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July 2nd, 2005, 12:08 PM | #31 |
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Hi Wayne, I have used several different types, and they are all optically equall, so any will do just fine. If you are thinking of doing what I think you are, which is to try and spin 3mm thick ground glass on a cd player motor, i'm afraid you are going to have to think again. There is no way in hell, it will be able to support/drive that kind of weight, not to mention the cost of the glass in the first place. I did a similar design, but using a powerfull motor. It worked well untill the glass cracked, which it has a tendancy to do, it happened twice. I spent a lot of money following that concept, and although it worked very well when it did, it was fragile and the glass would actually shatter. Sereously, you should consider the design I have chosen. It cost me in the region of a grand to arrive here, but it is simple to make and robust. Alternatively, you can buy mine off me, if you make me a reasonable offer as I will be selling it very shortly.
Kind Regards, Nick |
July 2nd, 2005, 12:56 PM | #32 |
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Nicholas,
Thanks very much for your reply. Yes, you are correct in that was my intention. Thanks for the advice, I will not go down that road. Im still stuck between going either spinning or static route. I like the static route better so long as i can get a quality ground glass. I see many are using the Optosigma 1500 grit GG, and http://www.laser2000.co.uk/optosgma.htm are the UK distributor. So im going to go down this path to see where I get. Thanks again for the advise, you have probably saved me money and headache. BTW, how much are you looking for, for your finished adapter? Im sure your get a good price selling on here (considering every potention buyer is probably on this forum. You have proven results from it. Can I ask why you are selling it? Wayne. |
July 2nd, 2005, 01:08 PM | #33 |
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I have got some very good results using a nikon viewing screen. In fact, all of the shots of the girl (my girlfriend) in the music video for lynden David Hall video were shot using exactly this method. Even though I am not really adamant that the use of a condenser is necessary with a spinning gg, for very quick results, i would recomend buying a nikon or even better beattie viewing screen, with built in condenser. A quick, cheap option, which will provide bright, hotspot free images, without the hastle of having to play around, and refine your design, also the extra brightness from the condenser will help hide the grain. If you are going the static route, you should definatly ensure that you use very fast lenses, and preferably good quality ones such as nikons.
I am going to sell my entire rig, as I will have to buy one of these new panasonic dvcpro hd cams when they come out later this year, and If i'm doing that, I may as well pick up a used mini35. But first I am going to have to try and make some money. PS, that optosgma glass looks very good, but there is quite a long shipping time from the states if i remember correctly. Woth ringing them though. Cheers, Nick |
July 3rd, 2005, 04:46 AM | #34 |
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Nicholas,
Thanks again for your advise. I have found a couple of nikon focusing screens on ebay: http://cgi.ebay.co.uk/ws/eBayISAPI.d...e=STRK:MEWA:IT http://cgi.ebay.co.uk/ws/eBayISAPI.d...e=STRK:MEWA:IT Would these be ok? They are used, but it maybe something to use and experiement with until i receive the optosigma ground glass. I am using a Nikon Nikkor-S F1.4 50mm lens. http://www.laser2000.co.uk/optosgma.htm is the UK distributor of OptoSigma products. You say it takes ages to ship, does this mean they probably dont stock the products, and would have to order you think? Thanks, Wayne. |
July 4th, 2005, 09:06 AM | #35 |
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Hi Wayne, sorry it took so long to get back to you, I have been a bit busy to get online. Those look ok, as long as they do not have any markings on them. Give it a shot. I have used the Nikon 'D' type focussing screens, i believe it is. If you want something really effecient with light. I think they are many times brighter:
http://www.adorama.com/BTF2.html?sea...20f2&item_no=4 You could buy one of these. Much better to take advantage of the exchange rate and buy from the states obviously, and you can get it half price. |
July 4th, 2005, 09:38 AM | #36 |
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So Nicholas,
The focusing screens with the grid are out, right? Just the plain ones? What are the grid ones for? |
July 4th, 2005, 09:39 AM | #37 |
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I'm not entirely sure, but i would imaging they are for architectural photography.
Definatly no good for your purposes |
July 4th, 2005, 10:30 AM | #38 |
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Good message
This is excellent public awareness work. The substance is good and the treatment excellent. Congratulations.
PS. And yes, the technique is great. |
July 4th, 2005, 11:28 AM | #39 |
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Nicholas,
Thanks for your help. I have ordered my Optosigma GG from the UK distrabutor http://www.laser2000.co.uk/optosgma.htm Talk to Lisa Pettigrew on the phone, she was very helpful. She said it only would take about a week to ship from the states (they didn't actually stock it). £23 for the 1500 grade 50mm GG (note its $23 on the actualy optosigma website) so its more expensive to us in the UK. Postage was £15 as well. So not the cheapest route. I can only hope and keep my fingers crossed that this is going to be up to the quality. If not maybe ill think about an oscillating device. It will be annoying if I do have to have the ground glass moving, as that would mean that i could have just ordered GG from knight optical instead. I'll let you know how i get on. Thanks, Wayne. |
July 4th, 2005, 05:36 PM | #40 |
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You probably should have called Optosigma in California and cut out the middle man... but they would probably charge you some outrageous postage. I ordered some parts and had them shipped to Australia within 4 days, but it cost me $48 for postage... ouch.
You will still see grain on the static Optosigma on bright/high contrast out of focus areas, 1500 grit is the same as 40 micron (I think) so in theory the Knight Optical GG is going to be no different? It all depends how far you want to take it whether you're happy with the grain... and if you don't have a good lens you will most likely need condensers. Andy |
July 5th, 2005, 01:28 AM | #41 |
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Any,
--- "You probably should have called Optosigma in California and cut out the middle man..."---- You probably right there, not sure why the postage costs are so high though. ---- "so in theory the Knight Optical GG is going to be no different?"---- The difference is £15 compared to £44. If i see the grain in the optisigma GG and decide to oscillate it, then it would have been cheaper for me to get the knight optical straight away. But experiementation comes with a price i suppose. ---- "and if you don't have a good lens you will most likely need condensers."---- I have bought a used Nikon Nikkor-S 50mm F1.4 lens. I have also bought a condensor les from Knight Optical, does a great job at getting rid of the hotspot, but has a bit of distortion. I got a 50mm dia, 63mm FL, i should have got a longer focal length i think. Cheers, Wayne |
July 5th, 2005, 02:49 AM | #42 |
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What I meant was I think the GG from Knight will probably be identical in terms of performance to Optosigma as they both have the same finish.
They charge so much cause they send it via DHL or UPS... they won't ship via regular mail (which only cost $10 to Australia vs $48). I tried 80mm FL condensers and the distortion can be eliminated by moving the condenser further from the GG at the expense of image size (basically magnifies the centre) but the chromatic aberration was still a problem. Going to try 120mm FL next. |
July 8th, 2005, 08:11 AM | #43 |
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Nicholas,
What are you guys talking about here because me, I am lost. Are you guys talking about how to make a 35mm Adapter or something. Ok let me give you guys a great business Idea. For example Nic, why don't you make this adapters for cheap and sell them on Ebay. I mean, I will buy it since 1, They will be cheaper. 2, I have seen some sample results from your film. 3, It will save me time. So you guys that knows how to make this things, please come up with a way to make it available for us that do not know how to build one, etc. What do you guys think? |
July 8th, 2005, 08:34 AM | #44 |
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I didn't know how to build one, much like you, and I spent many many long painfull hours reading, learning, building etc. I didn't do this for anyone else, this was purely to enable me to make the types of images I wanted to. There are people, making these adapters, and selling them for very reasonble prices, as they have invested enough into large productions to make it woth while.
If i were to build them, given the cost of my time, they would i'm sure not be competitive with the awsome mini35 adapter in tearms of price and quality etc. As for me, If I wanted to go into product design, that is what I would do, and i'm sure I could make a lot of money from it. That is exactly what my parents have done all their lives, and my brothers also, and I help them where possible. However, I am a director/filmaker, not a product designer. I have little interest in manufacturing an adapter for people who have little or no inclination to learn about the device, and selling it on for a price which makes it available to anyone with a camera. I have responded to many many emails, and made several posts, giving as much advice as possible to anyone who seeks it, and I will help determined filmakers as much as I can. The knowledge is here, on this website and easily accessable, you just have to read. Alternatively, if you can't be bothered, go and buy an adapter from redrockmicro. Theirs seem excellent, and at an incredible price. |
October 24th, 2005, 02:04 PM | #45 |
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I was never good with Optics. Luckily we didn't cover them in High School Physics or I would have failed. How much math is involved in figuring out the focal lengths on various lens combinations vs image size needed on the GG and the mounts and distances to your primary lenses, etc. Making the stuff on a lathe or designing the physical parts wouldn't be so much a chore but the math to know this lens will need to be mounted x" away from the glass and the macro lens will have to be this type and magnification for that image size...Man.
Or is this all trial and error? Lastly, how much more light do you find yourselves throwing at a scene as it is going through this extra image transfer? You have two iris settings to account for too unless the Macro is left wide open, which I suspect it is. I need to read more on this one. Keep up the good work. Sean McHenry
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