Hi there, I'm not sure if my design is one that is readily in use. I built it many months ago. It is motorised, fairly quiet and not particularly complicated to fabricate. I recently tested it for my new short, please take a look:

www.pixelloft.com/riddle.htm

Anyone who is interested in knowing more, please feel free to email me.

Many thanks, Nick

i downloaded the bigger file and once the russian started talking it glitched and all i could get was audio after that...

Sorry about that, i am reuploading the file, a fresh, working one will be on the server in about 20 mins.

Thankyou for your patience.

damn... I can not get it work :(

Sorry and thanks for your patience.

Nick

Looks great! :)

Nice use of lighting. From the screengrabs it looks like you used an XL1s?

I had problems too, same point. I'll try downloading again tomorrow.

Failing me at 2:58, fresh downloaded mov player...

iTS FIXED AND READY FOR DOWNLOAD NOW.

I didn't realise I had used all my webpace, doh!! and they have been deleting chunks as i upload.

Sorry, thanks for letting me know

Nick

That looks awesome! Mind divulging your construction method details etc?

Nick,
The movie was AWESOME. Please share your design.



Scott

Beautiful images. Job well done.

Sorry, there is another thread, where I have discussed the design:

http://www.dvinfo.net/conf/showthread.php?p=328572#post328572

Any chance of getting a couple shots of the inner workings?
Also, what kind of lighting were you using? What is the lens?

Overall this was great piece.

Some comments (Just my opinion! so please dont take offense)

* Maybe the web compression degraded the orginal resultion, but the movie seemed to lack a lot of resolution/sharpness (was the softness due to the adaptor?).

*could be my CRT display (PC monitor, UK/) but the blacks seemed milky, perhaps its just my taste , i would personnaly like it a litter more contrasty.

Other than that, what i really liked:

no vignating/hotspot, loss of light seems minimal considering that the shot was practically in the dark!

Also was it XL1 or XL2 and what other setup deatails can you give please (lens, frame mode, etc)



Anhar Hussain

I think it may well be your monitor on the fritz. There is no loss of resolution, obviously the web version is heavily compressed and these artefacts do degrade the image considerably. I have checked this on broadcast montors, and my monitors have recently been calibrated so I am pretty sure its ok, but if anyone else notices this, please let me know, so I can do my best to resolve the problem. The camera is an XL1s and the movie was shot in frame mode 25fps. For all those who are wondering how the system works, I will do my best to explain more clearly. I will try to get some pics uploaded, but I am a bit busy at the moment. Think simple, ok here goes.

1. Take a big ass bearing with an internal diameter of about 55mm
2. Fix it into something, i used a piece of MDF with a hole in it, for weight reasons.
3. the outer wall is now fixed and the inner wall spinning freely and accuratly.
4. Fix you glass into the inner wall of the bearing.
5. Get a machine shop to make you a groved pully which also attaches to the inner wall of the bearing.
6. Fix your motor into a box, along with the unit i have just described.
5. Get a pully belt, and wrap it around the motor pully and around the pully which is now attached to your bearing.
7.Switch it on, and your inner bearing wall will begin to rotate.
Tinker, and Job done, you should have a rotating piece of ground glass.

Hope this helps.

Nicholas....

nice work....

i tried to dl the larger mov directly, but the link is messed up,,, ie it only goes to stream on the large file.... (you can dl the small version)...


the design that you used had a theoretcial flaw of spinning fast in the center and much slower on the outside edge....

i did not see this effect in the resolution that you provided... did you experience this at all at certian rpm's of the motor?? or was it noticeable with the better monitors???

thanks
skv

Sorry about that, I have sorted those links now, so you can download a larger version if you wish. It all works.

The problem you mention did not occur at any shutter speed. This is not an artifact present in the film. I am very particular about stuff like that. I used an excellent quality optical ground glass, which is paramount in making these things from my experiance. Diffusion paper, and sanded glass in my opinion can't provide the level of acuracy achievable with a good quality optical GG. I used a motor from a video player with 12v of power. Seemed to work very well indeed. The artifacts you mentioned were present having initially constructed the device, but with a bit of lubricant on the bearings and having left it on for an hour to break it in, the rpm was hig enough to not have any artifacts at all.

Hope that answers your question.

Nick

1. Take a big ass bearing with an internal diameter of about 55mm

damn you beat me to it...about a week ago I started looking for the parts to do just that. I was going to use a Pillar block bearing...but that might be to heavy. Have a source for the bearing you used or was it a local source?

the design that you used had a theoretcial flaw of spinning fast in the center and much slower on the outside edge....

Even if you do come across this problem shooting off center should solve it (only the center in essense does not move...the difference in speeds on good glass shouldn't be noticable)

It is a very robust and simple design.
For the bearings, Local source, I don't know about the states, but over here in the uk, there are hundreds of bearing suppliers. Give one a ring, tell them what you are looking for and 'bob's your uncle', Job done.

Cool!, thanks for the reply,

Have you thought about using an XL2 on your next project? (or maybe sony FX1/Z1 that would be great for blow ups!)

>>>>1. Take a big ass bearing with an internal diameter of about 55mm
<<<<<
Should I check the doctor for that?

Besides the technical part, which is great, the film and story have high quality.

thanks for fixing the links.....
i wanted to dl it and burn to dvd and see it on the bigger tv screen.....



""""I used an excellent quality optical ground glass"""""


could you expound on that just a tad as to the grain or ????

thanks ,
skv

Very nice. I also would like to know the details about the ground glass you used. Where did you get it? What are the specs of the glass?

And how'd you avoid having a hotspot?

Excellent video, very impressive and very inspiring!

I did a search for Nick's other posts and it looks like he's using a Knight Optical 40 micron GG and a macro to get rid of the hotspot? I ordered a GG from Knight Optical, it was only 5 micron finish, too much grain, but the annoying thing was it came with a flaw in it. Not impressed. I recommend Optosigma.

Cheers
Andy

Thanks Andy, for your kind comments.

I am using a ground glass from knight optical. I have to say, if you want a custom job, give them a call and they will try to get you whatever you need. They also replaced a £40.00 gg, free of charge, because it cracked duiring heavy use. Just to clear things up for people, a macro will not get rid of the hotspot, the macro is merely to allow your camera lens to focus on the screen which is very close to the camera.

A condenser, much like the ones used on focussing screens can be used to help eliminate a hotspot, however it will reduce your image size. I have done numerous tests with this, it seems the main way in which this works is by utallising the brighter cental part of the image, and essentially magnifying it in size. If you take a nikon viewing screen apart, you will see this is the case. i.e, if you buy a 28mm lens, you won't see all of your fov.

The best way, to eliminate the hotspot, which is incidently what I have had to to, it to use a gg without any condenser, and buy very good quality fast lenses. I have been using nikons. I made the mistake of buying a fast vivitar, 24mm, and thought i had a bargin. Next to my nikon 28mm with the same apeture, the vignetting was incredible. The apeture on the vivitar, f2 was about 3mm wheras on the nikon at f2 it is about 40mm. I'm sure someone knows the reason for this on here, and this could be causing a problem for some people.

It doesn't matter how good your adapter is, without good lenses, it will always look crappy.

Hope this helps

Thanks for the info, but I found what you say not to be necessarily true. Using my Canon 50mm 1:1.8, hotspots during the day and there is not a step down mechanism on it, so I am stuck with that aperature. BUT on my SEARS cheap 1:2.0 lens, there is a step down and I get the same hotspot with it. So maybe the condenser is a necessary evil?

BTW, I have a couple of extra lenses lying around that when looked through make the image smaller - are these condensers?

I can not really comment on your design or the issues you are having, as I havn't seen it first hand. The fact that you are comparing 2 questionable lenses with eacholer, will of course lead you to draw your own conclusions, and without looking at your GG, lenses etc, i couldn't really comment on your hotspot problem. It may well not be the lens in your case, it could be the GG etc.

I am however comparing a 28mm nikon 1.4 lens, with an £800 retail value with that of a 24mm f.2 vivitar with a £80.00 retail value, both set to F2 and I can assure you, there is no hotspot with my setup using the quality lenses, where there is with the lesser ones. Again, this is with a well built adapter. I am not sugguesting buying an £800.00 lens for your rig, as your problem may well lie elsewhere. Therefore, the condenser is only really a necessary evil, if you are to use cheaper lenses, or you have a problem elsewhere in your design, and I can assure everyone from my own experiance, that this is the case. If you have seen my film, and feel that a condenser is a necessary evil, than you are sugguesting that I have a hotspot on my short, which doesn't appear to be the case, this why I am confused with your argument.

I appreciate your opinion, and can understand the appeal of using a condenser, for ease. I would however also not choose to use a condenser for another reason, as it does blur the image towards the edge of the 35mm image plane. This i would imagine is due to the different focal distance between the center of the condenser, which is closer to the macro lens and the outer edge of the condenser, which is further away.

Hope this helps make my point a little clearer. I'm sure there are numerous different designs which all work equally well, however this is the best result I have found, and as I have said can only talk from my own experiance.

Nick

Nick,
You are right about the cost of the lenses. I am using a charity shop cheap lens that I found with a Canon EOS 750, so I think it is not in the range of $800.00, so in that case, you point is well taken.

And no, I didn't see any hotspot on your film, it looked great (as I stated earlier), the dark shots looked great, with lots of brightness.

Hi Nicholas,
Firstly, great short, very inspiring. Been through all your website as well, very nice stuff.

I am also from the UK (Brighton in the South East), so finding a good source for ground glass is hard.

I see you got ya ground glass from Knight Optical. Could you tell me which type you used from them?

http://www.knightoptical.co.uk/acatalog/DiffusersGroundGlassDiffuser.htm

they have Ground-LEGB, Ground-B270 and Ground-UV fused silica

Do you think they would be able to custom cut a cd shape for me? I emailed them but get no reply.

Cheers,
Wayne.

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

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.

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

Nicholas,
Thanks again for your advise. I have found a couple of nikon focusing screens on ebay:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=7527166585&ssPageName=STRK:MEWA:IT

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=7527167308&ssPageName=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.

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?searchinfo=beattie%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.

So Nicholas,
The focusing screens with the grid are out, right? Just the plain ones?
What are the grid ones for?

I'm not entirely sure, but i would imaging they are for architectural photography.

Definatly no good for your purposes

This is excellent public awareness work. The substance is good and the treatment excellent. Congratulations.

PS. And yes, the technique is great.

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.

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

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

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.

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?

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.

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