flowdesign

I just want to share some info that’s out there if you dig deep enough, but honestly, it’s a pain to track down. Here’s the deal: brands like Nitecore and Xtar don't actually make batteries. They just buy cells from the real manufacturers, slap on a protection board (either their own or from someone else), and wrap it in their own label. If you check the specs from the world’s actual battery giants—Samsung, LG, Sanyo, or China’s EVE—you’ll notice something fishy: none of them make a 21700 cell with a crazy 6000mAh capacity. So, whenever I see those "super capacity" claims from these third-party brands, I’m highly skeptical. When you’re picking a battery, ignore the marketing fluff and look at Capacity, Max Discharge Current, and Cycle Life. Capacity is obviously how much juice it holds. Max Discharge is the big one—it’s what allows your video lights or flashes to run at high power without quitting on you. Cycle Life is basically how many times you can recharge it before it’s trash. In my experience, most flashes and video lights need about 20–25A of max discharge to handle 90% of what you’ll throw at them. This means your video lights stay bright and stable, and your flash recycles way faster. Protection boards (PCBs) are there for safety—to keep things from blowing up if there's a short circuit. But here’s the catch: they often throttle the battery's performance. For instance, I’ve used high-power cells with added PCBs on Marelux flashes, and even though the cell itself was strong enough, the PCB blocked the power flow and the flash wouldn't even turn on. Plus, adding a PCB makes the battery physically longer, so it might not even fit in your gear. If you’re still with me after all that technical talk, here’s how I spend my money: The "In-Box" Battery: If a light comes with a branded battery, I’ll use it. At least you know the manufacturer (hopefully) tested it with that specific device. Buying "Raw" Cells: For extras, I buy directly from the cell manufacturers (like Lishen, EVE, etc.). Why? Because I can see the real spec sheets and know exactly what I’m getting. Plus, it’s way cheaper. Check this price gap: Lishen (The Manufacturer) 5000mAh: Usually around $5–$8. https://liionwholesale.com/collections/batteries/products/lishen-21700-lr2170sd-9-6a-flat-top-5000mah-battery-genuine Nitecore (The Label) 5000mAh: Usually $20–$30+. https://nitecorestore.com/products/nitecore-nl2150-21700-5000mah-rechargeable-li-ion-battery?currency=USD I’m not trying to judge Nitecore or any other brands. I just don't think the "extra value" they provide is worth the massive markup. Personally, I’d rather go straight to the source. It gets the job done just as well, and I’m not paying 3x the price just for a fancy sticker.

Hi Dave, could you share more details about your design, quite curious about the structure of it. I assume it must be a hollow but sealed to be waterproof, right?

I get one about 2 years ago but I have to say it's not so good as I expected. Especially when you are trying to adjust the buoyancy by squeezing it, if you squeeze too much air out, you have to tak off your mouthpiece and blow it again, so on and so forth, then you will give up to use it again...🤣

Two options so far: You can get this M82 Filter Holder for MFO-3 from Nauticam, put a common 82mm lens cap on it or screw another UV filter. Try this 3D print hood as a cheaper alternative.

Consider to add a hood to protect the lens😄

That's exactly something cannot be predicted before printing🤣 I have tried different materials (PETG, PETG-CF, TPU80, TPU95, etc.), overall is ok but you have to accept the tolerance even you are using the same setting on same printer. Tips for the installation, if it's too tight to assemble, put two parts into warm water (NOT HOT!!!) to soften it, then you will feel easier to put it on the right position.

I was using TC1.4 and new 100mm macro in my last dive trip, for me I'm really satisfied witht the image quality, here is a corp of central part for your reference. This is a tiny Anker's Whip Coral Shrimp about 6-7mm in length.

I did some modification to my LSD, to make is eaiser to attach\deattach from the strobe, the major part can be clipped on the BCD for most of the time underwater.

I'd expect the similar result as using Sony FF body+90mm macro, larger FOV, zero to almost infinity focal, and slightly negative magnification. And maybe faster AF?

Interesting, I suppose that RC mode only has the relevance with camera body, seems I need try the lens before making the order. Thanks for the suggestion.

Honestly, I can’t even imagine trying to chase blackwater critters with a 90mm — that thing would make it impossible.😆

Thanks for the suggestion, so what do you think about the focus speed and accuracy comparison for these two lens?

Hi Alex, I believe now you are always using MFO-3 in the blackwater, considering the focal area change, will you also change the strobe position a little bit or still keep the same as what you showed in this pic?

Hi Chris, fully agree with MFO-3's advantages, I used in my last dive trip together with new Sony 100mm macro, really incredible result, even it was my first "real" blackwater dive. But considering to have two MFO-3 is a really "Crazy" idea😊 I know you have very rich experience on various macro lens for M43, just want to know the overall impression between 30mm and 60mm+MFO-3 for the blackwater? Focusing speed, focal length, FOV, etc. Big thanks in advance~

I have no experience of M43 UWP, but theoretically it must be more powerful than TG series in most cases. Consider over 85-90% of our diving is only for macro, we rarely need to shoot macro and wide angle just in one dive even for the dives at the same day. Which means, I don't have to consider to use one lens fits for all, and if the existing wet lens can be used to enpower the entire setup, that's great, but if not, I'm also fine with that😀 Since the marco setup is much more important, I'd like to know: Does 60mm is enough for both normal macro and blackwater, or 30mm is recommended for the blackwater? As what Chris mentioned, panasonic 30 might be a better choice, but anyone has chance to check whether it could fie the same port as OM 30mm? It is 63.5mm in length, 3.5mm longer than OM 30mm.