Car Trails: Merging Multple Exposures
I love shooting in the cities. I find it a real challenge to be able to work with city lights and with the sky and with, with all the traffic. It can be difficult to balance everything and so I find it challenging and I really quite enjoy it. Took this when I was living in Washington D.C. this is Pennsylvania Ave down here and of course we've got the Capitol building back up there on the hill and you can see that because of the time of day that I was shooting which was just about dusk. Well it was dusk, a little bit past dusk but not quite pitch black that the length of the exposure which was only 30 seconds long did not give me star trail or car trails that were complete. So I'm missing a gap here in this image I'm also missing a gap in the reds here and in here I'm missing a gap and there's no reds here but we can layer them all together to create a more fluid star trail throughout the scene. Now what I also did as you can see, is I used several different exposures. So here I was a l...
ittle bit brighter and then these two I was a little bit darker because I wanted to be able to preserve the values in the frame. So here, in this frame, you know some of these lights may be a little blown out. The Capitol in the background is certainly blown out but I like the shadow detail that's coming out of the rooftops. Well in the next image these lights look a little bit better but all the shadow detail is gone in here and in here. But I also have a little bit better detail in the Capitol building which I think for me, is going to be important. So, we'll blend these three images together in a very similar fashion that we did in the last image. So we'll start by selecting these three and going up to Photo, Edit In, Open as Layers in Photoshop. So we've got all those, you know and by the way let me just backtrack to show you guys what I just did, when an image opens in Photoshop for the first time it typically has this window around it. It's called a title bar and a lot of times it'll be quite large and what I like to do is tap my F key. That changes the screen mode so that I have a pure gray background and this way when I zoom in and out of my image I can just kind of move it around by pressing my spacebar down with my hand. It's just sort of the way that I work. I thought I'd share that with you all. Now, the brightest image ended up being on top. And let me just double click Properties here. To close that panel up so I can see all my layers. The brightest one is on the top and then I've got the darker ones underneath and you can see this car trails are different in each one. Well, there's a couple of things that I can do here. So for example, if I just go and click on this top layer and then click on the bottom layer while holding my shift key I can select all the layers and choose Lighten. Once again, just like we did with the star trails and I can hit Lighten and suddenly boom there we go. We've got all these car trails going through here now. The only problem that we have now is that we've also allowed some of the lights to be a little bit too bright and actually they're looking pretty alright in this case but our Capitol is still a bit blown out and that, I'm not overly fond of. Alright, so let me just take the brightest one off for a second and you're gonna see how dark the rest of that frame actually is. Right, so this is the darker frames. But when I bring it, when I turn it back on by clicking the eyeball I get a lot more shadow detail in there and that's kinda what I'm wanting from this particular scene. I don't want it to be overbearingly bright but I just don't want it to be a black, absolute black mass either. So, by selecting all of these layers and changing our blending mode to lighten we were able to get a somewhat more continuous car trail throughout the frame. Again, remembering I only had 30 second exposures on each one of those shots and that's not a long enough time for a car to navigate all the way up and down Pennsylvania Avenue. Alright, so next comes the fixing the Capitol and while this may not seem like a big deal to people living outside of D.C. we know that there's plenty of detail in there and if I take this layer off you're gonna see that is actually a good amount of detail in that photograph. So, what we can do is simply punch a hole through this layer. Now if you wanna think of it very simply we could just grab an eraser tool and if I was on this layer and I used my eraser tool it would just be erasing that actual layer and showing me what's underneath and it would look something like this. Right, that's what it's seeing, it's going right down into these bottom layers but that's a dangerous way to work. If you make a mistake, you don't have a lot of, you don't have a lot of room to maneuver after the fact. So, I generally do not use my eraser tool and I also just noticed as some of you watching me have that the tripod must have slightly moved in between these exposures. So, what I'm gonna do is once again click on this upper layer. Then shift click on this lower layer and align those layers together by going up to Edit, Auto-Align Layers and click okay. That is going to be crucial. If I punch a hole in the upper layer and it's looking down in the other layer it won't be quite even. Alright, so we decided that we're not going to use the eraser tool but what we'll instead use is a mask. And a mask will do the same thing. White will let this part show through and this part will be black and that will show us the bottom Capitol. So, to start with we may want to choose something like the quick select tool and I'm gonna click on that layer. Notice how I have the sorta, no smoking sign here. I'm gonna click on that upper layer and now I can actually make the tool function and don't be afraid to zoom in you guys. We gotta, we wanna be accurate as possible. So I'm just click in there and that does a pretty darn good job right out of the, that was just one click. So now, let's see what happens when I create my mask and once again I need to be on that layer. So, I click my mask and it is actually just the opposite of what I want. Right, so before, after. That's not at all what I want. So my mask is opposite of what I need and that's not a problem. All I'm gonna do is click on the mask and then if I'm on a Macintosh I'll hit Command I and a PC, Control I. And now you can see we've got detail in the building. So, before, after. Alright, and once again we have control. Now it seems to me that the top of that building looks a little fake 'cause it's kinda dark. Not too bad. But in an effort to make things look perfect I could click on this mask and I'm gonna alt click on the mask and you could see that this is the black part of the mask. So if I felt like this ended up being too dark I would need to paint with light. So, alt click on my mask to get it back. Grab my paintbrush and flip flop my color here to white and of course wherever I paint is gonna get rid of that. Need to change my opacity to zero percent. Wherever I paint gets rid of that and you can see that I just painted into the black portion of the mask. So, what you might wanna do is take little bites out of it. You know maybe, I don't wanna be at 100% but maybe 50% kinda just sorta blends those two together and gives me the look I want. And I think that looks a little bit more natural. So when we come back here, yeah it's got a much more natural look to it now. So, we were able to use the brighter exposure for all the lights out in here and the shadows and details in here but we were able to use the darker exposure for the actual Capitol itself and when we combined all three together and changed the blending mode to Lighten that allowed us to get complete car trails throughout the entire city.