I have read threads that said a wide angel camera lens on a projector shortened the throw (ie; increased the projected image by upto 50% or more). Well, I put on a Raynox HD lens from my Canon HV20 on my Sharp DT-500 and while it makes the image MASSIVELY bigger, it's also EXTREMELY blurry to the point of a blob where you can't tell what anything at all is.

What is the deal hear? Does anyone know of what lens or lens setup I'd need to shorten my throw with the DT-500 (increase the projected image size without having to move it further away)?

Thanks!

I tried the Raynox ( because of it's low barrel distortion ) and quite a few other wide angle adapters some time ago with the same results. I believe the lens element diameters were just to small , and the result was massive edge/corner focus problems.

The only one that I found would work acceptably was the Sony VCL-HG0758. Even with this one, it's rather finicky to position it correctly. You have to build a mount for it that allows you to adjust the height, pitch, and distance from the projector's prime lens. When you hit the sweet spot, you can get perfect corner focus. this involves quite a bit of trial and error. I got the best results when the wide angle adapter was pretty much parallel with the projector lens, and the beam entered the rear element of the wide angle adapter as close to the middle as possible.

I tested it with a Mits HD1000, Mits HC3, and Epson HC400 with pretty much the same good results.

http://www.amazon.com/Sony-VCLHG0758-Performance-Conversion-diameter/dp/B000063XWC

Of course, you could go for the Navitar ScreenStar series of wide angle adapters. These are designed specifically for projectors, and have adjustable mounts available. They are, however, quite expensive.

Using the 'mirror trick' is a far easier way to increase the throw with much less fiddling though, in my experience anyway.

Jonathan

Give www.avscience.com a call they have navitar lenses that will work with your application

You got some more informations about this "mirror trick" (tips & tricks on how to do it?)

Thanks

You got some more informations about this "mirror trick" (tips & tricks on how to do it?)

Thanks

It's not really a a trick. You bounce the image off of a mirror (preferrably first/front surface mirror, but some regular mirrors work fine as well) and it will shorten your throw, but this will not help me. I need a short throw lens + at least two large mirrors for my project.

I wanted a cheap way to do it though.

I tried the Raynox ( because of it's low barrel distortion ) and quite a few other wide angle adapters some time ago with the same results. I believe the lens element diameters were just to small , and the result was massive edge/corner focus problems.

The only one that I found would work acceptably was the Sony VCL-HG0758. Even with this one, it's rather finicky to position it correctly. You have to build a mount for it that allows you to adjust the height, pitch, and distance from the projector's prime lens. When you hit the sweet spot, you can get perfect corner focus. this involves quite a bit of trial and error. I got the best results when the wide angle adapter was pretty much parallel with the projector lens, and the beam entered the rear element of the wide angle adapter as close to the middle as possible.

I tested it with a Mits HD1000, Mits HC3, and Epson HC400 with pretty much the same good results.

http://www.amazon.com/Sony-VCLHG0758-Performance-Conversion-diameter/dp/B000063XWC

Of course, you could go for the Navitar ScreenStar series of wide angle adapters. These are designed specifically for projectors, and have adjustable mounts available. They are, however, quite expensive.

Using the 'mirror trick' is a far easier way to increase the throw with much less fiddling though, in my experience anyway.

Jonathan

Did the Sony lens have a macro on? The Raynox without any magnification beforehand is literally a huge blob of light, nothing at all can be even remotely distinguished. It's a large blob of color. I found out that some sort of Positive lens (a magnifier; ie, convex type positive lens) is required before my Raynox lens to have even a slightly infocus picture, but to get it in focus I have to put the Ranox too far from the magnifier, which lays rights against my DT-500 lens and it's not very high quality of a lens.

So, I'm wondering if the Sony lens had a Macro attached since it was able to focus. It's impossible to focus the Raynox.

Yes, i would like some more detail on your implementation too. I used to use the mirror method myself but found it to be too bulky after a while and did away with it. If that wide angle lens will do the job i'm quite interested, and don't worry, i am used to tweaking things so i'll be fine with the time it takes.

I ordered the lens jrw recommended, i'll try to post back here with my results when i get it.

I ordered the lens jrw recommended, i'll try to post back here with my results when i get it.

Good luck. I wonder what would make that lens work, but not the one I have. I think I need a macro lens first, because the wide angle I have magnifies the picture way too much by itself.

Looking forward to your results. My projector is short throw already (compared to most), so maybe that's what it didn't work.

The Raynox I tried was the DCR-6600PRO, a .66x wide angle adapter. There was no macro on the lens.

http://www.raynox.co.jp/english/dcr/dcr6600pro/indexdcr6600eg.htm

I chose this one first because of the low barrel distortion specs. I could position it so that it had good centre focus, but, the corner focus was always way off.

I ended up dragging one of my projectors to the camera shop where I purchased the Raynox. I tested several wide angle adapters while I was there including some from Olympus, Canon, and Kenko. all had the same corner focus problem. I tried the Sony, which has a significantly larger rear element compared to the others, and found that it worked.


I MacGyvere'd a temporary mount together using some L brackets, a pipe clamp, weather stripping, machine screws, and wing nuts. This allowed me to adjust the pitch of the lens. I adjusted the height by shimming the the board it was on. This was just for an experiment to see if it would work, and the projector was on a table top.

http://lise.ca/oldrootdirectory/olympictheatre/mountside.jpg

http://lise.ca/oldrootdirectory/olympictheatre/mountfront.jpg

http://lise.ca/oldrootdirectory/olympictheatre/mountlens.jpg

As I mentioned in the previous post, the setup was still rather finicky. Once I had it positioned correctly, the centre and corner focus was good, and there was no noticeable chromatic aberration. There was a very small amount of barrel distortion, but, not really objectionable. I used a grid / circle test pattern for the setup.

I mainly tested with a Mits HD1000, which has a longer throw than the Sharp DT-510, however, I also did some tests with my Epson HC400, which has a throw about the same as the DT-510 with the zoom at it's widest. I didn't scrutinize the HC-400 as much as the Mits, but, it seemed to perform about the same.

One unexpected bonus was that, once positioned correctly ( distance from projector prime lens and pitch ) raising and lowering the adapter lens woud give me close to 50% screen heights of lens shift before the corner focus went out.

Hope this helps,

Jonathan

Excellent, thanks that actually helps quite a bit.

I just got the lens today, and while i haven't precisely tuned it yet, i must say it works just as well as a first surface mirror but without the bulk.
From what i can observe, since i now have a wide angle lens in front of me, the main requirement seems to be that it needs to have a large diameter rear lens assembly. This gives it the ability to take in the large sized light output from the projector and focus it. Most others are probably designed to work with a smaller subject.

I just got the lens today, and while i haven't precisely tuned it yet, i must say it works just as well as a first surface mirror but without the bulk.
From what i can observe, since i now have a wide angle lens in front of me, the main requirement seems to be that it needs to have a large diameter rear lens assembly. This gives it the ability to take in the large sized light output from the projector and focus it. Most others are probably designed to work with a smaller subject.


Jarrod1937

I am not clear what lens you got ...was it the Sony lens?. I've been thinking of getting the Infocus X10 but because of its long throw length i was planning on getting a different projector like the Optoma HD65 until i saw this thread. Has anybody had any luck with the infocus and a wide angle lens? Any other lens that works as well as the Sony or better?

Thanks
jcanaca

Jarrod1937

I am not clear what lens you got ...was it the Sony lens?. I've been thinking of getting the Infocus X10 but because of its long throw length i was planning on getting a different projector like the Optoma HD65 until i saw this thread. Has anybody had any luck with the infocus and a wide angle lens? Any other lens that works as well as the Sony or better?

Thanks
jcanaca
Yes, it is the sony that i got. I recommend buying it used. I got mine for $100 off of the amazon link jrw gave.

Glad it worked for you Jarrod. What projector are you using it with?

Jonathan

jcanaca,

I stopped testing when I found the Sony, so there may be others out there, but I tried quite a few. It's possible that the Century Optics .65x might work as well, as it appears to have a large rear element ( 58mm thread, same as the Sony )

http://www.amazon.com/dp/B0000ALKE5/ref=asc_df_B0000ALKE5862428?smid=A1P9QRDRYY6FXL&tag=dealt5709-20&linkCode=asn


I think if you wanted 'better', you'd probably have to go the Navitar ScreenStar route. The least expensive .65x Navitar's MSRP is $995 ( The Mini ScreenStar which works with imagers up to .8"), although AVS may be able to give you a better price. The top-end .65x HD ScreenStar's MSRP is $2,500.

Jonathan

jcanaca,

I stopped testing when I found the Sony, so there may be others out there, but I tried quite a few. It's possible that the Century Optics .65x might work as well, as it appears to have a large rear element ( 58mm thread, same as the Sony )

http://www.amazon.com/dp/B0000ALKE5/ref=asc_df_B0000ALKE5862428?smid=A1P9QRDRYY6FXL&tag=dealt5709-20&linkCode=asn


I think if you wanted 'better', you'd probably have to go the Navitar ScreenStar route. The least expensive .65x Navitar's MSRP is $995 ( The Mini ScreenStar which works with imagers up to .8"), although AVS may be able to give you a better price. The top-end .65x HD ScreenStar's MSRP is $2,500.

Jonathan

Ok, So mine is like a 35mm thread, but is mangifies the images like more than 4x its original size, but a complete blurry blob. I have to move the lens about 2 feet from the projector's lens to get an infocus section of the image and it's ginormous, but from that distance the wide angle can only capture a small piece of the projected image.

So, if I got say a wide angle with a 72mm thread should that work correctly with my DT-500?

You want to keep your image near the middle of any optics you "drop" in front of the projected beam to ensure the "best" results. Further, you should probably note that the projected beam out of your projector DOES NOT usually come out of the middle of the lens elements / stack. Further, you then have to "align" (perpendicular with said "drop in" lens) with the projected beam. IF you don't do this, it will result in both distortion and image shifting.... some of which you might want while the other you don't.

The choice of "glass size" needs to be as large as you can "afford".... but on the other side, needs to be of "good quality" which is tough to achieve as the optics size increase. Further, the "magnification factor" needs to be closer to 1 for less magnification and likely better results. The more you "push" this factor, the more likely you will be "un-happy" with the results.

Based on your previous post of info, your main problem is your choice of a small lens. I didn't see the "magnification factor" but suspect its probably .5 or .65, try something closer to .75 / .8. As people indicated, you are unlikely to be successful directly mounting the lens to the front of the existing lens stack of the projector so you will need to find / make an appropriate mount much like those shown or found with "high quality" adapter systems mentioned.

Glad it worked for you Jarrod. What projector are you using it with?

Jonathan
I have an Mit hc3000. I figured i had a good chance of it working since you tested it with an hd1000, and they have pretty similar internals.

You want to keep your image near the middle of any optics you "drop" in front of the projected beam to ensure the "best" results. Further, you should probably note that the projected beam out of your projector DOES NOT usually come out of the middle of the lens elements / stack. Further, you then have to "align" (perpendicular with said "drop in" lens) with the projected beam. IF you don't do this, it will result in both distortion and image shifting.... some of which you might want while the other you don't.

The choice of "glass size" needs to be as large as you can "afford".... but on the other side, needs to be of "good quality" which is tough to achieve as the optics size increase. Further, the "magnification factor" needs to be closer to 1 for less magnification and likely better results. The more you "push" this factor, the more likely you will be "un-happy" with the results.

Based on your previous post of info, your main problem is your choice of a small lens. I didn't see the "magnification factor" but suspect its probably .5 or .65, try something closer to .75 / .8. As people indicated, you are unlikely to be successful directly mounting the lens to the front of the existing lens stack of the projector so you will need to find / make an appropriate mount much like those shown or found with "high quality" adapter systems mentioned.

Thanks. I don't know what the magnification of the lens is. It came with my camcorder I bought. So, I just decided to give it a whirl on my projector. It's very wide angle though, so it's probably .5 at least.

would something like this work???

148709

well it could BUT I think that you are going to find that .45 is going to make things very big very fast.

well it could BUT I think that you are going to find that .45 is going to make things very big very fast.

oh, ok i get it. i was backwards.:D

I've used this in past with good success.

http://www.amazon.com/Olympus-WCON-08B-0-8X-Wide-Extension/dp/B0000511RI/ref=sr_1_1?ie=UTF8&s=electronics&qid=1248633165&sr=8-1

You don't want too much zoom or else distortion will creep in. 0.8x is the most I would go.

I just noticed that my lens is a 43mm 0.3 Raynox MX-3000 Pro Semi-Fishey Wide Angle lens. Perhaps THAT is why I've had issues. I put a wal-mart magnifying lens in front of my projector lens then the wide angel a couple inches in front of it and thins looked a bit better, but the diameter is still too small even when I minimize my projected image all the way. I think I need a 72mm thread lens with with a 108mm outer thread and maybe a macro, between .65 and .8.

jcanaca,

I stopped testing when I found the Sony, so there may be others out there, but I tried quite a few. It's possible that the Century Optics .65x might work as well, as it appears to have a large rear element ( 58mm thread, same as the Sony )

http://www.amazon.com/dp/B0000ALKE5/ref=asc_df_B0000ALKE5862428?smid=A1P9QRDRYY6FXL&tag=dealt5709-20&linkCode=asn


I think if you wanted 'better', you'd probably have to go the Navitar ScreenStar route. The least expensive .65x Navitar's MSRP is $995 ( The Mini ScreenStar which works with imagers up to .8"), although AVS may be able to give you a better price. The top-end .65x HD ScreenStar's MSRP is $2,500.

Jonathan

How much larger is the image from the same distance with you lens?

I think the XX factor is all you need to figure this out.... image size without wide angle / xx factor of wide angle. Thus, .8 will give you a 1.25 increase while .6 will give you 1.67X larger.

I just noticed that my lens is a 43mm 0.3 Raynox MX-3000 Pro Semi-Fishey Wide Angle lens. Perhaps THAT is why I've had issues. I put a wal-mart magnifying lens in front of my projector lens then the wide angel a couple inches in front of it and thins looked a bit better, but the diameter is still too small even when I minimize my projected image all the way. I think I need a 72mm thread lens with with a 108mm outer thread and maybe a macro, between .65 and .8.

MTyson,

This maybe better for your tests.... http://www.bhphotovideo.com/bnh/controller/home?O=search&A=search&Q=&ci=0&sb=ps&sq=desc&sortDrop=Relevance&ac=&bsi=&bhs=t&shs=wide+angle+lens&ci=2102&at=Rear+Mount+Threat_74mm&basicSubmit=Submit+Query

Also how far away from the projector lens do you place the wide angle lens? Do you have a mount for it?

jcanaca

The difference is 90 inches without the lens to a max of 140 or so with the lens, using the sony. I can actually do max zoom and use the lens, and with precise placement, get little to no distortion.

MTyson,

This maybe better for your tests.... http://www.bhphotovideo.com/bnh/controller/home?O=search&A=search&Q=&ci=0&sb=ps&sq=desc&sortDrop=Relevance&ac=&bsi=&bhs=t&shs=wide+angle+lens&ci=2102&at=Rear+Mount+Threat_74mm&basicSubmit=Submit+Query

Also how far away from the projector lens do you place the wide angle lens? Do you have a mount for it?

jcanaca

The lens .3 lens has to be placed about 1.5-2 feet away from the image to get a small section in focus...other wise it cannot come close to being in focus anywhere, just a massive blurry blob. It makes my menu MASSIVE and only part of it stays in focus. To be able to put it closer and stay in focus I had to put a magnifying glass in front of the lens first and then place the .3 wide angle in front of it by about 2-4" to focus and the lens just isn't big enough to focus the entire image.

hmmmm... doesn't seem to make much sense since the beam at 1-2 feet for a .6 chip "shooting" an 8 foot image from 12-14 ft is going to be at least a 1/2 foot wide ... in "gross math" terms. Of course, my "optic science" ain't what it use to be... :-) BUT I had no problem playing with these "filters" on an x1 back in its "hey day" and getting a "good image" with the filter "attached directly" to the front focus ring of the x1. I think you need to check out a better (wider diameter filter) at "close to your projector" lens stack.

one question: what happens when you just look thru your "filter".... is the view clear? Based on my "experience", I think you might have the filter backwards.

MTyson,

The Sony I recommended is .7x, so a magnification factor of about 1.43x as budwich noted in his post ( 1/mag factor = image size increase )

You can also think of it in terms of throw distance. If you need 10' of throw for a 100" diagonal image natively, then your throw will be reduced to 7' with a .7 wide angle adapter.

If your Raynox adapter was a QC-303 .3x snap on, there's a specific warning on the website that the lens won't focus at the 'infinity' setting of the prime lens, so it's very possible this was your issue ( aside from the rear element being too small ).

http://www.raynox.co.jp/english/video/egwidedvr.htm#qc505

Jonathan

hmmmm... doesn't seem to make much sense since the beam at 1-2 feet for a .6 chip "shooting" an 8 foot image from 12-14 ft is going to be at least a 1/2 foot wide ... in "gross math" terms. Of course, my "optic science" ain't what it use to be... :-) BUT I had no problem playing with these "filters" on an x1 back in its "hey day" and getting a "good image" with the filter "attached directly" to the front focus ring of the x1. I think you need to check out a better (wider diameter filter) at "close to your projector" lens stack.

one question: what happens when you just look thru your "filter".... is the view clear? Based on my "experience", I think you might have the filter backwards.

My Raynox is crystal clear and naturally, from pure curiosity, I decided to try it backwards (the large front end towards my pj lens) since the other way wasn't working.

From anywhere remotely close to my projector's lens the image IS MASSIVE, but beyond blurry. I mean BEYOND! Not like you can see text that is very blurry, but to the point that a text menu is a giant smudge of color.

Now, as I move the lens further away from projector's lens while having my text menu up (a great way to view sharpness and focus) eventually the letters become in focus at the center area (and the it seems to multiply the menu box by 3 or 4x its normal size). However, obviously, from the the distance needed to get it in focus using the Raynox I'd need a GIGANTIC Raynox since the image coming from my projector is far too large for a tiny 43mm wide angel lens, which is why it only captures a small section of the entire image.

Now, if I put up a $3.00 Wal-Mart 3x Magnifying glass in front of my projector lens by half an inch to an inch away and then my Raynox about 4" in front of the magnifying lens I'm able to get much more in focus. However, the lens still isn't big enough (especially due to the tiny rear thread) from that far away to correctly focus the entire image without blurry sides/top/bottom/ parts of the image and with too much chromatic abberation.

So, either I need more magnification in front of my projector's lens before my Raynox, so I can bring the Raynox closer to magnifier placed in between my projection lens and the itself, or I need a different wide angle lens altogether.

Maybe I need to try a large rear threaded wide angle lens between .60 and .8 that also has a very large (like 108mm) outer thread?

OK. by "clear", I mean prefectly infocus. Actually, what jrw posted about that particular lens is the problem... that it doesn't focus at infinity. It would appear not all wide angle lenses are "equal" probably due to the design and number of elements. This is an "optical problem" and I have seen a similar issue in "camera land"... eg. canon slr went from a bayonette mount to an EOS mount on their lenses.... there are cheap adapters for the mounts BUT they don't work at "infinity" due to the design and focus points of the lens system.

My particular "no name set" is perfectly viewable in the "normal" direction but is "tunnelled" in the reverse (only the center is in focus). The "filter" is quite thick with an overall length of 1.75 inches.

The conversion lens have lost their "popularity" in recent years as camera man's have gotten better at providing wider ranges on lense stacks... you might be able to track down a cheap used .6-.8 wide angle adapter at a local pawn shop or such. I know I got my set (both telephoto and wide) for less than $50 a long while back. Good luck.

Further, you will note that some of the adapters on the Raynox site are "thicker" and don't have the "don't focus at infinity" associated with them.