February 24th, 2004, 01:44 AM | #976 |
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Check out the other threads on this subject for more up to date info in the designs. For one you need to get rid of that fresnel and relace it with a codenser lens. Another thing you might want to try is reverse mounting your 50mm relay lens (they have ready made mounts for this purpose) because it turns it into a +20 achromat diopter. You wont need your screw on macro then. Btw condenser goes between GG and relay lens with the curve side of the condenser facing the relay lens. Let me know how it works for you.
-B |
February 24th, 2004, 06:56 AM | #977 |
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Once you dress that glass with the finer aluminium oxide things should look better. You are going to have to spend a lot of time rubbing it on the sheet of glass with the powder in water. It will look smoother pretty quick but the larger pits and scratches from the 200 will have to be worn down completely and that will take much longer, say about two hours.
Yellow?? Fresnel maybe or one or another of your lenses may have a separating composite element in it. I had an Angenieux 10 x 150 do that to me. Put each lens up against the light to see if there are any roadmaps coming in from the rim or edge discoloration. I think the frensel can go back to being a reading glass. I suspect you won't be getting runout on the disk because of the mass. Run-out of itself will not cause you excessive grief unless it is itself excessive. But it will cause a small softening of the image through moving it minutely in an orbital motion. Run your cam and the Agus, then shut the disk motor off. As the motor spools down you will see the image walk slightly if the run out is too much. Another thing which will cause this effect is if the two surfaces of the glass disk itself are not flat and parallel to each other. When you dress your groundglass, take very special care not to put pressure on it in case you break it or wear it away unevenly. A perfectly flat block with the groundglass stuck to it would be the ultimate way to go however getting it off without breaking will be a challenge. The telescope makers use a special pitch (black tar stuff) and great care when applying it so as not to break the glass with heat stress. To get the glass off they simply cool the whole thing in a chiller. The pitch goes hard and cracks off the glass. |
February 25th, 2004, 08:16 AM | #978 |
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I have received an email reply from Hiro at Ohara Glass which reads as follows :-
"" Dear Mr. Bob Hart; I am finally ready to submit my quotation for 10pcs of S-BSL7 D120.0 - 15.0 X 1.2T disks as follows: 1. Glass Type = Ohara S-BSL7 General Optical Properties as per Ohara Catalog Standard 2. Outer Diameter = 120.0 +/-0.2 (mm) 3. Inner Diameter = 15.0 +/-0.2 (mm) 4. Concentricity between OD and ID = 8 micron meter or less 5. Thickness = 1.2mm +0/-0.3 (mm) 6. Surface condition = Ground Our price for quantity 10pcs is F.O.B. Japan JPY3,400.- / pc F.O.B. stands for " Free on Board ". This means the price includes the cost of the product itself and the cost for clearing customs in Japan. Therefore the consignee ( customer ) needs to pay international transportation fee. The reason why we offer F.O.B. price is it we have no idea how the consignee wants to transfer the goods ( by ocean-ship, or air-freight, or postal parcel ). If you have a specific requirement for transportation method, we can quote our price which includes all such costs and you have only to receive the goods at your door. Please let me know how you want us to ship the goods. Does my explanation help you understand? Lead-time = 4 weeks after receiving Payment by remittance I look forward to serving you soon. Best regards; Hiro Tsuruta, Ohara Inc. "" END OF QUOTE. Note that these optical grade glass disks are only ground finished on all surfaces and would require dressing with the finer aluminium oxide on one surface for groundglass finish and full polish on the other. |
February 25th, 2004, 02:44 PM | #979 |
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Bob's glass discs
Bob it seems to me like grinding one side of the glass disk back to completely clear and perfectly flat again is not going to be a easy task. Besides the time it would take to do that - you would also need to have a perfectly flat gring surface AND the pressure pushing down on the disk would also have to be perfectly even from edge to center. If you dont your going to have a slight bit of optical distortion when looking thru the disks. Perhaps it would be a good idea to have this final step done commercially as well somewhere.
-B |
February 25th, 2004, 11:14 PM | #980 |
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Brett.
You are quite correct. I have a local optical eyeglasses outfit will be doing that part for me. To anyone. Can anyone advise me of the copyright legalities in the US of a small movie or segment which promotes a couple of performers who do R & B covers mainly at pub gigs. There are two issues, the rights of original composers over the portions of their works which have been performed and also protection of the mechanical and music rights of the two performers of their own originals. They are not going to fussed over the mechanical rights of a live performance but their original works have not been released in the US and are not protected. I ask as I have a hasty five minute video they needed urgently compiled from their own archive footage, - VHS video in extremely low light and some recent footage shot direct into PD150 and also via the non-inverting AGUS35. Whilst I would like to post the footage here for interest of AGUS constructors, I don't want to expose the performers to suit in the US or compromise their viability if they tour there and find their work has been copyrighted by some opportunist. They do pay some sort of tribute fee here in Australia for performances at paying gigs but how this works in the US with uncontrolled distribution via the web is unknown to me. Any advice would be appreciated. |
February 26th, 2004, 02:43 AM | #981 |
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I got news for all of you hoping to be able to use their XL-1 for this projekt.
I'm in contact with some German optical companies trying to find a way how to use a small powerfull lens with high luminous intensity. It is planned to capture the full 36mm width of 35mm stillcamera format. The second task is to use a anamorphotic pre lens to project the 16:9 Image on the whole CCD in 4:3 to use the full resolution of your Canon XL-1. |
February 26th, 2004, 09:26 AM | #982 |
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count me in...
Dietmar, I am refining my xl1 version of the adapter and have come to some technical roadblocks. While these types of adapters seem to do well with standard DVs, xl1 issues pertain to FOV. Feel free to contact me offline if i can be of assitance, dinor@hotmail.com...
-D |
February 26th, 2004, 09:50 AM | #983 |
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I should be able to prototype my relay lens design (*should* be good for ~20mm f2.0) for the XL1 today, I'll report back if it's performance is note-worthy.
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February 28th, 2004, 03:31 AM | #984 |
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Bob, what little I know is this:
When your performers are performing tunes written by other people, the issue is one for the publishers of the written composition. As your artists are producing a completely new 'recording' of the tune, they are not infringing on the copyright of the original sound recording - only the written composition. Most US artists are registered with either ASCAP or BMI who monitor and pay royalties for 'performances' of composed pieces. A performance doesn't necessarily mean a 'live' performance, and includes radio and video airplay as well. Typically, nightclubs pay a 'blanket license' to ASCAP or BMI or both, which is a flat fee, covering them to have any musician perform any tune in their place. Some clubs may not pay such a fee and just hope to slip through unnoticed. I also suspect that blanket licenses don't cover recording made in such a place and then subsequently broadcast elsewhere. There are ASCAP and BMI spies out there (at least there were in the '80s when I knew one), who report performances of ASCAP/BMI tunes that they've come across in local places looking for infringement. As far as your artists' rights, its really up to them to protect themselves, by copyrighting both their original music and the sound recordings they've made of that music. If they were registered with ASCAP or BMI, they would then also be up for the same royalty payments for performances of their music as other artists. If you're wanting to play this by the law, you might contact someone at ASCAP or BMI here in the states (don't have the web addresses handy) and request some information on your dilemma. I'm sure they'd be quite interested in accommodating someone who obviously is interested in trying to do it 'the right way'. Quite frankly, I'm unsure of the strictness of enforcement, or whether your limited use might just be "ok" - better safe than sorry, I suppose. Usual disclaimers apply: I'm not a rep for either of these agencies - don't hold copyrights myself, and this knowledge is passed on to me by people who have had dealings with the agencies in the past. Your best source of information will be from the agencies themselves.... I'm just throwing out what my current understanding is... (this is probably deserving of a separate thread, as it has nothing to do with with the adapter :) |
February 28th, 2004, 06:13 AM | #985 |
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Jonathon.
Thank you for your advice. I have now some leads to chase down. There is an equivalent organisation in Australia - A.P.R.A.. True - it's got nothing to do with the AGUS35 construction projects except that I want my music video footage to be trouble-free. - Some was shot with an AGUS version. |
March 2nd, 2004, 05:44 AM | #986 |
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Accidental special effect. I am looking for some advice on how to replicate an effect which appeared quite by accident and I have found impossible to replicate.
I shot some test footage on a PD150P using an AGUS35. One of the clips is a view of a R & B and popular covers performer who was classical trained but does pub gigs and performances. His guitar work in these genres remains highly complex, crisp and ornamented. I had framed and focussed for sharpness on the guitar plank halfway between playing hand and the frets with viewpoint looking down the plank. The nature of shooting with the appliance, an AGUS35 non-inverting version requires that the image be erected in post unless the camcorder is itself inverted for the shoot. I got my greasy hands for a short time on an After Effects v5 machine and I inverted the images in this which has this fantastic box thing which you can click on one edge to pull the image over and letterbox all at the same time. To do this one also has to first de-interlace the footage. I also had a try at a filmlook method described at www.dvinfo.net. Due to haste and limited opportunity I didn't get it entirely right and I had to rework the original clip on my Adobe Premiere machine which I know my way around. When writing to tape, I had a copy of the original messed up After Effects version of the music clip which I had brought back to look at in Premiere. I chose the wrong .avi file to outload to tape. On tape playback there is this fantastic strobing effect on the strumming hand on the guitar whilst the rest of the image is unaffected. The effect is not visible on the .avi file. So far I have not been able to replicate the effect in Premiere v6. It may be a co-incidental artifact produced by the AGUS35 which has disk opacity defects, but whatever, the musical people who saw it like it. Camcorder settings were manual. Shutter was 1/50sec. Lighting conditions were outdoors undercover in bright daylight with 1000w of bounced supplementry light. If anyone has any clues on how to do this again advice would be greatly appreciated. |
March 2nd, 2004, 06:04 AM | #987 |
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You said that you de-interlaced it with haste. Do you think you could have went to de-interlace the wrong field? I've done a similar thing while converting from 30fps to 24fps, I shot the thing in frame mode unintentionally and was experimenting with converting in Vegas. There is one clip where the guitarist of this band I was shooting went down to the ground while staying on his feet.. and then as he shot back up it had this cool motion strobing effect.
I'm not sure about the technical aspects of any of it, but I've had the same thing. |
March 6th, 2004, 04:37 PM | #988 |
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weird idea?
about canon xl1
i'm not an owner of xl1, but... if i'm not wrong - you can remove your lens from the camera? right? if this is the case - why do you need ANY "normal" lens, but just agus 35 and relay lens? agus35 is inverting the picture (making it upside down). sure. but normal lens also. so if you remove normal (canon's lens) you do not need any inverter - right? all you need is relay lens which will help you in focusing to GG. am i wrong on this? filip |
March 6th, 2004, 07:57 PM | #989 |
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Unfortunately, I am not a lens person so I can not make good advice.
I think the relay lens would still have to be able to project the image sharply on the camcorder CCD and NOT invert the image which a normal objective lens does. It will have to be a complicated lens to do this. |
March 6th, 2004, 11:46 PM | #990 |
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update, pic
I was gonna put some footage up but I decided to screw up my GG, accidentaly broke it in half. Whats a good source for UV's? BestBuy?
anyways...no footage but here is what ive done in the meantime. I made this rail dealie., this thing is rock solid. pic http://aequantum.com/DSCF0003.JPG John
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