Jump to content

Tom_Kline

Industry
  • Content Count

    1272
  • Joined

  • Last visited

  • Days Won

    31

Everything posted by Tom_Kline

  1. I don't think so. To get to near 1/10000 of a second one has to turn down the power. For example- This site has some actual measurements: http://gock.net/2012/01/flash-durations-small-strobes/ The first strobe listed is a Canon 580EX At full power the duration is just 1/250 s. At half power it is close to 1/1000 s. To get to near 1/10000 s. one has to go to 1/32 power. Other strobes are not as quick. Both Broncolors had longer than 1/1000 s. duration at all settings tested. It would be cool if we had data like this for underwater strobes! I typically use my underwater strobes at 1/2 to 1/4 power so I expect the flash to be closer to 1/1000 s. rather than 1/10000 s.
  2. You can only go as far as the synch speed is a limit. Lower ISO might help to reduce the ambient part. Still, the strobe may not be able to stop the fish movement. I think I have come across this issue as well while photographing salmon. The female flicks her body several times in one second when she digs her redd (salmon nest). The speed at the tip of her snout is extremely fast (head moves in opposite direction to the tail). I have had to toss out numerous flash shots due to blurring. Ambient exposure was almost nil in many shots so I think it is due to the flash exposure being too long - 1/1000 sec. (I have heard of this as being an example of flash duration) may not be short enough for some movement.
  3. You should post some examples. A couple of possibilities: 1. The blur is coming from the ambient light part of the exposure. 2. It is coming from the flash part and the flash duration is too long for the fish movement. Few if any of the strobe manufacturers provide info on the duration of their flashes. They should do for given fractions of flash output: full, half, quarter and so on. The duration goes down as power is reduced. If you are going TTL this will be an unknown unless your strobe provides a readout of the output.
  4. I shot the Nikkor 14mm f/2.8 D quite a bit a few years ago but that was on a 12MB DX sensor (D2X). I got OK results even with a Wideport but the Superdome was better of course. Tom
  5. I have used the Canon 24-70/4 lens under water. I used it for many of the underwater shots taken this year in Hawaii that are on my website. I used a Seacam Compact Port. It may have a radius that is the same as an 8" hemispherical dome but do now know for sure. I used the lens with a Canon 500D achromatic diopter to focus closer than the minimum focus distance. I had to apply lens correction in post to fix a bit of vignetting. The macro feature is useless in a housing.
  6. The new Canon 28mm macro lens with the ring flash is an EF-M lens, designed for the EOS-M mirrorless cameras. The 60mm EF-S macro lens is quite popular among Canon APS shooters. Do not have one myself so cannot comment. I would recommend an AF lens over a MF lens like the Venus. You can still MF the Canon lens but will need a focusing gear, also for the Venus lens. I seem to recall that the Venus lens has a manual diaphragm - you should check on this. A manual diaphragm is going to be particularly challenging to use under water if even possible as you will need a control gear for this as well.
  7. I have made several postings here. As well you can see a few videos on my website that show my setups in action. I am using Seacam equipment. Main things you will have to figure out for your housing is how to attach the pole and how you will integrate remote control.
  8. I carry my housing, accessories and camera on board. I took the attached shots while at the Big Island this spring. I used the 1DX camera to take these pix so is not visible inside the housing. I used this f.64 brand bag. It is several years old, has been on several trips and thus shows some wear. The stuff you see on the floor in the open bag shot went into nooks and crannies. No space was wasted - the 100mm macro lens in a soft bag fit inside the stacked port extension tubes. A very short flat port is on the housing. The cover has pockets for small accessories, batteries, and spare O-rings. The external strap with fastex buckle is to make sure it does not blow up. I wore the watch ;->
  9. Some purpose built underwater strobes have very wide angle coverage such as > 100 degrees. For example I have been able to use a single strobe with a fisheye lens. Many purpose built underwater strobes also have a warm color temperature. Whereas many of the wide angle underwater strobes are medium to large sized (more recent strobes though are a bit smaller than those from the film era!) those intended mainly for macro use can be quite compact. Another advantage is that adjustments are accessible under water with simplified controls. You should be able to take "great" photos with a housed strobe but you need to be aware of limitations such as output intensity, coverage, color temperature. Tom
  10. New may refer to a new medium that has not yet been invented. In perpetuity is major league red flag. I would walk away from this - only use your own form. IMHO your contract must be explicit in the extreme that you are licensing for one use only - this does the opposite.
  11. I had one come apart on me while watching mantas at night on the Big Island - needless to say it was full of water before the end of the dive as well as not being able to hold the strobe. Not a good design for a strobe arm since it easily unthreaded. Locktite or something similar to the rescue.
  12. Looks too powerful to be a dive light or torch in British lingo. For me, the noun version of torch is something with flames leaping from it! :->> A slaved strobe, maybe with a lensed snoot like the LSD - note the sharp-edged spot of light on the bottom. Maybe a night dive?
  13. I agree - we just need to see the housings. As well, wait for any "issues" to get sorted out.
  14. Given that the Sea&Sea internal correction lens is made specifically for this port - this will theoretically give you the best result also given that you are using the optimal port extension per Alex above. Nevertheless I am finding the S&S lens works very well with the Seacam superdome tuned (optimal port extension) to a given lens. A consideration is that the curvature of the virtual image varies by focus distance - flatter closer up. Tom
  15. The strobe's guide number is for the flash exposure only and is mainly useful as a guide to compare strobes. This assumes the various manufactures use the same method to determine guide number. Underwater guide numbers are generally not the same as air as your surmise. However for underwater strobes the angle of coverage is more important than guide number - the wider the better since we tend to use the edges of the light from the flash. Shutter speed will also affect the overall exposure with longer exposures increasing ambient light. For underwater photography I tend to increase ISO rather than decrease shutter speed to increase ambient light exposure since I want to stay close to the synch speed whenever possible.
  16. I have used several old manual focus Nikon lenses on Canon DSLRs - pre-Ai, Ai, Ais it makes no difference. For example I have a vintage two-part 1200mm ED lens (not Ai or Ais), - it was a bit less expensive than the Canon lenses that is two stops faster. Good for those long distance wildlife shots over water. I have not however used any old Nikkor under water in a Canon housing. The issue with Seacam is that the Nikon gears are a slightly small diameter than the Canon gears. The only MF Nikkor that I have tried under water is the 15/3.5 lens. That was over a decade ago and in a Nikon housing. Since I was doing remote control I pre-focused. However only a few pix were in focus - I soon replaced this lenses with the 14mm AF!
  17. I watched the two vids. They are a brilliant way to expand the content of your book. These two alone might be worth as many pages as the book itself given the full screen view of pix that each would require a two-page spread! Obviously a lot of work went into creating the material - such as showing step by variations of lighting as well as diagrams and pix showing you in action. Very well done! Tom
  18. So which one? They have a number after MIR (in Russian the letters look like an M, backwards N, and a P). See this link for examples: https://en.wikipedia.org/wiki/Mir_%28lens%29
  19. Which old Russian lens? Specify lens port that was used.
  20. "This is a result of the shorter distance between lens and sensor" Can you explain why this is so? I remain skeptical.
  21. The lens has a very large diameter and thus may require a special port and port extension tubes for your housing adding more to the cost than just the lens. This may be one reason why we have not seen much published. It may be more useful for those shooting video when the video mode does not use the full size of the sensor. The 8-15 is much easier to adapt and works well under water.
  22. The Nikonos lenses were well known for their sharpness. This is because the 15, 20, and 28mm lenses were designed to work in water. They are less optically compromised compared to using an SLR lens in a housing. You can read many threads here dealing with the challenges of using SLR wide angle lenses behind dome ports. The early Nikonos cameras (models I to III) were entirely mechanical (no electronics) but were not problem free. I would recommend you find the Church and Church books on the Nikonos cameras and lenses to study up on them. A lot of good info here: http://www.southern-nikonos.com/
  23. It does look like a Nikon flash shoe that fits over the rewind crank - would need an actual body to make sure. You would need gears to fit on your lenses to couple with the gears in the housing to focus and set aperture. There are a lot of film options: other housings and Nikonos cameras.
  24. "- anyone know a strobe that natively supports any of the manufacturer proprietary wired digital TTL protocols?" Seacam Seaflash models 250D, 150D, 100D, and soon the 70D support Canon and Nikon (as separate versions of each strobe model) digital TTL.
×
×
  • Create New...