16:9 Screen Vs. 2.37:1 CIH Screen - Page 8 - Home Theater Forum and Systems - HomeTheaterShack.com

Reply
 
Thread Tools
post #71 of 96 Old 10-12-08, 06:25 PM Thread Starter
HTS Senior Moderator
 
Prof.'s Avatar
The Mad Professor
 
Join Date: Oct 2006
Location: Murraylands South Aust
Posts: 8,367
My System
Re: 16:9 Screen Vs. 2.37:1 CIH Screen

Quote:
takumi wrote: View Post
scaler? vertical stretch? i have a lot to learn.
OK..so it looks like you're starting from scratch..
This makes it a simple choice if you follow what a lot of people have done, who have an anamorphic system..

DLP projectors have a number of makes that provide vertical stretch..and is generally the preferred type of projection system..

Vertical stretch is where the projected image is electronically stretched vertically by the projector, which makes people look tall and skinny..and then the lens expands the image horizontally to restore the correct geometry..
Without going into all the other aspects of this..I suggest that you have a good read of my "16:9 vs 2.37:1 CIH Screen" in this forum..as well as the postings by Mark Techer..
You will find all you need to know about Anamorphic projection..

As far as the makes of projector to look at..These would be my choices..

Benq
Optoma
Sony
Panasonic

All have the vertical stretch facillity..but some of the earlier models may not..

I see your theatre room is 23' long..so I would get a projector that has a fairly long throw lens, to help reduce pincushion effect..

Prof..
Home Theatre...the never ending story!


To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
Prof. is offline  
Sponsored Links
Advertisement
 
post #72 of 96 Old 10-12-08, 10:54 PM
Senior Shackster
Victor B
 
Join Date: Oct 2008
Location: plano tx
Posts: 100
Re: 16:9 Screen Vs. 2.37:1 CIH Screen

long throw lens, i guess that would narrow my choices. I will do a search on the pincushion effect
takumi is offline  
post #73 of 96 Old 10-17-08, 10:14 PM
Mark Techer
 
Join Date: Jan 2008
Location: Brisbane, Australia
Posts: 613
Re: 16:9 Screen Vs. 2.37:1 CIH Screen

A long throw can be determined by two methods -
1. The Throw Ratio where the native 16:9 image width is divided into the distance from the screen to the projector.
2. How many image heights the projector can be back from the screen.

If we take my BenQ W5000, at the min zoom (smallest image) the TR (from 1) is about 2.2) or 3.1 times the image height. Therefore I would really consider the BenQ W5000 to me a mid range throw device, not a long throw device which would be closer to 3.7x the image height...

Mark
Mark Techer is offline  
 
post #74 of 96 Old 10-18-08, 07:40 PM Thread Starter
HTS Senior Moderator
 
Prof.'s Avatar
The Mad Professor
 
Join Date: Oct 2006
Location: Murraylands South Aust
Posts: 8,367
My System
Re: 16:9 Screen Vs. 2.37:1 CIH Screen

Quote:
Mark Techer wrote: View Post
If we take my BenQ W5000, at the min zoom (smallest image) the TR (from 1) is about 2.2) or 3.1 times the image height. Therefore I would really consider the BenQ W5000 to me a mid range throw device, not a long throw device which would be closer to 3.7x the image height...

Mark
Mark...At a 2.2 TR..do you notice much difference in pinchusion effect over your previous Sony projector..which had a much lower TR I believe.?

I always thought that the earlier BenQ projectors had a fairly short throw lens, but I'm at 3.5 times the image height, with a 1.8 TR.!!

Prof..
Home Theatre...the never ending story!


To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
Prof. is offline  
post #75 of 96 Old 10-19-08, 11:24 PM
Mark Techer
 
Join Date: Jan 2008
Location: Brisbane, Australia
Posts: 613
Re: 16:9 Screen Vs. 2.37:1 CIH Screen

Quote:
Prof. wrote: View Post
Mark...At a 2.2 TR..do you notice much difference in pinchusion effect over your previous Sony projector..which had a much lower TR I believe.?

I always thought that the earlier BenQ projectors had a fairly short throw lens, but I'm at 3.5 times the image height, with a 1.8 TR.!!
Prof,

Maybe I have got the math wrong...and it looks like your right...

My screen is 949mm high x 2.37 = 2250mm.

1st row 2000mm.

2nd 3000mm (a bit tight).

Projector, just behind that at about 3200mm.

Therefore TR should be 3200mm / (949 x 1.78) = 1.89:1

Sorry for the confusion about the 2.2TR...

So anyway, the pincusion was less than the 1.3:1, but not totally reduced. My screen is adjustable, so I can compensate here.

I am however looking to extend the Throw Ratio, so will most likely go to a VC lens next.

The TR won't change as TRs for VCs are taken off the Scope Image width, not the 16:9 image width, but the projection distance will increase 3200mm to over 4250mm allowing better spaced seating.

Also with a VC, you don't get pincushion at all and I can actually go back to a flat screen. What you get is "barrelling" but the barrelling is much less than the pincushion.

CA that normally runs vertcially with a HE will now run horizontally, but I am not expecting to see any CA with my new lens (a shamless plug ) that is under development right now and will use achromatic doublets.

Lastly is the focus issue where typically a DIY prism lens tends to loose a bit of shapness towards the edges, the VC maintains sharpness all the way and this is why Panamorph used the VC design for so many years. If there is to be any loss in sharpness with the VC, it will be seen at the top and bottom of the image not the sides.

My lens is also cylindrical, not prismatic, so I have designed anstigmatism correction into the design as well...

The only problem with using a VC is that the lens must remain in the light path all the time or the 16:9 image become much taller. This is not really a problem (with 1080 anyway) as the light levels, pixel density and colour all remain the same when leaving the lens in place - which I have been doing anyway with my HE lens. Removing the lens may even reqire two (or more) calibration settings...

Mark
Mark Techer is offline  
post #76 of 96 Old 10-20-08, 06:47 PM Thread Starter
HTS Senior Moderator
 
Prof.'s Avatar
The Mad Professor
 
Join Date: Oct 2006
Location: Murraylands South Aust
Posts: 8,367
My System
Re: 16:9 Screen Vs. 2.37:1 CIH Screen

Quote:
Mark Techer wrote: View Post
Prof,

Maybe I have got the math wrong...and it looks like your right...

My screen is 949mm high x 2.37 = 2250mm.

1st row 2000mm.

2nd 3000mm (a bit tight).

Projector, just behind that at about 3200mm.

Therefore TR should be 3200mm / (949 x 1.78) = 1.89:1
It looks like your screen size and TR are almost identical to mine...except I don't sit quite as close as you do..don't have the same resolution as the W5000..


Quote:
So anyway, the pincusion was less than the 1.3:1, but not totally reduced. My screen is adjustable, so I can compensate here.
I'm guessing that with your current set up now, you probably have about the same amount of pincushion that I'm getting..
It would seem that the W5000 would fit nicely in my room..

Quote:
The TR won't change as TRs for VCs are taken off the Scope Image width, not the 16:9 image width, but the projection distance will increase 3200mm to over 4250mm allowing better spaced seating.
WOW!!.I had no idea that VC would increase the projection distance by that much!!..which would put my projector outside in the yardl!!

Quote:
Also with a VC, you don't get pincushion at all and I can actually go back to a flat screen. What you get is "barrelling" but the barrelling is much less than the pincushion.
That would be nice to have but unfortunately I don't have the length in the room..

Quote:
CA that normally runs vertcially with a HE will now run horizontally, but I am not expecting to see any CA with my new lens (a shamless plug ) that is under development right now and will use achromatic doublets.
I'm very interested to see the pics of that lens when it's finished..

Quote:
Lastly is the focus issue where typically a DIY prism lens tends to loose a bit of shapness towards the edges, the VC maintains sharpness all the way and this is why Panamorph used the VC design for so many years.
That would be nice to have..


Quote:
If there is to be any loss in sharpness with the VC, it will be seen at the top and bottom of the image not the sides.
I would find that annoying, because I'm more aware of the sharpness, top and bottom of an image when watching a movie, rather than the sides..and it's only when I specifically look at th sides that I notice it in some scenes..

Quote:
My lens is also cylindrical, not prismatic, so I have designed anstigmatism correction into the design as well...
Cool!!

Quote:
The only problem with using a VC is that the lens must remain in the light path all the time or the 16:9 image become much taller. This is not really a problem (with 1080 anyway) as the light levels, pixel density and colour all remain the same when leaving the lens in place - which I have been doing anyway with my HE lens.
Likewise for me...I'm even leaving the lens in place for all AR's of the movies I buy or rent, so everything is viewed in cinemascope...even if the occassional head gets chopped off!!

Prof..
Home Theatre...the never ending story!


To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
Prof. is offline  
post #77 of 96 Old 10-20-08, 10:11 PM
Mark Techer
 
Join Date: Jan 2008
Location: Brisbane, Australia
Posts: 613
Re: 16:9 Screen Vs. 2.37:1 CIH Screen

Quote:
Prof. wrote: View Post
It looks like your screen size and TR are almost identical to mine...except I don't sit quite as close as you do..don't have the same resolution as the W5000..
1080 rez allows you to sit close as you simply do not see the pixel structure. 2x the image height is actually quite good, but until I saw this for myself, I didn't believe it...



Quote:
I'm guessing that with your current set up now, you probably have about the same amount of pincushion that I'm getting..
It would seem that the W5000 would fit nicely in my room..
Probably would...I like the BenQ despite the neg reviews it got from around the world....

Quote:
WOW!!.I had no idea that VC would increase the projection distance by that much!!..which would put my projector outside in the yardl!!
I want the projector behind the seating and not above it, so this is the only way to do that...
Quote:
That would be nice to have but unfortunately I don't have the length in the room..
Can't have everything


Quote:
I'm very interested to see the pics of that lens when it's finished..
There will be plenty of pictures, don't worry about that

Quote:
I would find that annoying, because I'm more aware of the sharpness, top and bottom of an image when watching a movie, rather than the sides..and it's only when I specifically look at th sides that I notice it in some scenes..
And the reason I am going cylindrical this time too - you can adjust the focus of the lens to be razor sharp corner to corner - prisms will never allow that..


Quote:
Likewise for me...I'm even leaving the lens in place for all AR's of the movies I buy or rent, so everything is viewed in cinemascope...even if the occassional head gets chopped off!!
I won't chop heads. I use eithe the 4x3 mode or the letter boxed mode to ensure that I have true CIH for those ARs...

Mark
Mark Techer is offline  
post #78 of 96 Old 10-21-08, 05:47 PM Thread Starter
HTS Senior Moderator
 
Prof.'s Avatar
The Mad Professor
 
Join Date: Oct 2006
Location: Murraylands South Aust
Posts: 8,367
My System
Re: 16:9 Screen Vs. 2.37:1 CIH Screen

Quote:
Mark Techer wrote: View Post

Probably would...I like the BenQ despite the neg reviews it got from around the world....
I've only ever seen good reviews..What are the negative aspects?

Quote:
And the reason I am going cylindrical this time too - you can adjust the focus of the lens to be razor sharp corner to corner - prisms will never allow that..
So, still no possibilities for marketing the new lens.?

Quote:
I won't chop heads. I use eithe the 4x3 mode or the letter boxed mode to ensure that I have true CIH for those ARs..
.
I'm afraid I've been utterly spoilt with cinemascope images..to the point where I'm very reluctant to watch any movies in 1.78...It just seems so boxy!!..almost like the old 4:3 box TV..

Prof..
Home Theatre...the never ending story!


To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
Prof. is offline  
post #79 of 96 Old 10-22-08, 06:39 AM
Mark Techer
 
Join Date: Jan 2008
Location: Brisbane, Australia
Posts: 613
Re: 16:9 Screen Vs. 2.37:1 CIH Screen

Quote:
Prof. wrote: View Post
I've only ever seen good reviews..What are the negative aspects?
Where to begin? I don't want to come across as negaitve, but there are many issues with these projectors. BenQ have done the right thing and arranged repair or exchange when faults are reported so well done to them for that. The 8720 was a beast of a projector, and I had just hoped that quality would have been carried into the new models. It seems that was not the case and that legacy ended at W10000.

Some of the issues are simply manufacturing - the have done the right thing by keeping prices low, but QA did drop a touch - it had too. Take the lenses for example. Many (not all, as mine seems to be one of the good ones) have silicon contamination. I am told that this means that the sand used to make the glass was not pure silcon sand, and I have even seen artifacts such as "blue blobs" (like dust blobs on LCDs) projected on screen from several W5000s and a W20000.

Light leakage is a concern and it too can be seen on screen in some instances because of the way the vents are aligned.

FW updates - BenQ have been really good here updating FW for free and even arranging pick up and drop off of the units for people - talk about great customer service here!!!

But for the money, this product is still one of the best projectors out there and allowing true HD for that price is something BenQ have done well...


Quote:
So, still no possibilities for marketing the new lens.?
No, I have the ZEMAX designs now Just looking for manufactures that can make that diameter lenses. As soon as I get glass, I will be posting images - lots of them


Quote:
I'm afraid I've been utterly spoilt with cinemascope images..to the point where I'm very reluctant to watch any movies in 1.78...It just seems so boxy!!..almost like the old 4:3 box TV..
Scope is great, but not everythig was filmed that way, so in the name of "preserving the art" I will watch the smaller ARs when such films are presented as such.

For me, AR change is easy. I just switch from Letterbox to the 4 x 3 mode. For you, you would also have to toggle the EZ View mode taking the player back to WIDE first, then switching the projector to 4 x 3...

Mark
Mark Techer is offline  
post #80 of 96 Old 10-22-08, 06:00 PM Thread Starter
HTS Senior Moderator
 
Prof.'s Avatar
The Mad Professor
 
Join Date: Oct 2006
Location: Murraylands South Aust
Posts: 8,367
My System
Re: 16:9 Screen Vs. 2.37:1 CIH Screen

Quote:
Mark Techer wrote: View Post
Where to begin? I don't want to come across as negaitve, but there are many issues with these projectors. BenQ have done the right thing and arranged repair or exchange when faults are reported so well done to them for that. The 8720 was a beast of a projector, and I had just hoped that quality would have been carried into the new models. It seems that was not the case and that legacy ended at W10000.

Some of the issues are simply manufacturing - the have done the right thing by keeping prices low, but QA did drop a touch - it had too. Take the lenses for example. Many (not all, as mine seems to be one of the good ones) have silicon contamination. I am told that this means that the sand used to make the glass was not pure silcon sand, and I have even seen artifacts such as "blue blobs" (like dust blobs on LCDs) projected on screen from several W5000s and a W20000.

Light leakage is a concern and it too can be seen on screen in some instances because of the way the vents are aligned.

FW updates - BenQ have been really good here updating FW for free and even arranging pick up and drop off of the units for people - talk about great customer service here!!!

But for the money, this product is still one of the best projectors out there and allowing true HD for that price is something BenQ have done well...
That is surprising!..I had no idea they were having so many problems..and no FW update is going to fix light leakage problems, or contaminated lens elements..and I can't see BenQ looking for a replacement lens, that doesn't have any contamination!!..

I would have to seriously re-think about getting one, when I upgrade to 1080p..
Pity really, as they looked to be a good choice for Anamorphic projection..
It's good to hear at least, that BenQ are doing the right thing by their customers..

Have you had this problem of light leaking onto the screen..or does the lens help to block this off.?


Quote:
No, I have the ZEMAX designs now Just looking for manufactures that can make that diameter lenses. As soon as I get glass, I will be posting images - lots of them
Probably your best bet would be China..I had the name of a lens manufacturer in China who would make up any type of lens..and in relatively small quantities..I'll see if I can dig it up..


Quote:
For me, AR change is easy. I just switch from Letterbox to the 4 x 3 mode. For you, you would also have to toggle the EZ View mode taking the player back to WIDE first, then switching the projector to 4 x 3...
Actually it's the same for me...The player stays on WIDE all the time and I just have to press 4 x 3 on the projector remote to go to 16:9..

Prof..
Home Theatre...the never ending story!


To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
Prof. is offline  
Reply

Bookmarks

Tags
169 , cih , screen

Quick Reply
Message:
Options

Register Now




PLEASE COMPLETE ALL REQUIRED FIELDS BELOW... THANKS!

REQUIRED FIELDS ON THIS PAGE
YOU MUST COMPLETE ALL OF THESE

Username
Password
Confirm Password
Email Address
Confirm Email Address
Random Question
Random Question #2




User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
PLEASE READ BELOW PRIOR TO ENTERING AN EMAIL ADDRESS!

ATTENTION!

YOU MUST ACTIVATE YOUR ACCOUNT!

Activation requires you reply to an email we will send you after you register... if you do not reply to this email, you will not be able to view certain areas of the forum or certain images... nor will you be able download software.

AN INVALID EMAIL ADDRESS WILL CAUSE YOUR ACCOUNT TO BE DELETED!

See our banned email list here: Banned Email List

We DO NOT respond to spamcop, boxtrapper and spamblocker emails... please add @hometheatershack DOT com to your whitelist prior to registering or you will get nowhere on your registration.


Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML is not allowed!
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 


For the best viewing experience please update your browser to Google Chrome