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markdrayton

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Everything posted by markdrayton

  1. I have 3 Inon Z240 Type 4 strobes available for sale. The strobes are in very good used condition and fully functional, never having flooded. They all have Inon Z type ball mounts. I have Inon neoprene protective sleeves for 2 of the 3. All the strobes have the original Inon documentation and manuals and spare o-rings. They have each a white diffuser and 4600K and 4900K warming filter/diffusers. I will throw in Glowdive Dome push fit diffusers for 2 of the 3 strobes. Strobes are in the UK. Looking for £325 each. In the first instance, I'd prefer to sell 2 of the strobes with sleeves and dome diffusers as a pair.
  2. I have twinned my fiberoptic cords into an Inon L Sea&Sea type adapter and use a Nauticam to Sea&Sea bush on my Nauticam DSLR housing. So my 2 normal strobes fire off the one fiberoptic port and the mini-strobe off the other. Works very well.
  3. Walt, I think youll find its an extra 20mm extension thats needed with the Kenko 1.4x TC
  4. Hi aviator8. Are you sure those gels you are referencing are optical gels? They look like lighting gels to me - 20x24 inches. If so, they aren't suitable for use as barrier filters in front of a camera lens. They are designed to be placed in front of theatre or filming lights. Of course Lee and others do make a more limited range of optical gels but they are far more expensive.
  5. As the visible light spectrum is usually regarded as starting at 400nm, if the UV torch truly produces a point wavelength of 385nm, no barrier filter would be needed. In practice, the light is likely to emit a spectrum of wavelengths extending to some degree into the visible range and so will be detectable both by eye and the camera sensor. (Do you see blue light when it is in "UV" mode?). The extent and intensity of this spread into the visible spectrum determines the need for yellow (minus blue) filtration. Wratten 12 filters have a sharp cutoff at about 500nm. Many lights designed for underwater fluoro photography actually produce a spectrum peaking around 455nm - visible blue light. This is because that higher wavelength is a more effective fluoro excitator than shorter wavelength true UV. Of course a downside of barrier filtration is that any fluoro effect below the cutoff frequency (say 500nm) will be lost. However without barrier filtration, lights with significant emission within the blue visible spectrum will tend to overpower the relatively weak fluorescence with their directly reflected blue light.
  6. Hi aviator8. The yellow barrier filters used in partnership with blue excitation lights for underwater fluoro photography are typically a deep yellow Wratten/Tiffen 12 or other manufacturer equivalents. I am not aware that Cokin make a Wratten 12 equivalent - I understand that their 001 yellow filter has a different spectral curve. The precise results are liable to depend on the spectral composition of your blue video lights. Some photographers prefer to use yellow filters and masks produced by their blue light manufacturers to ensure an appropriate matching of light and filter spectrums. Firedive (https://firedivegear.com) produce custom yellow filters and masks that deliberately let a little of the blue excitation light through to the camera. This usually results in a deep blue as opposed to black background and slightly cooler images as the returning fluorescing green/orange/red light is mixed with some blue. Whether or not this is better than the more usual Wratten 12 filtration is down to personal preference. Obviously for accurate preview of the scene, yellow mask and camera filters need to match. To accurately preview the results underwater on camera, you need to flip the mask up to view the LCD screen. The fluorescent light produced by marine organisms is usually orders of magnitude less than that produced by normal reflected light so you will need to use high ISOs, particularly if you want to bring out the subtler oranges and reds that tend to be lower intensity than the prevalent fluoro-green. This also makes close-up photography easier than wide scenes where it is difficult to get large amounts of light onto the subject matter. Still shooters will more easily produce good quality results using blue excitation filtered strobes. Mark
  7. As I said, functionality varies from camera to camera. Sony introduced an option to link spot metering to flexible spot focus mode on the A6500 (which my wife has) but not the A6300. No, but the Sonys do have a flash-lock function (FV lock) that can be assigned to a button. Can't say I've used it but as I understand it, it allows a TTL flash exposure value to be calculated from a pre-flash and stored and then recalled following recomposition as often as you like. Might be useful in some circumstances, but perhaps that would negate much of the theoretical advantage of TTL?
  8. Adam, I think it's more complicated than that. While it doubtless varies from camera to camera, my understanding for the Nikon D500, is that the spot metering zone relates to the focus mode. Spot metering locks a small metering area to the centre of the frame only when Auto or 3D focussing modes are engaged. For Manual focus, Single Point and AF-S Dynamic Area, it is the user selected focus point that determines where the metering zone is centred. For Dynamic Area AF-C and Group AF-C, the user selected focus point initially determines where the metering zone is centred but the camera may move both the autofocus point and spot metering zone if it detects that the subject has moved within the frame. So for spot metering without AE lock, you are only limited to where you place the subject in frame in Auto or 3D tracking focus modes. Returning to TTL, my understanding is that engaging spot metering on the D500 alters the TTL algorithms used by the camera so that it no longer tries to balance the strobe output with ambient lighting of the whole scene but instead, adjusts the strobe output to correctly expose what it thinks is the main subject - i.e. the subject material around the metering spot. Where the metering spot is relates to focus as above. Again, the detail of this complexity probably varies from camera to camera. Mark
  9. Most of these kit lenses extend considerably with zoom. I expect at worst, some lenses may collide on zoom with the WACP and possibly cause damage unless used with a long port extension, in which case they may not perform well optically at the wide end. I have also read that lenses with smaller front elements - slower aperture - work better optically with the WAPC. Maybe someone from the Nauticam world can comment as this is relevant to potential use with the new Nikon Z series where there is a narrower range of autofocusing lenses?
  10. I think you're confusing two Z7 functions. It is the "Low light AF" custom function that increases low light autofocus capability from -1EV to -4EV. This is not an assist light but works with internal electronics at some expense of autofocus speed so should only be used in extremely low light situations. The "AF assist illuminator" on the other hand may be used in low light and outside a housing does shine a green light onto a close subject. As with most other housed cameras, I doubt that the assist illuminator will be useful underwater, but this has nothing to do with the Z7's inherent low light autofocus capability. Incidentally, neither of these functions work with AFC mode. The D850 and D500 DSLRs low light autofocus capability is better than the Z7 by specification (-4EV central spot and -3EV for the rest) and as far as I know this is available in AFC mode. -4EV corresponds to half-moonlight illumination so extremely low light and may be a lot darker than most of us try to autofocus even underwater. However, in his Z7 field report, Nikon Ambassador Marcel van Oosten suggests that the Z7 Low Light AF accuracy in AFS mode is even more accurate than with the D850. He does also say that from his limited experience (using pre-production firmware), that AF is in general not as fast as on a D850 and that tracking a moving subject is more challenging. Mark
  11. I agree that the Sigma 17-70 Macro is no Jack of all trades underwater and certainly not a good underwater macro lens. However it does retain a useful specific but more occasional role in my lens collection as a flexible fish portrait lens. It has a good reach for shy creatures but also allows you to fit in all but the largest species that allow closer encounters.. Mark
  12. Hi Mark. I cant offer personal comparative experience with the Nikon 10.5. I would suppose that as a much more modern and expensive lens, the 8-15 might be optically better, but of course as a zoom lens, design compromises will have been made. These compromises arent obvious to me in underwater use. Regards, Mark Hi Mark. I cant offer personal comparative experience with the Nikon 10.5. I would suppose that as a much more modern and expensive lens, the 8-15 might be optically better, but of course as a zoom lens, design compromises will have been made. These compromises arent obvious to me in underwater use. Regards, Mark
  13. Hi Mark. Optically, the greatest difference is substantially less chromatic aberration with the 8-15. Subjectively, the lens is also significantly sharper. As expected, these differences are more pronounced towards the edges of the image. A downside is the reduced useful zoom range on DX meaning less reach. If youre not careful It is also easy to waste a few pixels by zooming out too far and cutting off the corners. These issues can be avoided by using a Kenko 1.4x teleconverter although this does sacrifice a few degrees of coverage at the wide end. Optically this combination works well behind a dome. When I last looked, no manufacturer offered a zoom gear for the combination so I use the standard Nauticam gear and a removable collar that provides the necessary extension. For me the image quality improvements far outweigh the minor downsides and I have retired my Tokina. Regards, Mark
  14. Yes, me too. A thread from the Strobe neoprene jacket caught in the O-ring. Salt water rapidly entered the Strobe body itself from the battery compartment. It is not fully sealed. Maybe gas pressure from the short-circuited battery cells is what does it? Mark
  15. This warning by Panasonic doesn't appear to be new. Here's a link to a thread that's 8 1/2 years old, discussing Sanyo's then recommendation that Eneloops should not be used in waterproof lights: http://www.candlepowerforums.com/vb/showthread.php?243109-Eneloop-s-safe-in-Waterproof-lights There must have been very many Eneloop cells used in underwater strobes since then. It would be interesting to know what are the circumstances of use in strobes that might lead to hydrogen venting. I would suppose that any increase in pressure within a sealed battery compartment might be a greater functional concern than a risk of hydrogen conflagration when the gas is released?
  16. Hi Kirsty, Welcome to Wetpixel. Like you, I have usually used the second slot for backup. With the D500, in this configuration write speed is limited by the slower card i.e. the SD slot. For most underwater shooting, the large buffer and the limitation of strobe recycle time on high speed shooting bursts means that the SD card write time isn't a real limitation. However, there could be occasions when shooting longer bursts of fast action, using natural light or possibly low strobe power mean that you would like to clear the buffer as quickly as possible. Usually these situations would be predictable and it's easy to switch second slot function on the fly. If needed you could then back up to the SD card in retrospect. I don't think there's a right answer to how to configure the slots on a D500 - it depends on your shooting preferences. Life just got a bit more complicated compared with the D7200. Of course the advantage of an XQD card isn't just write speed. Read speed is also potentially higher so uploading images should be faster as long as you don't have a bottleneck somewhere else in your system. Mark
  17. Or to put it another way Justin, regarding macro lenses underwater, Sony APS-C shooters face fairly similar choices to Nikon APS-C shooters (60mm or 105mm) and Canon cropped frame shooters (60mm or 100mm). For small stuff the longer focal length lenses offer much more useful working distances for a given magnification and diopters are more effective. For medium or larger sized subjects, longer focal length lenses force you to back off if you want the entire subject in frame. Apart from perspective differences, this introduces a longer water column that is liable to reduce image contrast and quality and at the larger subject end may require more power from your strobes. As we often don't know what creatures we will find before committing to a dive, I often find that Sod's law dictates that the optimal lens for a particular subject is the one that's topside! Mark
  18. I agree with all Chris's observations. Compromises are part and parcel of all photography, whether it be size and portability, flexibility, usability, durability, cost and of course IQ. Photography in the aqueous environment imposes an additional major layer of compromises, not the least of which being the need for refraction correction for wider angles of view. Understanding the compromises we are all making is important as apart from helping with equipment choice, it will determine subject selection and approach and best camera settings. Although there is currently a resurgence in interest in more sophisticated water contact optics, the simple dome port with all its optical compromises remains the most practical and cost-effective option for most of us at the moment. Just how much IQ compromise we are willing to accept, particularly at the edges and corners, ends up being a personal decision. I am sure your 10-18 will perform adequately behind the Fantasea 155mm dome, but assuming that the different diameters are more or less proportionate to their radius of curvatures, I would expect better performance behind the Zen 170mm dome with which I have experience. To a degree it is possible to compensate for the poorer edge performance of smaller domes by using smaller apertures (perhaps no larger than f11 to 16). Although I am primarily a DSLR shooter, together with my daughter we also use an A6000 (land and underwater) and A6500 (currently only land). I agree that both of these cameras are very technologically advanced and capable at their relative price points. Limited lens choice was long an Achilles heal for Sony E/FE mount cameras. Although this has been steadily improving for the full frame lenses, Sony don't seem to be investing in new lenses for their cropped sensor cameras. This forces Sony cropped sensor users to consider using the FE lenses, but their size, weight and cost negate one of the advantages of cropped sensor CSCs. For underwater macro use we use the Zeiss Touit 50mm f/2.8M Macro and the Sony FE 90mm f/2.8 Macro G OSS, both of which are quality lenses. For wide-angle, the Sony 10-18 is good. The Zeiss Touit 12mm f/2.8 is said to be even better but of course it doesn't deliver zoom flexibility. But to complete an underwater set, a fisheye is necessary if you want to really close in that water column distance and get the most striking perspectives. In my opinion it's there that the Sony system struggles with native options. I hear good reports of Fantasea housings but have no personal experience. I have lots of Nauticam experience and although more expensive, Nauticam currently clearly provide a more mature and comprehensive system that is continuing to evolve and expand. That may be important now, but as your underwater photographic journey progresses, it may become even more important. For underwater photographic gear, post sales support is also important and you may wish to take availability of local support into consideration when making equipment purchase decisions. Mark
  19. Hi Matt, It is true that the nodal point of zoom lenses may vary according to the focal length. By how much is a feature of the particular lens design. The housing manufacturer's port extension recommendation is therefore likely to be a compromise. As Chris said above, extensions come in fixed increments so there's also likely to be an additional compromise there. Despite this, there is some leeway in optimising the port extension and you can expect reasonable performance from this lens behind the dome and recommended extension throughout the zoom range. I have experience with the Sony 10-18 and it works pretty well behind a medium sized (170mm) dome. It would probably work marginally better with a larger dome, but ~170mm is pragmatically a good solution for use on mirrorless APS-C CSCs. As a rectilinear lens, it is unlikely to perform very well at the periphery of the image with a mini-dome (~100mm). Should you at some time in the future want the advantages of using a very small dome port for close focus work, you would need to consider fisheye lenses. Currently there isn't a high quality native APS-C E mount fisheye lens in the Sony range. One workable alternative if your housing provider has an appropriate port/extension is the Metabones E mount to Canon adapter coupled with a Canon mount Tokina 10-17 lens. There is a Nauticam solution for this combination but I don't know about Fantasea. Mark
  20. Hi Matt, Since no one has answered so far, I’ll give this one a shot. There’s no intrinsic reason why a 50mm lens on an APS-C camera can’t be used behind a dome port. For instance, the Sigma 17-70mm Macro that has been quite popular with underwater cropped sensor DSLR users as a “Jack of all trades” lens includes that focal length and is usually used behind a large dome port. But there are a few things you should consider before using this combination: Firstly, the optical advantages of using dome ports are most significant in the more peripheral parts of images produced by wide-angle lenses. There is little optical advantage using a dome port compared with a flat port at the relatively narrow angle of view provided by 50mm lenses on APS-C. Secondly, the lens needs to be able to focus on the quite close virtual image produced by the dome. Not all lenses have this close focussing ability. Lenses that don’t focus close may sometimes be used successfully behind a dome by adding a positive dioptre close-up lens on the filter thread. Thirdly, the dome needs to be placed optimally in relation to the dome by use of an appropriate extension to achieve good optical correction. This usually means placing the nodal point of the lens close to the centre of radius of the dome port. For lenses not widely used underwater it can be difficult to establish the nodal point of the lens and sometimes the centre of curvature of the dome is also difficult to establish. Fourthly, the uses underwater of an intermediate focal length lens such as 50mm are likely to be different from use on land. For scenic shots, shorter focal lengths than 50mm are preferred as they force a closer approach to the subject matter, reducing the murky intervening water column and making it possible to illuminate the subject with strobes. 50mm is a useful fish portrait focal length that works OK behind either a dome or flat port. 50-105mm is also a useful focal length range underwater on APS-C for macro shots as long as the lens has very close-focussing abilities (preferably able to achieve 1:1 reproduction). For close macro work with a 50mm lens, a flat port is far preferable to a dome as working distance will be very short and a dome port will eat into this distance. The diameter of the dome port may also make it difficult to get close enough to the subject as rectilinear lenses don’t work well behind mini-domes. Finally, it is nearly impossible to add wet close-up lenses to a dome port and even if it was physically possible to do so, the added distance between 50mm lens and wet lens wouldn’t be optically optimal. I hope some of this helps. There are a lot of new technical considerations when moving from land to underwater photography. Mark
  21. I have no knowledge of the usability, reliability and durability of Meikon housings, but the cost is of course going to be a lot less than for the excellent Nauticam ones. I agree that the Sony 10-18 is a fairly affordable lens that delivers pretty good results together with a degree of flexibility, and it is what my daughter uses for much of her underwater wide-angle work when she isn't using a fisheye. In my opinion it would be a better option than the Z 16/70 for most wide angle work because of its much wider field of view and ability to focus on subjects close to the dome, but of course the OP already has the Z 16/70. Incidentally the Sony 10/18 also works well behind a 7" dome port on the Nauticam system. The 10/18 is a bit too wide for fish portraits apart from the very big or perhaps some bottom dwellers that allow you to get very close. It all comes down to what type of shots you are looking for. Of course Ikelite also already produce a plastic interchangeable port/lens housing for the A6300 that is substantially cheaper than the Nauticam system: http://www.divephotoguide.com/underwater-photography-special-features/article/review-sony-a6300-ikelite-housing/ When I changed from an Ikelite system to a Nauticam system a few years ago, the improvement in ergonomics and pleasure of use was quite considerable.
  22. Hi Antonio, The Zeiss 16/70 is a great travel lens and although a little bulkier, it is far better optically than the 16/50 PZ. My family and I have used both lenses extensively with A6000 and A6500. The Z 16/70 works fine behind a 7" dome. We use a Zen glass dome. It doesn't require a diopter and the corners are OK with the usual caveat of the need to stop down when using a dome (at least f8 to f11 depending on your personal sharpness standards). The 16/70 range underwater on an APS-C camera is a bit of a Jack of all trades but master of none. As a rectilinear lens, at 16mm underwater, it is not very wide but still fine for reefscapes etc. although a fisheye lens would allow you to get a lot closer and provide more dramatic perspectives. This focal length range does work well for medium to large size fish portraiture and for catching the more shy large pelagics. The greatest drawback of this lens underwater is that it doesn't focus close. Unlike say the Sigma 17/70 macro on a cropped sensor DSLR, this lens just doesn't cut it for macro or anything small, so full utilisation of the versatility of the zoom range is negated. Although I haven't tried it, the Nauticam WWL-1 wide angle conversion lens is said to work very well in front of the kit 16/50 PZ and flat port and provides full zoom through and up to 130 degrees angle of view. The sharpness is apparently remarkably good despite the limited optical quality of the kit lens. Mark
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