Large Format Landscapes

[Jose Rodriguez]

This confuses me, though of course it is a beautiful image, you say it's a pinhole and then you say it's 75mm, can you explain how you've arrived at that I'm not that familiar with pinholes so forgive me if I'm asking a dumb question.

Thanks for your comment!

The camera:

[Jose Rodriguez]

Pinhole cameras are wonderful devices with infinite DOF (with some reservations). There is generally an optimum pinhole diameter size d for a particular focal length F and wavelength of light lambda, a relationship first postulated by Petzval (yes that famous that old timer), such that D = (2 X FX lambda)^1/2.

So for the image above when we apply the Petzval relation we have D = (2 X 75 X .0005)^1/2, which is the sq. root of 0.075 which is .274 mm. That is 274 µm or about 11 mil diameter hole.

The f/no would be FL/d which is 75/.274 which is f/274. He obviously used a slightly different aperture diameter or a different value for lambda.

Nate Potter, Austin TX.

Thanks Nathan for your comment!
The real aperture diameter is 0.325, then FL/d = 75/0.325 = f/231

[Jose Rodriguez]

Qué maravilla, Jose. No sabía que tenías una de éstas. Abrazos.

Great photo, Jose. I didn't know that you had that camera. Nice surprise. ;-)

Best regards.

Gracias por tu comentario!
La verdad es que ya no la tengo, la vendí hace unos cuantos meses y la verdad es que la echo de menos.
Algunas veces pienso en comprar una de 8X10 o fabricarmela yo mismo. La lamina con el orificio se puede comprar muy barata por eBay del diametro que se quiera y lo mejor es que ha sido realizado con un laser, que le da mas perfección y por lo tanto mas calidad de imagen.
Saludos!

Thanks for your comment!
The truth is that I no longer have it, I sold the camera a few months ago and sometimes I miss it.
I'm thinking about buying a 8X10 pin-hole camera or to make it by myself.
The metal sheet with the hole can be bought very cheaply (eBay) in the diameter size that you want and the best is that has been done with a laser ray, giving you more perfect circle form and therefore more image quality.
Greetings!

[Jose Rodriguez]

Taken on a trip to Yosemite end of October. All taken on Neopan Acros 100 developed in D76 with Wista SW 5x4

Attachment 107139 Attachment 107140 Attachment 107141

Bruce

Great shots of a really beautiful place!
Wow! Amazing cloudy skies.
Well done!

[Jim Becia]

There have been some nice photos posted recently. Ken, Preston, Austin, Isaac are just several that come to mind. I finally have some new scans from work done this fall. This first one is taken with Velvia 100 with my Ebony 8x10 using a Nikkor 450. I just starting to learn the tendencies of Velvia 100. It will take some time to understand the film. I would have tried Velvia 50 here, but the wind made it too chancy. This is taken at what is known as the Dells of the Eau Claire River here in Wisconsin.

[Jim Becia]

One more for today. This was taken along the St, Louis River in Jay Cooke State Park in Minnesota. It was my first time there. What a rugged river. Anyway, this image was taken with my Ebony 8x10 using a Fuji 300 5.6 and Velvia 50.

[vinny]

There have been some nice photos posted recently. Ken, Preston, Austin, Isaac are just several that come to mind. I finally have some new scans from work done this fall. This first one is taken with Velvia 100 with my Ebony 8x10 using a Nikkor 450. I just starting to learn the tendencies of Velvia 100. It will take some time to understand the film. I would have tried Velvia 50 here, but the wind made it too chancy. This is taken at what is known as the Dells of the Eau Claire River here in Wisconsin.

Nice one, Jim. Yeah, v100 is no RVP but there are times when I wish I had some loaded for 8x10.


Here's a new one from a spot close to home.
Homemade camera, 450mm nikkor M @f45, ilford fp4 in pmk N+1



bear creek by vinnywalsh.com, on Flickr

[EOTS]

Great photographs, Jim!

[Jose Rodriguez]

Great photographs, Jim!

I agree!
Powerful colors!

[lbenac]

Great shots of a really beautiful place!
Wow! Amazing cloudy skies.
Well done!

yes absolutely beautiful.
I could live with a print of the second one in my office.