Infrared Hot Spots on the Fujifilm GF 35-70mm f/4.5-5.6 WR

This video covers correcting mild infrared hot spots with the Fujifilm GF 35-70mm f/4.5-5.6 WR using Lightroom Classic. These techniques could also address mild hot spots from other lenses and most raw editors.

Fujifilm GF 35-70mm f/4.5-5.6 WR Hot Spot Tests

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Transcript for Fixing Infrared Hot Spots with the Fujifilm GF 35-70mm f/4.5-5.6 WR. Duration: 14:10.

• 0:00 Your best infrared images will come from lenses free from hotspots. Hotspots in infrared are overexposed or color-shifted circles that appear with specific lenses at certain apertures and under some lighting conditions. Mild hotspots can be corrected in editing. Severe hotspots can ruin an image. I recommend avoiding
• 0:22 lenses that produce hotspots, but can I follow my own advice? At wide angles, I tend to shoot with prime lenses, as modern wide-angle zooms are prone to hotspots. But every once in a while, a deal comes along that is too good to pass up. And I need to break my own rules. In this case, it was the Fujifilm GF35-70mm F4.5-5.6
• 0:48 WR. Compared to other zooms in the GFX system, this lens is lightweight and affordable, especially when on sale. However, it does have a mild hotspot. Let's talk about it and how to fix them. Here are the hotspot tests I shot with the GF35-70mm. You can see vignetting across all of these test shots. At all focal lengths, a
• 1:12 faint hotspot is visible at F11 and becomes obvious at F32. Since diffraction on my GFX50S starts at F8 and is heavy at F11, I'm not likely to shoot this lens at F11 or higher anyway, where the hotspots are the most noticeable. I've shot over 700 images with this lens using 590, 720 and 850nm high-pass
• 1:39 infrared filters, as well as the IR chrome filter and a UV IR cut filter. Of these 700 images, I've edited 85 of them to share. Of those 85, I've only had to correct hotspots on 4 images. No other images I've shown here needed hotspot correction. Let's look at these 4 images and my hotspot corrections for each. One of the
• 2:03 patterns you'll notice the most with these 4 images is that the hotspots tend to be more visible when I'm shooting the sky, when the sky appears in the center of the image. So let's look at this image. Let's go into masks. The first thing I want to do is show you a sort of hotspot visualizer that I created to help me see these
• 2:22 hotspots. This is a layer that exists here and it's currently disabled because I don't want it in my final image, but when I turn it on, it's going to do a couple things. It's going to increase the saturation all the way to 100 and it's going to increase the dehaze to 100. What this does is this helps me to see the hotspots. In
• 2:40 fact, you can even see here right in the middle, a couple concentric rings where the hotspot is and maybe even this broader space. And these are the areas that I want to tackle. I've got a couple masks in here to address hotspots. Let's look at hotspot 1 first, which is the smaller of the 2. Now, if I disable this hotspot,
• 3:00 you'll see the hotspot becomes more plainly visible both here and in the side panel. One of the things that you should frequently do is look at the side panel. You might get a different perspective by either looking at the side panel or by shrinking the view. Sometimes the hotspots are easier to see depending on how big
• 3:18 your monitor is and your configuration. You can either shrink your image that way or you can look at the side panel to see these. So when I look at this hotspot 1 correction, if you look here, you'll see this is the current hotspot. If I turn this on, then it diminishes it. I'm rarely going to be able to eliminate them
• 3:35 completely, but that's okay because remember, I'm looking at this with the saturation and the dehaze cranked up to show me sort of the worst case scenario. So you can see with this case, I used a radial filter and I tried to mimic close to the size and you'll end up dragging the size of this. If I drag the outer edge of
• 3:56 this, this is one of the reasons that having the dehaze is turned up, you can see that dragging it increases the impact and I want to eliminate that, those sort of extra sort of artifacts, that darkness there to try to zone this into just the right size and you can do it sideways as well. So you can use this tool to get
• 4:16 initial size of the radial gradient, right, but the feathering as well. Let's look at hotspot number two. This is the this broader space and if I hide this, then you can see that there's a bit of a change here as well and it starts to show up as a kind of a brighter splash that exists, a splash of white, a big circle of white
• 4:39 that exists in this image. This is more common in the images that I have with the sky and then my correction here when I turn this back on, I frequently find that the saturation in this visualizer being 100% is really good to help me see the hotspot. Sometimes the dehaze doesn't work as well, so you could always turn that
• 4:56 down and then get a different view of what this looks like. When you turn on, here's my second hotspot fixer that I look at. Now you can see this broader light spot patch here that exists and that's what this second mask is attempting to do is to bring that down. And again, I can still see that dot in the middle. We just need
• 5:15 to be close because when I hide the visualizer, which has the saturation or the saturation and dehaze turned up all the way, it's going to eliminate that view and take us back to normal where the hotspot is hopefully harder to see anyway. I'm using those tools to try to get close, but I don't need to get perfect. And if I
• 5:34 switch off the masks altogether, now this is what the final image looks like. I can zoom out to get a better view. I still see a little bit of a hotspot there. And sometimes with images like this, I struggle in trying to figure out how much of this is a hotspot, how much of it is vignetting in the image. Usually with some of
• 5:52 these, I just eventually kind of throw in the towel and say, "You know what? This is good enough. It's not an obvious lens flare in the middle, like a hotspot looks like, so I'm going to let it go." So you've kind of got to use your judgment on how much effort to put into these things. So this next image, another outdoor image
• 6:08 with a lot of sky in the image. So we have here another shot of the pier. In this image, there is a little bit of a hotspot in the center. So let's turn on my mask so we can see what this looks like. I just have... that's the only mask in this image is actually to correct this one hotspot. And so if I roll over it, you can
• 6:26 see the size. It's actually pretty small. And if I disable it, you might be able to see the effect of the mask. And this one's a little harder to see because it's mainly a discoloration of this center spot here. So let me re-enable this. Let me turn on this sort of mask visualizer that I have here and this cranks up the
• 6:45 saturation. And let's see if I have dehaze on it. I didn't have dehaze on on this one. I could turn up the dehaze and see what the result is. And now if I turn off this mask, now you could see that hotspot appearing in the center. So let me turn it back on. And let's turn this off and see what the corrections that I
• 7:04 made are. So let's look at this hotspot. And the corrections that you have for hotspots are typically going to fall into a very limited number of categories. Typically exposure. So I might make a very small adjustment to exposure. You can see this adjustment is very small. And then the other one is going to be color,
• 7:21 temp, and tint. And this is where turning the saturation up all the way. Let me turn off the dehaze because I don't need all the dehaze in this one. So now I just have an overly saturated image. And if I go back into my hotspot, what you'll notice is that now with this heavy saturation, if I make adjustments to the temp,
• 7:42 now I'm getting too blue, too cyan. If I go back in the other way, I'm going to get too orange. This will allow me this high saturation will allow me to dial in the very precise amount of adjustment that I need for this particular image. In this case, I think it was at 10 was my original value. If you're not sure, you could
• 8:01 just type in values. So you could say type in five and hit enter. And then you could type in 10 and hit enter and make very fine adjustments. If it's hard to do with your mouse, so you can get those adjustments that you need. You can do the same with tint. So what I'm typically doing in a hotspot is I'm trying to draw a
• 8:18 radial gradient with my mask that matches the size and the shape of the hotspot. And then I'm going to make these fine tuned adjustments, typically exposure and then the color temperature, sometimes saturation, but mostly it's going to be exposure and color temperature that I'm adjusting. All right, let me turn off my
• 8:36 visualizer mask and go back to normal. This was a very desaturated image. The look that I was going for sometimes if you've kicked on this high saturation to try to hone in in your hotspots, you might have to step away from your image for a bit to come back and see if it looks good because that saturation is going to be very
• 8:52 jarring. All right, let's move on to our third image. This is another image with lots of sky and a little bit of lake here in the middle. And let us turn on the visualizer that I've created here. And these visualizers, they're very easy to create. Let me create another one just to show you how if I shrink my image down so
• 9:13 that I can see around the edge, you can see that this is a linear gradient that appears. In fact, if I just delete this mask, let me delete mask one and I'll recreate it so we can see how it works. So I'll create a new mask, select linear gradient. All right, I'm going to hold down the shift key while I drag away from
• 9:32 the image. That'll make sure my line stays straight. And basically I'm applying a mask that's going to cover the entire image. That's the intent of what I'm doing here. And once I've done that, then I can kick up the saturation all the way if I need to, or I could kick up the dehaze if I wanted to. In this particular image, I
• 9:48 just need saturation. And you can see everything looks pretty good here. But if I remove this hotspot layer that I've created, then we've got a very bright spot. Let me turn it off. And now we have a very bright spot that appears in the center of this image. Let me turn it back on. So it's very much more level in the
• 10:09 center. I turn it off. Now we have a much brighter spot in the center. So this hotspot isn't so concentrated. It's a little bit more broad. And if I look at the details of this hotspot, you can see the size of it there. I'm making a rather large adjustment for exposure, which is typically the adjustments that I'm making
• 10:25 tend to be negative 0.2 to 0.2 or smaller. This one's a little bit bigger than that. And I've made a black adjustment well because I'm trying to match the water because the water is much darker and I wanted that to match as well. And then of course color temperature that I'm adjusting here. So each one of these is going to
• 10:42 be sometimes a little bit different, especially in a lens like this where the hotspots appear infrequently. You're not going to be able to maybe create a single hotspot corrector. You've noticed that each one of these is a little bit different because it depends on the lighting conditions. All right. Let's move on to the
• 11:00 final image. This will be yet another image with a lot of sky. And if I go back to full size, this one was particularly tricky. We had hotspots in the center that kind of cut across these clouds. So this was very difficult to deal with. If I look at the first hotspot, let me get rid of both of these first.
• 11:19 And you'll see it a little bit better over here on the side. You could see a kind of a hotspot here in the center. Sometimes when I have these small concentric ones, I will build up. I'll gradually start from the broader ones on the outside and then I'll work inward. So this first hotspot was a broader circle to try to address this
• 11:36 a little bit. And this reduced the exposure, a very small tweak to the color temperature and a very small tweak to saturation. And then a second hotspot adjustment, which just tweaked that a little bit more, a little bit more narrow. So a tighter circle to address these. This might be the style that you would expect if
• 11:56 you had a consistent hotspot that was appearing from image to image across lenses. I've seen this type of fix work regularly to address that. So creating two concentric rings that address the different levels of severity of the hotspot and getting those kind of honed in to the point where you need to be. If you wanted to
• 12:15 build a tool to look at the saturation and have an impact, I could go to create a mask, linear gradient, hold down my shift key, drag up. That fills up the whole image with the mask. And now I can take the saturation all the way up and I can take the dehaze all the way up. And now let's see what happens. This one's very
• 12:38 dark. So the dehaze might be too much on this one. Let me take the dehaze off, go back to zero on that. So we're just doing a saturation. Now let me turn these hotspots off and we'll see what this looks like, what this image looked like before. Now in this one, you could be forgiven of thinking that this was just
• 12:56 something in the clouds. But after I looked at it enough, I'm like, nope, this is not just a little round bump in the clouds. This is a hotspot. And so by adding in these two adjustments, I just sort of diminished the effect so that the result was that it would blend in better. You can still see a little bit of the outline when I
• 13:13 have the saturation turned up. But when I turn the saturation back off, then it blends in nicely. I suppose if I look really closely, I could see the faint hair of an outline here, right around here. And if I wanted to address that, then I could just go in to this hotspot and start to tweak the feather and get that to address
• 13:32 that a little bit. And then until I get that to go away. So a lot of fiddling that has to happen when you're working with hotspots. This is why it's still recommended to avoid these. But again, with this particular lens, I've been able to get a lot of great shots with a very nice, lightweight, affordable lens. That gives me more
• 13:52 flexibility than a prime. But the downside is, is that occasionally I'm going to have to correct some of these images to fix the hotspots. What is your approach to hotspots? Let us know in the comments. If you find these videos helpful on your infrared photography journey, like, subscribe, or comment. Hope you enjoyed. Thanks.