Topic: 5 x 7 pinhole construction and a few thoughts along the way

[astrobeck]

I'm in the making of a 5 x 7 pinhole camera and wanted to share a shot of it before it gets too much farther along.

I'm making it out of some plywood scraps in my wood shed/workshop and hope to have it finished by the end of next week and early enough to practice a few shots with it before World Pinhole day rolls along..

It will be about f/250, with a depth of 4.5 inches.  This should give me an exposure length of about 90 seconds for Harman Direct Positive paper, and about 4 seconds for ASA 100 film.

Anyway, a couple of thoughts came to mind today during construction:

I really wish someone made spray on felt...in black of course!

Cookie dough looks just like wood filler...dare I say I used cookie dough today to fill a hole in a void in the plywood!

You can NEVER have enough clamps.

Sanding surfaces smooth is my least favorite part of woodworking.

My router scares the bejeebies outta me.

I can still hear the phone ring over the sound of the table saw.

I wish tripod sockets/inserts came pre-installed in boards.

An emery board works great as a fine file in tight spots.

I still have all my fingers!

Here's a shot of the camera so far.
and as always, thanks for looking.

[LEAFotography]

Oooooo this IS looking great!

How are you making the pinhole?

Looking forward to seeing the next update!

[Phil Bebbington]

Great stuff, Becky. I was very pleased to read that you still have all your body parts - that makes it a total success!

[Mike (happyforest)]

Becky

Why not try flocking power, instead if felt.

http://rubberstamping.about.com/od/supplies/p/FlockingPowder.htm

It looks as if it could be a good substitute.

Great camera by the way.

Mike

[astrobeck]

Mike- flocking powder!  That might be just the thing...I'll have to investigate...  I had no idea such a thing existed.  Thanks! 

LEAF-  I hand drill all of my pinholes in uber thin brass shimstock from a hobby store.  They only cost pennies to make, and I find hand drilling to be very meditative.
And by hand drilling, I mean slowly twisting a sewing needle through the stock to make the hole and then sanding, sanding, sanding to get it perfectly smooth and round. 

Phil-Yes, coming out of the shop with all my parts still attached is a good day's work! 

Thanks all! 

[gary m]

These are real easy to install for tripod mounts http://www.homedepot.com/h_d1/N-5yc1v/R-202704508/h_d2/ProductDisplay?catalogId=10053&langId=-1&keyword=1%2F4+20&storeId=10051

[jojonas~]

flocking powder seems like a good idea! I'd forever worry about loose flock coming on the film though...

here's another idea, sheets of flock: http://www.fpi-protostar.com/flock.htm
as seen here: http://www.flickr.com/groups/yashica_tlr/discuss/72157622734630140/

[LT]

good stuff Becky.  I'm keen to see how this progresses.

[Francois]

Tee nuts are definitely the way to go for tripod sockets.

I often use spray adhesive and felt from the craft store when I need to make something light tight.

Cookie dough??? If you want to make a good patch that won't crumble or attract insects, mix some loose saw dust with some white glue. Carpentry glue also works fine. Mix in a cup and pour in the hole. Dries in about an hour and does a better job than the commercial wood fillers.

If you need something super tough, use the old krazy glue and baking soda trick. Put a bit of baking soda in the hole (make sure the baking soda has been sifted to avoid lumps), saturate with glue, add a bit more baking soda and a bit more glue. It will take some time to get dry but the result will be about as hard as a rock!

Routers are just about the safest tools you can use. Using guides held with clamps is the only way to make something straight with them.

[Diane Peterson]

I am so happy you posted this Becky! Making the camera is as much fun for me as shooting the pinholes..Francois's sawdust works very well BTW.. I am including a d..........of the two pinholes( for demo purpose only, hope that is ok)... I just finished..made of cigar boxes, foam core and some decoupage decor.... brass shim pinholes and shutters made of cut off film canister and lid with thin velcro on its edge to make light tight, also a shutter I copied from a purchased pinhole camera that works great. Fstops are 189 and 239 depending on the focal length. I also added some large corozo nut buttons that are screwed in to give a bit of a lip for opening. Even though most all cigar boxes are wooden ..I definitely cheated by Becky's standards for her beauty. I am a true admirer.



Forgot to mention, these are both 5x7 cameras, and I created a way to hold my film/paper in place while shooting cause obviously I am not using a film holder.

[jojonas~]

gosh! you are both so inspiring! I've only made teeny tiny pinhole cameras so far~ this makes me want to level up!

Forgot to mention, these are both 5x7 cameras, and I created a way to hold my film/paper in place while shooting cause obviously I am not using a film holder.

I'm very much interested in how you made that construction, if you want to share? I usually tape mine or put them in the lid of the thing I'm using so the box part holds it.

[Nigel]

Excellent work guys. There is little more satisfying than making something yourself. I've recently mastered the brilliant (and free) Google Trimble Sketchup and I'm spending way too much time coming up with camera ideas!

[Nigel]

I should have added, I never get around to making them!  So I'm very impressed!

[LEAFotography]

Thanks for the pin hole tips Becky!  I have a 0.3mm drill bit ready to use with craft drill, but I like the sound of hand drilling more!

Lots of other great tips and ideas here too, for light proofing, mounting, and beautification...and of course Nigel's fine point, getting round to it

[Diane Peterson]

jojonas........when I am initially measuring to put the foam core layer around the inside  I also cut a piece of black matboard about 1/2 inch deeper than the foam core and then add that under the foam core at the edge where the top of the film or paper would need to go.. but don't glue it down..it stays in very well cause the foam core holds it in place..then when I get ready to put paper or film in I just slide it under the foam core and it stays there..if you need pictures or drawings just let me know..the pinhole is obviously in the lid of the cigar box and I kinda make a layer of foam core around the pinhole area just to insure no light leeks..been very successful so far..

NIGEL, I like the design for the 120 format camera you have here..I have been wanting to do that anyway..so maybe your drawing will get me going...

[Francois]

Excellent work guys. There is little more satisfying than making something yourself. I've recently mastered the brilliant (and free) Google Trimble Sketchup and I'm spending way too much time coming up with camera ideas!

You could always get them 3D printed on Ponoko or Thingiverse

[astrobeck]

The 1/4-20 inserts I like to use are these, http://www.amazon.com/Threaded-Insert-Threads-Tensile-Strength/dp/B00207NF6W/ref=pd_cp_hi_0
They are a pain to get in straight, but when they are in ( I recess mine just a smidge)  they look nice and will stay in forever.

Here's another shot of the assembly process.  This view is looking in from the film holder side.  This is a glue up of the rails that hold the film holder in place.  I cut a groove for the small ridge that sticks out of the filmholder and serves as part of the light trap.
That stick in the middle with "BAD" written on it is just a brace. 

All that's left to do is paint the inside black, install the pinhole, add the back and then take it for a test drive sometime this week.  I may need to add some felt here and there to make it absolutely light tight, but so far it seems to be pretty snug.

I'll probably finish it with tung oil, since it's easy, looks nice and holds us fairly well in my arid part of the world..

So far I've been calling this one the Cinco-seven...     

[jojonas~]

thanks for the tips diane! I sent you a pm and I've already noted your nifty shutters

becky: looking good! and by the name it sounds like a classic already B-)

nigel: looks like something I built.. uhm... 4 years ago?! time sure flies
took some nice pictures with it but I remember having problems with not building the frame advance knob sturdy enough.

[astrobeck]

First test shot out of the Cinco-Seven pinhole.

This was a 2 minute exposure on Harman Direct Positive paper, then dunked in caffenol for about 4 minutes.

So far so good!
I still need to stain/finish the outside of the box but at least I know it will make fairly nice photos.
I'll post a photo of the completed box as soon as the outside is done...

There were a few thin clouds in the sky, but they whooshed away.
enjoy!

[Ezzie]

Congratulations! Well done!

[LT]

This is brilliant, Becky. I'm really impressed.

[Phil Bebbington]

Outstanding result, Becky.   So impressed.

[jojonas~]

great work~ and the harman positive seems to go nice with caffenol

[astrobeck]

Thanks!   
I was very happy to watch this one develop in  the tray last night and show no sign of light leaks or other disturbances.

Yeah, caffenol is the way to go with the Harman Direct positive paper.  It gives it a nice stain that I really like.

Thanks again!   

[Nigel]

Wow, Becky that's a great shot. With the Direct Positive paper do you just work out your exposure based on iso3 and pinhole size? Anything else (special magic) that needs to be taken into account?

[astrobeck]

Hey Nigel,
I do rate the paper at ISO 3 and then work out the pinhole size for exposure....that gets me fairly close, and then I just let it go 'about' half as much time again to allow for reciprocity and clouds., sunshine intensity, etc.   I live at 7205' elevation, so the light is pretty strong where I live.

The recommended time for this camera (the pinhole size is .018, and the focal distance is 4 3/4 inches) works out to about 90 seconds.
This exposure was 2 minutes.  I think somewhere in between would be just about right, as my exposure was a little bit too long I think.

When shooting pinhole, I always err on the long side, and then just kind of "feel" the exposure/be the emulsion kind of thing. 
The information leaflet that comes in the boxes of Harman DPP  has good ballpark figures, so if you are considering it, you should go for it!

The rest is just holding your lip right when making the exposure. 

[Nigel]

Thanks Becks, it is tempting.  My real stumbling block is not having a darkroom set up, there's a lot more work in making a space light tight than building the camera..... the results are great though!

I love the phrase..

and then just kind of "feel" the exposure/be the emulsion kind of thing.

[astrobeck]

A few more thoughts about construction:

I wish plywood makers would fill in more of the voids in the plys...

I used a flashlight in a dark room and shined it all around the glue joints to test for light leaks.  I also shined the light through the wood panels to check for pinholes and blemishes, voids in the wood.  The front panel, which is a thinner piece had quite a few voids where I could see light, faint, but light all the same. 

Painting the interior with 2 coats of flat black remedied this. 

It's cheaper and safer to buy small pieces of moulding to use as bracing and light traps.  I am a chicken when making thinner cuts on the table saw, so usually just buy thinner pieces of trim, then cut them to length.   

[Ed Wenn]

Becky: This has been a wonderful thread to read, so thanks for kicking it off.....the bonus at the end of the forum rainbow is - of course - your test shot of the truck. Fantastic!

On a related note, you all know about 3D printing, right? It hadn't occurred to me until Francois' comment how much of a boon 3D printing will be to people who like designing and building their own low-end cameras. The 21st Century version of what Becky's done here with this wonderful pinhole camera will be to design on the computer like Nigel did and then send the design off to a 3D printing service (or visit in person) where it'll be printed out in either plastic(ish) or metal. Strap on your lens and shutter and you're good to go. I'm very excited by this prospect, it's really not that far away either.

http://www.3dprint-uk.co.uk/

Excellent work guys. There is little more satisfying than making something yourself. I've recently mastered the brilliant (and free) Google Trimble Sketchup and I'm spending way too much time coming up with camera ideas!

You could always get them 3D printed on Ponoko or Thingiverse

[Francois]

I must admit that 3D printing is a terribly exciting technology. The simplest ones use the fused filament technique. And while the printers are in themselves quite expensive (Makerbot makes some of the cheapest), there is an open source design project called Rep Rap which allows you to build a small printer from parts found here and there.

Becky: plywood quality is variable depending on its rating. Plywood is rated by a letter code. AA means good quality on both faces. AC means good on one side, not so good on the back.

But if you want to see something awesome, ask to see some Russian Plywood. This stuff is dreadfully expensive as it's used in furniture making... but what a sight! No holes, no cracks, no knots, perfectly glued thin layers. Incredibly beautiful.

[LT]

But if you want to see something awesome, ask to see some Russian Plywood. This stuff is dreadfully expensive as it's used in furniture making... but what a sight! No holes, no cracks, no knots, perfectly glued thin layers. Incredibly beautiful.

Marine Ply is pretty high quality and sturdy also - necessarily so ... Have you seen what sea water does to things?

[Francois]

Oh yeah! Salt just eats up almost everything except brass.

What makes marine plywood so strong is the glue they use to hold it all together.
A few thin layers of marine varnish on top of that and it becomes really tough and rather nice looking.

[astrobeck]

I forgot to include a photo of the back of the camera and how it works.....   

I epoxied rare-Earth magnets in the back and the camera box.  The magnets are recessed into drilled holes and fit perfectly.

It works great and there's no fiddling around with elastics, bungee cords, latches, or dowels or pins to hold the filmholder in place.

The super magnets hold strong, so I'm very pleased with this design.   

[LEAFotography]

Wonderful! Thanks showing us your progress! How exciting

[Sandeha Lynch]

Good work Becky.

Question though.  Wouldn't rare earth magnets have a visible impact if you were using fast film?  Maybe only if you left the film in there a long while?

I once used some kind of marker pen on a homemade darkslide and both shots had a line across the negs!

[Francois]

Film isn't affected by magnetism.
I just love Neodymium magnets!
I have some strong enough to stick all the way through my hand. And once they stick, they really hold on!

[Sandeha Lynch]

My comment was based on the assumption that some rare earths are radioactive.  Whichever might be used in a magnet, though, I have no idea.

[astrobeck]

Hmmm...
I do not know for certain, but I "assumed" that photo paper would be okay.

But since you asked...I'm going to do a test.

I'll load a filmholder and then just puts magnets on it in several places and let it sit for a week, then I'll develop the paper....

I'll be back here in  a week with results.

Glad you like the design!   

[Sandeha Lynch]

Heh.  I'd heard that some highlighter pen inks were a tad 'active', but leaving film in the holders kinda proved it for me.

They say a few of the old Pentax lenses you should never put under your pillow or carry in your pocket.   

[Francois]

Well, phosphorescent materials are slightly radioactive... but so little that you can carry a glow in the dark medallion all your life without ever noticing anything other than it glows at night.

Neodymium magnets are not radioactive either. But they will zap your credit card's mag strip clean real fast.

Even radioactive lenses made using thorium oxide or lanthanum won't even fog your film even though they are supposed to get more radioactive as time goes by.

[astrobeck]

Interesting...I have a thorium lens....I didn't think it would get "more" radioactive over time though....
 

[Francois]

I read that it does because it destabilizes the other materials used... or something along that line.

But personally, I'd have to test it to believe it as it's totally counter intuitive.