So, either this:

Or this (minus the skin colour and the circular lense popping out at the top)

Here are some example images of the type of photos these cameras (and the rest of the cameras available on the site) can produce. *faint* (note: these example are in black & white, needless to say you can produce photos in colour too). And the Fisheye...

T^T I hate times like these where I'm so undecisive.

Here's a site I found Called "The Holga Wall." It's a site dedicated to photos taken by Holga cameras. Beautiful photos. =]

Guild Wars I say...!

Please note: liisa will be travelling throughout July and will only be able to check email periodically. She will contact you as soon as possible and confirm all course registrations.

Unless otherwise noted, daytime classes are for ages 10 to adult and evening classes are for ages 16 to adult.

Please check individual course descriptions for prerequisites and equipment requirements.

Week-long Programs

If you wish to attend both a morning program and an afternoon program in the same week, you are welcome to hang out at delirium for your lunch break. You must provide your own lunch and liisa will not be teaching during that time.

Digital Basics Series - Daytime

Each class is $30 or $100 for the series if you register for all 4.

D1 - Camera Tues. August 5 1-2:30 p.m.
D2 - Computer Wed. August 6 1-2:30 p.m.
D3 - Image 1 Thurs. August 7 1-2:30 p.m.
D4 - Image 2 Fri. August 8 1-2:30 p.m.

Kids Photo Fun Camp - ages 8-13

Course fee: $100
Monday - Friday August 11-15 10 a.m.-12 p.m.

Teen Photo Camp - ages 12-18

Course fee: $150
Monday - Friday August 11-15 1-4 p.m.

Getting Started

Course fee: $80
Monday-Friday August 18-22 10 a.m.-12 p.m

Intro to Black & White - ages 12 to adult

Course fee: $150
Monday-Friday August 18-22 1-4 p.m

Composition & Design

Course fee: $80
Monday-Friday August 25-29 10 a.m.-12 p.m

Basic Darkroom 1 - ages 12 to adult

Course fee: $150
Monday-Friday August 25-29 1-4 p.m

Evening & Weekend Courses

Digital Basics Series - Evening

Each class is $30 or $100 for the series if you register for all 4.

E1 - Camera Thurs. August 7 7-9:30 p.m.
E2 - Computer Thurs. August 14 7-9:30 p.m.
E3 - Image 1 Thurs. August 21 7-9:30 p.m.
E4 - Image 2 Thurs. August 28 7-9:30 p.m.

Getting Started

Course fee: $80
Tuesdays August 5-26 7-9:30 p.m

Composition & Design

Course fee: $80
Wednesdays August 6-27 7-9:30 p.m.

Pinhole Photography Workshop - ages 12 to adult

Course fee: $80 (does not include lunch)
Sunday August 17 10 a.m.- 4:30 p.m.

Black & White Weekend - ages 16 to adult

Course fee: $150 (does not include lunch)
Sat. & Sun. August 23-24 10 a.m. - 6 p.m.

Chemistry of Photography – Tuesday-

Film Canister Pinhole Cameras

These photos are pictures I took with a film canister pinhole camera. I actually have some I like even better, but I have placed them in a “special” place. One that I can’t find.

The photo on the left shows a person in front of shelves of pottery. On the right the images are of ceramic sphere scultpures.

Pinhole pictures are primitive and can be addictive when you find yourself looking at all kinds of boxes, going "what if."

My Tuesday Chemistry of Photography class was pinhole camera day. I love to use a pinhole camera and, during KEY camp, I had a constant supply of loaded cameras at hand. The students made and used two pinhole cameras. One was made out of black film canisters and the other was made out of a small size Pringle can (which I will write about later).

A professional photographer friend saved his black film canisters. That might be a problem now, as the world moves to digital. Each camera took two canisters.

Canister one: The students paint a small circle or square of liquid white out on the side, centered, and put a pinhole in the center of it. This made it easier to find the hole. I think I had two sizes of needles that I used. The directions state an 0.4 mm pinhole. On the bottom of this canister they made a line with white out to line up with the hole they put in. This is the camera.

Canister two: The lid of this one was discarded. The bottom cut off and a steak knife was used to cut a straight line through the side. This is the shutter. It spreads enough, when you place it over the camera, that when you twist it, it will expose the hole, and take a picture.

I cut squares of print paper ahead of time and had loaded a bunch in the dark loading bag. I did not ration these out. They are so small that, a Jr High student will be bored before they reach their limit, unless they are so excited about it that you are thrilled they want more paper. 

When doing this with a class, the thing to remember is to put a black marker in the bag. As each student hands you their camera, you have them tell you their initials. Print paper in hand, you write their initials on the back of the paper and take the camera into the dark bag and load it in their camera. Put the lid back on tight and make sure the shutter covers the hole. It's good to have one thumb over that hole when you put the camera in your bag. They can then check that mark they made on the bottom to see where the hole is on the side.

They have already developed paper from day one, so they can develop and leave their pictures in the stop bath and get back in line for a new paper. 

Images are a bit surreal and fuzzy at times. If you google pinhole cameras, you can find some fun stuff. Han Wolff took a pinhole pic of the Eiffel Tower that is a great design.

Era viernes. Ese día era perfecto. Pasamos el tiempo juntos y habíamos ido de visita al centro. A la vuelta fuimos a su casa, una habitación cutre en un piso compartido. Decidimos volver a la calle, ese habitáculo era demasiado asfixiante para poder articular una palabra sin extingir todo el oxígeno que quedaba. De repente bajando una cuesta él se detuvo. Me dijo:

- Yo creo que esto no puede continuar así, no puedo más. Tus padres no me quieren, he tenido que irme a un puto piso compartido con gente que ni siquiera sé su idioma y me siento solo en esta ciudad llena de gente complicada y apática. 

- Pero, ¿qué te pasa? Hace un momento estabas bien... venga, vamos, no te desanimes, ahora no.

- Es que no puedo seguir fingiendo que todo es genial cuando por dentro me estoy muriendo de ganas de gritar al primero que pase.

- Te dije que lo pensaras antes de venir, te lo dije muchas veces y tu erre que erre, sin hacerme ni caso.

- No empieces, que pareces mi madre...

- No empiezo, es que te lo he repetido cientos de veces y tú estabas tan desesperado allí que querías salir de una vez, que no podías más, que no querías pasar ni un día más sin mí... y mírate ahora... ya no piensas en nosotros, sólo en lo difícil que es esto. Nadie dijo que iba a ser fácil...

- Ya lo sé, por eso me tengo que ir.

- ¿Irte? ¿A dónde?

- Volver a mi casa.

- Pero si acabamos de bajar...

- No. Necesito irme de esta ciudad. 

- ¿Me estás dejando?

- Sí.

Silencio.

Era la primera vez que me dejabas...

[gallery]

Yeah!

PALITA: THE PINHOLE CAMERA is Watching!!!

Oubliez un peu votre ordinateur ! Téléchargez, imprimez et construisez votre propre sténopé, conçu exclusivement avec les images et illustrations de Corbis. Suivez les instructions et amusez-vous bien !

http://www.corbis.readymech.com/fr

Em Corbis encontramos uns recortáveis para criar uma câmera fotográfica bem giras. Baixa, imprime e monta a tua própria câmera escura e sai pela rua presumindo de câmera. Tem actualmente 5 modelos.

That said he recently has been playing with the idea and his Nikon D50 and came up with a really unique lens the other day. Working for P&G for almost 11 years now, I thought this one was worthy of the blog! I'll have him send me some images that he captures and post them here for you to see. I'm figuring that once he "pops the first image, he just won't stop" (Insert Pringles Jingle here).

Pinhole with instantaneous viewable results are pretty cool in and of the idea itself, but the lens is pretty neat looking and definitely eye catching. Imagine the looks this would get on the street! LOL

Rock on Art!

Pinhole Camera 93/365, originally uploaded by Gallery32/Chocolata.

Today is Worldwide Pinhole Day and I made this camera out of a cereal box and instructions for the Populist 35mm. It was simple to make and worked like a charm. I customized it with some Moo stickers of my photos. I will post some photos when I get them developed.

Have a great Sunday!

T

Makes me glad I kept my darkroom and a hefty stash of film.

Thanks, Photojojo!

La visione delle varie tecniche che utilizza non disorienta, ma rende attenti alle varie possibilità offerte dalle Polaroid, il suo veicolo d'espressione privilegiato. Si va dal distacco dell'emulsione al trasferimento della stessa su altri supporti o contenitori, alla riproduzione di particolari di un soggetto in una sorta di ciclo che viene poi ricomposto (ciclopsie), creando pattern e suggestioni nuove, fino ad approdare alle prospettive multiple, che danno un nuovo approccio alla fotografia di architettura. Infine si giunge alla fotografia stenopeica, che è strettamente funzionale al progetto Città senza tempo in cui Bolchi ripercorre i luoghi visitati, cercando di ritrarli in un modo quasi atemporale, con l'utilizzo di apparecchi a foro stenopeico autocostruiti ed un sistema di decentramento di sua invenzione.

Idee in Bianco e Nero ha intervistato Beppe Bolchi per approfondire la conoscenza della sua interessante produzione e delle sue sperimentazioni fotografiche.

IiBN: «Il tuo percorso professionale appare fortemente legato all'utilizzo delle tecnologie Polaroid, dalle pellicole a sviluppo istantaneo alle macchine che ne permettevano l'utilizzo. All'inizio della tua esperienza con queste tecnologie cosa ti incuriosiva e stimolava maggiormente? Pensi che un giovane possa ritrovare qualcosa di analogo nelle moderne tecnologie digitali o credi che le illimitate possibilità di post-produzione possano distogliere troppo da una seria progettualità?»

BB: «L’inizio della mia esperienza con la Fotografia a Sviluppo Immediato è stato motivato dalla curiosità di capire come questi materiali si potevano piegare a ricerche espressive e creative, anche perchè Grandi Fotografi le avevano e le stavano utilizzando. Fotografavo già da moltissimi anni, anche se non a livello professionale, avendo investigato un pò tutto ciò che si poteva fare a quei tempi, quando la matericità delle pellicole Polaroid mi ha attratto inesorabilmente. Purtroppo non credo che alcuna tecnologia digitale posso o riesca a ridare le stesse emozioni di realizzare delle immagini fisicamente e solo con la propria capacità e le proprie mani. Sono sistemi completamente diversi, come cucinare nel forno a legna oppure nel microonde, pensate che profumi e sapori possano essere gli stessi? Proprio la progettualità ne rimane penalizzata, quando si ha la possibilità in ogni momento di tornare indietro o cambiare direzione, è troppo facile farsi prendere la mano e inseguire il risultato più alla portata di mano piuttosto che a qualcosa di pre-visualizzato.»

IiBN: «In alcuni tuoi progetti - Ciclopsie e Prospettive multiple - utilizzi la scomposizione dei soggetti ritratti e la loro successiva ricomposizione; sono progetti molto differenti, ma che denotano uno sguardo analitico ed un tentativo di sintesi che sia anche creativo: come ti sei imbattuto in questa ricerca?»

BB: «La mia passione per l’Architettura si è trasformata in passione per la Fotografia di Architettura e mi sono reso conto che l’iconografia classica, di Gabriele Basilico per intenderci (che è stata anche quella degli Alinari e del Canaletto!), non poteva soddisfare l’esigenza di vedere e interpretare in maniera completa un’opera architettonica. L’evoluzione stessa dell’Architettura richiede modi diversi di rappresentazione e di interpretazione, ma purtroppo gli Architetti non se ne sono accorti e pretendono che le loro opere siano viste sempre e solo alla maniera dei loro disegni progettuali, cosa che trovo molto limitativa.»

IiBN: «La prima volta che lessi un articolo sul tuo progetto Città senza tempo, rimasi particolarmente colpito sia dalle foto, certamente evocative e nel contempo rese austere dal rigore della loro prospettiva, sia dalla determinazione con la quale per la realizzazione di questo progetto hai addirittura progettato e realizzato due pinhole decentrabili; ti senti intimamente legato a qualche immagine realizzata nel corso di questo progetto, in cui ripercorri luoghi che in qualche modo hanno segnato la tua vita?»

BB: «Tutte le immagini di Città Senza Tempo sono parte della mia vita. E’ stato un progetto fantastico e in certi casi anche emozionante, rivedere a distanza di anni o decenni dei luoghi che magari ricordavo solo vagamente, che evocavano tempi e situazioni diverse, che riportavano alla memoria eventi e persone a me cari, è stata una esperienza che consiglio a tutti di fare. Un percorso lungo le proprie memorie, soprattutto se fotografico, aiuta a capire meglio se stessi. Se devo proprio segnalare un luogo, una immagine, ebbene quella del collegio in cui ho frequentato le Scuole Medie, i portici austeri e silenziosi che hanno accompagnato la mia crescita da adolescente, è quella che più mi ha emozionato.»

IiBN: «L'utilizzo del foro stenopeico costringe a lunghe pose che evidenziano alla fine solo le strutture e rendono evanescente uomini ed ogni altra cosa "non stabile": ciò che volevi venisse evidenziato nel ritrarre questi edifici ha per te anche una valenza "psicologica", nel senso di avvicinare il più possibile il ricordo che ne avevi con la resa finale e farne infine partecipe chi guarda?»

BB: «Fotografare con un apparecchio a foro stenopeico consente di rappresentare tutto ciò che è fermo e di cancellare o nascondere tutto quello che si muove. Non volevo che ci fossero automobili, né persone riconoscibili, volevo che le immagini fossero le più vicine ai miei ricordi, senza dover indicare un’epoca precisa, luoghi senza tempo, appunto. Solo le lunghe esposizioni riescono a soddisfare questi parametri, oltre al fatto che la mancanza di dettagli precisi dovuta all’assenza di lenti e obiettivi, conferisce alle immagini quell’aura e quella patina che ben si addice a un progetto di questo tipo, pur senza perdere niente in termini di riconoscibilità dei luoghi.»

IiBN: «Sembra ci siano sempre più problemi a reperire le pellicole Polaroid; dalla tua esperienza come valuti la cosa? Ci sono pellicole che vorresti usare ma che non sono più reperibili?»

BB: «Spero ancora, come hanno annunciato, che qualcuno riesca a rilevare la fabbrica e ad assicurare la continuità della produzione. La perdita delle pellicole a sviluppo immediato sarebbe veramente tragica, sia per tantissimi professionisti che ancora la usano con soddisfazione, sia per tutti quelli, e sono molti, che ne hanno fatto il mezzo privilegiato per realizzare immagini fantastiche ed uniche. Dovendo indicare quelle pellicole che più mi mancheranno, senza dubbio cito la SX70 per quelle a sviluppo integrale e le 665 e 55 bianconero positivo/negativo per le pellicole a distacco, ma anche la 59 per le immense potenzialità creative.»

IiBN: «Gran parte della tua produzione fotografica è basata sulla sperimentazione di alcune tecniche fino a reinventarle, quasi sovvertirle. Il modo in cui utilizzi il formato panoramico, invece, sembra rifarsi molto alla tradizione del genere. Ciò è dovuto a una scelta stilistica precisa? Ritieni che la fotografia panoramica non si presti alla sperimentazione quanto altri generi?»

BB: «La fotografia panoramica, con apparecchi ad obiettivo rotante, è già di per sé un pò fuori dagli schemi e infatti offre visioni fuori dall’ordinario. In questo caso, però, la sperimentazione è proprio offerta dalla tecnologia digitale, con la quale si possono raggiungere traguardi impensabili con le tecniche tradizionali, ed infatti ci sto lavorando e presto spero di produrre un apposito progetto.»

IiBN:: «Vedo che ti occupi anche dell'analisi di portfoli; ti capita di vedere nuove proposte originali che siano rese anche immediatamente fruibili o spesso manca quella marcia in più che unisce la coerenza di una visione all'originalità di un'idea?»

BB: «La lettura dei portfolio è una attività affascinante, che consente non solo di vedere continuamente nuove proposte, ma obbliga a valutare criticamente anche la propria di produzione. Non è facile trovare dei lavori finiti, completi, per lo più si tratta di progetti abbozzati, di cui i fotografi chiedono un parere sul relativo svolgimento e consigli su come portarlo avanti. Nei pochi casi in cui, per me, c’è originalità, tecnica, equilibrio e creatività, i pareri degli altri possono essere discordanti, c’è una mancanza di uniformità nell’esprimere le valutazioni e forse è giusto così.»

Potete trovare le fotografie di Beppe Bolchi sul suo sito Fare fotografie.

Here is one of the photos Steve Kennedy took of me using a pinhole camera.  (I know I have big lips) It's going to be shown at Scafuro / Acosta Gallery from May 2nd through to May 7th!  Thanks Steve!

Peyote pinhole camerafrom Corbis ReadyMech Cameras

Several years ago while visiting the street market at NYC's Union Square Park I stumbled upon a photographer selling photos of city scenes. The images were uniquely different: Small (most not much more than 4 inches square), black and white, and slightly blurred, with many having a strangely skewed perspective. They had an attention grabbing, hand-crafted look to them.  The photo I eventually purchased was one of the Brooklyn Bridge taken with a pinhole camera. 

Pinhole photography allows you to make a photograph that requires only a light-tight container with a tiny hole in one side (as a camera) and any photo-sensitive surface in it. The pinhole camera is often hand-made from any available container (soda can, opaque plastic container, oatmeal box, etc.). The experience of image-making becomes a little more special and magical when created with a hand-made camera; the infinite depth-of-field, skewed perspectives, and slower exposures available with a pinhole camera create the potential for greater creativity in the finished image.

The photographer who made my Brooklyn Bridge picture used an empty 35mm film container.  He punched a tiny hole in the side, placed a single frame of unexposed 35mm film within, sealed the container, and placed it atop a piling on the shore of the East River, facing the bridge.  Here comes the interesting part: Since it's difficult to accurately aim such a crude device, and exposure times are lengthy and variable, you never know exactly what quality of image you'll end up with, until the photo is developed. 

“I can build a pinhole camera out of almost anything imaginable," he told me. "It just takes imagination. The only problem is that film and the chemicals to develop it are harder to find and more expensive. Digital photography is rapidly taking over."

It's fortunate that the next Worldwide Pinhole Photography Day is scheduled for April 27, 2008.  Pinhole Day is an international event created to promote and celebrate the art of pinhole photography.  According to Pinholeday.org:

On this unique day, we encourage people throughout the world to take some time off from the increasingly technological world we live in and to participate in the simple act of making a pinhole photograph, and to share their visions and help spread the unusual beauty of this historical photographic process.

To find out how you can become a part of WPPD, read the page on How to Participate.  And thanks to Corbis ReadyMech Cameras, you can download, print and build your own pinhole camera, designed exclusively with Corbis images and illustrations.  I'm told that making and using a pinhole camera is easy.  And these cameras are artworks in themselves.

Photos of Your Mother pinhole camera from Corbis ReadyMech Cameras

Apparently Corbis is not the first to design cut-out paper cameras.  The Dirkon, a Czechoslovak paper camera, was first published in 1979 in the magazine An ABC of Young Technicians and Natural Scientists for readers to cut out and make themselves. 

The Dirkon 

Googling "pinhole camera" returns a surprisingly large volume of hits.  Here are two:  Pinhole Visions: The Art of Pinhole Photography contains a directory of resources, discussion area, and galleries of pinhole photographs.  And for more examples of cameras and information on pinhole photography in general go to The Luminous Landscape.   

~TAB

Paper Source sells a pinhole camera made of paper for $27.95.  A little glue, a ruler, a pencil, and you're ready to go. A roll of black electrical tape for patching any light leaks would probably come in handy too. The best part is that it takes 35mm film so you can just drop it off at your local photo lab. (found via Jen Lemen over on BlogHer)

Don't want to shell out $27.95? Head on over to Creative Techs to print out your very own Dirkon pinhole camera template. Very cool, and it takes 35mm film too. 

Make a camera and start shooting so you're ready for Worldwide Pinhole Photography Day, April 27, 2008. My contribution to the 2006 WWPD is on the right. A view of the Lawrence Arts Center, 2 second exposure, 5x7 matboard/duct tape camera. Exposure directly onto b&w photo paper, traditional darkroom process.

Fee: $80 - includes all materials
Ages 12 to adult
Prerequisite: none
Class limit: 4

Schedule

]]> http://bimyoudays.wordpress.com/2007/10/13/formlessness-and-the-destruction-of-self/ Sat, 13 Oct 2007 18:32:27 +0000 bimyoudays http://bimyoudays.wordpress.com/2007/10/13/formlessness-and-the-destruction-of-self/

as she plays the lines between herself and the piano and herself and the piece become blurred. it is as if the individual forms of self, piano and piece lose their distinctiveness and become formless. while destructive in essence it is inherently the creation of something new and formless, an extension of self.

this image was captured with a homemade pinhole camera on polaroid spectra film. the exposure was 3 minutes.

Using only a Canon Ixus 60, a playing card, four bits of sticky tape and one badge (to poke the pinhole), I think it worked out pretty darn well! Here are some of the early results... Please tell me what you think! The last photo will take you to my scattered Flickr site.

Note: Zero photoshopping/post photo-taking effects done.

yessss.

Lunar eclipses are far more abundant, and quite often can be seen very well in the northern part of the U.S. This is what we were able to see very early this morning. Not all of the children were up, for only 2 of them were brave enough to face the 05:00 wake up call and actually watch. We've seen other lunar eclipses, but this was was great. The moon was full, the sky was totally clear, and we had a virtually clear area to observe, unobstructed by trees or houses...for a while anyway. It took a while, but we were finally able to see the moon fully covered by around 06:00 or so (I didn't look at the clock, but lunar eclipses take far longer than solar). While it didn't have the Corona of a solar eclipse, you could definitely see a subtle glow around the area of the moon. The only bad thing was that as soon as it was covered, the sun was about to peek over the horizon, so the visibility diminished greatly and we weren't able to see when the moon peeped back out from under the earth's shadow again. Also, while most of the observing time was unobstructed, but the time of full coverage, the house across the road was getting in the way. Oh well...at least we got to see it while it was under the earth's shadow! It was very cool...and a good lesson in astronomy for the 2 that were watching. I'm thinking it would be great fun to simulate both a lunar and a solar eclipse for science this year. The kids would really enjoy pretending to be the sun, the earth, and the moon.

That was how my morning began, and what a beginning it was! It was worth the early wake up call to watch, for it was probably the best lunar eclipse I've ever seen. And the kids were excited too, which of course makes it all the more exciting for me...kind of like how Christmas is far more exciting when you see how excited your children are.

Off to finish up with breakfast...yes, we are running late today. The only drawback of being up too early and then going back to bed for a "few minutes". ;)

The device has three physically coupled sub-units: a miniature solar box "oven" with one reflector, a protractor for measuring the reflector angle and a pinhole "camera" for aligning the device properly with the solar rays. The substrate is made of foam-filled poster board held together with plastic package sealing tape. The reflector is aluminum foil glued shiny-side out. Black gaffers tape and black permanent marker were used to control undesired light reflections.

Box "Oven" sub-unit

The miniature box "oven" is not really an oven, but it is similarly constructed. It has a cube volume of 5 cm on each edge. The reflector is a square of 13 cm on each edge. Instead of measuring internal temperature, as in an oven, we will use a photocell driving an electrical meter to measure light intensity. Temperature measurements take too long to stabilize. The photocell I used was scavanged from a defective solar powered calculator. I coverd it with a piece of paper to diffuse and reduce the amount of light. An analog meter was used because a digital meter makes it too difficult to search for a peak response. One has to wait too long for the digits to stabilize.

Protractor sub-unit

A clear plastic protractor is taped to the device. It is used to measure the angle of the reflector after the peak light response is found.

Pinhole "camera" sub-unit

The pinhole "camera" is not really a camera. But it does focus an image of the sun on a screen. When the device is properly aligned so that the solar rays enter the box aperture at a 90 degree angle, then the sun's image will be seen in the center of a cross-hair that is drawn on the projection screen. For this to work, much care needs to be used in the construction of the device so that all the edges are straight, corners are square and lengths are accurate. Use a sharp knife to cut the poster board. The lens of the camera is a pinhole in a piece of aluminum foil. Most of the foil is covered with flat black fabric tape to keep light reflected from that surface from getting in the oven and causing an error in the reading.

How to Use the Device

1. Align the whole unit with the sun so that the image of the sun, a tiny white dot, is in the center of the target cross-hair.

2. Adjust the angle of the reflector for a peak response in light intensity.

3. Read the angle of the reflector from the protractor.

4. Repeat the first three steps several times and compute the average of the readings. The average will be more accurate than any single reading.

Results

I took five readings. They were: 118, 121, 120, 122 and 121 degrees. The average is 120.4 degrees. Converting that to "reflector angle", as defined in the first installment, gives: 180.0 - 120.4 = 59.6 degrees.

Conclusions

The result for the best angle for a solar box oven reflector being 59.6 degrees is only 0.4 of a degree away from 60.0 degrees, the angle used in many actual designs. The spread between the largest and smallest measurement was: 122 -118 = 4, or +/- 2 degrees. In the first installment, I wondered if the reflector angle (90 + 45) / 2 = 67.5 degrees might be a better angle than 60.0 degrees. But 67.5 falls significantly outside the result of 60.0 +/- 2.0 degrees. So, for whatever reason, 60.0 degrees appears to be the best angle.

The reason for this might be found in a more complicated analysis taking into account such things as the fact that much of the light entering the box oven comes from directions other than directly from the sun. Any reflector in this type of design will not only concentrate light coming from the sun but also block the entry of refllected and diffused light from other parts of the sky and terrain.

In a subsequent experiment I covered the reflector with a sleeve made of flat black paper. I could slide the sleeve up and down to test the effect of reflector length on the outcome. The results were still consistant with 60.0 degrees as long as the reflector was at least as long as the box aperture was wide. When the reflector was a fraction of the box width, these were the results:

fraction ; best angle

0.333 ; 55.0

0.625 ; 56.0

0.833 ; 58.0

1.000 ; 60.0

>1.000 ; 60.0

My intention is to use the best angle I found for each of the four reflectors in a pyramidal consentrator design. I have almost completed that oven and will test it soon.