rodeo_joe1

<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>

<p>Bela, Lionel; have you got any shots from just <em>before</em> the stealth plane crashed into that lovely old church?</p>

<p>Nissin's Di866 has slightly more output than even the SB-800/900/910, and costs around half the price. I can vouch that it measures a couple of GN points higher on my flashmeters than any other make of hotshoe gun. Also Nissin have a "heatproof" model (MG8000 extreme) that's supposed to be able to fire continuously at full power for longer than any other similar flash. However I haven't used one, so can't personally vouchsafe that claim.</p> <p>A pre-loaded battery insert makes changing batteries a doddle too.</p> <p>The only minus point against the Nissins is the rather eccentric interface, which requires many button presses to get set up.</p> <p>BTW, I'd experiment with what you can do with a cheap Fresnel page reader, two bits of cardboard, some sticky-tape and an elastic band before spending money on that BB thingamajig.</p>

<p>I don't think there's a "one size fits all" answer to gig shoots. The example below was taken in a small intimate venue where using flash and/or getting up-close-and-personal with the performers would have been intrusive, and would have made me very unpopular with the rest of the audience and the band. In fact most of the venues and artists I shoot are like that.</p> <p>I'm not wholly convinced that faster glass is the answer either. The lens I was using was a 105mm f/1.8, but at f/1.8 there was no way to get the guitarist's hands, guitar and face all in acceptable focus, so I ended up stopped down to f/2.8, and may as well have been using a fast zoom or more modest prime.</p> <p>The touch of "luck" in this case was the nice side/back-lighting from a window; decent daylight and the fact that the artificial lighting wasn't too unbalanced from the window lighting. Night-time or theatre gigs are almost invariably fully artificial light, which can be a real challenge. However the coloured stage lighting usually adds a bit to the atmosphere. If not, a B&W conversion can make a good get out of jail free card. The only constant really is that you <em>need</em> a good high ISO capability on the camera to CYA.</p> <p>FWIW. I'm nearly always looking for a good expression and/or body shape in the performer, and I tend to concentrate on one member of the band at a time. Overall band and stage shots tend to look a bit messy and getting a tight composition is much more difficult. Not having a microphone shadow on someone's face is always a bonus! Personally a bit of movement in a musician's hands doesn't bother me. It shows they're playing and not just posing.</p><div></div>

<p>"....not the Greek ideal (1.618)." - A format ratio of 1.618:1 was never the Greek ideal. The Golden mean or Golden ratio was applied by the Greeks to the <em>diagonal</em> of a frame, in order to arrive at a "perfect" proportion within the frame. It's also the root of our rule-of-thirds, which is an approximation of dividing the frame dimensions by the Golden ratio, and can be applied to any ratio of height to width. In that application it does work, but not as a guide for deciding frame dimensions. It was never intended for that purpose.</p> <p>The above unthinking application and misunderstanding of the intended application of the Golden ratio has now resulted in us watching our video, computer and television content through a letterbox. It has nothing to do with aesthetics at all, and everything to do with rendering older viewing and taking equipment redundant for purely commercial purposes. It just shows that we can be sold any BS, including an unnaturally narrow view of the world.</p> <p>Look at the contents of any art gallery or museum. There are almost no canvases that have a format ratio of 1.618:1, and in fact most "masterpieces" have a ratio much closer to square than they do to being an elongated rectangle. Since canvases and frames can be cut to any dimensions the artist thinks suitable, doesn't it seem odd that elongated canvases are thin (pun intended) on the ground? Did Rembrandt, Leonardo, Van Gogh or Monet go for canvas ratios of 1.618:1? Definitely not! Even the standard still 35mm format is overlong for most purposes, and that was arrived at purely as a matter of convenience by Oskar Barnack so that his prototype leica could take cheap cine film using a simple sprocket counting advance mechanism. Shame it's stuck with us for so long really. It doesn't even fit the 1.4:1 ratio of ISO series paper sizes or any other standard printing paper size.</p>

<p>Is the Sigma lens "intelligent" enough to recognise what camera it's attached to and adapt it's AF accordingly? Seems to me that applying AF fine-tune to a lens would be a global adjustment that would remain the same whatever camera body it was attached to. The camera can recognise an individual lens, but AFAIK it's a one-way communication. I fear that adjusting the lens to one camera body would affect its performance on another camera.</p> <p>What was wrong with camera body AF fine-tuning?</p>

<p>Tilt and swivel screens on <em>all </em>of Nikon's DSLRs should be a standard feature IMHO. Not just on a few lower end models. Then no need to stoop, twist or grovel to see what the camera's seeing. However a small mirror angled so that you can see the screen in it would be another cheap alternative. Should be possible to knock up a cardboard holder at 45 degrees with little effort, and using a plastic mirror would reduce the risk of scratching the camera or its screen.</p>

<p>Addendum. The apparent variation in polarisation across my D800 rear screen was caused by the plastic protector. I had an "Aha!" or maybe "Doh!" epiphany last night and tested the theory this morning. With the plastic protector removed, the entire screen is dimmed by looking through a polarising filter and rotating it. I guess the manufacturing stresses in the plastic protector cause it to act as a variable wave plate.</p> <p>Phew! The laws of physics still stand firm I'm relieved to say.</p>

<p>Thanks for that Tom, but in nearly every advert or spec for strobes you see it written as W/s or some variant of that. Watt-seconds are indeed the more correct units. I would prefer the much less confusing unit "Joules" to be used exclusively, but that seems to have fallen out of common usage. Probably because the airheads that write advertising copy don't know what it means.</p>

<p>A belated vote for "modifiers". There's far too much commercialised BS attached to them these days, with ridiculous claims being made that definitely need to be debunked. Light is light, and the laws of optics can't be broken at the whim of some air-headed advertising hype!</p> <p>Sorry, got on my soapbox a bit there Steve.</p>

<p>Call me an old Luddite, but I've never seen the point of the AF-ON button either; certainly never used it in anger and am quite happy forgetting it exists. First pressure on the "GO" button works fine for me, and in fact I find it a pest if the camera suddenly and unbidden decides to follow focus. As for using auto AF points - Yikes, that's a definite step too far! Gimme the single centre AF rectangle every time. Or at most a single point I can steer around the screen, except that usually takes far more time and effort than the "focus and recompose" method.</p> <p>So just because it's there Bennett, that doesn't mean you <em>have</em> to use it.</p>

<p>Can you fire the SB-800s with the camera in manual exposure mode (shutter speed =< 125th) and/or using the P-C socket and a connecting cable? If not then I'd suggest the camera flash circuitry is defective.<br> Also check the flash setup menus to see what flash synch speed you have set. I'd choose one of the (Auto FP) options and a default synch speed of 1/60th - none of which should matter in manual exposure mode though.</p> <p>There isn't a "museum" or "discrete" setting on the D4s is there? That mode would almost certainly disable any flash.</p> <p>As a last resort, try the two button factory default reset on the camera before declaring it faulty.</p>

<p>"How could the same sunlight falling on your skin harm a CMOS sensor?" - By saturating the photoFET elements for a start. Also I'm not sure how stable the microlens and RGB filter layers are. It may be that sustained exposure to bright light could degrade or fade those filters. Plus there's the heat generated by sunlight and absorbed by the IR filter in close proximity to the AA filter. Altogether it's not an exercise that I'd want to try out on my camera. But if you want to see exactly how much sunlight exposure <em>your</em> sensor can take, then go ahead.</p>

<p>Short answer - No. Don't worry about it.<br> It's probably best not to point the camera at the sun with the shutter open and lens removed however!</p>

<p>You seem to be the guy to talk to on the subject of OLEDs then Andrew. Some years ago I bought a small MP3 player with a blue matrix-type OLED display. I went to use it the other day only to find that the display had totally faded to near invisibility. Is this limited lifetime still an issue with OLEDs or AMOLEDs?</p> <p>I don't want to get you into trouble with your employers if the answers is a resounding "YES" BTW. Your silence might speak volumes!</p> <p>Edit: After looking at the rear display of my D800 through a polarising filter. It appears that the plane of polarisation varies across the display. I get a black line that "wipes" across the display as I rotate the filter. Incidentally there's really no such thing as circular polarisation. A so-called circular polariser is simply a plane polariser combined with a 1/4 wave plate that de-polarises the light again in one direction. So a circular polariser fitted backwards simply becomes an ND filter.</p>

<p>FPS is a pretty crude way to calculate exposure these days. The shutter speed can be totally different from the frame rate in video, or even with more sophisticated film cameras that allow the shutter angle to be varied.</p> <p>Surely it doesn't take a lot of mental arithmetic to multiply the frame rate by 360/shutter angle to get the fractional shutter speed? For example 24 FPS and a 180 degree shutter gives you 1/48th of a second. 30 FPS and a 90 degree angle will be 1/120th second.</p>

<p>Just to clarify the difference in rating between continuous lights and flash. Flash is rated in Watt/<strong>seconds</strong> (or Joules), not just Watts. So a 400W/s flash will be many times more powerful than a 1000W Tungsten or Halogen lamp. In fact 1000 Watts of continuous light is pretty weak and needs something like 1/60th and f/5.6 for 100 ISO at 2 metres distance. Depends on the reflector of course, but even with a polished reflector, 1000 watts of hot light is pretty dim in photographic terms.</p> <p>A 400W/s flash has around 200 times that light output, allowing exposures of around f/22 and 1/250th second at 2 metres. The colour temperature is close to that of daylight, which effectively gives you an even higher exposure. So my advice would be to ditch those pathetic hot lights and go with monolights. As stated above, modelling lights are going to be a lot cooler, and can always be turned off once the lights are set correctly. 400 W/s monolights usually come with a modelling light of only 150 Watts max.</p>

<p>Okay, hopefully the picture will upload before the gateway times out this time!</p><div></div>

<p>My idea of a relaxing end to the day. The comfy armchair and a bit of strumming or fingerpicking on "Ole Faithfull". Wonderful tone!</p> <p>Tech data: D800 with 105mm AF Micro-Nikkor + Speedlight in a softbox/brolly camera right and 42" silver reflector camera left. Softbox could have been placed a bit higher after viewing on computer, but can't be bothered to retake now. After all, this is about relaxing; right?</p>

<p>FYI, all LCD/TFT displays work by means of polarisation Peter.<br> Light from the backlight (or a reflector) is plane polarised by a filter layer and passes through a Liquid nematic crystal cell that twists the plane of polarisation in proportion to the voltage applied to the cell. Light from the LCD cell matrix then passes through a further polarising filter. The result is that each LCD element can regulate the amount of light reaching the eye of the viewer. But obviously quite a bit of light is absorbed by the polarising filters involved, which is why backlit LCD displays are a bit dim and power-hungry devices.</p> <p>OLEDs and similar technology might eventually give us better displays. Until that sunny day you know darn well baby...... Ooops, sorry, slipped into the lyrics of an old song.</p>

<p>I'd concur that it's probably a poor contact fault on the resistor track that monitors aperture position. The maximum aperture position gets most use, so is the most likely place to get worn out and/or dirty. A quick squirt of contact cleaner might well sort the problem out, but obviously the track or FRE has to be exposed first.</p> <p>FRE stands for "Functional Resistor Element" BTW, which is a fancy name for a variable resistor track. Have a look at this thread - http://www.photo.net/nikon-camera-forum/009JnY</p> <p>Apparently people have fixed the problem without exposing the FRE, and using WD40! I would <strong>not</strong> recommend following that procedure, since it's just not logical to attack the mechanical coupling ring in such a way - especially with something as penetrative as WD40. The FRE is actually located under the top-plate at the rewind knob side of the camera. However the diagram and link on that page shows you what you're dealing with. The full repair manual can be downloaded from here:<br> http://elektrotanya.com/nikon_fe-fe2.pdf/download.html</p> <p>Chip, I'd look at the condition of the foam rubber seals around the camera back and in the mirror box before deciding whether to throw money at repairing that FE. Chances are the black foam is turning to goo, and its replacement plus fixing the aperture resistor may make the camera uneconomic to repair.</p>

<p>Why are we even discussing a camera based on a rumour? Five pages (and counting) of pure speculation, wishful thinking and "what I'd like to see Nikon do is....". I know it's been a slow couple of weeks on this forum, but let's keep a sense of proportion guys.</p>

<p>"- what is the source of that?" The yellow to red areas in DXOmark's sharpness and CA measurements; KR's sample pictures in his 24mm lens roundup; Photozone's resolution column charts that hover around the "fair" to "poor" region for the corners at nearly every focal length; the few pictures I took myself while I briefly had my hands on a sample.......</p> <p>The D700 is quite forgiving compared to the D800 and variants Wouter. I used to use an old 200mm f/4 Ai Nikkor on the D700 quite happily. It just doesn't cut it on the D800 I'm afraid, and now sits pretty much unused, replaced by the 200mm setting on a Tamron 70-300 VC. Shame, because it's such a neat and lightweight little lens, but I see little point in using a 36Mp sensor if your glassware can't keep up with it.</p>

<p>My take on this would be that if AF is a must, and AF performance is your main concern, then I'd agree with Shun 100% that AF-D lenses shouldn't be a priority on your shopping list. When Nikon first moved their prime designs to cheap plastic AF bodies the quality suffered I'm afraid. I have old manual focus metal-bodied Ai-S primes that outperform their AF versions, simply because the plastic version AF tolerances were more sloppy in those days.</p> <p>When I first bought into the Nikon DSLR system I already had a shedload of Nikon MF and AF lenses. Was I going to bin them all without trying them on the D700 and later the D800? Was I heck! And you know what, most of those old lenses are still well capable of taking pixel-peepingly (is that even a word?) good pictures on a D800.</p>