Everything posted by Chris Ross
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Has anyone used the Tamron 90mm f2.8 Di III
Phil Rudin has reviewed it already, the review is in the latest Underwater photography magazine: https://www.uwpmag.com/ It's a free sign up to download it.
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Getting the most out of Olympus 12mm 2.0
There's quite a few. The 12mm is good in that it works OK in a small dome I believe. The 12-40 and 12-45 are both great lenses, probably need a 170mm dome at least for them though and there's the 8-25mm as well. Or adapting the Canon EF 8-15 lens is a great solution. On m43 this gives you a lens that goes from a full frame fisheye all the way through to a 14mm lens (28mm full frame equivalent) in field of view. So it is effectively a 8mm fisheye combined with a 7-14mm lens (with barrel distrortion) in terms of field of view.
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Technical Query
Are you talking about subject recognition? that shouldn't recognise dust and bubbles. I would think you would need to develop a routine of some type, don't know if you use back button focus, but this solves lots of issues. Cameras generally will jump to the background rather than foreground in my experience at least so you should be able to take advantage of that. If you're troubled by a dust bunny or something, move the focus point away so the camera doesn't see it. If you have tracking focus that works use that and AF when you are over the subject then let tracking takeover. If you are talking fast moving big animals, pre-focus on your fin tip which will get you closer to the right focus point. Plus a blower bulb is your friend, blow out your dome just before assembling it.
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Technical Query
The minimum focal ldistance is specified from the focal plane at the sensor, you need to subtract the flange length and the length of the lens and adapter. This works out to be focusing very close. I think you possibly need to keep the dome clean and brush off bubbles if they form. Also consider change to just using just the centre or a single focus point and place it on something with decent contrast if you are not doing this already. If you use back button focus you an control what the camera focuses on better, if needed focus and re-compose is easy this way. I use that lens on my setup and it rarely gives me problems.
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Strobes or Housing-Which one to risk?
Good to see, I think many travel insurance policies exclude checked baggage.
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DIY Fiber optic cable mount
I assume you are trying to mount fibre optic cables to a polycarbonate housing to trigger using the camera onboard flash. Most compact housings usually come with an accessory or have one available to mount fibre optics over their flash. The price for the item you linked seems quite excessive - probably why it's discontinued. If you have a TG-6 this item seems quite reasonably priced: https://www.housingcamera.com/aoi-fca-01-fiber-optical-cable-adapter-for-tg-3-tg-4-tg-5-tg-6-cameras.html?srsltid=AfmBOopnMsdJR7u-RZHSxfJxGkmfrKWORmn2Ox2V7Lwa6TvFNBCC_qLI If you are making something yourself seems like double sided adhesive tape might be a good option. as for size, most of the dedicated ones sold seem to cover the entire flash window. There's threads on 3D printing accessory in this forum, be worth searching through them, to see tips on printing and materials to use when printing. Have a look at this thread: A couple of files linked there you could modify.
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Housing Lanyards
Any ships chandler should sell something similar I've bought a few like this from our local one.
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7Artisans 4 mm
Hunting around on the webpage found a diagram showing the lens is 54mm from bayonet to top of front element, which is almost the same size as the the Panasonic 8mm. This suggests it would be close to working with a fisheye dome and no extension, same as the Panasonic lens, however with a 225° field it would need to sit a little forward of where a 180° fisheye would. It's probably something you would need to try in the housing to confirm. I would agree though that the Sigma with AF might be a better option, though you would have to hunt around to buy one second hand.
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Strobes or Housing-Which one to risk?
It appears flying to Fiji out of LAX, that Fiji air is the only option unless you want to connect through Auckland on AirNZ at greater cost and apparently they are pretty strict on carry ons, probably as they are effectively the only game in town? Flying somewhere else like the Phillipines will probably open up a lot more possibilities. Another strategy to use is of course the vest which you can don if you encounter this behaviour and know exactly what to remove to get the weight on spec. Also mentioning the lithium batteries which are not allowed to be checked. On the topic of insurance, read the fine print, I have seen policies that exclude things like cameras if they are checked sometimes with an allowance that it is covered if the airline forces you to check the bag.
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Flare depending on strobe model
It will help to visualise how the plots from the Retra post compare to the field of a fisheye lens. The often quoted rule of thumb is to separate your strobes the the same distance as the distance to your subject. With wide beams you may point them out some more. If you take the zone diagram from the retra link and copy and superimpose them to show the strobe coverage from each strobe, you can then superimpose the frame width of a fisheye lens - assuming about a 135-140° horizontal field. you will see opposite the strobes the beam is centre plus zone 1 (green brightness) If you look at the plots of brightness in stops you will see the Seacam is 1.5 stops brighter in Green (zone 1) at constant centre brightness. So to get the same exposure the Seacam would be turned down a bit on centre brightness compared to the Z330. To me it seems that the more even beam would be less prone to flaring as the strobe is turned down with lower power in the centre compared to the less even beam. Add to this the tendency towards a cross shaped beam with the Z330 and the fact you are probably aiming the wide beam strobe out some more it gets the bright central beam further away from the dome glass as it leaves the strobes. The other thing to note is the very outer parts of the beam don't contribute much to the image even with the fisheye lens plus the fact that the Zone 3 (magenta) is at least 4 stops less bright than the centre of the beam. the beam widths are: Zone 1: 90° Zone 2: 108° Zone 3: 126° Zone 4: 131° All based upon the Retra webpage here: https://www.retra-uwt.com/pages/flashgun-light-comparison
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Nauticam a6300 vs Seafrogs A7RV
Not what I was trying to suggest - the suggestion is to look for full setups possibly including the camera, Sony A6xxx series that is a bit newer or branch out into other camera makes potentially. A6700, you'll probably only get new, but the 6600/6400 might be a possible choice. There's a 6400 on wetpixel now dropped to $1050. I know you like yours, but I feel you get what you pay for, though the returns are diminishing of course. A new ikelite setup is also an option.
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Papua New Guinea trip
Out of interest I had a look at flights to Kavieng and Hoskins and they seem to have changed since I went, Each destination will require a round trip to Port Moresby it seems. Some trips are direct others through another airport, depending on what day/time you want to travel. Careful checking of timetables and flight availability will be needed.
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Nauticam a6300 vs Seafrogs A7RV
For me, this is comparing apples with watermelons, yes the Seafrogs housings work and keep out the water and certainly some people are happy to use them, but they have limitations as Barmagalot outlines above. The lens support is limited as stated and it appears there is little attempt to optimise the dome positioning beyond making sure the supported lenses don't vignette. Not to say that some people aren't happy using them of course. I would also suggest huge improvements on land don't necessarily translate to the same benefit UW. Especially if you are looking at using any of the rectilnear wides behind a dome that is too small or not optimised. A good alternative for an upgrade might be to see what is on offer second hand through the classifieds.
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Marelux Apollo III
To be fair, the main point of comparison was the ability to rapid fire in which the Apollo clearly was the leader and a couple of sentences of quality of light compared with the OneUW and the Retra. He does seem to like the strobe. I'm also not 'not clear on what MTL actually does - it seems like it's a reduced power setting to allow the strobe to keep up a rapid fire rate? Perhaps it activates additional components internally like a larger or faster charging capacitor to assist?
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Retra Pro Max - Accu issue
Wondering what are you basing this on? Generally speaking the voltage displayed by a cell is only part of the story, I would think you would want to know what happens to voltage under load for each of the cells, what sort of load it can produce (in amps) as well as a capacity test before drawing any conclusions. I should add that the larger beam on the retra means that you will use more battery power. Some back of the envelope calculations show that comparing a 100° beam strobe and a 130° beam strobe, all else being equal the 130° beam needs 1.7 x the lumens to achieve the same lux (to get the same exposure) on a surface assuming the cone shape beam is evenly lit in both cases. This means 1.7x the battery power is required. This is the price of a large beam that is evenly filled with photons. As I recall the Retras used to publicise a 130° beam and the YS-D2 for example was around 100 to 110 or so depending on the diffuser used. This of course is idealised but should be good for an order of magnitude difference.
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Canon V1
It does seem like it would be a great compact option with effectively a wide m43 sensor. The $64,000 question of course is will anyone make a housing for it??
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Inon Z-XXX Prototype at Paris Dive Show
Agree that fibre is the way to go though there are some housing options where you can't do this, Ikelite is one, Seacam also though they have a full Canon or Nikon TTL built into their strobes which works over wire - apparently quite well.
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Seafrogs USB-C connector
USB bulkheads typically have a sealed cap on top to keep water out of the the connection. If you wanted to use the housing under the water, you would need a waterproof connection there. These connections are typically expensive. Dive and see make them, you would probably need a custom solution which would be quite pricey: https://diveandsee.com/connectors/usb/. Perhaps talk to them to see what they can offer, but the cost of components could be more than you paid for your housing!
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Domes and Teleconverters: Entrance Pupil ( Nodal Point )
To go with a TC you would need about 200 Euro +/- for the Kenko TC, the Nauticam 20mm extension to add on and a zoom gear. To me it seems quite worthwhile, but only you know your budget. If you decide to go with a Kenko, make a post here to confirm the correct version.
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Nauticam Wet-Mate Dome Port 38013?
If you want to do this with something small, consider using something like the INON wet wide lens, which is quite a bit smaller, you'd have to work out if you could use the Nauticam bayonet to attach it to your system. They seem to have reduced the range of cameras they support recently, but the old UWL-100 worked with Sony lenses. see this page: 💬1 - The Ultimate Wet Lens Sample Post | Mozaik UW Scroll down to the sea fan pic here: It's taken with the dome, which you don't need if you only want medium wide, but gives decent quality with the view of an 18-20mm lens in a smaller package. The Quality without the dome should be similar. The image is large and you can download it and the EXIf data is included so you see where the lens is zoomed to, taken with the same 16-50 lens.
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Manual focus fisheye with 4.33 Nauticam dome
Yes you could preset when focusing very close and it works quite OK on land, but as you focus very close with the lens it becomes more sensitive and you can't use hyperfocal distance like you can on land. In CFWA you want to focus on one of the closest objects as more of your depth of field is behind the focal point. If you don't you might find parts of the nearest object are out of focus. The other thing to consider is with CFWA you may need to change distance a little due to obstructions or the size of your subject, which could be annoying. Long story short if you are going to use a MF fisheye lens get a focus gear. You'll probably need focus peaking to help you focus.
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Domes and Teleconverters: Entrance Pupil ( Nodal Point )
If you are using the 8-15 with a 1.4x you get a 11.5-21mm fisheye. The region from 11.5 to about 15mm is unusable effectively as it has big chunks of the corners black and won't do circular of course. So whatever you do I'd suggest it would be a shame not to have the full 180 deg diagonal fisheye available to you. Just to be sure you are aware the order is camera-Sony 1.4x- adapter - 8-15 Lens. This means the nose extension on the SONY 1.4x needs to fit inside the adapter. It is known it fits inside the Metabones, it probably fits in the MC-11 but it pays to check. You need someone with an MC-11 to put one on the other to confirm. This combination (sony 1.4x) needs a custom zoom gear if I'm not mistaken. The MC-11-Kenko 1.4x-Canon 8-15 has an off the shelf zoom gear available from Nauticam. There was a post from one of users, Gudge, who poste about this a while back and that will have the details for using the Sony 1.4x, I'm travelling now and don't have time to search. I think Wolfgang could also advise on the zoom gear. I'd suggest if you are wanting a WACP substitute zooming will be important and this may be the controlling factor that decides which way to go if time is tight. I would also suggest that using the standard extension recommendations will be fine, any improvement from fine tuning is going to be in the second or third decimal place.
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Domes and Teleconverters: Entrance Pupil ( Nodal Point )
😂Yes we both went off topic a ways but it's interesting stuff . We disappeared off into the weeds to show that millmeter precision in entrance pupil positioning is nice but not essential to use the 8-15mm lens and that you can produce pleasing images with sub-optimal setups as long as you are not miles off base.
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Domes and Teleconverters: Entrance Pupil ( Nodal Point )
Yes no doubt, but IMO not enough to worry about if you are in the ballpark, I'd be happy for you to post shots showing all this harm to your images and I don't mean chessboards, sure it's telling you something but how much impact does this have on the final image quality? the examples I've seen that were 10mm out vs a lot closer didn't set the world on fire withe differences in quality to my eyes.
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Domes and Teleconverters: Entrance Pupil ( Nodal Point )
Yes I know that, but not really an option if you have a camera in an Ikelite housing, the larger 8" dome they offer is not ideal either, a bit too big to get in close. The compact dome under discussion is really only for fisheyes for CFWA work where it lets you get in really close, It's a compromise to get that in your face CFWA perspective at the price of less than perfect corners. The fact it does as well as it does is quite surprising really.