rodeo_joe1

<p>According to Nikon's figures, the SB-700 has slightly less power than the SB-600. Or the figure in the manual might just be a more realistic GN than the usual bloated ones that makers invent. In any case I think having two fairly evenly matched speedlights gives a bit more flexibility in lighting setups, and if you move to manual control it certainly makes it easier to control ratios.</p> <p>Have you considered a 3rd party flash? More light for your dollars, and then you may not have to sell the SB-600 at all and can keep it as a backup. There are quite a few makes that now offer Nikon compatibility, and without the inflated price tag.</p>

<p>Scratches won't affect the sharpness (i.e. resolution) of a lens, but they can reduce contrast and give rise to flare if the light hits them. Without seeing the scratches I wouldn't want to give a definite yay or nay to whether they'll affect the image quality, but I would be asking why they're there - on the inside of the glass - in the first place. That's a sure sign of amateurish dismantling, and not what I'd expect of a lens rated "excellent".</p> <p>Give the lens a harsh test and shine a torch (flashlight) through the lens. That'll show up any dust, scratches or other blemishes like mad. You may see more signs of amateur tampering, like smears from improper cleaning. If so, then IMO you should definitely consider the "upgrade". If shopping in person, then take that flashlight with you to examine the other lens too!</p>

<p>Absolutely not. It's an Ai-S manual focus lens. In fact I don't think it's possible to even squeeze a Dandelion chip onto the rim of it, because the glass goes out to the very edge of the mount.</p> <p>I looked at mine with a view to adding a chip but decided there just wasn't enough room. I think even a factory CPU version of the lens is almost out of the question without the optics being totally recomputed and possibly compromised by having a smaller rear element.</p>

<blockquote> <p> J = F / w</p> </blockquote> <p>I don't think you can just divide the luminous flux by the solid angle and come back with a luminous power figure. That seems to take no account of the fact that the area of the circle of illumination is proportional to the <em>square</em> of its radius, which in turn is proportional to the tangent of half the beam angle. It's the area of illumination at a fixed distance that you need to work out for each lamp and then normalise by multiplying the Candela figure by the area of illumination.</p> <p>Therefore the formula I'd use would be: (Tan illumination angle/2)^2 * Candela figure; to arrive at a figure proportional to the total light output power. From that you can work out the relative efficiency of each lamp. A bit more work then needs to be done to arrive at an absolute Lumen value, but you only need to do that for one lamp and then use the relative efficiency figure for the rest.</p> <p>As bill says, the filament is emitting light pretty much into a 360 degree solid angle - (I'm not sure why you're converting to Steradians, that's just complicating things unnecessarily. Simple degrees will work just as well and can be more easily normalised from the first column of data.) Therefore the efficiency of the reflector/diffuser will come into play.</p> <p>By working out a theoretical area of illumination, I actually got a bigger variation in efficiency than you've shown; with the 57 degree lamp being over 2.7 times more efficient than the 12 degree lamp in the same series. However, that assumes that the illumination will be absolutely even across the solid angle, which of course it can't be. So the given Candela figure is presumably taken in the centre of the beam, where it will be at a maximum. A bit of inverse square law then needs to be applied to find the (theoretical) level of illumination at the edge of the beam. After working out the integrated light level, you'll probably find that the R figures are much more even. Lesson 101: Never take manufacturer's figures at face value.</p> <p>And when it comes down to it, we're talking about extremely inefficient old hot filament technology, giving out far more heat than light. So who really cares? All you need to know is that it'll burn your hand badly if you touch it while it's lit! And for some time after it's switched off as well.</p>

<p>My experience with Samyang has been variable. The 85mm f/1.4 and 35mm f/1.4 lenses have proved brilliant, so I took a punt on their 24mm f/1.4, which proved to be not so brilliant. The first sample had ridiculously bad decentring and had to go back. The replacement is OK-ish. I tried the 14mm a couple of times, but only had about 5 minutes to play with it each time; indoors and without a tripod. Even so the corner sharpness looked OK, and that was wide open on a D800. Also the display sample of 24mm T/S I tried gave good IQ. Both the T/S and 14mm display lenses behaved suspiciously much better than review pictures posted on the web. So I fear that there's a lot of variability between samples.</p> <p>If you can find an understanding dealer that'll take returns without question, then you might strike lucky with Samyang and get a very good one. However your mileage will almost certainly vary.</p>

<p>Apart from the D4s, I've yet to see a camera that has a convincing (or even useable) image quality at an ISO speed higher than 6400. Even so that's about 6 times faster than any film could achieve.</p> <p>My use for high ISO's is music or theatrical performances, where even small amateur stages are usually lit well enough to keep the ISO at or below 3200. I also like the ability to shoot land and cityscapes handheld in fairly low light conditions. Twilight especially shows some wonderful lighting that just doesn't occur at any other time of day, and having the ability to catch fleeting light conditions like that is one of the many reasons I love modern DSLRs. By the time I'd set up a tripod the light would have completely changed or gone.</p> <p>Only once have I pushed the ISO to its max, and that was in a dimly lit music club. The amount of post-processing needed to reduce the general noise and red speckles was painful, but I think the end result was worthwhile for at least one of the shots. It's not something I'd like to repeat too often though.</p>

<p>Jay, that old 15mm f/3.5 lens fetches around $1000 used. For a single focal length that's not much of a bargain compared to the extra flexibility of the 14-24mm Zoom-Nikkor. Also all the reviews of this lens are less than enthusiastic about its sharpness and being prone to flare. Even " the one who shall remain forever nameless on these pages" (K.R.) gives it a poor review, except for its lack of distortion, and he gives rave reviews to almost <em>anything and everything</em>.</p> <p>Yes, it would be nice to think there was a perfect lens out there that had no distortion or vignetting and gave a perfectly sharp image from corner to corner at maximum aperture, but unfortunately no such animal exists. (Apart from the distortion, the 14-24 comes pretty close though).<br> You do your research, pays your money and settle for whatever compromises you think you can live with. If you're sensible, you also thoroughly check out the sample of lens you've just bought for decentring and other faults as soon as you get it as well. That's after buying from a reputable dealer that'll exchange the lens without question if found to be faulty.</p>

<p>I'm with Jose and Ilkka that the 14-24mm is the right tool for the job - plus a high tripod to get you at half wall/ceiling height and prevent having to tilt the camera up. The barrel distortion, which can be quite noticeable as Andrew suggests, can be rectified in post-processing. And if you want to do exteriors properly, then the 24mm PC-E Nikkor is the right lens to get. It'll also do interiors very well if space isn't that much of an issue, or if you don't mind stitching images together.</p> <p>On full-frame, in a tight space you need a 17mm lens or shorter; then the >90 degree horizontal coverage can still take in a whole room if the camera is placed in one corner. With DX you're basically stuffed if you don't have anything shorter than 12mm - and there aren't that many good quality ultrawide zooms to choose from.</p> <p>I've used old 28 and 35mm PC Nikkors quite successfully on digital. They can be picked up reasonably cheaply and save a lot of post-processing in straightening up large interior shots if the trapezoid distortion got by pointing the camera up is objectionable to the client. They can be useful in places as big as a church, for example, but in smaller interiors you often need something a lot wider.</p>

<p>Chuck, monolights <em>are</em> flashes. It's another name for a studio strobe, one that usually contains a modelling lamp as well as the flashtube, and has a combined power pack built into the back of the flash-head. A decent set of monolights will be well outside your stated budget.</p> <p>If you don't want to use flash, then IMHO your only other sensible option is to use compact fluorescent type photo-lamps. These have a colour temperature very similar to daylight and give out very little heat. Conventional tungsten lamps OTOH are quite uncomfortable to work with because of the heat they generate. You'd need about 1.5 to 2Kw of Tungsten lighting to get a decent level of exposure whereas CFLs will give you a similar amount of light for an input of only about 300 to 400 Watts. That's using clusters of 3 to 5, 30W or 45W tubes per lamp. I'd recommend using a smaller cluster of tubes of a higher wattage, because you'll get a smaller number of shadows and a harder light. It's easy to soften a hard light, but nearly impossible to harden a soft light.<br> CF lamps also have some of the drawbacks of LED lamps, in that it's difficult to get a properly hard light from them and their light output isn't very high per tube. However, they're very affordable and slightly more flexible than LED panels. CF lamps are available in a range of powers, sizes and cost from one's like this: <a href="http://www.photosel.co.uk/studio-lighting/continuous-lighting/light-kits/table-top-studio-light-kit-26w-1300lm-5500k-90-cri.html">http://www.photosel.co.uk/studio-lighting/continuous-lighting/light-kits/table-top-studio-light-kit-26w-1300lm-5500k-90-cri.html</a> upwards.</p> <p>WRT flashes causing eye damage to animals or children. There is no evidence that this can occur, provided the flash is used sensibly and not repeatedly fired directly into the eyes of the subject. Even then it's probably no more than temporarily uncomfortable and causes no permanent issues. I know because I once accidentally fired a quite powerful speedlight directly into my own face. I saw a large spot for some time, but my sight completely recovered within an hour or so. Naturally you wouldn't fire a flash into your subject's face from a few inches away in the normal course of things, I hope. And after all, indirect flash lighting only has around the same brightness as daylight, and nobody claims that a quick glance out of the window can cause eye damage!</p>

<p>Guys, I really don't think the internal resistance of cells makes very much difference to the recycling time of a <strong>modern</strong> flashgun. Anecdotes about flashes designed decades ago are a bit meaningless WRT this Metz 48 AF-1.</p> <p>If you stick an ammeter across the average rechargeable AA you can draw well over 10 amps from it - in fact it'll probably blow the internal fuse of your ammeter. Not so much so with Alkalines, they do self-limit as their energy runs down. But you've only got to time the recycling of a modern flash using various types of cell to see that as long as the state of the cells is good, then there's very little difference in timing between cell types or total voltage. All that happens is that cells with a higher mAH capacity can keep the recycle time down to its minimum for longer. Until the flash overheats that is.</p>

<p>In the old film days, many Zeiss and Leica lenses came with tiny air bubbles in the glass. Those air bubbles were often many times bigger than the tiny and insignificant little spot on your lens Allan. That was the way the glass came out in those days, and the little air inclusions were almost unavoidable. Those old lenses were among some of the best ever made, and still are. In fact some photographers claimed that you could tell it was quality glass <em>because</em> it had bubbles in it.</p> <p>So, Allan, take the excellent advice to do nothing with the lens except go and make pictures with it. That little silver speck is almost certainly a small area where the anti-reflection coating has come away - or not been applied in the first place. It's not even dust that can be removed, just an area of glass that's slightly more reflective than the rest. I've seen much bigger spots like that on lots of lenses that still perform perfectly. Don't obsess about it. Put your mind at rest and take some pictures with the lens to show yourself it performs as it should. But bear in mind it's a relatively cheap kit lens, so don't expect absolutely perfect image quality. I suggest you go online and look at reviews of the lens to see how you can expect it to perform.</p> <p>Edit: I've just looked at this review of the lens<br> http://www.ephotozine.com/article/nikon-nikkor-af-s-dx-18-140mm-f-3-5-5-6g-ed-vr-lens-review-23219<br> If you scroll down to the picture of the front element, then you'll see spots on their lens as well. There's no telling whether they're removable dust or permanent from the picture, but whatever they are, the authors of the review obviously weren't fussed about them.</p>

<p>When I ran an Epson (never again!) that had a stubborn head clog, I stripped it to the ceramic nozzle plate and used methylated spirit to unclog it. It took a while soaking out the dried ink, but eventually came good. You might try just running the head over a paper towel or similar soaked in meths or just plain water. - I'm not sure about the Windex - its unknown ingredients would put me off. Anyway, this doesn't need any dismantling and it's worth a try.</p> <p>I'm not sure what type of black ink the 3880 uses. Plain old water is usually the best solvent for pigment-based inks, and alcohol better for dyes, but YMMV.</p>

<p>".. I would make it with five cells and run it at 7.5 volts." - Except that NiCd or NiMH cells only have a maximum voltage of 1.35 volts each. So the most you'll get with 5 rechargeable cells is around 6.75 volts - about what you'd get from a fresh set of 4 Alkalines. Even then I doubt that the slight extra voltage will buy you a faster recycle time. Modern flash circuits are far better regulated than the old 45CT-x and 60CT-x simple inverters. They have to be to accept Alkaline or NiCds or NiMH cells interchangeably.</p> <p>Unfortunately, the miniaturisation of modern flashes also means that they're more susceptible to overheating, and most decent ones have an overheat detector that simply switches off the inverter until things cool down, or they "throttle back" the recycle time to prevent overheating damage. Either way, they're not built to deliver endless maximum power pops at short recycle times. The only current flash that I know of that promises that is Nissin's MG8000, but it ain't cheap!</p> <p>There was a lot to be said for the big old unbreakable Mecablitz hammerheads, and that's why I've still got mine. All seven of them!</p> <p>BTW, yes, the Metz rechargeable packs did have an extra cell in them; precisely to make up for the lower voltage of NiCd cells over disposables.</p>

<p>That speck must take up all of 0.001% of the glass area! It'll make absolutely zero difference to the image quality of the lens - no more than if you had a bit of dust the same size land on the lens. My advice would be stop worrying about it, forget it and just use the lens. I assume you got it for a good price, so you can't really complain about an absolutely minute defect that won't make any difference to the pictures.</p> <p>I don't think you'll have any luck with Nikon, since warranties aren't transferrable from the original purchaser unless bought as a gift. No matter how recently the lens was purchased new, what you have is a "used" lens, and your only real recourse is to the person that sold it to you. Unless the lens still has blank warranty cards and the person you bought it off hands over the original store receipt; in which case you might get away with registering the warranty in your own name. But quite frankly I don't think it's worth the hassle of losing use of the lens for however long Nikon takes to decide a course of action.</p> <p>Also bear in mind that this is basically a "kit" lens at the lower price end of Nikon's range.</p> <p>Edit: The speck is probably a tiny area of AR coating that somehow got loose. Maybe through assembly or by having some dust land on the lens before going into the coating chamber. These things happen. It's not the end of the world.</p>

<p>Actually, the difference between f/1.9 and f/1.8 is around 0.156 stops - nearly 1/6th of a stop. So the difference should really be less than 1/7th (0.138) of a stop between the prime and zoom according to DXO's figures.</p> <p>Anyway, we're not talking about absolute errors here, we're looking at the difference in transmission between the two lenses, which should be so slight as to be almost invisible. Not creating a jump in the histogram or being a glaring difference in exposure. I refer you to my test done and reported just earlier today, where my f/2.8 Tamron zoom and an Ai-S prime gave a virtually identical histogram and visual brightness for the same exposure settings. OK that wasn't using the 24-70mm Nikkor, but surely Nikon can get as good a transmission figure as Tamron can?</p> <p>Edit: If you read the DXOmark charts properly, the 50mm f/1.8 and 24-70mm zoom Nikkor have virtually the same T-stop deviation at 50mm. However whether this tracks to f/2.8 on the 50mm G lens is another matter.</p>

<p>"...the Nikon brand, while nice, is extremely expensive for a speedlight." I have to agree that new Nikon speedlights are well overpriced. However, you can pick up used SB-25s for not very much, considering how powerful and flexible these little units are.</p> <p>No budget monolight is going to give you the luxury of controlling power from the camera or having TTL, so you're more or less stuck with fully manual control of the lights anyway. I have 3 SB-25s and an SB-24 (the SB-25 offers more features). They have the same power as a modern SB-910. I wouldn't hesitate to recommend an SB-25 as a good manual or Auto-Aperture flash for this sort of job. You really don't need the power of a studio strobe, because dogs are generally fairly small subjects and you can gets the lights in pretty close.</p> <p>Buy the SB-25s well, add some stands, swivel adapters, a set of cheap radio triggers and scrim and foamcore for home-made diffusers and reflectors, and you could probably bring your home studio in for under $350 US.</p>

<p>AFAIK, hybrid type (so-called "ready to use") C-size cells aren't available in mAH capacities any higher than those of AA-size cells; despite costing a lot more. IMO the value of having cells with a low self-discharge far outweighs that of pure capacity. But that does depend on how often you use them. YMMV, but if you go a week or more between use of the flash, then having hybrid type cells would seem to be a must to me.</p> <p>So if you need low self-discharge, then there seems little point in building a C-size battery holder, since the mAH capacity will be much the same. It appears to me that often when you buy a C cell, and especially a suspiciously lightweight D cell, all you're getting is an AA in an oversized wrapper.</p>

<p>The lighting on each of those linked pictures is slightly different. One is lit with soft light from camera left, for example, while another obviously has a hard kicker at rear. In fact using a rear kicker is probably the best way to get good separation between black dog and black background.</p> <p>As for lights - definitely not LEDs. At the current state-of-the-art they're well overpriced and well underpowered. They're also nearly all of the "panel" type construction which makes them useless for giving a hard light or for snooting down to a spot. Whether flash would be suitable depends on the temperament of your dogs. Some animals are spooked by flash, but domestic pets usually take it in their stride and don't even seem to notice it much.</p> <p>The good news is that most of your lighting can be done by careful placing of reflectors. You probably need only three lights at the most to achieve the sort of effects seen in the linked pictures. Getting the dog's coat glossy enough to catch the reflected light is another matter!</p> <p>Why not email Fred Levy, the author of the "Black Dogs Project" and ask him what lighting he uses and how he goes about setting it up?</p>

<p>None of the above.</p> <p>1. The flash circuitry will almost certainly have regulation to prevent it taking more current than it can handle.<br /> 2. The recycle time will be much the same - see (1)<br /> 3. The flash won't know the difference between battery capacities - only their voltage counts. And again see point (1)</p> <p>I'm really not too sure what you're trying to achieve here Dan. There won't be much weight saving, since battery capacity and weight are fairly well linked. i.e. 4 C sized cells are likely to weigh nearly as much as eight AAs, and won't offer twice the mAH capacity.</p> <p>Also, the capacity of a cell in milliamp-hours doesn't necessarily relate to the amount of current it can deliver - that depends on the internal resistance of the cell, its type and construction. For example the old NiCd AA cells only had a capacity of around 500mAH, but their internal resistance was often lower than modern hybrid NiMH cells, and as a consequence they gave a faster recycle time with older and less well-regulated flash units.</p> <p>Proper high-voltage external power packs give a faster recycle time because they have their own inverter circuit built in that can deliver 360 volts or thereabouts to a flash designed to take such an input. Not because they simply contain more or higher capacity cells.</p> <p>So, would carrying 8 extra AAs be any more annoying than trying to knock up a reliable battery insert, cable and C cell battery holder + drilling a hole in the flash for the cable + the awkwardness of constantly carrying the external power pack? Plus again the fact that it'll take longer to recharge the C cells than it will to charge AAs.</p> <p>Alternatively you could buy a nice Nissin Di866 that takes extra battery inserts ready loaded for a quick change of cells. It takes about 10 seconds to swap the battery inserts over. The cells also go into the insert all the same way round - nice touch. And are you using high capacity hybrid type AAs? These last a lot longer between charges than standard NiMH cells due to their low self-discharge characteristics.</p> <p>Edit: "...we engineers usualy build things with higher than specified tolerances." Yeah, and then the production engineers downgrade everything to pare costs to the bone. You're lucky these days if a single component is overrated above the bare minimum needed to just work.</p>

<p>It's possible that the aperture hasn't been adjusted properly at the factory - like they forgot to adequately grease the zoom mechanism on a number of these lenses.</p> <p>Dror, look into the zoom lens with the aperture lever pushed fully up and see if any of the aperture blades are visible. You might see an angular opening (incorrect) rather than a perfectly circular one (correct). Then look again with the lens on the camera and see if the opening is still circular. If you see any of the iris blades poking in beyond the circular aperture mask in either case, then you need to return the lens for replacement/adjustment.</p> <p>Another possibility is that the aperture on your 50mm f/1.8 lens isn't closing properly. Because who's to say which lens is giving you closer to a true f/2.8?</p> <p>WRT vignetting: If that's the "fault" then the central brightness of both images should still be roughly the same, and only the outer ~1/3rd of the image circle should be affected. However at first glance vignetting can be mistaken for underexposure.</p> <p>Just tried the same thing with my 28-75mm f/2.8 SP Tamron zoom wide open at 50mm, and a 50mm f/1.2 Ai-S Nikkor set at f/2.8 - almost zero difference in exposure histogram. Certainly no overall shift in one direction or the other, although I did notice than the MF prime gave a noticeably cooler colour rendering than the zoom. That was with both lenses pointed at a plain painted wall with their focus set at infinity and both on manual focus; otherwise the AF lens couldn't find focus and would lock the shutter. The degree of vignetting looked very similar on both lenses too.</p> <p>Edit: How many comparison shots did you take Dror, and in what lighting conditions? Daylight can change very quickly, sometimes much faster than you can change a lens. Try the same again under constant artificial light or manually controlled flash. It's pointless using I-TTL controlled flash for such a test.</p>

<p>I'm curious whether the 200mm f/4 Ai-S Nikkor was reformulated from the plain Ai version? From the mir.com site it appears they're optically identical, but the glass used may have been changed to a lower dispersion type.<br> <br /> You see I have a 200mm f/4 Ai version that I was fond of using on the D700, but the D800 really shows up its flaws (lateral CA mainly). In fact I think my 80-200mm f/4 Ai-S zoom Nikkor is a better match to the D800, but a bit heavier and bulkier than the neat little 200mm prime.<br> So I'm wondering if it's worth looking for an Ai-S version as an "upgrade" since they don't usually cost very much.</p>

<p>"..focal length used was 170mm." - Well, that's about the maximum real focal length of the new 70-200mm f/2.8 VR zoom Nikkor at portrait distances! Time was when the focal length(s) marked on a lens were pretty much what you got. Not any more it seems. It does feel like being short-changed and totally misled.</p> <p>Edit: BTW, Elvis, Tamron's 70-200 f/2.8 SP VC lens is every bit as good optically as the Nikon version, and at about 2/3rds of the price.</p>

<p>The Nissin range are very good, but a lot more expensive than YongNuo, while still being cheaper than the Canon or Nikon equivalent. I've been using a Nissin Di866 for some time now and found it totally reliable and very powerful. Not sure if it's the only model that supports FP/HSS, since I haven't looked at the spec of other Nissins. One or two flashes in the Metz range might be suitable as well, but I have no experience of any current Metz model. The Metz flashes that I've used in the past have been very reliable and well-made.</p> <p>You might also want to search for other threads on high-speed synch in this forum, because it's possible to "fool" a camera into Focal-Plane synchronisation while firing almost any old flash via the P-C socket. I've done this with an ancient Metz 45CT-1, and the results were perfectly useable.</p>

<p>Very sorry to hear about your medical event Roy.<br> However I briefly handled a Df at a trade show and it looked and felt like a cheap, gimmicky toy to me. Nuff said in my book! If I really needed better low-light performance than I get from my D700 or D800, then I'd be saving my pennies for the phenomenally sensitive D4s. Unfortunately, by the time I save enough pennies there'll be something even better on the market for sure.</p>

<p>Why wouldn't the radio triggers be synchronised? Or more to the point, <em>how couldn't </em>the radio triggers be synchronised? The signal from the transmitter travels at the speed of light, and the decoding delay in the receivers might add all of a few nanoseconds onto that. And any delay will be the same for both receivers, so the cameras <em>have</em> to be fired at the same time.</p> <p>We all know that the range advertised by trigger makers is very optimistic and terrain dependent, even for the top-end models. However it's not very often that you need to use a remote more than a few feet from the camera, and these things will work reliably at least up to 50ft away - I know because I've tried it. Leave your camera unattended any further away in an urban environment and you're likely not to have a camera or tripod to come back to!</p>