I will be shooting a feature in February hopfully with XL2s and "Homemade Mini35" devices. I have read most of the posts and it is still confusing, But i understand the basic premise. I've started this thread from scratch just for the Xl2. Hopefully we can all come togther and build something solid! I will be doing my homework in the next couple of days.

Please Contribute. I need to Dimentions of and Xl2 lense front.

I've been tweaking with a static adapter design for over a month now for my XL2. I've just finished documenting it on my website at:

http://www.holyzoo.com/zoo_updates.php

So far the design is as follows:

1. 35mm M42 lens
2. Adapter to 55mm filter size
3. Empty 55mm filters as spacers.
4. +4 Closeup Filter
5. Thorlabs 1500 Ground Glass
6. 2 +10 Hoya Macro Closeup Lenses
7. Stepup adapter from 55mm to 72mm
8. 16X IS XL1 Lens
9. XL2 Camera Body

It requires zooming in past the 55mm rings, then focusing manually on the ground glass, and voila - 35mm look, basically. I'm not sure how the XL2 20X lens would behave.

I can see improvements being made on the static design by either using a high end focusing screen instead of ground glass, or adopting a microcrystalline element technique.

Outside of these two improvements, I think the static adapter's potential is exhausted, and one would have to go with a rotating/oscillating ground glass/focus screen design. I personally haven't even touched that design yet, so if someone has achieved this and has fairly exacting details on the design, that would rock.

Wow, thanks, this is very usefull !!

Let us know if you can solve the "problem" of the ground glass... this is also getting me crazy...

Hey Steve

Is your AIM Hollyzoo. I would like to talk to you over the internet.

amazing work. I'm truly impressed.

Just for being correct... Steev did u mean step DOWN filter...

How much did u pay for the 55mm to screw mount adapter ??

Ah, yes, step-DOWN is correct. Man, the step-up vs step-down is still confusing. I've corrected this error on my web page. Sorry for the confusion. Also, my AIM name is "holyzoo" for anyone who cares to chat.

The 55mm to screw mount adapter was comprised of 3 adapters as one, that SRB came up with. The cost came to be about $70 shipped from UK to US. The parts seem to be a M42 to 49mm adapter, male to male 49mm coupler, and a 49mm to 55mm adapter. I will leave out whether they are step up or step down. I always get it wrong! :) This surely beats the $200 quote I received from a local machine shop to custom build a part.

Btw, I'm looking into Medium format Beattie screens as the focus element. I wish I could see if anyone else has used one with this kind of design. Focus screens let in way way more light than ground glass and I have a feeling that the grain is next to nothing based on my first tests with a Hasselblad screen.

Dunno if someone already posted that, but i found this site that sells beattie screen, they also have grid free screens (I never found grid free glasses).

http://www.intenscreen.com

Dario, yes that's the manufacturer that I'm talking about. You can buy them from BHPhoto.com and Adorama.com but I think they are special orders.

I've been emailing a sales associate at the parent company, reflexite, and found the follwing plain screens with no markings that are close to 2" diameter:

Mamiya 645, 1000S________ 2.185 x 1.61"

Mamiya C220________ ___ ___ 2.214 x 2.322"

Pentax 67________ ___ ___ ___ 2.914 x 2.324"

Rollei SLX & TLR__________ 2.453 x 2.186"

All of these are about $150 US each. Question is can they be modified to fit in a filter ring?

And what about buying an oversized glass and then cutting it ?? Is there someone who knows if that's possible ??
They are anything but cheap! :(

Steve,

I'm just getting into 35m adaptors. Wondering where focus/aperture/zoom is controlled once you go into this? I am guessing that you lock the camcorder into focus on the ground glass plane, and also must focus using the 35mm lens? Can you get this down to a science so it doesn't take forever to set up shots?

Thanks,
Josh

If you were to go the route I have, the procedure I'm finding that seems to work reliably is to zoom past the Vignetting of the 55mm rings, then focus all the way clockwise on the 16X IS lens. Then this should not be touched (easier said than done). From there, all focus is done with the 35mm lens.

Regarding exposure, you can stop down on the 35mm lens which will alter your depth of field, or stop down on the 16X IS lens which will preserve your depth of field and just prevent over exposure. The ND filter is a bit overbearing on the 16X IS, so I haven't used it much.

So, I wouldn't say it's a science, but an art, I suppose. I still think of this adapter as an experimental art tool, rather than a professional solution.

Besides the noticeable grain, I'd say focus calibration is the next biggest flaw with this "add-on" design. Using a fixed relay lens would be a better way to go. I'm just out of money to spend on getting an XL to Nikon adapter. I think that is a next step.

I'm hoping that a cost-effective solid solution comes to light from someone in the community here.

Any other XL designs out there??

What do I need to know to adapt this to other cameras? If the CCD size and focal length of the camera is different than the XL2, will this alter the setup?

I sort of look at these setups as two pieces. First, the 35mm lens to a focus plane. Second, getting the camera to focus on that plane.

In that regard, I'm wondering why there is so much distance between the 35mm lens and the ground glass? Isn't this usually a much shorter distance in most 35mm cameras?

Also, if the focus plane was further away from the camera lens, wouldn't you be able to eliminate one of the +10 macro lenses?

Sorry for the questions, but I'd like to help break this down into some basic formulas that could be adapted to a number of cameras.

Joshua, the focal length of the relay lens will impact everything up until the ground glass plane.

Regarding the 35mm lens to ground glass distance, I compared it with an actual camera body, and it's a comparable distance, 43-45mm or so, which is approximately what is specified for an M42 lens. So I consider the ground glass to lens distance the simplest part of the equation.

Regarding distancing the focus plane from the camera lens to eliminate one of the +10 macro lenses. I tested it (I know - I need a Test Chart):

http://www.holyzoo.com/111/xl2/35mm/images/1_Macro.jpg
http://www.holyzoo.com/111/xl2/35mm/images/2_Macros.jpg

I think it's a slight improvement with only 1 macro, but it adds 2" to the overall length of the adapter. I'd love to know how to easily get rid of the distortion.

Steev,
With just the macro on the camera, focus on some print that fills the whole screen. This should limit it to just the macro. It's possible that it's the macro. I use a DVX100a with a +10 hoya macro and mine looks distorted around the edges. I'm probably going to throw down the money for a century optics version.

http://www.sunrushmusic.com/micro35/micro35test.htm

I was checking out your band's web site. I think it's a funny coincidence. I am in a few bands and run an independent record label. I got started in the video world making music videos, and it's expanded from there.

It sounds right. The distance to the GG is supposed to be 44.5mm, right? Why the +4 macro before the GG?

I noticed that SRB sells 55mm spacer rings for around $5 (or maybe its 5 pounds?), so you don't have to take apart existing filters.

So what is the latest evolution in ground glass versus focus screens? Did you have to cut the glass in picture 26 to get it fit in the ring?

We're just finishing up our first music video with the XL2 and pretty blown away with the results. It'll be finished by end of year. I'd love to get some feedback on it when we're done.

Regarding the +4 Macro, I guess I got the idea from James Webb's design. I thought it was to possibly correct distortion, but found that it just reduces the amount of spacers needed between the 35mm lens and ground glass. I don't think it's adding any distortion, but I could do a better job at ascertaining that.

I didn't have to cut the glass to fit. The 2" diameter glass from Thorlabs fit good enough, with just a little slop, inside a 55mm ring.

I'd much rather have a cut Beattie focus screen though. When I get $150 to blow, I may try it. Otherwise, I'm wondering if Dan Diaconu's moving ground glass mechanism will prove to be the superior path. I'm waiting to see what system he's devising and how much it'll cost.

Btw, here's a short video shot in about an hour of playing around with the adapter:

http://www.holyzoo.com/111/xl2/35mm/video/DarbyDanceEdit2.mov

Joshua, you wouldn't happen to be a programmer too eh? I've got the whole protools setup etc...

My adapter is a spinner. It uses 'etched-looking' vinyl as the gg.

Have you seen this: http://www.satinsnowglass.com/. Thorlabs has some ggs too.

I'd love to check out the video when its done. I'm trying to find a forum to talk about music video production, and DVi seems as good a place as any.

About the +4 macro. From what I see of the James design, it was a Vivitar +1 and +2, but they were empty, just spacers.

What's the part number on the Thorlabs glass? and on the SRB M42 adapter? Can we get this down to a part list?

I want to try this on the cheap. I'm thinking about picking up some of these $10 +10 macro lenses, to test the concept. If I can get it to work on my camera, I'll upgrade.

The rotating glass has an obvious quality advantage, but it's way more complex than I care to deal with. What you're working on is much more elegant to me, and the quality looks very good. It has it's own look that is quite charming.

James, I tried a glass-inside-55mm-ring direct from SatinSnow. They were very responsive and sent the item right away. I regret to say that the Thorlabs 1500 is far finer, and further, was very inferior to a focus screen. I'm sure it would be great as a viewfinder piece, but what I received, no way it would work for what we're doing.

James, can you post more on how you constructed your spinning adapter?

Joshua, regarding James design. Look at #7. It's a Vivitar CU +4, not empty.

The SRB adapter was a special concoction they threw together. If you contact them now and address Ian Broomhead, he should remember me and what he sent me.

The part number for the 2" diameter Thorlabs glass is:

DG20-1500 - Price - $14

http://www.thorlabs.com/ProductDetail.cfm?DID=6&ObjectGroup_ID=1132&Product_ID=36117

Ah, I see the +4 now. My mistake.

SK Grimes will make the female M42 to male 55mm part for $60. Discounts for quantities.

I can put together the same thing using four off the shelf (though not necessarily easy to find) parts for $35 including S&H, but it won't be as strong or elegant.

The M42 lenses look pretty cool. You can get a lot of vintage lenses on eBay as cheap as $5.

Maybe someone can explain why a plain focusing screen is better than the Thorlabs 1500 ground glass? From what I read in the Intenscreen web site they are made of acrylic. Is this really better?

What about this Nikon screen for $25?

http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=37515&is=REG

Why not use a simple macro extension tube insthead of an expensive M42 screw mount ?? I found a tube for my 35mm photographic Pentax lenses, it has a perfect mount and a female filter screw (59mm) on it.
It is built up of four segment and every segment has a normal filter screw to be conncted to the following,so you can use as many "parts" as you want changing the macro extension (and in our situation changing the distance to the GG).
It's WAY CHEAPER and it works fine IMHO.

Finally my mount (I'm just missing to build the wax gg) looks like :

Mount 1 :

35mm Pentax Lens -> MacroTubePentaxMount -> 59to49StepUpRing -> GG -> Macro -> 24mm Relay Lens -> NikonXL1Adapter

Mount 2 :

35mm Pentax Lens -> MacroTubePentaxMount -> 59to49StepUpRing -> GG -> Macro -> 72to49StepDownRing -> Standard XL1 Lens

Joshua, I've seen a focus screen be both brighter and finer than any ground glass.

Regarding the Nikon screen through BHPhoto, my question is what size is it?

Right now, I have my eye on this one:

http://www.bhphotovideo.com/bnh/controller/home?O=WishList.jsp&A=details&Q=&sku=4402&is=REG

It's a little over 2" by 2"

Dario, how's your Mount 1 version with Relay lens on Nikon mount coming along? What Macro Lens are you using? Is there less lens distortion? If you figure out how to make a good wax focus plane, please do tell. :)

Dario, can you post a link to these macro extension tubes? Maybe I missed them.

Hi folks - especially Steev -

I find those adapters pretty impressing. It's been a while since I studied the art of the home-made mini35 - the M42 lenses are definitive the way to go!

Steev, how much will I have to set aside (in terms of money) for a XL-2 adapter? How much did you spend, all in all?

Best regards,


Sebastian

Sebastian, I've spent a total of $700 to develop my current version. Some of the parts weren't needed, but were part of the experimental process.

Here's a breakdown of needed parts and costs as I see it:

35mm Lens - $35
Thorlabs Ground Glass - $38
Optical Parts from Adorama - $250
M42 to 55mm Adapter from SRB - $70
Spanner Wrench & Cleaning Supplies - $90

So that's about $500 minimum. I've found that spanner wrenches are expensive, trial and error with an array of random parts was critical, trial and error adds up in $$, and cost savings comes in unexpected places. I called 15 local companies and had 2 call me back to give me free samples of 3 micron Aluminum Oxide abrasive powder.

Which leads me to my final comment. I received my 2nd ground glass from Thorlabs after the first one arrived with imperfections that I smoothed out with the 3 Micron AO. The 2nd ground glass is not good enough to use as is either. I'd have to do a quick grind on it with the Aluminum Oxide and a 55mm UV glass blank like I did for the first one. So I can't say this is fail safe.

I would still say that a Beattie Focus Screen would work right out of the box. Only question is how to trim it to fit in a 55mm ring. That would be another $150 from BHphoto.

Not exactly a cheap endeavor overall.

After doing more successfull work with deep depth of field with the Manual lens on the XL2 recording 24p with tasty post production, and now having a flawed but artistic way of doing shallow depth of field with this home brew adapter, I think I can call the mission generally satisfied (Lens distortion, grain, and all).

<<<-- Originally posted by Joshua Provost : Dario, can you post a link to these macro extension tubes? Maybe I missed them. -->>>


This is exactly what I bought (I have lot of good 35mm Pentax K lenses).

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=15240&item=3861555054&rd=1

If you look closer at the pictures you'll notice there are 3 or 4 rings, they have a screw mount between them.

The last front ring has a standard pentax bayonet mount (but there are models for every make) and the last ring on the back has a standard "male" mount (the same present on the lens).

My one is 52mm in diameter and the first one with the lens mount perfectly fits a 49 to 52mm step up ring.

I'll post some pictures ASAP.

steev u said u r thinking of using a beatie screen..dont u think the fresnel on it will give wobely output when u spin it?

Dogus, this is a static adapter, not spinning.

Here's one of the tests that led me to think the Beattie would be fairly grainless. It's using a Hasselblad focus screen. Problem was that it has those god awful marks on it. So the only thing I'm able to see that's significant is the dirt, scratches and marks. I wasn't very careful in testing so the screen got scratched up a lot.

http://www.holyzoo.com/111/xl2/35mm/video/35mm_Prototype_Dog_Dolly_DV25.mov

The file is in DV25 QuickTime and is 20MB. I suggest saving to hard drive to watch.

So now imagine a screen of that quality, with no marks, no scratches, and no dirt.

Dario, are there any developments with your Mount 1 design?

"Mount 1 :

35mm Pentax Lens -> MacroTubePentaxMount -> 59to49StepUpRing -> GG -> Macro -> 24mm Relay Lens -> NikonXL1Adapter"

I thought I'd post my results with a Beattie screen. It was a bit of work to sand it down in order to fit into a 55mm filter ring, but I got it eventually.

http://www.holyzoo.com/111/xl2/35mm/images/HolyZoo35_Static_Adapter_32.jpg

http://www.holyzoo.com/111/xl2/35mm/images/HolyZoo35_Static_Adapter_34.jpg

Grinding a $150 focus screen on coarse sandpaper is not a comforting feeling. So far, the Beattie is way way brighter than ground glass. Also, for mysterious reasons I was able to get rid of more optical elements, namely one of the +10 macros. As a result, I am not seeing anymore lens distortion. AMAZING!!

Here's some test footage with this improvement:

http://www.holyzoo.com/111/xl2/35mm/video/35mm_Static_Beattie_Test.mov

There's less grain, but it's still an issue. But I think well thought out shots, and using the newly discovered grain reduction technique in After Effects with a grain pattern still, it's the best option without tackling a moving element design. http://www.dvinfo.net/conf/showthread.php?s=&threadid=36545&perpage=15&pagenumber=2

Regarding a moving element design, I'm cheering for Dan Diaconu. Hopefully he comes out with something killer. As for now, I think I'm done with the Static Adapter for XL2 mission.

http://www.holyzoo.com/111/xl2/35mm/images/HolyZoo35_Static_Adapter_35.jpg

http://www.holyzoo.com/111/xl2/35mm/images/HolyZoo35_Static_Adapter_36.jpg


Time to shoot some stuff.

<<<-- Originally posted by Steev Dinkins : Dario, are there any developments with your Mount 1 design?

"Mount 1 :

35mm Pentax Lens -> MacroTubePentaxMount -> 59to49StepUpRing -> GG -> Macro -> 24mm Relay Lens -> NikonXL1Adapter" -->>>


I'm waiting some filter rings, as I don't have strong macro filters my relay<->gg distance is a bit longer than Steev design.
i got everything right now, just waiting for the filter rings, as soon as they'll arrive I'll post some shoots...

Anyway I must admit the only interesting thing of my design is that with the macro tube is possible to mount every kind of lens with a very low expense....

I'll let you know.

Steve,

Wow, how long did it take to grind down the Beattie screen?

Have you noticed if there is any direct relation between the macro strength and focusing distance? If M42->GG is supposed to be 45mm, can it be 22mm with a 2x macro, 11mm with a 4x macro, etc.?

Josh

Joshua, it took me about an hour to grind it down and fit it into the filter ring.

I believe the focusing distance is a fixed thing. Of course you can put macros in between the lens and GG and shorten that required distance, which I was doing, but now I'm not. So it's now just one +10 macro and it's working. I'm thinking the Fresnel design of the Beattie screen helps in not needing to zoom to far in on it, compared to a straight ground glass, but I'm not certain.

I took it out today in the daylight and it's pretty damn gorgeous.

http://www.holyzoo.com/111/xl2/35mm/stills/35mm_Still23.png

I think capturing the grain pattern will be a must on shoots so I can always be able to do grain reduction in post if need be.

Steev, what macro are you using?

Aaron, I'm using a Hoya +10 Diopter (2-element):

http://www.adorama.com/HYCU1055.html?searchinfo=hoya%2055mm%20%2010&item_no=1

Thank you kindly sir :)

Aaron, all questions/suggestions/feedback are welcome.

I had contacted a sales rep at Reflexite/Beattie to enquire about sizes and they gave the ones below.

The dims are in inches as follows:
Mamiya 645, 1000S________ 2.185 x 1.61"

Mamiya C220________ ___ ___ 2.214 x 2.322"

Pentax 67________ ___ ___ ___ 2.914 x 2.324"

Rollei SLX & TLR__________ 2.453 x 2.186"

So the Mamiya 645, 1000S is what I purchased through Adorama since it was closest to the 55mm size. I'd say it's closest to what you're wanting too - about 1.9 inches or probably a little less. I'm assuming 35mm format Beattie screens are generally too small, but you may want to contact Reflexite and ask for dimensions on their 35mm screens. I had been communicating with Carrie - carrie.baubie@reflexite.com

Also, I had to make sure to position the trimmed focus screen in horizontal position within the filter ring after screwing it into the macro diopter, then nervously/carefully secured it with the retaining ring with a spanner wrench.

I tried the adapter again with my 16X manual lens and still doesn't work. But it does work with the 16X IS lens. I'm assuming it would work with the 20X IS lens too (would be good to hear if anyone has had success with the 20X lens in this situation).

Whoa where did my previous post go? Odd...

Thanks for the info Steev. I'm going to try a beattie screen with my DVX as soon as I have enough spare cash to get one. I'll let you guys know how it works out.

Are you using a condensor lens in your setup? If you're getting that great of imagery from without one it might be interesting to see what would happen if you added an aspheric element both in front of and behind the lens (design I am going to use for my DVX). That would give you condensed light on one side and regathered light on the other.

Also, why didn't the setup work on your 16x manual?

Some one was looking (Aaron?) for the flange distance of a medium format camera. Try this link:
http://www.graphics.cornell.edu/~westin/misc/mounts-by-register.html

Whoa! Thanks man! Just what I was looking for.

Aaron, I'm not using a condensor lens. Somewhere I started thinking that a mild strength diopter was the same as a condensor, and I did try it in front of the GG originally but didn't see any difference except a reduction in focal plane distance requirement which was good. But I've now removed the diopter from the setup. Is a diopter the same as a condensor? If I was going to add two aspheric elements, where would they go? Sandwiching the focus screen?

Regarding the 16X Manual lens, it has a different behavior than the 16X IS. With the manual, I have to go into Macro mode at wide to focus on the GG. But I also need to zoom in to get rid of vignetting. So the problem is that I can't both zoom in AND use the macro adjustment. I could try tweaking the hell out of the backfocus adjustment, but I figure that is not a good solution. Conversely, the 16X IS lens seems to lock in on a focus point and stays locked through zooming. The calibration method is to manually focus all the way to closest (fully clockwise while holding camera normally), then zoom in past the vignette, and amazingly it works.

very interesting observation Steev. Assuming the macro used was a achromat then it should provide very similar results. Interesting to note that you did not see any real improvement. How close was the lens to the actual focusing screen?

My plan was to, as you mention, sandwich the focusing screen between the two plano convex aspheric elements with the curved surface pointing away from the screen.

You can see such an element here:

http://www.optosigma.com/miva/merchant.mv?Screen=PROD&Store_Code=OS&Product_Code=pg85

Interesting information about the 16x manual!

<<<-- Originally posted by Steev Dinkins : James, I tried a glass-inside-55mm-ring direct from SatinSnow. They were very responsive and sent the item right away. I regret to say that the Thorlabs 1500 is far finer, and further, was very inferior to a focus screen. I'm sure it would be great as a viewfinder piece, but what I received, no way it would work for what we're doing.

James, can you post more on how you constructed your spinning adapter? -->>>

Hi Steev,

could you let me know where our product fell down, as a small independant, I have the ability to fine tune the process to produce even finer grain screens, I had been told by many who have purchased our glass for this application that it was good, but am more interested in hearing the bad.

So any feedback you can provide directly to me I would be thankful for.

Dave Parker
Ground Glass Specialties
Satin Snow Ground Glass
www.satinsnowglass.com

Steev,

Do you have before and after footage using Chris Rubin's AE technique? My results weren't convincing...and I'm hoping to be proven wrong.

- jim

Jim, I tried the technique again tonight and it didn't work very well. I'm now convinced that the grain is subject to much change (dust shift, filter ring shift, etc) which would be hit and miss in post.

Much like a lot of things, I have lost some faith. So I've ditched the grain reduction technique as something to rely on. If I was playing it safe, I'd avoid moving shots with this adapter. If I was living dangerously, I'd do all the camera movement I wanted, and fix the grain issues in post, frame by frame if need be. Maybe the grain reduction technique could "help" in that case.

I'm still waiting on Dan's moving design. But till then, there's much to play around with with impressive results (I've found that a lot of grain stuff doesn't even show up on a TV):

www.holyzoo.com/111/xl2/35mm/video/35mm_Beattie_Outdoor_Test2.mov

Your work looks good enough -- I wouldn't pay the grain too much worry. Shown any of this footage to "normal" people yet? Try it and ask them to spot a "problem" with it and see what they say.

- jim