Hey all,

Just wanted to post a link to some info as to how I built the Snod35 35mm adapter:
http://snodart.com/hbe_snod35_v1.php

The short films Cache, After Class, and The Seeing were all shot with the Snod35:
http://snodart.com/shorts.php

Also, I made this depth of field tutorial for a DIY adapter DVD/kit that didn't end up working out. You can view the tutorial here:
http://snodart.com/tutorials.php

If you want to watch the full version of the tutorial, please download it by saving it to you computer (to save my bandwidth). Otherwise the tutorial can be viewed in sections. Thanks.

-Justin

Justin,

I just ordered a few parts from your diy list. I like your solution for adjustable focal plane for the focusing screen. Right now i have an EOS mount extension tube set, but would like to convert to Nikon F, and having it glued instead would be a pain to change. Good thinking!

After reading your experiments with motors, i decided to do a little more search before buying one. Do you have any experience with this model http://www.hobbyengineering.com/H3425.html ? It's mentioned on Daniel's DIY, another great starting point for novice tinkerers. http://www.jetsetmodels.info/pics/basic_35mm_dof.pdf

Anyway,
just wanted to say thanks.

Very good tutorial. Nice work. I have also done almost the same thing with my 35 adapter.

Hi Yev, that motor is a solarbotics 12mm motor. I have tested it several times and with the design of the Snod35 it just didn't stand up to the Sanko motor. As you mentioned, Daniel uses the motor with several of his designs. From what he has told me, he is getting a good circular vibration pattern with the motor. The Sanko motor is just such a great motor that the 10 or so other motors that I tried just didn't compare.

I am currently working on a design that uses thin metal wire instead of the nylon threaded rod. I feel like I have tried just about everything to get the smaller motors to perform well, but I suppose there is still hope. It kills me that the Sanko motor is no longer around.

Thanks for the post Igor. DIY 35mm adapters can be addicting.

I've got a macro adaptor set (+1, 2, 4 and 10) and still can't seem to get the camera closer than 1.5' from the focusing screen (canon XL1s - stock lens or with a 50mm lens dirrectly attached to the body of the camera with a 2x conversion on it...so what every that ends up being after the multiplication from the chip size and the 2x adaptor). What is the likely culprit here? How do I make this bad boy macrotastic?

oh...and great site mr. Snodgrass!

Hi guys,

if you cant get that Sanko motor anymore I designed another gg-vibrator some time ago. It uses thin carbon pins and a normal pager motor.
You dont need a pancake motor anymore.

You can also build yourself this device and if you cant get thin carbon pins you may use thin steel pins.

I improved it on my last vacation and now the new VH-57ND design looks a little bit different than this photo.

best regards
Daniel

Cole, thanks for the comment about my site. I wish I could help, but I don't have any experience with the XL1s. All of my adapter work has been on the DVX.

Daniel, I've tried a few types of metal wire and am still not getting great results. I think I will buy your design pictured above (VH-57ND?) to take a look at it.

what's the normal minimum focusing distance on the DVX?

Cole,
see if this article helps any:
http://www.cinevate.com/phpBB2/viewtopic.php?t=13

It talks about minimum focusing distances and has a 37mm by 25mm CAD printout of a typical focusing screen.

On my GL2 it seems i can put it right against the lens and it can focus on it.

Have you tried your snod35 with an HD camera? i'm working on building a similar adapter for my hv20. we'll see how it goes

any recommendations where to get those 72mm spacer rings? they seem to be tough to find nowadays.

Anyone know how you get a 51mm Ahcromat in a 72mm Ring?

use a 51mm ring and a step up/step down to get there.

no 72mm spacers, but other sizes on ebay. Think there will be enough space in a 62mm tube if i conserve space a bit more around the 36x24mm vibrating ground glass? what is a normal amount of vibration? does it need a lot of extra space? what is the diameter of the FD mount? what size filter would i need to just be able to glue the filter to the front of a filter?

Noah Yuan-Vogel,

I have yet to try the Snod35 on an HD cam. My guess is that it would perform as well as the other pre-made adapters though. I'm basing this on the fact that I have shot in very low light and at high f/stops with little to no sign of grain.

As for the spacer rings. I bought them from an ebay seller. I haven't seen them listed lately though.

Here is on old listing just for reference:
http://cgi.ebay.com/72mm-Spacer-Ring-Brand-New-Adapter-Metal-72-mm_W0QQitemZ300021485185QQihZ020QQcategoryZ79000QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

..and here is the sellers ebay store:
http://stores.ebay.com/ASIAN-CAMERA-LLC

A note about the 72mm spacers... they work great and are a decent price, but I have come across a few that did not thread into each other well. I don't think they are cut and threaded to precision, but again I have only come across a few that were duds.

I'm not sure how well the 62mm spacer would work. The ground glass holder only needs about 2-3mm of room around the edges to vibrate, so I would imagine that you could slim things down enough to fit.

FD mounts (and most mounts) are around 45mm inside diameter and 55mm outside diameter.

I'm not sure what you are asking as far as the "filter" goes.

Rich Hibner,

I would use step up/down rings as Cole mentioned.

Thanks for your answers. I'm just waiting for some parts and then we will see how it goes. i'm planning on trying a different focusing screen option though since I'm not yet sure I like the idea of grinding my condenser lens. the results I have seen from CD groundglasses have looked pleasing, so I intend to test CDs as well as some other polycarbonate and acrylic samples with varying grit sandpapers I've ordered. If anyone has any suggestions regarding what yields best results, I'd love to hear it. polycarbonate? acrylic? effect of grinding at varying coarsenesses? My understanding is that less grit allows more light transmission, so imagine with a oscillating solution it will be best to find the coarsest grain that also works in terms of resolution, grain, diffusion.

Grinding is very slow and I never had good results. There are always scratches that is very hard to remove. Aluminum oxide dont leave scratches, so try to find sand dust of this kind. gg has to be rough and shiny at the same time, but then you got vigneting problem that you have to solve with aditional condenser lens. Daniels wax tutorial is great and wax grain is perfect but you loose to much of light. I think that best is to leave all this and yust buy Canon focusing screen.
It is very good, no vigneting and very fine grain.

When i said grinding I meant with aluminum oxide powder. I used to use an optosigma 1500grit groundglass which had some issues with transmitting some aerial image. With the results ive seen other people getting from spinning sanded CDs, i figure it will be much easier to cut and sand a bunch of polycarbonate squares and have easily exchangable and replaceable focusing screens. from the samples ive seen with such focusing screen materials, the transmission characteristics seem quite favorable. working with plastics could just make things a lot easier as opposed to glass. I'll let you know how it goes. In my experience, pre-made canon/nikon focusing screens are great in terms of low-grain and certainly of better quality than i'd likely be able to create on my own, but i think they lose a lot of light. Plus, plain matte focusing screens arent as easy to come by as I'd like. I guess if things dont work out, i could always buy a used beattie intenscreen focusing screen at b&h for $65

Huan, this is my test with ee-s focusing screen. Left side is clean screen, right side is pasted (just for testing;so its very clumsy looking) with microcrystaline wax (nivea baby cream...). This is 4 stops gain and very slight vigneting.

I have had great results with grinding my own glass. I did several tests with various grits of aluminum oxide and silicon carbide. In the tests I critiqued the images for hot spot/vignetting and for grain. The best overall image was from the glass ground with the 12 micron aluminum oxide.

For the best results, fully rinse the glass every 5 minutes or so (Your gg and the glass that you are using as the base surface). I found that with 12 micron aluminum oxide I can get a nice ground surface by grinding for a total of 20 minutes. So, that would be four, 5 minute grinding times... stopping between each to fully rinse both pieces of glass.

Using 25 micron aluminum oxide or 500 grit silicon carbide will slightly improve the glass's ability to diffuse the light. In my tests however, the difference was only slightly noticeable with very wide lenses (28mm and shorter). I can use my 35mm with the 12 micron grit aluminum oxide glass with no signs of vignetting. My 28mm does fine most of the time depending on the setting. The 25 micron aluminum oxide and the 500 grit silicon carbide are much more difficult to grind and often leave several noticeable pits in the glass surface. Also, with these two grits of lapping powder, the grain becomes an issue.

I tested the Canon Ee-a and Ee-s screens and noted an equal amount of vignetting/ hot spot (compared to the 12 micron aluminum oxide glass). I have also made a variety of wax screens (as per Daniel's tutorial). They seem to perform well aside from the light loss. The one issue with using the microscope slide glass is that they can create strange linear-shaped lens flare. Otherwise, I think they are great as well. My experience is that making the wax screens is much more challenging than grinding. Much of the success of the wax focusing elements depends on the thickness of the wax (distance between two glass slides) and the mixture of wax that you are using. I have looked for coated slides in hopes of eliminating the strange lens flare, but haven't found any yet. I know Edmond Optics sells very thin optical glass sheets that are coated. This would most likely solve the lens flare problem with the slide glass.

Finding/making a good GG is a challenge. I have been very happy with the 12 micron grit aluminum oxide glass, but I'm sure there are other good solutions out there as well.

A long while back reference was made to there being different microstructures to the pits created by sililcon carbine and those by aluminium oxide. The carbide pits are more like long chips out of the glass rather than near-round pits.

These can apparently be of such magnitiude as to require much dressing with the finer aluminium oxide to diminish them.

20 minutes by hand? I have been using a tumbler which cycles at about 95 per minute and for each stage I give them about 3 hours before I am satisfied the grade is even across the entire surface. This is however for full CD-R sized disks, not smaller focus screens.

Hi Justin,

Thanks for posting your tutorial online, very well done. I have a question as I await 1 pound of 9micron Alum. Oxide that is in transit. I will be using your method to grind the Nikon F3 focus screen. I believe you mentioned somewhere that you had been using your screen with only SD cameras ( not HD ) ( is that accurate ? ) and because I will be using it on an HD camera I thought I would try 9 micron ( also finding 12 micron aluminum oxide proves to be a bit more difficult in small quantities so I justified the purchase of 9 micron believing the higher resolution of HD would show the 12 micron grain too much ). I know you prefer 12 micron but I would like your opinion on what results I should expect with 9 micron. Is it a total waste of time ?
( I am using Daniels vibrating holder and have been testing with the Nikon D element and see quite a bit of a "hot spot". Also, I am curious how much pressure you use when grinding , would you call it firm, or light pressure ?

Bob,
That could very well be true, but I'm honestly not sure. From my tests, 500 grit silicon carbide came in at a close second to the 12 micron aluminum oxide. In my brief experience with grinding, I found that aluminum oxide of 25 micron and up caused too many chips in on the surface. The 500 grit silicon carbide will make a nice surface that is slightly rougher than a surface ground with the 12 micron aluminum oxide. The only issue with the 500 s.c. is that it is just rough enough that the grain becomes a slight problems in low light (and there is slightly more light loss). The advantage of using 500 s.c. over the 12 micron a.o. is that it does a slightly better job at diffusing the light. It is a very slight difference though, and frankly may just be due to the way I did the tests.

Jake,
You are right I have only ever used the Snod35 (and ground F3 plano-convex) with my DVX. Grain has never been an issue with the 12 micron and the DVX, so I would guess that it would do fine with HD as well. This would not be the case if the GG was stationary however. I would hesitate using the 9 micron aluminum oxide. The grain will be much finer, but the surface will most likely not be rough enough to hold the image on the surface, which will result in a hot spot. You might be fine in most situations, but as you use a smaller aperture or when the scene has a good deal of contrast, the hot spot will become evident. You may also notice that the image becomes progressively more yellow/brown as you close the aperture. It is worth a shot, but you might want to give it a good test run before fully trusting it to important footage. I have got great images with 3 and 5 micron grit aluminum oxide, but only with good light and a large aperture. Have you tried http://willbell.com for the 12 micron? You will have to call them; you can't order the lapping powders from their site. They have mailed small quantities of 3,5, 12, and 25 micron aluminum oxide in the past.

I used a Nikon D screen for a while as well. I would say that as far a grain goes the D screen is comparable to glass ground with 500 grit silicon carbide. The D screen is slightly brighter than the 12 micron aluminum oxide glass, which may be related to the hot spot that you mentioned. Keep in mind that vignetting and hot/spot may decrease as the the GG is moved further from the camera's lens. How far you can move it all depends on the camera and achromat you are using. I have tested various distances between the GG and the camera and honestly have not see much, if any, difference. Just FYI.

As for the grinding... I was thinking of putting together a quick video tutorial of how I grind the glass. Easy to say of course, but hard to find the time to actually do it. For now, to answer you question about pressure when grinding: You don't need to apply very much pressure at all. In fact, it is more like you are dragging the glass across the surface while applying very slight pressure. Using less pressure will not hurt anything; it will just take longer to grind. Too much pressure though can cause large pits (large in comparison to the microscopic pits that you are trying to get). Hope that helps for now.

I'm having some hotspot problems. So far I've only tested 150 grit sandpaper and 800 grit wetordry sandpaper. Both have so far resulted in too many surface scratches and a significant hotspot. I'm grinding an acrylic square that is placed behind a nikon condenser like the one ground for the snod35. Looks like way too much aerial image is getting through. Any recommendations? I thought the 800 grit would be better but if anything it showed an even more distinct hotspot. I'll have to test my 1500 and 2000 grit soon. Seems like it's just not diffusing enough... anyone know if maybe it's the way i'm grinding? Maybe I just need to grind longer? I mean it looks fairly well ground to me after 5 min or so of grinding since it's plastic which grinds pretty quickly.

Sand papar is not going to give you good results (in my opinion). The silicon carbibe and aluminum oxide are lapping powders used refine the surfaces of lenses. The grit of these powders is totally different than sandpaper (ie: micron grit). Also, I would suggest using good quality glass instead of acrylic. Acrylic is probably just too soft compared to glass to get and nice even surface.

Hmm... But I like the qualities of some of the spinning CD adapters ive seen and CDs are polycarbonate. Those are usually accomplished by sanding, right? Also, from what I understand, 800grit aluminum oxide sandpaper should be about equivalent to 12micron grinding aluminum oxide grinding compound in terms of particle size and grinding qualities. Youre saying its better as a free moving powder as opposed to a powder thats been glued to paper? Is there a significant difference? Maybe i just need to use glass instead of polycarbonate/acrylic. I wonder if its alright if i still use the same sandpaper. Maybe I can try grinding the focusing screen that i got the condenser with. I wonder if the split prism in the center can be sanded off or if it goes all the way through....

Thanks for the advice Justin, I have on order the 12 micron Aluminum Oxide from WillBell ( via phone ~ it was $15 for 8 ounces ). In the mean time I shot a bit with the 9 micron nikon f3 screen. Here is a little clip ( compressed to appletv format ). 35mm f2.0 nikkor lens.

http://idisk.mac.com/jaked/Public/35mm_9micron_test.m4v

Once I test the 12 micron maybe I can determine what is causing the vignetting, the nikon lens or the ground glass....

I am happy with the results so far ... thanks to you,Daniel Schweinert, and the many that contribute here.

Jake,
I couldn't get the clip to play well on my PC. I will take a look at it again on my Mac later. From what I could tell though (played choppy), It looked pretty good. Were you using the ND filters on the camera? Just FYI, you have to use actual ND filters in front of the 35mm lens and not the ones on the camera. The true test for the 9 micron is to close down the aperture. If all is well, the color should look the same and there shouldn't be any hotspot. If the focusing element is not diffusing enough light, then the images will turn a yellowish brown and a hot spot will start to show up (as the aperture is closed down).

Was the lens 35mm as in focal length? Keep in mind that many wide lenses will cause vignetting depending on the brand and quality. So you are smart to test other lenses as well. It was hard to tell the way it played on my PC, but it didn't look like there was any vignetting.

Keep pressing on.

Noah,
I know that the M2 uses a plastic focusing element. The focusing element of the M2 that I opened up did not appear to be ground. It was about 3mm thick and was a milky-white translucent plastic. Maybe some have got it to work, but it would seem that attempting to grind plastic would just cause too many large scratches.

That makes sense since I have noticed the softness of plastic results in very fast grinding so it is very sensitive to unevenness and more prone to scratches. A harder material would grind slowly and would even out more easily. I will try grinding my focusing screen, and if that doesnt work well, my condenser lens. Anyone see any potential problems with me using this on my canon HV20 with no achromatic diopter? At the moment it is configured so the focusing plane just fits in the frame when the hv20 is full wide and it focuses on the plane with no problems whatsoever. Could be the most compact vibrating 35mm adapter ever at a length of less than 2" and a maximum diameter of 62mm. Just have to get it to work right...

All I have left is grinding glass, and I've moved away from the plastic focusing screens and cut my own glass which I have been grinding using the wetordry 1500 grit sandpaper I have which should be about equivalent to 12 micron or less. Is there something about using the powdered abrasive that causes more diffusion in the ground glass? because im getting a focused image but way way too much hotspot and tons of aerial image. I guess I'll have to get my hands on some aluminum oxide powder. Anyone have suggestions of where to get small quantities quick? anything in new york? will using a powder definitely help? I know moving the camcorder back will help get rid of the hotspot but that is a last resort and there must be a way to get good diffusion and no hotspot at a close distance. any help would be greatly appreciated.

Justin,

Yes, the 35mm lens I am using has a 35mm focal length ( sorry I hadn't posted a reply sooner ). Also, to answer your other question, no ND filters were addded (however the canon hv20 may have its own automatic ND.. but I believe that is not user adjustable :-( ). I received the 12 micron aluminum oxide powder just yesterday. Using your 12micron "process" I ground the F3 nikon screen , I housed it in Daniel Schweinert's Vibrating GG holder VH-72ND and the achromat lenses he offers. I am happy with the results so far. When time permits I'll send some clips with the aperture closed down. Also, I'll have to purchase some longer lenses to get rid of any vignetting, although it seems the use of 12micron aluminum oxide has reduced vignetting to an acceptable level. Thanks for the advice. I am tempted to go for the redrock micro 72mm achromat or the cinemate achromat. Any thoughts on one over the other, Anyone ??? I need approximately 10+ diopter ( the redrock micro doesn't have its strength listed. )

Noah, I hope the clips will further convince you to go with the 12micron Alum. Oxide. Try to call the people at willbell.com. Ask them to expidite it, as they are in Virginia so it shouldn't take too long to get there.

(The clips are raw hdv format ( with a quicktime .mov wrapper )).

remember to RIGHT CLICK and SAVE AS / LOCATION :

http://idisk.mac.com/jaked/Public/12micron_NikonF3_element_35mmfocal__F2_clip1.mov

http://idisk.mac.com/jaked/Public/12micron_NikonF3_element_35mmfocal__F2_clip2.mov

I think I will first try a real focusing screen and then if that doesnt work as I'd like, I will find some 12u abrasive powder to grind with. Looks like the most readily available appropriate screen is a canon ee-a, will that fit in a nikon focusing screen holder? my adapter is all ready and built around a nikon f5 focusing screen holder, i imagine i an f3 type d screen or canon ee-a screen would fit in it with a little sanding or shimming? justin, looks like youve used both nikon and canon screens, how do they compare in shape and size?

This adapter project sure is taking longer than expected. Justin, your webpage made it all look so easy and quick. I guess my problem is I'm in a rush to finish it and i end up having to make/find my own parts instead of ordering them online. (my motor broke so instead of ordering a new one online, i found pager at a fleamarket and took it apart for the motor). How did you make all your parts, Justin? Things like cutting nice plastic circles are so much harder without the right tools. I've been doing a lot of cutting and grinding with my new dremel which i ended up buying for this project. I'm juts about done, i just need to figure out how to mod my HV20 camera to flip the image...

I have grinded a glass using 9 micron Aluminium Oxide. But the image is much darker compared to EE-A and EE-S focusing screen, which I consider it is not feasible. Since I have shot a whole Project with my DIY adapter using EE-S screen. The brightness is barely enough in some indoor scene. So anything darker than canon screen is unacceptable.
But there is a problem from these canon screen. Is that these screen produce weird edge "ghosting problem" when in some very bright situation, look at 4.jpg, notice the windows frame on the bottom left corner. And the bokeh "radial blur" problem(6.jpg). Both of the EE-A and EE-S shows similar problem. So I guess that the problem is related to the fresnel field design of these screens. I'm thinking if there are any method to remove the fresnel field to prove my point. I really satisfied with the performance of these screens, really sharp and bright. But the ghosting artifact is really unacceptable. Is it possible to use some plastic scratch remover and polishing product to grind away and remove the fresnel field(The shiny face of EE-S screen)?

All I have left is grinding glass, and I've moved away from the plastic focusing screens and cut my own glass which I have been grinding using the wetordry 1500 grit sandpaper I have which should be about equivalent to 12 micron or less. Is there something about using the powdered abrasive that causes more diffusion in the ground glass? because im getting a focused image but way way too much hotspot and tons of aerial image. I guess I'll have to get my hands on some aluminum oxide powder. Anyone have suggestions of where to get small quantities quick? anything in new york? will using a powder definitely help? I know moving the camcorder back will help get rid of the hotspot but that is a last resort and there must be a way to get good diffusion and no hotspot at a close distance. any help would be greatly appreciated.

If the hot spot is that bad then the surface is most likely not rough enough. The more transparent it is the worse the hot spot will be. Willbell.com is the only place that I know of who sells small quantities, but there may be others.

Increasing the distance between the camera and the GG will help with vignetting some. It only helps a little though. If you are getting a nasty hot spot, then it is most likely from the GG not diffusing the light enough (being too transparent).

Jake,
I'm downloading the clips right now. I'm not sure which of the achromats would be better. I would guess that they are about the same quality. I've used the redrock micro 72mm achromat with my DVX and it worked as expected. I didn't notice any chromatic aberration or soft edges. Oh, the redrock 72mm achromat is + 10.

As for the EE-A and EE-S screens. They are much brighter then any screen I have tested. The image just didn't look that good in my tests though. From what I could tell, the ghosting issue is a result of the fresnel surface of the screens. They just weren't made to capture moving images. If you remove the fresnel surface (not sure that you can), the screens won't be bright anymore. I think the bottom line is that light loss is the price you have to pay. The Brevis is known to have very little light loss, but some would argue that the price is paid in the quality of the image. Honestly, I have never had issues with the light loss and I normally only use 500 - 1500W of light for a given set up. I slapped my first static adapter on the day that I pulled my DVX out of the box though, so maybe that is why I don't see it as a problem.

Noah,
about making the parts and the project taking a long time... I built an Ed35 (static adapter) way back in Feb. of 2006. It took over a year for me to have a working DIY adapter that I could actually use for things other than tests. I love to build and have enjoyed my time with 35mm adapters. Honestly though, with the money that I have spent in all of this, I could have easily paid for a pre-made adapter (almost two!). And the time that I spent working on the various adapters... I could have taken on a second job and bought 3 more. Of course there is much more DIY adapter info out there now. Just make sure that it doesn't suck you away from whatever your passion is.

Jake,

The clips look good. Clip two (with the white flowers at the bottom right) looks like it was a little blown out. Notice how the blown out areas get that fuzzy hazy look. I get the same thing when I use the camera's ND filters. This happens because the image on the focusing screen is blown out. Using a built in ND filter on the camera will darken the image so that it looks okay, but there is no image info in the blown out areas of the focusing screen, so they retain a weird blown out hazy look. Once I started using ND's on the 35mm lens (when needed) instead of the camera, I was amazed at the quality change. Anyway, not sure if that was the case with this clip, but just FYI.

You may find it helpful to visit the P+S Technik website. The info to be found there is specific to the Mini35/Pro35 but valid for operating alternative adaptors.

do you mind if i ask what mics you used and how you recorded the sound?

thanks