Focusing in the dark

[Jack Bulkley]

Yesterday I tried to make a photo of the nearly full moon setting behind some silos near my house. I missed the focus on the silos. My plan was to blend a long exposure that picked up some details of the silos with a short exposure to get the moon without blowing out the highlights. My first test exposures were 15 seconds. By the time the moon had dropped to where I wanted it, there was some pre-dawn light, as planned, and my long exposure was 3 seconds. I thought I was far enough away for my depth of field to cover the silo and the moon. I was wrong.

I was using my Nikon D800. The live view was completely black in these conditions and the view finder wasn't any better. To complicate the issue, the camera was tilted up and difficult to get a good look at the screen to check my test shots. Clearly I should have done this better.

Here are my thoughts on not repeating this mistake. I would be glad to hear other ideas.

I could stop down further than f8 to increase the depth of field.

I could study and learn just where my DoF is for various aperture settings. I suspect I could have focused closer and still had the moon in focus.

I MUST look at the previews, zoom in and check the focus.

I could add light while I am focusing, but I doubt any flashlight I have would add enough light at this distance, > 100 feet, to do any good.

I could crank up the ISO for test focusing. Maybe the live view would show something then.

 

[Mainecoonmaniac]

Time allows, you could scout the location during the day and take notes on the minimal f stop you need for what you want in focus.

 

[jtk]

Merge the silos with the moon. Same digitally as with film

 

[Sirius Glass]

Merge the silos with the moon. Same digitally as with film

Good for those who do not have the will to do it in one photograph.

 

[jim10219]

A lot of older, manual lenses have distance scale markings on them, so you can set the distance at which the lens will render in focus. Be careful on older rangefinders though. I've found a few where the scale markings were wrong, even though the rangefinder itself worked properly. You might also have problems if you're using an adapter.

 

[jtk]

Good for those who do not have the will to do it in one photograph.

Eager to see Sirus rendition of this phenomenon.

I'm not confident that I could do it digitally or with rattle-trap 6X6 but could easily do it properly, in two exposures on 4X5 (manly man's format) on a tripod.

 

[Sirius Glass]

Eager to see Sirus rendition of this phenomenon.

I'm not confident that I could do it digitally or with rattle-trap 6X6 but could easily do it properly, in two exposures on 4X5 (manly man's format) on a tripod.

Not exactly rocket science, use a tripod, small aperture, and use the depth of field marks on the lens. Heck anyone who took a photography class in high school would know that. jtk must have slept though that class.

 

[jtk]

Sirius is missing the point. There are elegant ways to make images. If one wants the elegant one might want to try something that wasn't handicapped by his high school teacher.

 

[wiltw]

One technique to try is an adaptation of what we would do with film shots, composite in camera.

1. Focus precisely on silos, use flag to prevent exposure of the part of the sky with moon
2. Focus precisely on moon, use flag to prevent exposure of the part of the scene with the silo.

a flag used somewhat close to the lens would have a very blurred edge, so it would not be as noticeable.
With a 4x5 we might insert the film blind between portions of the scene being exposed. With digital you simply need to use a multiexposure feature. Or combine two shots into one with postprocessing.

 

[Sirius Glass]

Sirius is missing the point. There are elegant ways to make images. If one wants the elegant one might want to try something that wasn't handicapped by his high school teacher.

No, you missed the point. Using a smaller aperture and the depth of field easily solves the problem which allow the photographer to expend his efforts elsewhere.

 

[jtk]

Smaller apertures aren't cure-all's.

In modern (digital) times we can easily combine multiple exposures either in-camera or in post. As we all know smallest apertures can work against highest detail resolution while increasing vibration.

As well, if the OT guy's digital camera has both electronic and mechanical shutters his night shots will be a lot sharper, just as with macro if he turns off the mechanical shutter (again "modern times").