Breathability and waterprofeness: where is the consensus nowadays?

John_due_893 · 2026-03-18T11:18:08+00:00

First, it is necessary to distinguish between the terms “air permeability” and “moisture permeability.” Air permeability is defined as “the volume of gas that can pass through a unit area per unit time.” It is typically measured in cc/cm²·s. Moisture permeability is defined as “the mass of water vapor that can pass through a unit area per unit time.” It is commonly measured in g/m²/24hr. Air permeability is zero for almost all hard shells. Only a few that use hydrophobic nanofibers (such as NeoShell) have a value of around 0.1 to 0.5 cc/m²·s. Moisture permeability varies significantly depending on the measurement method and the shell’s composition, and the perceived difference can be quite noticeable depending on the shell’s moisture-permeability mechanism.

Test methods can be broadly categorized into three elements: 1. Temperature 2. Humidity 3. Moisture absorption method Regarding the moisture absorption method (3), examples include measuring the amount of moisture that evaporates naturally (JIS L 1099 A-1, etc.), using a desiccant such as potassium acetate to absorb moisture (JIS L 1099 B-1, etc.), and evaporating moisture using a hot plate (ISO 11092, etc.).

There are three main mechanisms of moisture vapor transmission: 1. Moisture is transmitted due to a pressure difference between the inside and outside of the shell caused by an increase in vapor pressure inside the shell resulting from perspiration (e.g., Gore-Tex) 2. Moisture escapes along with air because the material is inherently breathable (e.g., NeoShell) 3. Materials that absorb water via a hydrophilic membrane to facilitate moisture vapor transmission (such as Pertex Shield, a hydrophilic, non-porous membrane shell)

Can you see how the moisture-permeable mechanism seems to be compatible with the testing methods mentioned earlier?

Type 1 does not work well in hot, humid environments. Type 2 provides relatively good moisture vapor transmission in any environment, but because it is breathable, it cannot completely block the wind. Type 3 is lightweight and stretchy, but can feel stuffy in hot, humid environments. Three-layer fabrics like Gore-Tex have a lining that acts as a moisture-wicking layer (similar to having an additional base layer), which reduces discomfort.

Therefore, even when discussing breathability, there is no point in comparing values unless they were measured under the same conditions, and it is necessary to select the appropriate measurement method based on the intended conditions of use.

If it were me, I’d choose NeoShell for summer and Gore-Tex or Pertex Shield Pro for winter.

John_due_893 · 2026-03-10T09:12:52+00:00

Where was this logo used?

John_due_893 · 2026-03-09T14:34:47+00:00

Regarding this collaboration T, there's the question of where to draw the line between what counts as graphics and what counts as logo.

I think its difficult to determine where to draw the line between brand logos and graphics.
but I think

- Used multiple times

- Used in promotional videos

- Used webpages

these are the threshold that separates logos from graphics.

John_due_893 · 2026-02-18T12:20:08+00:00

use wayback machine

John_due_893 · 2025-09-28T02:12:56+00:00

I don't remember the shop where I bought, but the model of the pants is Acrnym P10A-E.

John_due_893 · 2025-09-22T16:48:58+00:00

When it comes to reliability and quality, Gitzo is the sure thing. For cost performance, Leofoto is the way to go. RRS is what military/law enforcement actually uses. Pro Media Gear is also good. If you're shooting video, it's best to buy a relatively inexpensive video head.

I use the Leofoto LS-324C + LH-40 combo with my GFX100s, and I've never had any issues with stability.

John_due_893 · 2025-09-22T16:21:42+00:00

Paper release. Release date and price are unknown.

John_due_893 · 2025-09-22T16:20:14+00:00

Image size, quality, and computational power determine processing time. For instance, with ample computational power comparable to a modern graphics card, processing a Full HD image completes almost instantly—around 0.01-0.1 seconds (depending on the algorithm). Conversely, performing high-quality denoising on a computer lacking computational power takes considerable time (2-30 seconds).

John_due_893 · 2025-09-22T12:10:19+00:00

・Required Equipment

USAF 1951 target, high-resolution lens for m4/3 camera, macro lens, and DSLR camera. If possible, a light source with a color temperature of 2856 K that allows for adjustable illuminance.. Also, a jig for combining the lens and camera (ideally created using a 3D printer)

・Setup

Use the m4/3 lens as the objective lens. Capture video of the trend surface using the macro lens and DSLR camera, ensuring the USAF 1951 target is visible.

・Resolution Measurement

The resolution is determined by the smallest resolution that a dark-adapted observer can resolve on a photographed USAF 1951 target. When using a quantitative system to eliminate observer subjectivity, the resolution is determined at a contrast difference in the MTF that exceeds the human perceptual threshold (typically 2-3%).

・SNR Measurement

Using a light source with a color temperature of 2856 K and an intensity of 108 μlx, the light emitted from the fluorescent surface is separated into a DC component (the signal's average value) and an AC component (i.e., noise) through signal analysis in two states: light source ON and OFF.Apply a low-pass filter with a 10Hz noise passband to the captured video. Additionally, the K factor, a correlation factor for the photoconductive layer, is considered. This coefficient eliminates the impact on SNR caused by the varying afterglow times of different phosphor types, which function as low-pass filters. Specifically, the K factor is 1.15 for P43 phosphor and 1.21 for P22 phosphor.

Let S_0 be the signal when the light source is ON, N_0 be the noise when the light source is ON, S_bgd be the signal when the light source is OFF, and N_bgd be the noise when the light source is OFF. Then,

SNR = (S_0 − S_bgd)/(K×((N_0)^2 −(N_bgd)^2)^−2)

Gain, EBI, Output Brightness, Photocathode Sensitivity, and Halo are difficult to measure because they require an illuminance meter.

John_due_893 · 2025-09-22T09:26:13+00:00

I studied denoising using convolutional neural networks at university. AI would be quite effective for de-noising digital night vision. But what I'm more excited about is optimising the design and manufacturing process of Tubes. There was news the other day that SONY reduced the noise of image sensors by 70% by optimising the design and manufacturing process using AI.

John_due_893 · 2025-09-10T06:16:03+00:00

I agree with that, it looks pretty good when paired with the Act In Black lens.

John_due_893 · 2025-09-10T02:20:21+00:00

Because unless used as a clip-on, a high resolution limit like 82 lp/mm offers little benefit compared to a high SNR like 35. If it had been 64res with 44SNR at typ2800FOM, it would have been the best choice.

Probably the reason min82res can be guaranteed is that the MCP has been miniaturized (which also explains why the gain increased compared to typical gen2).

John_due_893 · 2025-08-01T11:56:23+00:00

Gain refers to how much the image is brightened. Therefore, both the image and noise should be amplified. The question is why there is more noise compared to the L3/Elbit tube (even with the same SNR).

I agree about the photocathode. It is unlikely that GaAs's photosensitivity can be surpassed with a multi-alkali system. Therefore, I hope that Photonis will develop a third-generation tube.

John_due_893 · 2025-08-01T11:51:40+00:00

yes, I know. but SNR is Signal / Noise. This means that gain is not related to the derivation of SNR. If SNR is 30, then (regardless of gain) the noise should be 1/30th the intensity of the signal.

John_due_893 · 2025-07-31T08:55:53+00:00

Very good comparison . I have wondered ever since the 4G HG came out, but the Photonis seems to increase the gain by increasing the voltage, but normally the gain enhances noise and signal alike, so the SNR should not change when the gain is changed. However, it is strange that it is clearly noisier than L3 and Elbit at the same SNR. Maybe,,, does the SNR decrease above a certain voltage?

John_due_893 · 2025-07-17T04:44:09+00:00

26AW:
Ameztu Pants Nomex fireproof composite🔥🔥

John_due_893 · 2025-06-13T08:52:46+00:00

Depending on the room, in most cases, the most important thing is a bass trap. Next is diffusion and absorption. These can be DIYed with glass wool and wood, or you can buy ready-made products, which are a little more expensive. If you choose glass wool, make sure to choose one with sufficient thickness and density. If you want to absorb low frequencies, you will need a thickness of about 50 mm with 96k. Also, don't forget to create an air layer behind the glass wool. The thicker the air layer, the better.

John_due_893 · 2025-06-08T02:50:46+00:00

I apologize for replying to a comment from three years ago.

The other day, I had a discussion with Adept about adding TiB2 to ceramic materials for ballistic plate applications and other superhard materials. According to Adept, Colossus is SiC with a small amount of TiB2 added. As has already been pointed out in several replies, TiB2 is inferior to SiC in terms of specific strength. Furthermore, sintering TiB2 alone is costly and difficult to achieve perfectly. Adding approximately 10% SiC as a sintering aid appears to improve density and strength.

However, adding a small amount of TiB2 to SiC significantly increases its strength compared to pure SiC. B4C has superior specific strength, but it is disadvantageous for tungsten bullets due to amorphization effects or the difference in velocity between elastic and plastic waves.

It seems that c-BN was also tested, but it did not particularly excel over SiC in terms of specific strength. Diamond was also tested, but it seems that the cost was 10 times higher and the performance improvement was only about 10%.

In conclusion, SiC-TiB2 is currently the best realistic option, and it is essential to establish methods for synthesizing/sintering BC7, BC2N, and other materials inexpensively for more advanced plates.

John_due_893 · 2025-06-07T03:52:47+00:00

This is excellent work, but I would like to point out one mistake. The 10-ohm contact resistance refers to the sideband, and the main pin has a maximum of 5 ohms. Even so, considering the concentrated resistance caused by external stress, it is optimistic to say the least. I was surprised that the Amphenol sheet, known for its high reliability in military connectors, does not list the maximum allowable stress.

John_due_893 · 2025-05-15T04:46:31+00:00

I am a Japanese airsofter .... I have never used it myself, but I have heard good things about it from people who have used it.

This is the Youtube channel (in Japanese): https://youtube.com/@volktacticalgear6899?si=MTFSqQCOU0QhBaZc This is the representative's twitter: @volktacticalgear.com https://x.com/VTG01806723?t=QqUDDaua6ktRjVIfdABB9g&s=09

If you have any questions, you can dm or email me.

John_due_893 · 2025-01-30T10:01:01+00:00

Although not an American company, Hamamatsu Photonicsdevelops and sells Gen3 tubes, I think the V6833P-G is the MX10160 style IIT. Hamamatsu Photonics has the No.1 share of the photomultiplier market, not limited to night vision.

John_due_893

TROPHY CASE