How do I take this shot?

[macandal]

I took this photograph with my dSLR, Canon xTI. It was a 6-minute exposure.

87806

I want to do the same thing, but this time I want to use my 4x5 camera. I'm using Ektar 100 film. I understand that I can't simply use the same time I used for the digital exposure if I'm using film, right? So, what or how should I calculate what my time should be? Oh, and how do I focus to infinity with my 4x5 (that's what I did with my digital exposure)? Thanks.

[Light Guru]

What you are wanting to learn is Reciprocity Failure. Each different type of film has different reciprocity characteristics. If you have an iPhone there is a app called reciprocity timer that will calculate it for you.

[vinny]

What he said.
Focus your camera during daylight hours or on the moon.

[macandal]

If you have an iPhone there is a app called reciprocity timer that will calculate it for you.No. No iPhone.

[macandal]

What he said.
Focus your camera during daylight hours or on the moon.No, what I want to do is set it to infinity. How do you do that?

[ROL]

No, what I want to do is set it to infinity. How do you do that?

What vinny said. Focus on infinity, on the ground glass. Are you sure you even have a 4x5 VIEW camera?

I suspect not, as this is elementary VC technique. If otherwise, read up on basic VC use, either here or in books.

[John Koehrer]

With a 150mm lens at infinity, the ground glass will be 150mm from the front of the lens board.
option 2: Focus on infinity in the daylight, measure GG to LB and set up the camera to the same measurement for your shot

[ImSoNegative]

i think ektar 100 has very good receiprocity characteristics, i think focusing in the daylight would make things much easier, that way you could make sure everything is focused front to rear. would be k ind of hard to do at night.

[welly]

No, what I want to do is set it to infinity. How do you do that?

During the day, find something way, way in the distance and focus on that. Mark your camera with a spot indicating that position or don't touch your camera until later on.

[Leigh]

With a 150mm lens at infinity, the ground glass will be 150mm from the front of the lens board.
Not necessarily true.

The lensboard will be in front of the film by a distance equal to the Flange Focal Length of the lens in use.
For the eleven 150mm lenses in my database the Flange Focal Length varies from 132mm to 171mm.

None has an FFL that actually equals 150mm; the closest is 149mm, and only for one lens.

- Leigh

[vinny]

My longest tape measure ends at infinity by the way.

[Light Guru]

No. No iPhone.

Well the you will most likely have to calculate it manually. Consult the manufacture speck sheet for your film it will have reciprocity info.

[Greg Miller]

What vinny said. Focus on infinity, on the ground glass. Are you sure you even have a 4x5 VIEW camera?

I suspect not, as this is elementary VC technique. If otherwise, read up on basic VC use, either here or in books.

Focusing on infinity would waste about 1/2 of the depth of field. Better, with this scene, to focus on the hyperfocal distance.

[C. D. Keth]

My longest tape measure ends at infinity by the way.

Mine only goes to eleven.

[Light Guru]

My longest tape measure ends at infinity by the way.

Buzz Lightyear has a tape measure that goes to infinity and beyond.

[al olson]

Assuming that your camera has infinity stops, pull the front standard out to the stops and crank the rail as far back as it will go. Now you are at infinity. Or you can focus on a distant object with the ground glass during daylight as has been suggested.

The suggestion that you focus on the hyperfocal distance is valid if you are including objects in the near foreground. This, however, means that you need a focusing scale so that you can set the hyperfocal distance after you calculate it. Many large format cameras do not have such a scale.

To determine the exposure, use the ISO, time of exposure, and the aperture that you used on the digital camera. If, for example, your exposure was f/8 and four minutes at ISO 100 and you are using Portra 160, start out by reducing the f/8 aperture by 2/3 (160 is 2/3 of a stop faster than 100) so that you are 2/3 of the way to f/11, using the same four minute exposure.

Now you have to account for Reciprocity Failure. Under the same lighting conditions you can probably double the time without encountering difficulty. Now you are best off if you bracket, i.e. do exposures of 4 minutes, 8 minutes and 12 minutes, or to hedge your bet make a 6 minute exposure instead of the 4 minute. There is a good chance that all three of these exposures will be acceptable, although different.

[Greg Miller]

The suggestion that you focus on the hyperfocal distance is valid if you are including objects in the near foreground. This, however, means that you need a focusing scale so that you can set the hyperfocal distance after you calculate it. Many large format cameras do not have such a scale.


Not really. Just eyeballing the hyperfocal distance would be better than focusing at infinity (and I would be sure that if I miss I miss on the far side). It would bring more foreground elements into focus, which from the example is what the OP wants to do. Simply checking on the ground glass with a loupe (and maybe a touch of forward tilt for good measure on the lens plane) would ensure that objects at infinity are still acceptably in focus.

[C. D. Keth]

Assuming that your camera has infinity stops

Why would you assume that? The vast majority of view cameras don't have infinity stops.

[Brian C. Miller]

I want to do the same thing, but this time I want to use my 4x5 camera. I'm using Ektar 100 film. I understand that I can't simply use the same time I used for the digital exposure if I'm using film, right? So, what or how should I calculate what my time should be? Oh, and how do I focus to infinity with my 4x5 (that's what I did with my digital exposure)? Thanks.

Do you have a film camera other than LF? The problem here is that Kodak doesn't publish any reciprocity information for Ektar. You will have to experiment, and that means you should use either 35mm or MF to guage the film's reciprocity failure. The last time I spend time with Kodak outdoors at night was with E100S, and that was a 15 minute exposure by the full moon, I think f/2.8, but I'm not sure. Anyways, next time you have clear skies and a full moon, or someting similar to your photo, go and make a series of test exposures. One of them will turn out correctly, and that's the settings you'll want to use.

For focusing, as others have said, set the camera up during the daytime and then lock it into position. When night comes, just set it up on the tripod and you'll be OK. Focusing at infinity just means focusing on some mountains in the distance, and you're set. You can make pencil marks on tape or whatever if you really want to do that, but I'd just set it, lock it down, and don't mess with the focus.

Good luck!

[jnantz]

this should help you with reciprocity
http://www.apug.org/forums/forum40/57031-kodak-ektar-100s-performance-long-exposures.html

and this with the trails
http://www.weatherscapes.com/techniques.php?cat=astronomy&page=startrails

it looks like there was some light pollution on the left side
if you want to recreate that too, you will have to find a spot
that has dim ambient light that will bleed into your frame of focus.

good luck !
john