NEW projector from INDIA

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gunsreekanthvs

Member
Joined 2010
Thanks for the suggestions bishnu..

I already got a quote from lensel pune.. they now say that 317mm(75dia) triplet costs around 2000. I previously heard that triplet costs around 800 rs.

But I seriously dont see any other options.

Also, fresnels are availble in two thicknesses 2mm and 4mm ..which one should I opt and why?

Also I remember the collector fresnel(towards the light source) should have high focal length and the one towards the triplet should have equivalent f of triplet.

this means I should opt for 500mm for collector and the other fresnel should have 300mm .
Correct me in case my understanding is incorrect.

Thanks,
 
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bishnu.bhatta

Member
Joined 2010
gunsreekanthvs said:
Thanks for the suggestions bishnu..

I already got a quote from lensel pune.. they now say that 317mm(75dia) triplet costs around 2000. I previously heard that triplet costs around 800 rs.

But I seriously dont see any other options.

Also, fresnels are availble in two thicknesses 2mm and 4mm ..which one should I opt and why?

Also I remember the collector fresnel(towards the light source) should have high focal length and the one towards the triplet should have equivalent f of triplet.

this means I should opt for 500mm for collector and the other fresnel should have 300mm .
Correct me in case my understanding is incorrect.

Thanks,
Click to expand...

There is no such concept.focal length just specifies the point of convergence or diversion of a ray/light source.The first fresnel is used just to collect the rays.Google and download focalcalc application and you will be clear about it.

someone else had asked me another question as follows:

Is it necessary to use second fresnel of focal length nearly same as the focal length of triplet lens (projection lens) the as somewhere in forum i have seen if not doing so will cause blurred images.

For my design , i am using the following sequence:
MH Bulb>>Fresnel1>>Fresnel2>>LCD>>Triplet

so, in my case the distance between LCD and the triplet will be the focal length of the triplet (irrespective of focal length of the second fresnel)


About triplet cost, previously lensel was charging 800(2-3 yrs back) but now anywhere in india you won't get it below 2000(1800 in bangalore Allied Optics + shipping handling extra).So 2000 for a triplet is justified.
 
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pradvk

Member
Joined 2010
Hi budhi!

Can u please help me find a set of Fresnel lens and Triplet/doublets
I tried Lensel Optics Pune. They have stopped manufacturing these things for now.

I already have a 7" LCD screen and the cabinet.
Please guide me on the lenses(what will be needed in terms of optics) so that i can have at least 90-100" display with around 8-10 feet distance (screen to projector)

Or should i try getting the same ones that you have used here?

Thanks !

Regards
Prad
 
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atrisarkar

Member
Joined 2007
atrisarkar.googlepages.com
After three years since my first build (using a super 7" lcd) I've started with the second build. You can see the design and the results of the first build in the previous posts of the forum. I plan to keep the same design and use
1. S15 standard lumen lab lens kit.
2. Benq T52WA lcd monitor.

I started stripping the Benq T52WA monitor and here are the few pics.
I'm stuck in one step where we need to remove the 3 screws which attach the FFC and the controler board with the backlight. These screws are flat and extremely small. I tried around all the possible but nothing worked out. I'm a bit cautious while applying too much pressure as it might crack the circuit and also there are chances of the screw head getting spoilt (if thats not what happened already). If anyone has already stripped this before can you just help me out with this problem.


The monitor before stripping:
IMG_0136.jpg

Back:
IMG_0138.jpg

The Back casing removed:
IMG_0139.jpg

Removed the backlight power supply:
IMG_0141.jpg

The screws which have started creating the problem is circled in red. Any ideas??
 
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arkumar76

Member
Joined 2010
Stripping Benq G610HDA

bishnu.bhatta said:
Finally got a Benq 15.6 inch viewable (16inch monitor) monitor for my projector(G610HDA).Over the weekend met Aramosfet, together we went for shopping.It was a nice experience.Bought 250W OSRAM MH and OSRAM Ballast from BV iyenger stree.Then had some discussion with Aramosfet and after that we bought threaded rods,bolts,drilling bits and some hardware tools.
I must say, Aramosfet is a nice guy to work with...very cooperative.

Now that we have a prototype, we are planning to go for the projector design...but this time systematically with all past experiences documented.

Thanks Aramosfet...thanks DIYAUDIO.
Click to expand...

Hi Bishnu,

I am planning to build the projector.For LCD i am planning to go for BenQ 15" G610HDA and need your advice, How is your experience in stripping this LCD? Have you faced any FFC issues? Or can you suggest me some good 15" LCD monitor which doesn't have FFC issues.

Thanks
Arun
 
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bishnu.bhatta

Member
Joined 2010
arkumar76 said:
Hi Bishnu,

I am planning to build the projector.For LCD i am planning to go for BenQ 15" G610HDA and need your advice, How is your experience in stripping this LCD? Have you faced any FFC issues? Or can you suggest me some good 15" LCD monitor which doesn't have FFC issues.

Thanks
Arun
Click to expand...


Benq monitors are very easy to strip and don't have any FFC issue.Go ahead and get one Benq model monitor esp the 16 inch ones.
 
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maxpowr

Member
Joined 2010
budhi said:
Hi pcaddict,
Good Hunting!
Now you are really going at it.
The page magnifyier should be on the light source side and the thicker fresnel towards the projection optics side
But you have to judge it for yourself, that which of your two lenses is better for the image quality and take that decision.
the LCD has to be closely sandwiched between the two fresnels with about a 1cm gap on both sides.
Optics is a crazy science all lenses react differently to each other. The trick that I used is that keep your LCD aside as it is the most expensive and delicate part of the projector, one wrong tug at the FFC cable and your LCD is history.
Make a dummy screen of the same dimentions, with a cardboard sheet ,and slip into it a ohp sheet with some markings on it.
Use this to play around with your light source and mark all dimentions in a cardboard mock-up box to control light scatter. Once you get an image of the required quality and size, then go in for the final box and lcd placement.
Best of luck.
And yes smooth sides of fresnel are towards the lcd on both sides
Click to expand...

Dear Budhi,

First all thanks to providing such quality content and knowledgable thing about making projector, All has knowledge but no one distribute it but u did it is really a big thing, coming to the point >> i have all thing ready exept FRESNEL LENSE, CONDENCER LENSE AND THE FINAL PROJECTION LENS, i live in village call mandore>>jodhpur>>raj., so it is not possible to get all these lenses>> so i just request you if you can get these thing for me regarding payment please mail me at manish@jagprem.com eagelry waiting your reply

sincerely

Manish
 
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rahulmrmc

Member
Joined 2010
HI,
I am from hyderabd. i have imported fresnel lens 30cm A4 size brought from US. if any one needs give me a mail on rahulmrmc@yahoo.co.in

Others who are into DIY projectors- if you find making projector time taking& cumbersome, i have an idea.
I am having LOW cost LED light projectors with built in usb/sd projectors with 640*480 resolution with HDMI cable for Rs 13,500. and 800*600 resolution high end model for 16500. they come with 1 year manufacturer waranty and remote. contact me at rahulmrmc@yahoo.co.in if you need one.
rahul
9908050090
 
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