New to sight

Grandpa Ron · Aug 9, 2018

Hello to all

I have been in and out of the photography hobby for many years.

The digital cameras have made vacation snapshots almost fool proof so many of my photos are used to document 18th and 19th century artifacts or reproductions for yet another past time.

I enjoy building and playing with old items and techniques. Two of my latest adventures are experimenting with a pinhole camera and resurrecting and old 4x5 cut film, bellow box camera. That is what brought me to this website.

I just finished assembling a pinhole camera kit I was given. I have calculated the F stop to be 125 and it is loaded with Fuji 200 color film. I am looking for guesstimates as to shutter times.

I am wading through my stuff to find all the parts to my 4x5 camera, so I would be interested in knowing where you folks recommend buying film and processing.

I would also appreciate directions to the proper forums. From what I have read, you folks really enjoy many aspects of photography.

Thanks

ceemac · Aug 10, 2018

Welcome to the forum. I'm sure you will enjoy all the talented people here. I'm hoping you mean new to "site". The other might me a little overwhelming for us, although we could make it work.

Grandpa Ron · Aug 11, 2018

Oops, spell check does not catch every thing. :1398:

I have located the parts to my 4x5 camera and a lot of old old photo dark room gear that belonged to my uncle.

I actually have located his old "enlarger" he used to make prints. It looks like something from the late 1920 or early 1930. I have not used it in at least 40 years myself . It looks like a good winter project.

Derrel · Aug 11, 2018

Hey Ron, Great to have you here on TPF!

I saw your request for an exposure suggestion in another thread. Under bright, sunny outdoor conditions, using the Sunny 16 basic exposure guide...Let's see.... f/128 is...well, starting at f/16,f/22,f/32,f/45,f/64,f/90,f/128, so right at six stops smaller than f/16 of the famous Sunny 16 rule...

So with 200 speed film, f/125 is so,so close enough that we shall consider the aperture to "be" f/128.

So, we have f/16 at 1/200 second as our Sunny 16 baseline exposure; at f/22 we'd be at 1/100 second; at f/32 we'd be at 1/50 second;at f/45 we'd be at 1/25 second;at f/64 we'd be down to 1/12 second;at f/64,we'd arrive at 1/6 second; at f/90 we'd hit 1/3 second; at f/128 we'd be around a half a second, give or take.

If your calculation of the lens aperture is not super-precise and accurate as well, you could be off by a significant margin; the very small,small opening in the f/128 range would demand very critical measurement of the aperture, and it is possible I think that you "might" want to add some exposure time and see if that helps, especially if you're shooting color negative film.

Might want to check the reciprocity factor for the film from manufacturer's data, and see if the film needs a doubling of the exposure time at long exposure times, in the 1-second range or thereabouts; some films used to need double the exposure time due to what is called reciprocity failure, at long exposure times. This reciprocity failure was often seen during low-light work, where shutter-open times got pretty long. So, if you are using the camera in low-light times, when the indicated exposure might be say, 20 seconds, it might very well require 40 seconds of open-shutter time to get a good exposure, due to reciprocity failure. I think in bright,m daylight lighting, you'd likely not have reciprocity failure with most modern film stocks, but I have not kept up with this issue for over two decades now.