Planing holiday shoot - technical questions

[adamhiram]

I started playing around with some ideas for a holiday shoot using out of focus Christmas lights in the background. See the setup below.


20201114-DSC_0124a by adamhiram, on Flickr

I started off shooting wide open on an 85mm f/1.8 on a full frame body, with ambient metered for the background lights, and a softbox to illuminate the subject. Please note these are just test shots, so the color and positioning of the lights and lack of a real backdrop were not the focus here.

I think it is important to note the distances for this particular setup. I have about 20' to work with, which made 85mm a convenient focal length for the space. The camera is 12' from the subject, and the subject is 6' from the background. The reason the subject is so far from the camera is I need a field of view about 5' wide to fit a family of 3. Unfortunately, this also means I don't get the big blurry balls of light I wanted in the background since the camera-to-subject and subject-to-distance ratio is kind of backwards.

I expected to see something like this in the background:

20201114-DSC_0117a by adamhiram, on Flickr

Or possibly something less exaggerated like this:

20201114-DSC_0116a by adamhiram, on Flickr

But instead, I got this:

20201114-DSC_0112a by adamhiram, on Flickr

It's a good starting point I suppose, but definitely not what I was looking for. I moved the subject closer to the camera for a tighter shot, which was more along the lines of what I was looking for, but now it is not really wide enough to fit 3 people.


20201114-DSC_0115a by adamhiram, on Flickr

So my main question here is how do I get the background more out of focus, but still shoot wide enough to fit 3 people?

• I think the main culprit here is that the camera-to-subject distance is greater than the subject-to-background distance. For a tighter shot of just one person, it's trivial to achieve a shallow depth of field with the lights significantly out of focus, but getting the background out of focus for a group shot requires space. I can probably find another 5-10' of space to work with, but I don't think that will be quite enough.
• I can use a shorter focal length to get closer to the subject, such as 50mm, but that creates a new challenge with needing a wider background. They only make seamless so wide.
• I'm curious if a wider aperture might help here. Unfortunately the widest native 85mm lens for Nikon Z-mount is f/1.8, but I could also adapt an F-mount f/1.4, but I don't think an extra 2/3 stop will be quite enough. I suppose I could even adapt a (rented) Canon EF-mount 85mm f/1.2, but that's probably more than I want to put into this.
• The other option I considered is using a longer focal length. I've been considering picking up a 105mm f/1.4 or 135mm f/1.8 since switching to full frame, so one of those might work here. However they come with the same catch of needing more space, and nobody wants to shoot outdoors in December, especially after dark when you can actually see the holiday lights.
• I suppose I could just shoot the subject and out of focus background separately and composite them in post, but where's the fun in that?

So what do you think? Is there a reasonable technical solution here, or am I trying to do the impossible?

 

[Original katomi]

Hiya DOF
1/3 in front of focus point 2/3 behind are the so called acceptable sharpness
When you re shoot don’t focus on the head put that in the back edge of the focus at the limit of acceptable sharpness

 

[smoke665]

@adamhiram. If you get started and work quickly I'm thinking you could have that back wall knocked out and a bump out framed in by the first week of December, barring weather delays. Welcome to my world of set design.

You could gain some space by moving the couch and hanging the light strings on the wall, but I'm not sure it would be enough. I find this site helpful when designing sets. Camera Field of View Calculator (FoV) You don't say what aperture you were using on the test shots but I'm assuming you were wide open. You don't say if its full length or head and shoulders. The same FOV limitations apply to height also. As you've found there are some limitations that can't be be overcome. Shooting the family against a neutral gray background or black background then adding the lights background post isn't hard. Here's one way that works well

 

[Designer]

A longer focal length would make it easier, and I do understand the space limitations, so I suggest you look for a place outdoors with lights in the BG. Less formal than you wanted, but easier.

 

[adamhiram]

As I already guessed, I pretty much knew the answer... I used a similar setup a few years ago for tighter shots of my son when he was younger, but he wouldn't sit still enough to stay in focus at f/1.8. However the results were similar to the test shot below. I've had success getting a shallow depth of field on outdoor group portraits, but it required a lot of space, and the out of focus background was a wide expanse of nature, not an 8' wide wall of holiday lights.

I looked up some similar sample images and most of them seem to fall into 3 categories: tight shots of a single subject, large outdoor spaces such as Christmas lights at Rockefeller Center, or done artificially like @smoke665's example above or even with a vinyl printed backdrop. It was a fun idea, but it looks like it's back to the drawing board for pandemic-friendly locations!


20201115-DSC_0134a by adamhiram, on Flickr

 

[wfooshee]

That amount of bokeh you showed in the first couple of images comes from distance. You just need more space than you have. Which you've already figured out.

 

[smoke665]

It was a fun idea, but it looks like it's back to the drawing board for pandemic-friendly locations!

So I guess knocking out the wall option isn't under consideration???? I'm disappointed Adam I thought you were more serious about your hobby.

I wouldn't think twice about shooting with a gray background and adding the rest post. In fact I may have to appropriate the Bokeh lights on an upcoming Christmas shoot.

 

[adamhiram]

So I guess knocking out the wall option isn't under consideration???? I'm disappointed Adam I thought you were more serious about your hobby.

Here's the funny thing... My light stands go to 9.5', I have some DIY crossbars that can go up to 16' wide, I definitely have enough lights to cover that span, plenty of room in the yard, and I've been considering picking up a 135mm f/1.8 lens anyway. The real question is whether I want to invest that much effort to set it up, then try to talk the family into going outside after dark when it's freezing out so I can expose for the lights. We may just end up indoors with a white seamless backdrop, but I'm intrigued by the idea of doing a bigger build just to challenge myself and learn something new.

 

[smoke665]

but I'm intrigued by the idea of doing a bigger build

Funny thing, at the fall shoot, L'il Bit was testing the dimensions of the set. DW commented on it and asked what my plans were when the day came and she no longer fits the kid sized sets, my reply "build bigger sets".

 

[petrochemist]

I've run into similar problems when trying to shoot shaped bokeh shots indoors. I ended up standing in the corridor to get every possible bit of background distance even then it barely worked.
Shooting outside makes it much easier to increase the subject-background distance, & allows the use of longer lenses which have less DOF..,.

 

[adamhiram]

Still working through this challenge...

I moved outside where I have around 100' of open space to work with. This example was shot from about 12' from the subject at 85mm f/1.8, with a subject-to-background distance of around 50'. More space did the trick, and this was definitely the effect I was going for. However, this is also a pretty tight crop on my "test subject". In order to fit the family in the shot and still fill the background with out of focus lights, I am looking at an area of about 24' wide by 16' tall. Nice idea but also a non-starter.


20201119-DSC_0254a by adamhiram, on Flickr

Next I setup a larger background stand 9' wide by 8' tall with a longer string of lights and took some test shots at 135mm f/1.8. This was from about 20' from the subject with the same 50' subject-to-background distance, and this is more like what I was going for. I would need to extend the background lights to about 16' wide x 10' tall (at least with a 2x3 aspect ratio), something I can easily do by fully extending the light stands, adding a 2nd crossbar, and including a few more strings of lights in a more interesting pattern. This frame is not cropped, and should easily fit a small family in the foreground. I'm not sure it's worth the effort to actually do this shoot, but I am glad I figured out a way to make it work!


20201127-DSC_0316a by adamhiram, on Flickr

I'd love to see how this looks with a 200mm f/2, but I don't have any plans of getting one of those. I will follow up with some real shots if I wind up following through on this idea, but for now I'm just happy I was able to learn something new.

 

[JBPhotog]

Did you try a set up in this order,
Camera - lights - subject? Where the lights are quite close to the camera and you make a shape out of wire to tie the lights to it and shoot through that shape. The OOF lights should bokeh quite nicely and you won’t need that many. Lots of examples abound on the interweb if it interests you.

 

[petrochemist]

Did you try a set up in this order,
Camera - lights - subject? Where the lights are quite close to the camera and you make a shape out of wire to tie the lights to it and shoot through that shape. The OOF lights should bokeh quite nicely and you won’t need that many. Lots of examples abound on the interweb if it interests you.

That does sound like a good solution, if using led fairy lights. I must have another play at this

 

[adamhiram]

Did you try a set up in this order,
Camera - lights - subject? Where the lights are quite close to the camera and you make a shape out of wire to tie the lights to it and shoot through that shape. The OOF lights should bokeh quite nicely and you won’t need that many. Lots of examples abound on the interweb if it interests you.

That’s an interesting idea. Wouldn’t the out of focus foreground lights end up in front of the subject instead of behind them though? Not necessarily a bad thing, just a different look.

 

[JBPhotog]

Did you try a set up in this order,
Camera - lights - subject? Where the lights are quite close to the camera and you make a shape out of wire to tie the lights to it and shoot through that shape. The OOF lights should bokeh quite nicely and you won’t need that many. Lots of examples abound on the interweb if it interests you.

That’s an interesting idea. Wouldn’t the out of focus foreground lights end up in front of the subject instead of behind them though? Not necessarily a bad thing, just a different look.

Yes they do end up in front of the subject. This is why a simple stiff wire loop with the fairy lights attached to it allows you to avoid placing one in front of the subjects face. You also have the additional flexibility of moving the lights and/or your camera independently to get the desired effect. Placing the lights behind the subject means your variables are limited. A bit of grip gear to suspend the wired loop in the right place is pretty simple to set up.

This method has been used countless times as I am sure you have seen people using prisms and iPhone screens to add effects to the captured image. Adding fairy lights is just another spin on the same technique.