rodeo_joe1

<p>Use an empty (and washed) plastic milk container with a slot cut in it.<br> See this thread http://www.photo.net/nikon-camera-forum/00cCWO</p>

<p>Ellis, PWs are still only rated up to 300 Volts (or 50 Volts for the TTL versions), unlike any of the cheap wireless slaves you can buy off the internet, which are mostly rated at 400V. And neither the PWs nor cheapos will trigger a reverse polarity (firing pin negative) strobe. Maybe you were just lucky with the pack and component tolerances.</p> <p>I've had old kit from Bowens, that I now know puts out an O/C voltage of around 600 volts on the trigger socket, which fried a quite expensive transceiver type radio trigger. The real answer is to have the old flash kit modified to bring the trigger voltage down, and to have it fitted with a standard non-reversible jack socket on the trigger input.</p>

<blockquote> <p>"Along with the sensor's dynamic range, it records the unique variations of your digital camera, such as the effects of shutter speed and aperture mechanisms as well as the characteristics of the lens in use."</p> </blockquote> <p>That might be useful if you were dealing with a mechanical old relic from the film era, but it seems to me like a totally pointless exercise with a modern electronically controlled DSLR. Especially since you can only regulate the camera exposure to an accuracy of 1/3rd of a stop. No, I'll correct myself. You can actually govern the exposure to 1/6th of a stop by setting the ISO in half-stop steps and adjusting the aperture/shutter speed in 1/3rd stop steps. That's if you care to go to that amount of trouble. Even so, the reading you get from your light meter will probably vary more depending on exactly where you point it, than it ever would on any camera-dependant tiny tweak to its sensitivity.<br> Hype and BS multiplies exponentially by the second in this world.</p>

<p>LEDs for portrait photography? Did the guy try to sell you 19th century head-clamps and a posing chair too? Right, now that I've stopped ROFL.<br> Do NOT BUY LED lighting for portraits. It's far too weak in it's current state of the art, and only comes in panel form that can't be turned into a hard light, or snooted down easily for use as a hair light or kicker. Those panels also can't be used as a real softbox type source because they simply don't have the size or power. In short they're garbage for anything except video.</p> <p>"...high-end camera shop...the guy there was telling me about the new LED lights..." - You find fools in all walks of life.</p>

<p>Longitudinal Colour Aberrations (LoCA) are usually the result of what is called Spherochromatism. In other words the residual spherical aberration of the lens varies with light wavelength, making it impossible to bring all colours to the same focal plane. Since spherical aberration is very aperture dependent, it naturally diminishes as the lens is stopped down. The complex nature of the point-spread function of spherical aberration also means that there is a region where the colour fringes balance out and there is little apparent fringing. However, the SA is still there and exhibits itself as poor edge contrast, or maybe a slight halo effect.</p> <p>Before and after the best plane of focus the fringes will swap colour, from (usually) purple to the complementary green. And since it's an SA effect, its severity is often dependent on focusing distance as well. Lenses intended for portrait use <em>should</em> perform better at close range than at infinity - that's if the designer has done their job right.</p> <p>Sorry Andrew, but your theory of effective aperture changing with wavelength isn't correct. Except for a minute contribution to very high order aberrations. Even Apo lenses can't fully maintain one absolute focal length across the entire spectrum, but it's only the relative aperture number that changes, not the physical aperture. So there will be a difference in depth-of-field between red and blue rays, but the effect is absolutely insignificant compared to that of Spherochromatism.</p> <p>WRT that specific Sigma lens. All review pictures I've seen are less than impressive as far as LoCA is concerned, and coma as well.</p> <p>Just for comparison: Below is a quick snap of a rack of DVD sleeves, shot with the Samyang 85mm f/1.4 @ f/1.4 and at about 5 feet distance. It's close to a 100% crop - had to rescale it to fit the 700 pixel limit. Edit: D800 camera used.<br /> You can easily see the purple-red fringing before the plane of best focus turning to green-cyan beyond it.<br /> Incidentally, the much-maligned 85mm f/2 Ai-S Nikkor does much better in this respect at like-for-like apertures. However its in-focus definition isn't quite as good as that of the Samyang at wider apertures.</p> <p>P.S.Having just done this test I'm now drawn to preferring the little old Nikkor's rendering. Absolute sharpness ain't everything!</p><div></div>

<p>Oh well, if we're having fun it's the 8-800mm f/2 diffractive-micro-aspheric-Fresnel hybrid Apo Triple-Teslar with cryptochroic AR coating and utilising lightweight dilucium-propylacrylate and artificial diamond elements. Focusing and zooming are done by nanobot internal reconstruction (NIR) of the entire lens assembly. Due out in 2019 and costing a mere $30,000,000, which will be nothing when you take inflation into account. I hear that development is being held up because the speed of the AF system creates a mini sonic boom, and a special muffler system is having to be designed.</p>

<p>I'll never understand the attachment people have to these crappy old Vivitars. Even $40 is way overpriced for the functions they offer. No swivel head and having to swap modules between AA mode and manual power control!?</p> <p>Spend your 40 bucks on a new YongNuo or something similar. Landfill is where that old relic belongs.</p>

<blockquote> <p>"Is 200w x 2 sufficient for light tent use?"</p> </blockquote> <p>200 <em>Watts</em> - No! 200 <em>Watt-seconds</em> - more than enough.<br> Flash is rated in Watt-seconds, not plain Watts. Note the small "s" in the "200Ws" description denotes seconds, not a pluralisation.</p> <p>That kit looks plenty good enough for what you want to do Michael. Although you might want to add some black card or velvet to your shopping list in order to put some shaded outlining on your block of ice.<br> You also might want to make sure the modelling lights are turned off when firing that flash. 150 Watt halogen modelling lights are pretty bright and can add a slight yellow cast to the flash lighting. Especially since the flash power isn't automatically linked to the modelling lamp brightness.</p> <p>If you were going to be doing serious studio work with those flashes I'd say make sure they have a standard Bowens S speedring fitting, but that probably won't be important for what you want to do with them. The modifier fitting isn't mentioned in the advert you've linked to.</p>

<p>You'll have to narrow it down a bit Sam. Telephoto zoom, wideangle zoom, midrange, superzoom - what? There is no single lens that can be called "best", and even if there was there would be some variation from sample to sample in quality. Lenses that generally get very good reviews sometimes have poor quality control, and you may well get one that's poor to awful. This applies especially to cheaper 3rd party lenses. Even top-of-the range pro zooms have been known to have the odd "bad apple" in the bunch.</p> <p>You'll have to give us more of a clue as to your intended use (and budget) for the lens. But be prepared for much disagreement in the replies too!</p> <p>Edit: Sheesh Kyle! If the CA was bad enough to show on a portrait that must have been one dog of a lens. CA is usually only objectionable on high contrast sharp edges, and then only towards the edges of the frame. For an 85mm lens on a DX body that's just crazy.</p>

<p>I find it strange that almost nobody points out the depth-of-field implications of changing formats. Full-frame allows noticeably shallower D-o-F to be got for the same aperture, subject distance and subject size within the frame. Whereas DX allows greater D-o-F for macro and telephoto subjects. Admittedly the difference isn't <em>that</em> great, but it amounts to about the equivalent of one stop in aperture. So with an f/1.4 lens on FX you can get a shallow D-o-F that would require f/1 in a DX lens - with all the expense and loss of image quality that would go with an f/1 lens. But even a modest f/2.8 lens on FX will narrow the D-o-F to what would have required an expensive f/2 lens on DX - while keeping the better IQ you can expect by working at f/2.8 over f/2.</p> <p>IMHO, it's simply a case of "horses for courses", or picking the right tool for the job. Any job that demands high magnification of any sort would be better off shot on a smaller format; while shallow D-o-F or low light work is better done with a larger format. Why there are no dedicated bellows units available for the 4/3rds format I just can't fathom. If ever there was a format just crying out to be used for macro work....</p> <p>This "format wars" type of debate never raged in the film era, except among the most narrow-minded users. Most professionals had an armoury of 35mm, rollfilm and maybe a 5x4 technical camera at their disposal as a matter of course. The job dictated what was needed, or what provided the best solution. To be wedded to one format seems to be a very new idea to me.</p>

<p>Seems like a lot of money for a pretty standard softbox - big as it is.</p> <p>Let's see what its makers say it has going for it:<br /> "Soft, Flattering Light" - Yep, that's the whole point of a softbox.<br /> "Colorfast Material" - Is white a colour? Non-yellowing would be better.<br /> "UV Coating Eliminates Blue Cast" - Yeah right! Like a blue cast has ever been an issue with <em>any</em> softbox. A yellow cast maybe, and any UV coating needed should already be on the strobe tube.<br /> "Waterproof Material" - Like you're going to use a softbox in the rain with a strobe attached? Or stick the whole thing in the washing machine? The Polyester, Terylene or Nylon used in every softbox are all waterproof man-made fabrics anyway.<br /> "Aircraft Quality Duralumin Rods" - Duralumin isn't known for its springiness or bendiness. It worries me that such a material would take a set after a while and not tension the box properly. Use of carbon-fibre rods would be more impressive. In fact bamboo cane would impress me more as a choice of a lightweight springy material.<br /><br /> <br /> All the above (apart from the Duralumin) could be a list of features of any no-brand softbox at half the price or less. No mention of how good the stitching is, or whether there's any maker's warranty, or whether the rod pockets are deep and strong or simply bits of Velcro. No mention either of how the inner diffuser is suspended - thin elasticated material can perish quite quickly. What's the silvering like on the interior of the box? Will it go sticky and peel off if the box is kept rolled up? These are the things you really need to know about a softbox. Not some madey-uppy BS that could apply to almost any box ever made.</p> <p>Edit. The rim of the box doesn't look deep enough to prevent any sideways spill whatsoever. Nor does it look capable of supporting an egg-crate. If it won't take a skirt or egg crate easily then personally I wouldn't touch it.</p>

<blockquote> <p>"And, while we are at it, any other tips for doing a group demo on portrait shooting?"</p> </blockquote> <p>Hire or enlist a model or models (so that you can demonstrate both male and female poses and lighting) - don't rely on volunteers from the audience.</p> <p>Start simple with one single hard light to demonstrate the basic lighting patterns - Split, Loop, Rembrandt and Butterfly. Then bring in diffusers, reflectors, kickers/hairlights etc. Trying to start with a full 3 (or more) light setup is just going to confuse people.</p> <p>Make sure that the difference between hard and soft light is fully understood. A hard light with a low fill ratio is <em>not</em> the same as a soft light, and a soft light with deep shadows is still a soft light.</p>

<p>The major harm, IMO, is in how steeply cut all 3 filters are, with almost no overlap. As I mentioned before, if you photograph a continuous spectrum, or monochromator output, with any digital camera, you'll find great gaps in the spectrum in the yellow and cyan regions, with violet completely missing. This partly explains the problem you're having with the colour of bluebells Andrew. Some flowers have quite sharp spectral peaks - not obvious to the human eye, but attractive to bees and other insects no doubt. If the camera leaves holes in the spectrum, then how can you possibly expect good colour fidelity? It seems that all that matters these days is that the saturation is eye-wateringly high.</p> <p>Beside all that, the engineer in me hates seeing the waste of at least 25% of the light hitting the sensor. It must also vex semiconductor designers, who strive to coax ever more sensitivity and S/N out of smaller sensor sites, while a "simple" change of filtration could easily achieve the same end.</p>

<p>Firstly, make sure that you have the Nissin set to SD (Slave Digital) or Wireless Lighting mode. SF (Slave Film) will not work properly. SD mode may also be a bit temperamental, but Wireless Lighting slave mode should work reasonably well as long as there's not too much ambient light, or the flash from the camera isn't obscured from the Nissin in some way.</p> <p>If the above is followed: Does the Nissin fire at all apertures if fitted directly into the camera's hotshoe? If it does and assuming you're using Canon's optical wireless triggering system, then it might be that the on-camera flash doesn't deliver a strong enough triggering signal at smaller apertures. Why? I don't have the answer to that. Try placing the Nissin where it can't fail to pick up the camera's popup flash. Also, make sure that the popup flash itself is actually firing. If that doesn't go off, then there's no chance of the Nissin firing either.</p> <p>Edit. Remember you can swing the body of the flash (where the sensor is) to face the triggering camera, while the flash head is swung or tilted into an umbrella, or pointed towards the subject. This will make optical triggering more reliable. My experience with optical triggering however, is that it's quite unreliable if the triggering flash is behind the slave.</p> <p>If you're using manual mode and manual flash all the time, then you might want to consider using radio triggers. These are much more reliable than optical triggering and non-TTL versions can be got very cheaply.</p>

<p>Not sure it was noise that killed the CMY idea. Last time it was tried in a DSLR, AFAIK, was by Kodak in one of their Canon/Nikon DCS conversion jobs using a CCD sensor, and that's going back to the dawn of time in digital photography terms. The colour rendering was a bit weird to put it mildly, and saturation was pitiful. The noise thing might come from Kodak's rightful thinking that the ISO could be doubled by using such an array, so the camera tended to be used in situations where its contemporary Bayer competitors simply couldn't cut it. Any digital picture taken at 1600 ISO in them days was a marvel to behold, and naturally had "some" noise. But it was better than no picture at all from an RGB Bayer sensor.</p> <p>BTW, Just looked at the details of Fuji's X-trans sensor. Someone at Fuji obviously had too much cheese to eat before dreaming up that half-baked idea. I'm surprised it even got off the drawing board, being based on totally misguided ideas about aliasing effects. If you want that sort of pseudo randomness, then there are plenty of geometries based on simple triplets of triangular RGB sites, or on hexagons. Ones that don't multiply the redundant green filtering issue. Fuji seem to have been bashing their thick heads against the almost inconsequential "problem" of aliasing for some time now; and without trying the obvious thing of doing away with the quad stepping idea. Hey! Fuji, why not try grouping your sensor sites in <strong>threes</strong>, now there's one more radical (but less stupid) idea for you to try out.</p>

<p>Scrimping money on gear and offering a professional service to paying customers are two different and, IMHO, incompatible options. Remembering that uncle Joe among the wedding guests will most likely be carrying a D7000 and 3rd party 50-150 lens, or at least something similar. So as soon as someone mentions "wedding shoots", a tight budget shouldn't be the first consideration.</p> <p>To put yourself above the same league as uncle Joe you've got to show superior visual ability, have crowd handling and people skills, have better lighting equipment than simple on-camera flash (or apply it more skilfully) and in those situations where available light is called for, use a camera with lower noise/higher ISO capability. It's in the last area where FX wins and its better control over depth-of-field helps as well. It's down to you, Kyle, to decide which route to take, but pro photography isn't a cheap game to play.</p>

<p>I've done this with a D700 using the composite video out, the video-out automatically displays what the rear LCD screen of the camera is showing. Since there's no composite video output on the D810, the mini-HDMI connector performs the same function.</p> <p>If you care to read the D810 manual it tells you this on page 271 of the PDF version.<br> "When the camera is connected via an HDMI cable, HDMI displays can be used for live view photography and movie live view"</p>

<p>Hi Kyle. Yes, I'd suggest the 70-200mm as your next lens purchase. It's a must-have for formal portraits and weddings on FX.<br> Well, before I get blasted for saying that, obviously it's not the <em>only</em> lens that you can use for portraits and weddings, but it's basically the gold standard for that sort of work.</p> <p>WRT cameras. Build quality is a bit better on the D800/D810 than on the D610, plus the extra pixels in DX mode will squeeze slightly better IQ out of those DX lenses you've already got. It's your money to do with as you want Kyle, but if we're talking about investing in professional tools, then you should want to get the best you can afford - or hire.<br> See the D800 versus D810 thread below for some good advice on deciding which is more suitable. Personally the D800 does all I want and I have no plans to "upgrade" anytime soon. However frame rate might be an issue for you. Depends on your shooting style. Remembering that people were shooting weddings perfectly successfully on MF film not that long ago, with a frame rate of 2 FPS if you were lucky and quick on the winder knob - and with a "buffer size" of only 12 or 24 frames!</p>

<p>If you only have one camera body at the moment Kyle, then I'd leave paid wedding work alone, unless you go as second shooter or stringer. If you're going it alone then you really need a backup body. So if pro wedding and portrait work are your long term aim, then get a second body before anything else. If you get a D810, then you'll still be able to use your DX lenses on it with adequate resolution.</p> <p>A 50-150mm lens on DX roughly equates to a 70-200mm on FX, and while a kit of 24-70 and 70-200mm f/2.8 zooms will cover nearly everything in FX, they leave a gap at the wide end on DX. However, your 11-16mm on the D7000 will have that covered.</p> <p>I guess in summary I'm saying; don't buy a lens that's going to be redundant in the near future, if and when you go full-frame. Save your pennies for a 70-200mm f/2.8 pro quality zoom, which will do everything the 50-150mm would allow, since you already have the 50mm focal length. The Tamron 70-200mm f/2.8 VC lens is very nice. It's not that much more expensive than the Sigma 50-150, and quite a bit cheaper than Nikon's offering. Next on your shopping list though should be a second body, and whether you leap to full-frame or not this is a must for solo wedding coverage.</p>

<blockquote> <p>" I'd quite like to see an RGB pattern that didn't use the same RGB for different 2x2 blocks.."</p> </blockquote> <p>Exactly my reasoning for proposing CRBY as a filter matrix. Because the steep cut filtering is done only in the R & B sensors (except I'd also like to see the red sensor kick up at the violet end of the spectrum like the eye does), the cyan and yellow fill in any spectral gaps and the green channel must therefore have an absolutely complementary response.</p> <p>The processing would go something like (C - B) = G; (Y - R) = G'; (Y - G) = R'; (C - G') = B'. With a resulting data array of R + R'; B + B'; G + G'. Noise - being random - will tend to cancel with itself and yield a root2 improvement. But in any case a doubling of sensitivity/efficiency would automatically improve the S/N ratio.<br /> By crossing over the two extrapolated G & G' signals from their source sensors, there's no circularity in the colour subtraction and at each "pixel" step you get a different rendering. Thus we keep the steep filter cut that gives good saturation, while losing nothing down the gaps.</p> <p>Having a "white" unfiltered site, as advocated by Kodak, is just asking for saturation to be reduced and doesn't yield much advantage in spectral response after the processing has been done. Any additional RGB information has to be circular in nature since any data derived from the unfiltered channel will always be referenced back to itself. I.e. (W - R - B) = G'; (W - G - B) = R'; (W - R - G) = B'. W being a constant in each of these derivations means that R', G' and B' cannot be used to derive further colour information. Beside this, the W sensor might easily become saturated before the R, G & B sites do.</p> <p>P.S. Anybody hoping to patent this CRBY idea should note that this constitutes prior public disclosure and this is now public domain intellectual property.</p>

<blockquote> <p>"Note that the eye is much more sensitive to green, so it makes some sense to have two green cells in the Bayer filter."</p> </blockquote> <p>Glen, I've heard this non-sequiter argument in favour of the ridiculous Bayer filtering time-and-time again. It does <em>not</em> make sense to have more green gathered than red or blue. What you're trying to present the eye with (ideally) is an exact 1:1 representation of the colours in front of the camera. To present the eye with more green than there is in reality, when it's already very sensitive to green, is just crazy. That's like trying to give a diabetic person more sugar because they're overly sensitive to it.</p> <p>The reasons for Bayer filtering are: (1) Ease of manufacturing geometry and (2) Image-processing laziness. The fact that a one sensor-site step in any direction yields the same RGGB quad makes processing dead easy, and the filters can be relatively easily manufactured on a square matrix. Those reasons are now probably mostly historic, since we have very powerful GPU power within the camera, and Fuji and Kodak have shown that both sensor geometries and filter colour can be made very flexible these days. Pity that Sony seems stuck in its ways.</p> <p>Personally I'd propose a CRBY matrix, which still yields the same quad in any direction and uses a square geometry, but gathers as much red and blue as it does green, increasing light conversion efficiency by almost 100%. Another advantage is that such an array would avoid the current situation whereby monochromatic colours can "fall down the gaps" between overly tight R, G and B filters. If you think this isn't a very real problem, just try to photograph a true spectrum with any Bayer-filtered digital camera - Oooh! Where's the yellow, cyan and violet gone?</p> <p>My proposed CRBY matrix would need a bit more processing, inasmuch as the B and R signals would need to be subtracted from the Cyan and Yellow, respectively, to yield a green channel and additional R and B signals, but most of that could be done at an analogue stage using simple opamp summing and subtraction.</p> <p>Edit: Andrew said - "I have some shots of me speaking at a conference under a very yellow light, and recovering the blue channel is quite tricky"<br /> A neat trick that I came across Andrew, is to layer the offending image with a layer of solid colour of complementary hue to the colour-cast. By using a layer blend option (can't remember which one offhand), the complementary colour is added to the cast and reduces it considerably. Because it's a digital addition there's much less posterisation effect and much less damage done to the histogram.</p>

<p>Relax Andrew, it's never going to be as bad as the digital "dithering" that goes on with film's dye blobs randomly overlaying one another.</p> <p>Interesting though, and I find it a bit worrying that Nikon sees fit to bugger about with RAW data in such a way. (Why, oh why, don't camera designers get the analogue signal processed right <em>before</em> digitising it?)</p> <p>Of course, any white balance that isn't native to the sensor (i.e. not giving equal RGB effective exposure) is going to lose dynamic range in one way or another. It's just a question of where the lack of light is compensated for. If it's analogue compensated, then noise will be amplified in one or more channels; if digital then there's going to be some posterisation/quantization effect. If no in-camera compensation whatsoever is applied, then you'll do the damage yourself in post-processing. It's really a no-win situation - unless you care to carry a whole range of CC filters around and diligently stick the appropriate one(s) in front of the lens. Even then you're effectively lowering the ISO of the sensor to that of the channel receiving the least light. The dynamic range might be preserved, but at the expense of sensitivity.</p> <p>It might help if you imagine the dynamic range of each RGB channel as a fixed length of, say, cardboard and WB compensation as each of those strips of card being slid past each other. Now there's only one position where all three lengths of card can be accommodated together, and at other positions any bits of card overhanging the majority need to be chopped off to fit. OK, not a perfect metaphor, but I'm sure you get the idea.</p> <p>Edit: Just realised I haven't actually addressed your original question. It's my understanding that the "native" WB of most camera sensors is close to that of standard daylight (~6000K). However since every stupid Bayer filtered sensor is gathering twice as much green as is needed, that's also a moot point.</p>

<p>Before spending big money on Pocket Wizards, I'd buy a cheapo radio trigger kit. There's really no advantage to fancy transceiver designs if all you want to do is simply fire a flash from a few feet away. Plus, nearly all triggers, cheap or expensive, have a maximum rating of 400v across the trigger circuit. If you blow a $20 Chinese-made trigger you'll be a bit p*ssed off, but not as much as if you fried a $300 PW.</p> <p>Oh, yes; make sure you get the sync lead the right way round. No modern trigger will fire a negative polarity synch. In other words the "ground" of the trigger needs to be negative and the firing pin needs to be positive. I've had good luck with these cheap iShoot triggers: http://photoloving.com/index.php?route=product/product&path=59_61&product_id=136</p>

<p>Chances of getting the actual circuit from Bowens are slim, but inverter circuits are all pretty similar: An oscillator/chopper circuit followed by an HF transformer and PIN diode rectifier + regulator and one or more smoothing capacitors. There's usually feedback from the HT side to the LT side via an opto-coupler. A circuit diagram is almost useless for fault-finding purposes anyway.</p> <p>Not much to go wrong really. I'd suggest you start with the rectifier diodes and check them all out. Sometimes they're paired diodes in a single transistor-like package attached to a heatsink. Next suspect would be the opto-coupler. These little beggars will pop for no apparent reason. Thirdly I'd test the chopper transistors/FETs. After that, nearly all you're left with is the transformer, and if that's blown, then you're stuffed. Lately though, these things are (needlessly) being designed around an integrated controller/PWM oscillator. Again if that's gone, you might as well forget it and sling it back to Bowens for a motherboard transplant.</p> <p>Oh yes, don't forget the smell test. A burnt out resistor or other component will stink; and running your nose around the board can help locate the faulty component. Also do a visual inspection for dry joints, holes blown in plastic semiconductor packages, bulging capacitors, etc. Best of luck!</p> <p>Edit: Almost forgot the most basic check. There are probably internal fuses or fusible components. Check those first.</p>

<p>Sorry to be pedantic Mark, but Nikon don't make speed<em>lites</em>, Canon do. Nikon invariably spells it as speed<em>light</em>. Google will even correct you if you do a search for Nikon speedlite. </p>