.0 SW to 1.15 SW. The screen still feels bigger and more immersive. On the surface it seems like the new setup would be more appropriate for using a lens for the added brightness, pixel density and now minimal distortion using a longer TR. But I wasn't counting on how big a jump in PQ I was going to get simply from the longer TR itself. Contrast and blacks are significantly better and the improved optics are resulting in a sharper, smoother and more "solid" under-control image.(Yes, the longer viewing ratio is a factor, but doesn't account for all of the improvement) Pixel structure is now non-existent. It even seems to be less noticeable from closer viewing as well. Even though I'm still curious about what a lens would do for me, I'm so blown away by the results I'm getting that I'm just not that eager to try one. It seems like a good quality to have in this hobby is a "if it ain't broke, don't fix it" attitude, otherwise you'll always be wondering what you're missing, and not truly enjoying what you have. Just my 2 cents.

Is everyone who is taking these screenshots of zoom vs lens, just removing the lens and zooming the pic? Is anyone adjusting things like contrast, ect or are you all just removing lens and snapping away?

Another reason for dual projectors.

Exactly.

I have posted this also before. However, for those who have not seen the post before this may give some idea of different lenses of different quality/price range.

The pictures below are the screen shots of test grid, showing the performance of different Prismasonic lens models:

H-700: 2-element optics-> no CA or focus correction
H-FE700: 3-element optics-> no CA correction but an additional front element for focus correction
HD-5000: 5-element optics-> achromatic prisms for CA correction and the front element for focus correction

(4-element lens would be like H-700 lens in focus wise (no focus correction) and like HD5000 lens in CA wise (CA corrected)

Projector in the test was Sanyo PLVZ5 with a throw ratio of 2.0. As can be seen, also the projector itself introduces a small amount of CA. The used screen has a matte white fabric. The shots are from the horizontal edge (left in this case) of picture where the CA most exists, if it exists.

Test grid with NO lens (left edge)

Test grid with NO lens (left edge)

Test grid with the 2-element H-700 lens (left edge)

Test grid with the 2-element H-700 lens (left edge)

Test grid with the 3-element H-FE700 lens (left edge)

Test grid with the 3-element H-FE700 lens (left edge)

Test grid with the 5-element HD-5000 lens (left edge)

Test grid with the 5-element HD-5000 lens (left edge)

Anssi,

Can you post just the non lens and HD 5000 shots togther. I think that would better represent the kind of examples the OP was looking for.

One Note: This is not zoomed vs lens, but 16:9 vs lens. That may be a reason why original is bit brighter. Also I cannot lock the parameters in my camera so the exposure time or white balance may vary from shot to shot

If one takes the "Full Compare" image, crop each image, the A-Lens one and the Zoom image to create their own frame. View using Nero Photosnap viewer or similar so one can AB the images at the scroll of the mouse.

The differences are quite apparent.

At home I use a Dell 27" @ 1920 x 1200 calibrated, I even see a color shift between the two. The CA is quite a bit greater in the A-lens version, check around the black instrument and all edges. Check the horizontal "grate" below his feet and the floor etc, all edges are sharper and there is a greater depth to the image well in the zoomed version.

BTW right clicking on the image and selecting preview brings up "Windows Photo Gallery" one can A-B with that too......the differences are readily apparent.

Well I photoshopped this for you


Funny, but in my opinion, the only thing which is apparent is that the picture with the lens is brighter. This, btw, can easily be seen also from 'closeupcompare' of buttons, which I posted earlier.

Talking about the depth or detail visibility, everyone can judge which one of the rings inside the red circles can be seen more clearly..

.. to me this shows that based on these pictures, anamorphic lens has brought more details as well as more contrast to the picture. Again IMO better/more contrast layers can also be seen from the green square of 'closeupcompare', which I posted earlier.

I find less "haloing/CA in the zoom shot as well as a color difference. Look at the vertical disk, it has a blue "fringe" on the A-Lens version, the full perimeter of the instrument has more yellow "fringing"

But as per my prevoious post download the "fullcompare" image seperate the two images by cropping. Using Windows Photo Gallery(right click on image) and A/B them, the differences are easily seen.

For those who don't want to do their own croppin'.....download and A/B away!

A-Lens
http://www.dtvforum.info/index.php?a...e=post&id=8018


Zoom
http://www.dtvforum.info/index.php?a...e=post&id=8019

Does anyone know how to do a "mouse-over," wher one image is shown then switches to the other when the cursor is moved onto it?

Once the images are downloaded to ones PC, using Windows Image Gallery to A/B are just as easy.....

Put both images in a folder.....right click on the 1st image(A-Lens) select "preview" from the drop down menu......"Windows Image Gallery" will open displaying the "A-Lens" image, just click on the right arrow(next image) and it will go to the "Zoom" image...keep clicking on the same arrow and it will cycle between the two images.

I can see that, but it's a very subtle difference. Not particularly damning of the A-lens. I have a very large monitor too.

I've just opened your two links in different browsers and can click on each for a fast A/B comparision.

1. The CA is not as noticeable as you claim. Besides, sitting at your claimed 43.3 degrees, I doubt you'd see this

2. There is a slight geometry shift, however that would be due to how the prisms were set during image capture. My shoot-out of three prism lenses showed similar traits just by the way they were positioned in the light path created slightly different geometrical shifts.

3. There is slight colour shift, however this could (it is a petty difference BTW) be calibrated out and yet another reason why I suggested two projectors need to be used to document this. The advantage of the prisms lens used is that only one calibration setting is required as this lens has a pass through mode. This is one reason I don't move my lens on my own system.

The extra CA is noticiable to me on every edge, the extra CA on the instrument panel under the "bed" stands out like canine gonads on my monitor

The blue I mentioned was from prismasonic's close ups.

Color shift again to me is large and not petty, it's the diff between a fluro lighting and tungsten.....perhaps I am fussy about my images....and you are not as much?

At the end of the day there is an altering of the image and IMO not for the better.

2 things:

1. The colour fringing is in both shots, so possibly a mis-convergance error, not the lens.
2. CA, when seen from a HE lens (like the one used) will only be seen on vertical lines at the farestest edges of the image. So maybe your 'reference monitor' ain't so.

2 Replys:

1.Quite possibly, but it is more evident in the A-Lens shot, obviously indicating the A-Lens is amplifing the problem.

2. Dell 2709 & Eizo T965 only displaying what the images show!

Too me it looks like EE from the source that's more evident in the lens shot due to the increased brightness.

As far as color change, I'd write that off as either camera induced (maybe the auto white balance changed?) or just looking different from being brighter.

I had white balance locked; not set on automatic.
-Pete

Thanks Pete for your time.

"I posted those screen shots to help support (not prove, mind you) and justify my statement that with my equipment the visual quality between the two methods is essentially a tie. I was NOT trying to show that one was better than the other."

I think this is the key point here. On Pete's setup, and in his opinion, lens and zoom ties. I take the photos more as an evidence that he really did the experiment.

So, I think now, as someone already posted, its time to understand what are the attributes that make each setup better.

My next hometheater will be a CIH. I will build a home (yeah!). But here in Brazil we have a lot of constraints: its not easy to find curved screens, not even AT. I will not even talk about lens... And when you find you have an exorbitant cost. So, I'm really trying to figure out wich setup will be good for zoom and wich will be good for lens, and make my moves...

Hope you can start discussing that....

[]s Humberto

Something you missed about HE anamorphic lenses and your comment about "under the bed" is that they (if CA is visible) produce this abberation on vertical edges, not horizontal and the CA is non existant in the centre and progressively get worse towards the edges. A standard 2 prism lens might do this, not a CA corrected (5 element) lens like the one used.


And your point is?

I see what my eyes tell me....there is significantly more CA in the A-Lens version to my eyes.

My point is if it shows up on two monitors the artifact is in the photo.....not caused by the monitor.

In this example of Pete's, the zoom version is producing a darn good image....can't see the reason to spend extra $$$ for the undesireable artifacts.....more is not better to my eye in this example.

Each to their own!

So in the words of the late great Henry Ford "no matter if you think you can or can't, your right." In other words, you see what you want to see Nothing else really matters does it?


So why would CA be present 'under' an object for HE lens? If it was a VC, then yes. Ever think that maybe some of the colour smeer (yes I do see it too) was caused by CA from the projector's lens or simple mis-convergnece of the panels?


All this expert knowledge from a guy that watches Scope on a screen the same height as a old 29" 4 x 3 CRT

A picture is worth a thousand words.


Even if was so, the A-Lens is making it more visible.



Hmmmm...........the truth must be hurtin'..........

Hmmm, so long as capture devices don't distort the truth which is what appears to have happened here. How any screen captures have been posted on this forum that show barreling? When people complain about geometric distortions from anamorphic lenses, it is intersting to see that they didn't know that the A-Lens is not responsible as HEs do not barrel.


To a degree. A precion lens like the one used will simply pass all the light including CA or misconvergence from the projector or its lens. When we tested AB's "Horizon" last year, we quickly discoved some short comings with my BenQ that was used as one of two projection technologies on the day.

The lens will then magify the light (including an abberations in the light path) so, yes can make these look slightly worse. Is this a reason not to buy an anamorphic lens? No. This just highlights the limitations of the projector, so if you are really concerned about PQ, then will be aware that an upgrade is in order.


Screen envy Highjinks? Yes SIZE DOES MATTER