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-   -   Testing My 3D Printed 6x12 Camera (http://www.rangefinderforum.com/forums/showthread.php?t=157102)

JChrome 08-07-2016 08:01

Testing My 3D Printed 6x12 Camera
 
Happy Sunday All -

So I've wanted a lightweight 6x12 for a hiking trip I'm taking to Norway coming up. After lots of work, I've gotten most of the items sorted and I took ahold of my first printed prototype. The printing process used is laser sintering. I've found the resolution to be superb (granular to below 0.3mm) and it's also very strong (for items printed with a thickness of over 2mm).

My main concern now is testing it to produce consistent results.

Curent Lens: Mamiya Press 50mm F6.3
Back: Horseman 6x12

Some pics:



I'd like to solicit some help with what and how to test. Testing is incredibly difficult. You've really got to be systematic and rigorous. I'd love feedback and criticism.

Some thing's I'm actively testing:
1) Distance from Focal Plane to Film Plane
My general philosophy here has been to use a longer lens, shooting at a short focal length and a fast aperture. Overall the goal is to have a very narrow DoF so that you can measure how far off you are.

I shot some preliminary shots and I could see that @ infinity, many of the items in front were in focus but infinite was not, so I knew that the lens to focal plane distance was too long.

My first real test - shoot a subject measured @ 8 feet away using my Mamiya Press 150mm F5.6. I setup a table with a black box against a white background (the box is an empty 4x5 box :p). Then have a tape measure on its side. Have little black items mark each half foot in front of the black box. Shoot the first shot at 8 feet (which, if everything is perfect, then the black box should be in focus). Then focus the lens @ 9 feet. Then 10. Then 15.

Here's the first shot with the lens focused at 8 feet.


Here's the second shot at 9 feet.


I also shot with the lens at 10 feet and it's now out of focus.

Conclusion: Pretty sure 9 feet nails the focus here. The distance the lens travels from 8 to 9 feet is 1.3mm. So if I shorten the film plane to lens by 1.3mm, then my focus should be sharp. If my logic is off here, I humbly ask for criticism :D

2) Light Leaks

There are a few places where light could come in from:
1) Where the lens meets the body.
2) Where the horseman back meets the body.
3) The plastic that is being printed is porous. It looks black on the outside, but the inside is white (Shapeways paints it black for me). Direct sunlight could simply penetrate the body itself.

So I've come up with some a way of taping over certain parts, to potentially isolate where light is coming in. From my early photos, I can't detect any light leaks, which is good thing. I ran some more rigorous tests to isolate these, but every frame came out 100% overexposed (even when covering up the cracks from places #1 & #2 with gaffer's tape). So I suspect that place #3 is at play here.

I'll have to cover the entire body with gaffers tape to see what happens and if I've missed something. This is pretty disappointing though (just got the film back a couple of minutes ago). I suppose it's noteworthy that this only really happens in direct sunlight. Indirect sunlight won't do this.

Some thought for a remedy:
1) Cover the entire body in gaffers tape (ugly but easy and practical)
2) Cover it in some other material.
3) Add flocking (something I plan on doing) to the inside.

3) General structural strength

Overall it feels really solid. I designed an Arca swiss style plate into the body to act as a "foot" on the front so that it doesn't fall over and I can attach it to my ballhead. This is working well but it's a bit flimsy at the corners of the baseplate. I've redesigned and beefed up the mounts from the baseplate to the body.

4) Odds n Ends
I put a bubble level on the cold shoe and found that it wasn't dead center (using the bubble level on my tripod for that). What I think is happening is that the graflok style back is pushing up against the cold shot and flexing it (pointing it downward). I've changed that in my design. The good news is that when I put the bubble levels on the lens and on the back, they match, so I feel more confident that the film plane and the lens are perpendicular.

Thanks for the reading! If there are other methods of testing I should be doing, please let me know.

bobby_novatron 08-07-2016 08:12

Can't offer any suggestions or remedies, but just wanted to say that I'm really impressed with your camera! That's a very cool project. Best of luck with your camera and upcoming trip! :)

Moto-Uno 08-07-2016 09:17

^Quite the task you have here . Something that's worked for me as a light leak preventer
is to paint on a coating of "Liquid Tape". Is there any way a ground glass could be used to aid in your focusing tests ? This is an interesting project . Peter

JChrome 08-07-2016 10:02

Quote:

Originally Posted by bobby_novatron (Post 2637571)
Can't offer any suggestions or remedies, but just wanted to say that I'm really impressed with your camera! That's a very cool project. Best of luck with your camera and upcoming trip! :)



Many thanks! I'll keep the thread updated with new tests!


www.stillthrill.com

JChrome 08-07-2016 10:05

Quote:

Originally Posted by Moto-Uno (Post 2637585)
^Quite the task you have here . Something that's worked for me as a light leak preventer
is to paint on a coating of "Liquid Tape". Is there any way a ground glass could be used to aid in your focusing tests ? This is an interesting project . Peter



Excellent idea. Probably will look a lot better than the gaffers tape (if used on the outside). But I do plan on flocking the inside and that will most likely significantly reduce the light leaks.

Thanks again!


www.stillthrill.com

JoeV 08-07-2016 10:47

Great project. I'd recommend moving the tape measure a bit closer to the center of the field of view, because some of these lenses can have field curvature near the edge, meaning if you calibrate focus on the edge, the center may be a bit off.

From my pinhole camera experience, anything shiny, black or not, will reflect bright sun. Craft stores have adhesive black felt, in sheets, that works good as flocking.

Keep us update on your progress. Well done.

~Joe

JChrome 08-07-2016 11:28

Quote:

Originally Posted by JoeV (Post 2637599)
Great project. I'd recommend moving the tape measure a bit closer to the center of the field of view, because some of these lenses can have field curvature near the edge, meaning if you calibrate focus on the edge, the center may be a bit off.

From my pinhole camera experience, anything shiny, black or not, will reflect bright sun. Craft stores have adhesive black felt, in sheets, that works good as flocking.

Keep us update on your progress. Well done.

~Joe



Thanks. Yea that tape measure is in the photo only for reference, it's not what I used to measure the distance from the film plane to the subject (I used the tape measure directly from the camera to the box I was focusing on).

Good idea with the flocking, I ordered some from Prophoto. Looking forward to the next iteration and seeing what the flocking does for the shots.


www.stillthrill.com

splitimageview 08-07-2016 11:39

I'd love to help with this project if you're interested, in terms of the printing. Message me if this is of interest. :)

Spanik 08-07-2016 12:27

Great project and it looks great as well.

I'd start by trying to measure the register distance. Put the camera on something flat, remove the lens and measure from the lens seat to the film. Measure at several points around the circumference and compare to what a Mamiya Press should have. My experience with 3D print is that it isn't very precise not very flat/perpendicular.

First correct that and then use some paint/coating/flocking at the inside to make it lightproof.

JChrome 08-08-2016 15:30

Quote:

Originally Posted by Spanik (Post 2637620)
Great project and it looks great as well.

I'd start by trying to measure the register distance. Put the camera on something flat, remove the lens and measure from the lens seat to the film. Measure at several points around the circumference and compare to what a Mamiya Press should have.

This is a good idea. I suspect I am fine in this regard.

Quote:

Originally Posted by Spanik (Post 2637620)
My experience with 3D print is that it isn't very precise not very flat/perpendicular.

I would agree with extruder-based printers. But 3D printing using laser sintering is a completely different process. But I need to put my money where my mouth is and give you some results showing that it works well :D And that I plan on doing

JChrome 08-23-2016 17:57

So I've tested through a lot of the issues and I think Ive nabbed them all.

I added some flocking and it helped tremendously. Things are looking great. Here are some shots from Cape Cod on the beach and the Providence RI Amtrak train station. (BTW - I switched to the Mamiya Press 75mm lens instead of the 50 6.3. The 50 will vignette slightly but not the 75mm).

Next trip... Norway :-)








splitimageview 08-23-2016 18:39

looking really good!

JChrome 08-24-2016 04:01

Quote:

Originally Posted by splitimageview (Post 2642552)
looking really good!

Thanks!

This puppy eats film like there's no tomorrow. But the results are definitely worth it.

JChrome 08-24-2016 04:07

Quote:

Originally Posted by Spanik (Post 2637620)
Great project and it looks great as well.

I'd start by trying to measure the register distance. Put the camera on something flat, remove the lens and measure from the lens seat to the film. Measure at several points around the circumference and compare to what a Mamiya Press should have. My experience with 3D print is that it isn't very precise not very flat/perpendicular.

First correct that and then use some paint/coating/flocking at the inside to make it lightproof.

I also made some test shots with my 150 5.6 (again using a very thin DoF to show exactly where the focal points are) and it's sharp across the negative. I should be good here.

jamin-b 08-24-2016 05:06

Very impressive. So how do we order one !!! :D:D:D

JChrome 08-25-2016 19:57

Quote:

Originally Posted by johnwolf (Post 2642661)
I can't help with any of the technicals, but I will certainly express my admiration for your skill and initiative and creativity. All the best with it!

John

Thanks, John. It was definitely and obsession of mine. In fact, tweaking, adding, subtracting is an addiction, even to this day. I just wanna work on it, it seems. And every iteration, I find that I can do things better, different.

So, for example, I printed this entire thing as a single piece. Which is great for a lot of reasons - it's more lightweight, it's stronger etc. But I didn't think about the challenges of adding flocking. If I were to re-do the camera, I would change these two things mainly:

1) Make the lens cone narrower (there's lots of extra space inside).
2) Print the lens cone, back and adapter that mates with the 120 back all separate (and have holes to screw them together). With separate parts, it's easier to add flocking. And flocking is incredibly important, for lots of reasons.

I suspect a V 2.0 will be worked on soon.

JChrome 08-25-2016 19:59

Quote:

Originally Posted by jamin-b (Post 2642656)
Very impressive. So how do we order one !!! :D:D:D

Note sure if I should release it in the current iteration or work on a better, Version 2.0 that is all printed with separate parts. I'm still thinking about how I could potentially work this out. But I appreciate the enthusiasm! :)

Kent 08-26-2016 00:56

Kudos to you for this amazing project! I'll keep my fingers crossed for you.

ASA 32 08-26-2016 11:38

Wonderful! 21st century technology to use a 19th century process.

What name will you give your camera?

JChrome 08-26-2016 12:37

Quote:

Originally Posted by ASA 32 (Post 2643428)
Wonderful! 21st century technology to use a 19th century process.

What name will you give your camera?



Many thanks for the kind comments from you and Kent!

I christen her, The Cristina 612. The wife's moniker is the most important, in all lines of business.


www.stillthrill.com

Spanik 08-26-2016 13:19

Quote:

Originally Posted by JChrome (Post 2642638)
I also made some test shots with my 150 5.6 (again using a very thin DoF to show exactly where the focal points are) and it's sharp across the negative. I should be good here.

Great! That's good news. So it was nothing more than flocking? Just curious...

I don't doubt this eats film, try feeding a 6x17. But I do have a 6x12 back, a Mamiya 50 but I'm missing something in between. Got it?

JChrome 08-26-2016 13:58

Quote:

Originally Posted by Spanik (Post 2643469)
Great! That's good news. So it was nothing more than flocking? Just curious...



I don't doubt this eats film, try feeding a 6x17. But I do have a 6x12 back, a Mamiya 50 but I'm missing something in between. Got it?


Haha. I got it!

I added flocking and a load of gaffers tape to the outside to keep out the light. I'm currently in talks to print it out of another material so the gaffers tape on the outside isn't needed. The Flocking I think is needed regardless, to reduce the internal glare and deepen contrast.

Is your back a Dayi or Horseman?

Also the 50mm vignettes somewhat (slightly) but I think it adds character. The 75 covers it fully. But you couldn't go wrong with either lens. Both are super, IMHO.


www.stillthrill.com

Spanik 08-27-2016 06:20

It's a Sinar Zoom back. Can do 6x4.5, 6x6, 6x7, 6x9 and 6x12. I thought of coupling it to a Fuji SWD 75 but I have no idea for focussing. But the Mamiya Press lenses do have a helix build-in so that might be a better option. Doesn't surprise me there is some vignetting, they were intended for 6x9. Maybe the ones for the Polaroid version might be better, they do have a larger image circle IIRC.

Nokton48 08-28-2016 09:43

Very Cool. I love Crazycams.

Results look outstanding. Keep going with it. Push the envelope.

JChrome 09-03-2016 01:31

Quote:

Originally Posted by Spanik (Post 2643622)
It's a Sinar Zoom back. Can do 6x4.5, 6x6, 6x7, 6x9 and 6x12. I thought of coupling it to a Fuji SWD 75 but I have no idea for focussing. But the Mamiya Press lenses do have a helix build-in so that might be a better option. Doesn't surprise me there is some vignetting, they were intended for 6x9. Maybe the ones for the Polaroid version might be better, they do have a larger image circle IIRC.

Can your Sinar Zoom switch between 645, 6x7, 6x9 and 6x12 mid-roll? Or is each roll devoted to a single size? I could of course work to develop a back to fit the Zoom but it would take some time and I'd need an example of one to work with, iterate on etc.

The Mamiya lenses for the Polaroid 600SE do have a larger image circle because they were designed to cover the pack film (FP3000 and FP100 which are sadly no longer made). The three lenses designed for the Polaroid were the 75mm, 127mm and the 150mm. The 75mm covers the 6x12 and 4x5 fully. The 150mm vignettes on both (I've tested it). I've yet to try the 127mm but I suspect vignetting.

Re: Your Fuji SWC 75 - I've been thinking about building a lens cone that takes a Technika lens board and just sets it @ infinity. The majority of the shots are at infinity anyway. Oh how I'd love to get the Schneider 47mm and set it at infinity... mmmmmmmm...

Of course, having a helicoid is really useful as you can imagine. There are some 4x5 lens helicoids on the bay but I'd bet they are shoddy construction (aluminum).

JChrome 09-03-2016 01:32

Quote:

Originally Posted by Nokton48 (Post 2643962)
Very Cool. I love Crazycams.

Results look outstanding. Keep going with it. Push the envelope.

Thanks! More to come. I'm currently camping in Norway and I rarely get internet or electronic stimulation so the ideas are flowing like the river nile :)

JChrome 09-06-2016 17:43

Here are some of the first from Norway:












JChrome 09-06-2016 17:45

The camera performed really well. She is lightweight which was perfect for some of those major hikes.

The two biggest issues: leaving the dark slide in and forgetting I was not focused at infinity. The first issue can be taken care of by removing the darkslide completely. The second just takes diligence.

JChrome 09-11-2016 08:09

I've started work on a new design.

I began to notice that some of my images have darkening in the corners and some don't which confounded me. I realized though, that it's the faster apertures causing the vignetting.

Here's an example:

JChrome 09-11-2016 10:48

I am also seeing what appears to be a light leak as well, but it's unlike other light leaks that I've seen in the sense that it's only on one or a few photos.







I looked through a strip of contiguous shots and out of the 6 shots, it's really prevalent on one shot but not the rest. So I am at a loss for an explanation there.

Spanik 09-14-2016 12:02

Lost track of this thread when it was moved. Have to say there are some great images in it. Really, this is a lens that is underrrated so much it isn't funny. Well, it kind of is funny for us who have one and use it. I really have to use it more, it is a lens that performs so far out of its zone.

Now the vignetting... it is noticable, but on the other hand it doesn't bother me.

You got Norway captured like I remember it from 40 years ago. Wiiiiiiide landscapes, empty, lonely, wild and raw. Gorgeous.

JChrome 09-16-2016 05:27

Quote:

Originally Posted by Spanik (Post 2648885)
Lost track of this thread when it was moved. Have to say there are some great images in it. Really, this is a lens that is underrrated so much it isn't funny. Well, it kind of is funny for us who have one and use it. I really have to use it more, it is a lens that performs so far out of its zone.

Now the vignetting... it is noticable, but on the other hand it doesn't bother me.

You got Norway captured like I remember it from 40 years ago. Wiiiiiiide landscapes, empty, lonely, wild and raw. Gorgeous.



Thanks! Yep, Norway is still incredibly beautiful. Quite possibly one of the best places to hike/camp I've ever been.

And yes, the 75mm super Angulon is a beast of a performer. While there is vignetting, it's only at wider apertures. At f16 or above, it seems imperceptible.

400 iso film in direct sunshine is needed. You need to shoot at 1/250 or faster to make things really sharp if using handheld. Portra 400 is perfect. So 1/250 @ F22 seems to be the sweet spot.

I really wish I had a back that fit your Sinar Zoom. I only have one which will fit the Dayi/Horseman backs, at this point.



www.stillthrill.com

kuzano 09-22-2016 11:55

Only one question... paramount to my continuing to follow this...

I want a 6X12. I have been shooting Mamiya Press and MF Fuji for years.

Question.

Are you going to market this, or market the 3D files????? Please let me know. I am set on the lenses and backs.

JChrome 09-24-2016 07:10

Quote:

Originally Posted by kuzano (Post 2651820)
Only one question... paramount to my continuing to follow this...

I want a 6X12. I have been shooting Mamiya Press and MF Fuji for years.

Question.

Are you going to market this, or market the 3D files????? Please let me know. I am set on the lenses and backs.

I am planning on marketing it and am working through the details now but it might take some time :)

kuzano 09-25-2016 11:25

Please help me replace my FrankenKamera
 
Quote:

Originally Posted by JChrome (Post 2652316)
I am planning on marketing it and am working through the details now but it might take some time :)

Consider me a test/trial/purchase subject.

I simply must replace this monster with a 6X12 that uses my Mamiya Press lenses. I may make a mask to use my 65mm, and I may get a 50. I may put my 100 f2.8 on and mask as well.

Mamiya Press 75, Linhof 4X5 back, Mamiya 65 finder, Pine

VTHokiEE 09-25-2016 11:58

Quote:

Originally Posted by JChrome (Post 2652316)
I am planning on marketing it and am working through the details now but it might take some time :)

Very cool, would love to see this as a product.

JChrome 09-25-2016 13:59

Quote:

Originally Posted by kuzano (Post 2652622)
I may make a mask to use my 65mm, and I may get a 50. I may put my 100 f2.8 on and mask as well.

Could you explain a bit more about why you'd like a mask? You mean shoot 6x12 with the 65mm or 50mm and then mask the film? I'd recommend shooting the whole frame and then cropping if needed. Or, if you want to shoot 6x9, you could also get a Horseman 6x9 back (made for 4x5s). They are less than $100 and are great.

kuzano 09-25-2016 16:49

Quote:

Originally Posted by JChrome (Post 2652671)
Could you explain a bit more about why you'd like a mask? You mean shoot 6x12 with the 65mm or 50mm and then mask the film? I'd recommend shooting the whole frame and then cropping if needed. Or, if you want to shoot 6x9, you could also get a Horseman 6x9 back (made for 4x5s). They are less than $100 and are great.

Just an errant "brain fart". am so used to masking for other formats on large format. Thinking to be able to use my 65mm which is not going to cover 6x12 or 4x5.

May never happen, and don't want to throw out considerations that may hinder your plans and progress. Forget I said it.

I've been doing a lot of stuff with cutting down Polaroid Pathfinders, and slowed to a standstill on that. Have one cut down to the base rear plane, bellows, and repositioned front standards to maintain the parallel aspects of the front to back. I extended the back to flare out to 4X5 inch, and yet keep the square of the Graflex Crown Graflok back. But enough of that.

Forge on, please.

kuzano 10-16-2016 10:11

Howzitgoing?


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