Strobe Lighting

Photographing Roses against a white Background

Photographing Roses

A Rose by Any Other Name

I hadn’t started out to do a studio flash session photographing roses, but on thinking about what background colour would suit a white and pink rose, I realized that it had to be bright white and not grey, so the available window light session that I had planned quickly turned into something else entirely.

Photographing Roses Against a White Background

Img1141-EditPhotographing roses against a white background requires the same technique as for photographing a portrait, or anything else, against a white background. The background has to blown-out, but only just blown out, in order to avoid too much flare and contrast reduction from the resultant backlight. People sometimes talk about getting the background about 2-stops hotter than the foreground, which is another way to go, but I treat the background (which, by the way, needn’t itself be white!) like I would treat a snow scene. I will take a couple of shots with just the background lit, and increase the exposure, from metered, up a couple of stops or so, until it is just blown out. I will then turn the back-lights off and use the main light to get an exposure for the subject. For this shoot, I used 3 x SB900 strobes. 2 for the background, either side at 45 degrees, and one in a Lastolite Joe McNally Ezybox Hotshoe for the main light. I prefer to shoot manual as much as possible these days, so the Camera was set to 1/200 second at f11, ISO 200. The lens was a 105 mm Micro Nikkor on a D3, and I used 2 layers of diffusion in the softbox. All 3 flashes were set on manual, and the amount adjusted for correct exposure. I like this setup because nothing changes (except perhaps the ambient light), so all your shots are perfectly exposed and provided your strobes aren’t maxed out (1/1) you can take a small burst of shots if you need to, for instance with a moving subject.

Focus Stacking

Photographing Roses with a Manfrotto 454Photographing roses with a macro lens, close up, can lead you into problems with depth of field. This is often livable with, particularly if your shot includes quite a bit of stem and you are further back, but close-in you will have to make a decision about where to focus. I had just been reminded of the possibility of using focus-stacking in an article in Am Phog (Saturday 6th April 2013, Martin Evening’s Retouchers’ Guide), so thought I would give it a go here. By the way, Martin Evening’s books, ‘Adobe Photoshop for Photographers’, ‘The Ultimate Workshop’ and ‘Photoshop Lightroom’ are all very useful tomes if you get a chance to read them.

Focus stacking is often used in macro photography, especially for extreme close-ups of things like small insects. It is often not straightforward, however, and there are several gotcha’s to be aware of. It is best to use an uncluttered plain background because as the lens elements move, the relationship of the subject to the background can change, making the blend between layers harder to do manually (or trick the software and end up with a small areas of blur that really stand out). Having a lens that focusses internally helps (but doesn’t avoid the problem completely), and sometimes you get a better result by using something like a Manfrotto 454 Micro Positioning Plate. What this does is allows you to slide the camera and lens combination backwards and forwards by very small amounts using a thumb-screw. This can be much easier for small focus adjustments when you are very close in and the depth-of-field is only a millimeter or so, where the lens’s own focus ring gives too course an adjustment.

Photographing Roses Focus StackingPhotographing Roses, Align Layers DialogFor good focus stacking it is said to be best to use an aperture that represents the sharpest focus of the lens, which on my 105 is f8 or f11), in order to avoid diffraction effects. There are several good focus stacking software programs available, but I use Photoshop because I don’t do this very often and a bespoke software solution has not seemed warranted. The process is quite straightforward. Take a series of photographs (in this case of your roses) starting at the foremost focus point, working through to the rearmost focus point. Select the files in Bridge or Lightroom, then using the tools menu choose Photoshop –> Load Files into Photoshop Layers, or in Lightroom, right-click on the selected files and go to Edit In –> Open in Layers in Photoshop… Once the files are in a single Photoshop document. Select the layers and go to the Edit menu and choose ‘Auto Align Layers…’ using the Auto Projection method.

Photographing Roses, Blend Layers DialogThe next step is to merge the layered images together. Go to the Edit menu and select ‘Auto-Blend layers’ making sure that the Stack Images button is set and the Seamless Tones and Colours also checked. From then on it’s just a matter of clicking Ok and waiting a while. As I have mentioned, you may not get perfect results and, for this reason, you may want to manually select appropriate images, stack them, and blend them manually yourself. This is not for the feint-hearted, but does give you a great-deal of control over the final result and this is what I did here. I suspect, but have not checked out myself, that it makes a difference to Photoshop that the images are in depth-of-focus stacking order, rather than in a random order. Sometimes you get a really excellent result, other times less so. At the point of capture it is not always clear which bits of an image are at which depth, so you can end up going backwards and forwards a bit.

Until next time,

R.

Drop Collision Photography, Paddling About in the Water of…

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The Machinery for Drop Collision Photography

Drop Collision Photography

Splash Art Kit Mk II

First off, I was alerted to this new drop-image possibility by a review in Amateur Photographer (January 26th edition). The kit in question is the SplashArt Kit Mark II, manufactured by High Speed photography Ltd, 31 Roebuck Lane, Buckhurst Hill, Essex IG9 5QN. Their website is www.phototrigger.co.uk. Tel: 07905 836280. My pal Geoff was similarly taken and, without further ado, purchased said item and brought it round for a test shoot for which I supplied the set and the lighting.

There are 4 dials on the control box, with line markers but no scale markings or labeling,  so it all seems like guesswork to start with. From left to right (and top to bottom) the dials control; the size of the first drop, the time delay between drops, the size of the second drop and the camera delay adjustment. There is a small micro-switch that  controls the mode (1 drop, 2 drops or 3) and is responsible for firing off a round of drops and triggering your camera. As others before me have said, the apparatus is reminiscent of the retort stands we used to have in school chemistry lessons with an additional gizmo attachment at the end. The drop container looks like a small sandwich box of the type popular in supermarkets now, though this does not impede its functionality. Un-clipping the top to add colourants to the drop mixture will move the retort stand however, so you will need to refocus if you do.

For lighting the drop collision photography I used 2-3 SB900 strobes set to 1/128 power fired through a translucent (clear) plastic A4 ring binder cover (with the ring binder removed) to backlight the drops. I would have liked to use a translucent plastic sheet similar to those used on light-boxes or x-ray viewers, but I did not have time to source this for our shoot. I angled both strobes at 45 degrees, to begin with, both at the same height. I quickly realized that a diagonal spread of light would be better so moved one of the lights onto a light stand.

The Technique

Drop Collision Photography

Setting up the Focus Point

In order to start our drop collision photography, we set the SplashArt kit to 1 drop mode to find the focusing point. First time out I used the knife-edge method, but I have now found a better way. I used the dual threaded spigot that comes with my flash brackets. It has a thread each end and is shaped like a small metal reel. It is reversible so that it can be attached to two sizes of thread and then acts as the spigot that you clamp your bracket onto in the same way that you would use the top of a formal light-stand. I placed this in the drip tray and fired off a series of drops adjusting the position each time until the drops fell inside the small threaded end. This works much better because you don’t need a second person to hold it still whilst you focus and can get a more accurate result. When using a macro lens it is quite difficult to get the whole splash in focus, and this way you know where the front and back of the drip will fall, so you can focus on the front edge, back edge or in between according to what you prefer to be most sharp. As you can see, this drop was slightly to the right of the threaded hole at this point (greater splash to the right). It was also a 2 drop scenario because we hadn’t yet switched the SplashArt kit to single drop mode. You will notice that the drop is red colored. We didn’t start off this way, we began with clear water in the tray and the dropper, but this shot from later on in the shoot was necessary to reposition the camera focus following moving the drip container in the process of putting pink food colouring into the top and stirring it.

The next logical step was get a feel for where the drops fell in the two drop mode and how much camera delay would be required to get a pit, crown, or a pole.

Drop Collision Photography

Pit

Drop Collision Photography

Crown

Drop Collision Photography

Pole

 

 

 

 

 

 

 

 

 

Once this is done, the next step is to control the spacing between drops so that there is a collision. The size of the drops that collide seems important and I think that similar settings on the dials for the first and second drops (first and third dials) helped me get a satisfactory result with the SplashArt Kit. The sign that you are approaching the correct timing between the drops is when you start to see some action at the tip of the pole, for example:

Drop Collision Photography

Finding the Collision Point

Drop Collision Photography

Repeatability

Once this point is reached a smaller further closing of the gap between drops may be necessary, and thereafter just plenty of trials, until you get some attractive results. All the shots you see here in the slide show were made first time out with the SplashArt Kit Mark II. One session of 4 hours or so got us all these shots (minus a coffee and brief lunch break of course). There is a lot of variability between shots. I don’t know whether this is because the timer cannot perfectly control the drip valve, or whether there are timing issues with the flash. My SB900 strobes, as usual, were fired using my trusty Flex Mini TT1 with AC3 controller and TT5 trigger combination. This gives on-camera control of the distant flash which makes for less walking round the studio (kitchen) and speeds things up a little. I suspect that there is no particular issue with the flash timings (but can’t completely rule it out) as at no point do I see a double drop image which means that both flashes trigger at the same time. Not bad when the flash duration is 1/38500 of a second!!

More on the Lighting

As you can see from the slide show, and the production images, I have used a selection of coloured gels on the strobes along with changing up the position of the strobes relative to the translucent plastic background. I must admit that my selection of gels is a bit limited, but the combinations were:

  • White on White
  • CTO (orange) on White
  • CTO on Blue
  • CTO on Red

I have also got green gels (to colour match for flourescent lights) which might also have looked good but I didn’t think to try. Needless to say there are a couple of approaches to white balance settings in this situation. You can use tungsten or cloudy settings for, instance, to produce a uniform rich yellow or blue colour. Alternatively, as I did here, you can use the preset flash white balance to produce an overal neutral result but then gel the flashes to produce the colours. This is my preferred approach because, although it requires multiple strobes, you do get greater flexibility.

It would be possible to set up a single coloured, or patterned multicoloured (perhaps printed out on a home inkjet printer), background, and reverse light that to get similar results to the multi-strobe effect.

For water drop collision images you do really need to backlight. For milk images you can front light, and for the closeups you see in the slide show this was really necessary to counter some of the shadows produced by side lighting. In fact I ended up using three strobes. A single backlight and two front lights. The front lights were camera right at 45 degrees and camera left at 45 degrees but much higher up to light into the extensive crowns. We might have been ok with a single front strobe placed centrally and above the camera in order to throw the shadows behind the splash.

More on the Fluids

Since my first attempt at drop collision photography, I have been reading Corrie White’s Comprehensive Water Drop Photography Guide. You will find a lot more detail on what you might do to water to thicken it, and some further tips on lighting milk etc. What I have realized is that it is easier to get spectacular crowns, and some really interesting graphic shapes, using the thicker substrate of milk, than it is with water. In fact, as Corrie points out, there are some things that you just can’t do with water alone. Clearly thickening water with sugar or guar gum also has side-effects to the look of the resulting solutions, so sticking with plain water is probably best. Nevertheless the old school physics fact that water is densest at 4 degrees centigrade is worth knowing and using here. So next time I will definitely try using very cold water and placing some ice cubes in the drip dispenser and into the drip tray.

Colourings

We only had red food colouring at our disposal this time out. Clearly there are many others that you could purchase fairly cheaply. I have heard that some people use printer inks, but this may be quite expensive. Red looks great in contrast to the white milk. One tip for the milk shots using coloured drops, you need to stir the drip tray in between trials to whiten up the milk again. You could also put colouring into the drip tray and experiment with the two colours mixing together in the drip stem. I really do think that you are limited only by your creativity.

Things to Try

  • I really fancy having a go at splashes inside bubbles. Wow. Can’t wait.
  • Splashes where the drip container is a crystal glass, or similar, and can be seen in the shot.
  • Odd looking colour combinations.
  • Several splashes composited into the same shot.

Until next time,

Robin.

(Dipping my Toe in the) Water Drop Photography

Context

Water Drop Photography

A Single Drop…

I’ve seen a lot of fantastic drop collision photographs recently, both on the net and in magazines. It seems clear that there are at least two levels of water drop photography, the random ‘hit and hope’ style of droplet photography (without the collisions) and the more engineered droplet collision photographs made with the assistance of some complicated electronic hydraulic systems. Markus Reugals is perhaps the grand  father of the more technical approach, and another fine water drop artist is Corrie White.

Having read a little about water drop photography, I decided to have a go at the hit and hope style which is much less technically demanding but more reliant on good timing and good luck. A little research indicated that I didn’t need too much equipment and if I was prepared to be patient I could still get some good results. All I needed was a plastic bag, some water, a drip tray, a small strobe, camera and tripod and I would be good to go. If I could throw in a coloured background in addition then the world was my oyster. The set-up would prove to be a little Heath-Robinson, but nonetheless effective for that. I knew that those nicknacks would come in helpful at some point, and if I was to consider purchasing some mechanical drop making machinary, I at least needed to know what other technical issues might arise.

Practicalities

Here’s how I went about it.

  • Firstly I set up a turkey basting tray on the surface in the kitchen.
  • Next I filled this with water and suspended a resealable sandwich bag filled with tap water about 35cm above.
  • I placed a pin hole in one of the sandwich bag corners, and let it drip into the basting tray at a steady rate.
  • Next I set up my flash heads. You need these to be very close to the water-drops to get good exposure because you want to use the lowest possible manual flash setting that your guns will provide. I used 3 Nikon SB900s on a Joe McNally Lastolite TriFlash, set to 1/128 power, though I could have got good results with just one flash head, albeit at a higher ISO. This gives me approximately 1/38500 of a second.
  • Then I set an A2 sheet of coloured cardboard against the wall behind the tray and aimed the flashes towards it. In this way the droplets were both side and backlit both by direct flash and a coloured wash of light from behind. Ideally you would shoot through an opaque perspex to both soften and spread the light. Coloured gels can then be used to create interesting colour wash in the background and on the water surface.
  • Finally I set up my D4 on a tripod with a 105mm Micro NikKor and focussed on the drops as they hit the water. To get better accuracy I placed a sharp knife blade in the exact position of the falling water droplets and focussed on that. You need to attach a remote release, and depending on the camera body and system you are using you may use the built-in light control or perhaps radio triggers. In this instance I used Flex tt5 radio triggers as the D4 does not have a built-in commander flash. Alternatively I could have used a separate flash gun to provide the remote control.

 

Water Drop Photography

Splash and Drop…

Then all you have to do to start your water drop photography is watch the drips fall, and fire a few test shots to get the correct exposure. Obviously you need to obliterate the ambient light with the combination of shutter and aperture (I was using 1/250th second and f11) in order to avoid any ghosting. Watch out for your highlights. There is a tension between too much specular highlight and detail in the drops and the general brightness of the pool. After an initial trial I found that I was having to shoot downwards at too steep an angle. To counter this I needed to shoot from further back so I hooked up my 2x teleconvertor to the 105mm and this gave an effective focal length of 210mm and a greater distance from the droplet.There is a further issue with the positioning of the water droplets. I found it more convenient to have drops fall towards the front of the drip tray in order to have the frame filled to the top by the pool in the background. Otherwise the edge of the tray might be visible. I wasn’t brave enough to shoot into a pool with a meniscus!! Secondly there is considerable variation in the exact landing spot of the drops wich can easily vary by 5mm or more front to back, making critical focus a bit of a lottery. The higher the water in the tray, the flatter you are able to keep your lens. There needs to be some angle to ensure that the background does not include the edge of the tray (unless you have a 6 foot drip tray that is). Nevertheless the variation in focus drop to drop is countered by taking a lot of shots. Once you get your eye in, you can improve your success rate substantially. I did end up taking 765 shots in all, but there was quite a lot of experimentation to get my final set up.

Photoshop Embellishments…

Water Drop Photography

Embellished Drop and Splash…

As lovely as this image was fresh out of the camera, it was crying out for that something extra to really make it pop. Looking carefully at the top of the splash column I could see that there was a specular flare highlight at the top. If I had used f16 or f22 this might have been substantial enough on its own, but in this instance it required a helping hand.I have used a few techniques here. First of all I created a starburst in Photoshop (white on a black background), and then I sized and placed it into position on a separate layer. Change the blend mode to screen to drop the blacks out and Robert is very definitely your mother’s brother!! Photoshop has a lens flare feature (Filter | Render | Lens flare) but how do you get this into your image? Again the trick is to create a new layer. Fill it with black. Create your lens flare on the black layer (I used the flare for a 105mm prime). Change the blend mode to screen, reposition and set the opacity to taste to finish.

Sharpening is another interesting issue. If your droplet shot lacks that critical crispness, and quite a few will do, one way to counter this is to use octave sharpening. I first learned about this technique in a book by Lee Varis called Skin. The edition of the book that I have was published by Sybex in 2006. The book claims to be the complete guide to digitally lighting, photographing and retouching faces and bodies, and it really does do a good job at this. There are a few useful sharpening techniques that I would recommend you check for yourselves but the octave sharpening routine has general applicability above and beyond portraiture. The point of the technique is that you use multiple sharpening layers (4 in this case) to minimize the visibility of wide halos. Unsharp mask values are set, in order, at radius 0.5px, 1.0px, 2.0px and 4.0px all at an amount of 500%. Each layer has a luminosity blend mode, and the opacity is set at 100%, 50%, 25% and 13% respectively.

Water Drop Photography

Starburst…

There are plenty of online tutorials on how to make a starburst. The basic technique is to start with a white line on a black background. Apply motion blur to the line to get a lovely fade effect on the ends, then copy, rotate and resize the line to get the final effect. If you save your creation you can use it again at any point where a convincing starburst is required. If you create a large starburst, you can reduce the size without loss of quality.Over the last few days I have been experimenting with an electro-mechanical dropper and can confirm that there will be a part 2 to this article. Wow!! Here’s a taster, until next time…

 

And For Next Time…

Water Drop Photography

Something for the Future…

 

 

 

 

 

 

 

 

 

 

Cheers for now,

Robin.