Photoshop Imaging for Britmodellers

[TheBaron]

Hello everyone.

I thought the best way to start this series of occasional pieces is to review some of the basics that go into the image-making process, in terms of preparing good quality sources. We all want that final RFI to look its best, and sometimes just a few tweaks here and there can make all the difference.

Cameras

Nowadays of course, you can take perfectly acceptable general photos on your phone without investing in any heavy kit. It’s important to be aware however of certain limitations (dependent partly on your make of phone, and partly on the camera app you are using), particularly in areas such as depth-of-field. A standalone camera, or indeed a DSLR, will by their nature, give a greater range of controls, and/or quality of the final image.

The following photographic items should be present on both a camera and (excluding depth-of-field) a decent smartphone. These will allow you to control the image much better than the results from relying on ‘auto’ settings.

1. White balance. (WB) If you’ve ever taken a photo that came out too yellow or too blue, it’s usually because the white balance (WB) is set wrongly. Search for ‘white balance examples’ in Google images and you’ll get the idea immediately. You’ll generally see the control for this function referred to on menu items as ‘WB’. White balancing is simply a process of setting the camera to record the scene as accurately as possible, based on the colour temperature of the light source. This isn’t as complicated as it sounds. All light sources, such as the sun, a light bulb etc. peak in particular parts of the visible spectrum. You can see a simple representation of these values here: http://www.techradar.com/how-to/photography-video-capture/cameras/what-is-color-temperature-free-photography-cheat-sheet-1320923 On many apps and cameras you’ll see these different kinds of light represented by a graphical and easy-to-use symbol eg. a sun for bright daylight, a light bulb for tungsten light, and so forth. (Your manual should have a listing of all of those available to you). All you need to do is choose whichever one of these WB presets matches the light source you are shooting with. Although this isn’t as accurate as taking a metered light reading in Kelvins, it should produce acceptable results. It goes without saying that you shouldn’t shoot with mixed light sources. You’ll notice in some of the bench shots that I post, regions like shadows occasionally have a bluish cast: this is because I’m photographing under a tungsten light at the bench, and there’s still some daylight coming through the window. That’s ok for a WIP, you wouldn’t want that in an RFI…
2. Exposure. Many cameras and smartphones automatically work out exposure by ‘averaging’ the scene, in order to produce an image that attempts to mimic what your eye sees. In certain circumstances however, such as shooting your model in a lighting booth, an ‘average’ of the scene means your bright booth may come out perfectly exposed, but your beautiful model is much darker than in the flesh, with all your beautifully accurate paint scheme and detailing now visually compromised. This is the same problem you find shooting a photo of somebody in front of a bright window - they come out as a silhouette. You need to expose for the subject you are interested in, not for the whole scene. If your camera or app allows, take a controlled exposure reading from the model itself, or if your camera/app doesn’t allow this, but you can just manually increase the exposure by a stop or two to let more light in, then you should achieve a more acceptable reproduction. Another effect of this procedure is that with the booth being potentially over-exposed, any shadows or folds in the surrounding material of it should be rendered less visible. Again, check the manual for your specific device/software as to where these exposure controls are located.
3. Aperture and Depth-of-Field. This can also dramatically enhance your RFI shots. ‘Depth-of-Field’ is simply that region of the image that is in focus. Think of Hollywood cinematography in the 20s and 30s and all those close-ups of actresses’ faces - the out-of-focus background makes you focus more attentively on the subject. Smartphone users are limited by their hardware due to the small lenses used to construct cameraphones, but a decent camera or DSLR will enable you to change the aperture. The aperture is also sometimes referred to as the iris, and is measured in ‘f-stops’ (2.8, 5.6, and so forth). The smaller the number of an aperture, the smaller the depth of field, and the more light it lets in. So f11 will have far more in focus than f5.6, for example.
4. Image formats. Most smartphones and many cameras will store your image in JPEG format. Whilst this lets you store lots of images, the downside is that the JPEG format is what’s known as a ‘lossy’ compression routine for images. If used over an over on the same image it will eventually start to compromise the quality of the image (think of the days of recording sound on audio cassettes – each generation of copying had more and more tape hiss). If you’ve no option but to use JPEG in the first instance, check that you have it set to store images in the highest possible quality (sometimes indicated as an ‘H’ i.e., high-quality, symbol). If your camera lets you use the RAW format, this is the more professional choice, but requires extra processing. Don’t panic over this if you only have JPEG as an option however – for posting work online, if you use the highest quality settings on the slider when saving your JPEG image, you can do this 2 or 3 times before you may start to see any problems occurring. Print media however are more unforgiving due to the higher resolutions involved. If you are going to be working in Photoshop, save your work in either TIFF or PSD formats, which do not incur any ‘lossy’ algorithms to be used when storing them. Remember though at the end, you’ll need to turn your image back into a JPEG or PNG file to post it on the web for the adoration of fellow modellers.
5. Image size and Resolution. It is perhaps self-evident, but your initial photographs should be taken at the biggest frame size your camera allows. You can always make these smaller later, but give yourself the maximum scope and quality to start off with. Image size is measured in two ways, but nothing complicated. For screen-based work (web, video, film etc.) you always talk about image frame size in terms of pixels as the unit of measurement, e.g. an image is said to be ‘x’ pixels wide by ‘y’ pixels high. For image-printing, we use imperial/metric values to describe the size of the image (think of the traditional 6”x4”, 10”x8” values of photographic prints), but in addition, need to be aware of image Resolution. Resolution is also related to size, and sometimes confuses people. In simple terms it is simply the maximum amount of detail for a given area of the image, and is referred to for print media as ‘dpi’, or ‘dots-per-inch’. For example, a photo in a newspaper may be printed at 100dpi, and not look terribly good when looked at closely, whereas a glossy photograph in an art gallery may be at 1200dpi and look good even close-to. This is because the latter image has more detail than the former. For electronic screen-based media, like WWW, video and film, resolution is less important than getting the frame size correct, e.g. for an image to fill a widescreen video picture it has to be 1920x1080 pixels in size. For posting your images to the web therefore, you’ll always be going on frame size; if printing them out, you’ll also need to pay attention to resolution.
6. Aspect ratio (AR) can be found as a setting on many cameras & cameraphones, especially where they shoot video as well as stills. Don’t panic! When you find yourself confronted with an ‘AR’ setting, this stands for ‘aspect ratio’, and quite simply describes the relationship of width-to-height of a given image. You’ve probably seen in your TV manual that your TV has a widescreen 16:9 option. 16:9 is the aspect ratio of your screen in this instance, 16 units wide for every 9 high (in the same way that older, squarer televisions were 4:3). Which one do you pick? Well if want to shoot widescreen video of course, choose 16:9. For general stills photography, depending on the values your camera allows, you might want to use 4:3 for a squarer image, e.g. for a tank, or 16:9 for a wider, landscape kind of shot to get the full span of a B-29s wings in the frame. Remember you can always crop an image in Photoshop later if it’s not exactly right.

For the next instalment I'll look at compositing images of your model against actual photographs. Please feel free to add any feedback as this goes along

Tony

Edited May 27, 2016 by TheBaron

[jenko]

In have a feeling that this will be a definitive article on modern day photography "for dummies". Simple straight forward and in plain English.

Nice one Tony.

Dick

[dubster72]

Nice! A simple guide to getting the best out of one's photography

Perhaps a future instalment could cover backgrounds? I've found that different colour backgrounds dramatically affect the look of a photo.

Cheers

Patrick

[TheBaron]

In have a feeling that this will be a definitive article on modern day photography "for dummies". Simple straight forward and in plain English.

Nice one Tony.

Dick

Thanks Dick. I'll try and maintain that tone in future articles

Nice! A simple guide to getting the best out of one's photography

Perhaps a future instalment could cover backgrounds? I've found that different colour backgrounds dramatically affect the look of a photo.

Cheers

Patrick

Thanks Patrick - I'll get an article together for next week that deals with compositing aircraft onto photos: the same technique can be used to put it onto coloured backgrounds as well - was this what you meant?

Tony

Edited May 27, 2016 by TheBaron

[Admiral Puff]

Thanks, Tony. This is the kind of "idiot's guide" I've been looking for for years.

[TheBaron]

Pt.2 Organizing photos of your model for compositing in Photoshop

The following tutorial is intended for those of you who wanted to know how to composite photos of your model against a different background to the one you took the shot against. There could be a number of reasons for this: for example, you might want to put it into a historical photograph, either of a specific location or alongside the original aircraft type on which you based your build, or as somebody else has asked, simply to put your aircraft into a differently coloured background.

In any of these cases, there are specific selection tools and processes that you can use in Photoshop, however, the purpose of this instalment is to help you become aware of some of the common problems that you need to address if things like lighting, colour etc. are not to end up looking odd or contradictory between your model, and the background into which you choose to place it. Suppose we look at some examples:

1. Contemporary photographs:

_{Image source: Wikipedia}

If we were intending to put our own model into this image environment (I'm using aircraft examples, but of course ships, AFV's etc. all face identical problems), we can immediately see a number of issues that we have to be very clear about, long before we take a single shot of our own model.

Look carefully at this image. What is happening with light in it? What time of day does it seem to be in terms of the height of the sun? What direction is the sun shining from within the frame? Our own model would need to be lit in an identical fashion in terms of sun angle and direction if it is to match this photo - otherwise it will simply look visually 'wrong' because the mismatch in lighting will contradict the visual unity of the scene.

We can tell from things like the direction in which shadows are being cast that the sun is shining from the right of the frame, whilst the low angle picking out ground detail and texture indicates this is either an early morning/early evening shot. So if you usually use a photobooth for example to document your work, your usual lighting setup may not be accurate. Note the kind of light in the shot above as well: we have a slightly yellowed sunlight coming from the right, whilst the shadows on lighter regions like the building are very blue, due to the luminosity of the colour sky acting as a 'fill' light. So you may want to use two lights instead of your usual three, with a blue fill light in place of your usual white one.

What about the camera angle in this photo as well? This is extremely important in terms of perspective - we will need to photograph our own model to match the perspective in this scene. Here we can see that the camera appears to be pointing straight ahead, but note that the shot is taken with a wide-angle lens. How can we tell this ? Well, look carefully at the bowed distortion in the telegraph pole on the left, plus the large area of ground inclining towards us in the bottom of the frame. In a narrower field of view we wouldn't see such distortion, or indeed so much of the foreground.

Given that there is so much we have to look at before shooting our model, is this procedure very complicated? Well, not really. If you think about it all we did was look carefully at the photo to work out what we had to take care of in terms of lighting and camera angle in our own shot. Don't be intimidated because you're not necessarily used to doing such exercises - you make such comparisons every day with your own eyes, it's just that now you have to be more deliberately conscious of looking at the world.

To summarize:

What direction is light shining from?

What height is the light?

What angle is the camera pointing? (i.e., how is perspective working in the shot)

If you can answer these three questions, you are ready to take a photo of your model. You may not get it right at first, but practice will rapidly hone your visual abilities.

2. Historical photographs:

All of the the above issues that we have just looked at need to be taken care of here as well, but with older, non-digital photographs, we have additional matters that we need to consider.

Image source: Wikipedia

You immediately see the problem. Not only do we have to match the ground plane (perspective) and lighting in this shot, but we are also dealing with older film stock. As well as light and space, we also have to look at aesthetic issues.

Look at the photo again. It's not very sharp is it? Probably this is the result of either being a print from a small negative to begin with, or simply a scan of a lower quality photograph. Either way we are not dealing with pin-sharp digital images. Also of course, being a photochemical image, we are also contending with the visual textures produced by film grain in the original negative. If we take our sharp digital photo of our model and composite it in here, even if we get the lighting angle and perspective correct, we still need to pay attention to graininess and lack of sharpness in Photoshop. Also, look at the shadow of the aircraft. Our own model will need to have a convincing shadow also.

In terms of being able to take your model out of its original photographic context and place it into such backgrounds, there are a number of ways we can do this: either shooting it against a plain coloured background (much like green screen in filmmaking), or shooting it against an uncluttered background. I'll explain in the next instalment the pros and cons of such procedures.

After that's done, I'll post up the first Photoshop demonstration the form of a tutorial video, so that you can refer to it whilst you are trying out some of the software techniques we'll be covering. Before we start such processes, it's important in order to achieve good results that you are aware of the issues we looked at above first.

Finally, something necessary to flag up here of course is copyright: if you are using public domain images to display your work online there should be no issues (though still credit the original source), but if the work is clearly copyrighted by an individual or company you can run into legal issues if you reproduce such images online. Even just saying where you got the image from is not enough: unless the person or company has given you express permission to use the image, even for non-commercial purposes, don't post it. This is only reasonable if you imagine your own feelings at someone else purloining your photography.

Tony

Edited June 1, 2016 by TheBaron