Chris Ross

I see the new maxi output is quoted in GN, while the circular tube strobes have power listed in Ws. I would be interested to know how the maxi compares to the output of the circular tube strobes.

I think there are a number of issues you are facing - first adapted lenses and macro are always going to be a problem, the second a lot of zooms are slow on the long end and less light means AF suffers generally. Plus kit lenses generally don't have the best AF a company has to offer. Extension tubes may work, but you are back to the same situation you have when using a diopter, the focal range is relatively limited. Adapters like the Nikon FTZ or Canon ef-R are probably less impacted and there are a number of EF or F mount short macros that may work well enough? Generally short primes are pretty snappy to focus. On my OM-1 the 30mm Panasonic is noticably snappier than the 60mm macro up to at least 0.5x. An extension tube on a fast prime may work as well??? Seems like there's compromises to be made, perhaps one is to accept taking video in a crop mode with a lens that is fast to AF but not so good at min focus or perhaps a lens that only reaches 0.5x? The difficulty in focusing seems to go as you increase magnification, particularly beyond 0.5x. I'm wondering if the Canon STM lenses that go to 0.5x might do well enough for you under this scenario? Just some random thoughts.

Depends on the lens in question, I know the Nauticam 180mm dome has a max angle of view of a 16mm lens with exit pupil positioned properly as the dome is not a full hemisphere. This means the exit pupil needs to sit forward of the optimum spot to avoid vignetting. The marelux has a slightly bigger throat which helps with positioning but not sure if it can be placed 100% correct. The Sigma lens you mention has a long minimum focus distance (28cm) while some newer lenses focus a lot closer like the 17-28 f2.8 tamron which focuses down to 19cm. This means it works well in smaller ports. There are lots of posts on the forum discussing that the new Sony wide zooms and the Tamron 17-28 among others will work well in a 180mm dome. I'm sure some will chime in with direct experience. I don't recall the Lens you currently have being among them. You could buy the 17-28 tamron and the 180mm port for less than the price of the 230mm port alone and get a smaller lighter package that is easier to travel with. Probably the more important question though is if a 14-17mm rectilinear wide lens is the right lens for what you want to shoot. Fisheyes are very popular for reef scenics and wet optics with the WWL are popular for CFWA and make for a compact easy to shoot and flexible setup.

It depends on how much buoyancy you'll be adding. In general you want the buoyancy components up high as they will want to turn to be there anyway even if the rig is overall neutral and the classic way to do this is buoyancy on the strobe arms. But if the buoyancy you add is too high you'll have a significant torque trying to prevent you from rotating the camera to point up. I think something 500-600 gr of buoyancy on the arms is fine, i have this on my regular rig and I don't notice the torque. On my newer setup using the Canon 8-15 on the OM-1 to get neutral I needed 2.2 kg of buoyancy and tried it with two 670 gr arms and two 210 gr arms and twisting it was quite difficult and I ended up removing the two 210 gr arms and dived it about 450gr negative. The reason for the torque is twofold - the amount of buoyancy and the arms being quite long it was placed a long way from the centre of mass so a strong lever. I am thinking of adding about 400 gr of buoyancy to the base plate. So just weigh your rig on a luggage scale in water and come back for more specific suggestions. What to do will depend on how much buoyancy you need to get close to neutral

You don't need an app to do that for you, just process a copy and copy it in as a new layer and mask it, simple enough to do in Photoshop.

Thanks Dave, The point is it makes comparing the fields you get from various lenses easier, particularly if you are comparing a rectilinear to a fisheye where the focal length is not a good guide at all. The purpose of providing a field of view is to help determine what sized objects you can fit within that field. Generally what you can fit is defined by the width of the long axis - you don't frame subjects diagonally in general. The issue you have is that the the barrel distortion of the fisheye and WWL is not linear, the degrees of field covered per mm of sensor increases as you get further from the sensor - the corners are stretched. This means that as you zoom in you get narrower fields than you might expect. The example I provided above of an 8-15 lens on m43 , from looking at focal lengths it seems like it is a 2x zoom lens, but it's actually like a 6 -28mm lens or a 4x zoom and replaces a fisheye and a 7-14 rectilinear in horizontal field coverage. Back to the original question, the 10-17 was very popular because it zoomed from a fisheye all the way to a 22mm rectilinear lens, about a 3.5x zoom ratio based on horizontal field. The only full frame match for that lens currently is an FCP which is an expensive, heavy option. The WWL-C has a similar 3x zoom range but shifted to the long end and missing the fisheye end. AN 8-15 with an added 1.4x gives about a 2.5x zoom ratio but lacks the reach of the WWL-C and Tokina 10-17. The other factor with the fisheye is the barrel distortion which brings your subject forward in the frame - it appears bigger and fatter - so for reef scenics it's really unbeatable. SO the choice to replace a Tokina 10-17 is if you mostly used the 10-14 range of that lens, an 8-15 with a 1.4x will replace that very well, but if you were mostly using the long end of the 10-17 the the WWL-C with 24-50 is potentially a better choice. If you do both reef scenics and CFWA then you might want both.

Dave, I'd appreciate it if you could explain why it is an issue to compare lenses this way rather than just throwing insults. The diagonal field of a lens is just a convenient way to compare with a single data point but doesn't give the full picture.

No I have the correct data, I am quoting horizontal fields of view that I calculated, not diagonals as I stated in the text. I find this much better to compare what size objects you can frame with a given system The 130° of the WWL and the 180° of a fisheye is mostly stretching of the corners. So a WWL has 130° diagonal field which seems like a 10mm rectilinear but the horizontal field is 106° which is closer to a 13-14mm rectilinear. Likewise the fisheye lenses are nominally 180° diagonal, but the horizontal field is about 140-144° which is something like a 6mm rectilinear if such a lens existed. See for example these two images, taken on m43 - the first is the 8-15 fisheye at 15mm, the second is the 7-14mm at 14mm. They basically frame the door the same way, the calculated fields on the long axis are 67 and 63°, while the diagonals are 88 and 78°. Using diagonals you'd think the 8-15 at 15mm had quite a bit wider view, but based on the long axis field of view they are very similar, the fisheye just includes more in the corners. which for the most part are unimportant for an image.

Your wide angle choice depends on how wide you want to go and how much reach you need. Here's fields of view of a few options compared to what you get from a Tokina 10-17. I am comparing by horizontal field of view rather than diagonal as this generally sets what you can fit within a frame. Fisheye corners stretch a lot more so than rectilinear of the WWL, but usually you don't have important subject matter there. Tokina 10-17 DX: Fisheye - 22.5mm rectilinear 144- 81° horizontal field Full frame: FCP with 24-50: Fisheye - 23mm rectilinear 140-97° WWL-C with 24-50: 14-43mm rectilinear 106 - 42° 8-15 plus 1.4x: Fisheye- 16mm rectilinear 144-97° The closet match to a Tokina 10-17 is the very pricey FCP. You already have the 8-15 so adding a 1.4x to that with a Nauticam 140mm dome would be a good solution if you don't need the full reach of the 10-17. I wouldn't consider the 14-28 for use in a dome, you need at least a 230mm and I recall seeing reports the 14-28 is not that great UW behind a dome.

Good to see new products being released, would quite like to see the specs with sizes and weights, power source etc.

Perhaps or the magnification is low enough that the increased magnification disappears in rounding to 1 decimal place. For example 1.04x is 1.0x to 1 significant figure. With short focal lengths you don't have so much working distance to eat into and diopters have less power at short focal lengths. As I understand it the Zeiss 50mm doesn't get longer when focusing close -i.e. internal focusing which decreases focal length to focus closer- the power of the diopter drops away with the decreasing focal length. The Sony 50mm macro is on the port chart and the magnification with the CMC-1/CMC-2 is 1.4x/1.3x with much less working distance than the Zeiss. The Sony lens extends to focus close so won't lose as much focal length. I would suggest don't assume the value is a typo, rather try and verify it with Nauticam before you buy.

Looking at the port charts I see it suggests the CMC-1 will give you 1.3x and 17-75mm working distance which is a little tight on max magnification. The CMC-2 it lists magnification as 1.0x and 30-130mm working distance - the working distance is more usable, but the magnification at 1.0x is the same as the bare lens, which seems a bit odd?

Very slow AF I believe.

Not an easy choice, there's trade offs a-plenty in APS_C. Canon allows good WB, probably good AF with the old EF-S 60mm macro on their adapter, the 18-45 lens is also listed with the WWL. Sony allows you to use the WWL with the 28-60 which is a good solution by all accounts - the Zeiss 50mm seems to work well with the A1 - but how is it with the A6700? As I recall the 90mm was regarded as a bit slow until the A1 came along so AF seems to be a bit body dependent. On housings I see Marelux now has an R7 housing with an A6700 coming soon. If you were looking at photos I'd be suggesting m43 as a good option plenty of lenses to choose from there, but for video OM system doesn't have the reputation that Panasonic does and AF might be lacking with the Panasonic bodies for macro. If the OM-1 were good enough in video the 30mm Panasonic lens is very snappy AF and a wide choice of rectilinear wides available.

I think this is probably the real key to whether you should go for a rebreather - there are some people who just shouldn't consider them. For myself I'm fairly meticulous and if ever I've had UW issues come up I've coped quite well, but I'm not sure I'd trust myself to be as meticulous as I need to be all the time. I can 100% see the advantages but for 90+% of the diving I do I wouldn't be taking advantage of the long dive times and depth capability.

Hi Val, welcome onboard, good to have you here and hope you find the site useful. Probably best to ask the tech questions in the video forum, not everyone looks through the intro forum.

I can see why they are recommending it - seems mostly around space due to big file sizes and relatively small SSD internal drives from the reading. I do keep forgetting that you are quite constrained with a laptop, I do all my serious editing on a desktop and you can readily install a 4 or 8 TB SSD internally which you could edit from.

Again the interface speed is much faster in general than what is connected to it. I don't know what the price difference between the various models is but it always used to be the very top model was a sizable premium over a mid range one with a real world benefit that was rather small. Looking at those benchmarks if I'm reading them correctly, I'd be seriously looking at 3rd column 16C/40C model if could be had a decent discount, the last column M4 16C/40C model seems faster but not that much faster, and processing time seems connected to GPU cores for video rendering. Unless of course you see a pair of 8K monitors in your near future.😂

I'm not sure I understand what the issue with this machine is, but it sounds to me like a workaround rather than something you'd want to adopt regardless on a more capable machine.

Whether this is actually faster depends on the drive read/write speed rather than the bus speed. The T7 SSD will read/write at around 0.5- 1 GB/sec according to specs I found. Typically the internal NVMe SSD is faster at 2-3 GB/sec, the M3 is rated at 2.8 GB/sec. Whether this translates into a faster experience on one or the other depends on a number of factors, mostly around overhead that the bus and processor are handling. The Thunderbolt interface is very fast but typically it's not the limit.

I think for still images, these days it's not a very demanding task unless you are focus stacking or sometime like that with multiple images. Otherwise fast storage helps load big files faster. So the biggest gains would be in video rendering. I don't now if your current Macbook is portable size, but if I was considering it, I'd be inclined to go for a desktop and relegate the laptop to travel support.

Not the best view for ID, but it looks like a triplefin, perhaps the Highhat triplefin - Enneapterygius tutuliae

Yes I know, but the 787 needs it batteries to fly and banning phones or laptops would create a huge uproar. Hopefully it never happens but never under estimate what might come about from a knee jerk reaction.

It's not the strobe batteries I'm concerned about almost certainly it will be some other battery, just due to the numbers around. Yes they have equipment to deal with it, but if we get a bad incident that is not well handled there always the possibility of a knee jerk reaction which makes flying with Li-ion more difficult.