Kirsch
Active member
I get lots of questions such as the ones below. I have answered them before on Predator Masters and other sites, but since the questions continue, I will continue to post topics like this. I will do my best not to bring in too much science jargon:
I would like a 12 micron, 640 resolution thermal, why can't they start with a lower base mag., say just 1x in the 12 micron?
It is all based on science. In the world of Photography all the lenses are based on Focal Length. Focal Length is the combination of lens size and aperture of the lens. In sporting events you see those camera lenses that are huge. They are designed to be able to take pictures from long distances and stay clear. The bigger the lens and the higher the aperture (f/stops), the more base mag. You can get to around 1x on a 640, 12µm sensor be decreasing the focal length to 18mm. An example of this is the N-Vison Nox18mm which is a 1x thermal.
So what does this mean in terms of thermal? A bigger lens helps with creating a better thermal image. However, it comes at the sacrifice of expense and FOV. As the lens is made of Germanium (rare, expensive element), the bigger the lens increases the cost. This leads to companies using smaller objectives lenses to gain FOV. They can also do this by decreasing aperture by going from f/1.2 to a f/1.0 lens as an example. This is what Pulsar did in the last versions. The only other choice with the lens is to go smaller in diameter. However, when you go smaller, the thermals tend to struggle more with humidity and other environmental factors, so it is a balancing act as a 18mm lens will not cut through environmental factors as well as a 50mm.
Thermal companies have two additional variables they can use to get to a desired FOV/magnification. It is the sensor micron size and the resolution. The smaller the micron size, the less FOV and higher the base magnification.
Case in point, Bering Optics had the Hogster 25 and 35. However, they were getting lots of customer feedback saying customers wanted a scope around 3x base mag. I was one of them as I wanted a longer-range coyote scope for open-plains hunting. Based on the discussion, they had two main options increase lens size or decrease microns. They wanted to keep the Super Hogster reasonably priced, so they decided to go from 17 to 12 microns and keep everything else the same. This moved them from 2x base mag to almost 3x.
The higher the resolution, the larger the FOV and the lower the base magnification. So, to answer the original question, if thermals stay at 12 microns, moving from 640x512 to 1280x1024 will make a difference. By increasing resolution and keeping everything else the same, they can use the same other parameters and get a wider FOV and less magnification if they choose to do so. However, every hunting situation is different. Many PM members want wide FOV, while the next person in Europe is shooting foxes at 300m and needs a lot of clarity at long distances. As resolution hopefully continues to increase, you will eventually see a combination of larger lens options that start with a lower base mag, and allows the thermal to be digitally zoomed many times and still retain decent image quality.
Why The Big Drop In Thermal Prices The Last 10 Years? One of the many reasons price drops have occurred in the last 10+ years to thermals, is the invention of smaller micron sensors/detectors has allowed thermal vendors to not have to use large diameter lenses (75-100mm) to get magnification.
Hopefully, we will see the trend eventually move back to lower base magnification/wider FOV. This could be a reality as the higher resolutions could mean companies could produce a greater range of magnification/FOV and still retain decent thermal image quality even under digital zoom.
Why Is This So Confusing? It is all a juggling act with these parameters to try to get a combination of elements that provide what a hunter needs. In some ways, ATN may have it right. They tend to market their scopes like an ATN 1-4x, 2-8x, 4-16x, etc. Bottom line is the lens size, aperture, and/or resolution is changing in these models. I like this approach because the FOV and magnification should be a major part of every thermal purchase and should be based on terrain and min/average/max distance needs of the shooter.
Whenever I speak with a person about thermals, my first questions are what are you using it for, what is your terrain, what is your min/average/max shot distances, and what is your budget. A good thermal dealer with this type of information should be able to help guide a person to what model or models would be the best fit.
I would like a 12 micron, 640 resolution thermal, why can't they start with a lower base mag., say just 1x in the 12 micron?
It is all based on science. In the world of Photography all the lenses are based on Focal Length. Focal Length is the combination of lens size and aperture of the lens. In sporting events you see those camera lenses that are huge. They are designed to be able to take pictures from long distances and stay clear. The bigger the lens and the higher the aperture (f/stops), the more base mag. You can get to around 1x on a 640, 12µm sensor be decreasing the focal length to 18mm. An example of this is the N-Vison Nox18mm which is a 1x thermal.
So what does this mean in terms of thermal? A bigger lens helps with creating a better thermal image. However, it comes at the sacrifice of expense and FOV. As the lens is made of Germanium (rare, expensive element), the bigger the lens increases the cost. This leads to companies using smaller objectives lenses to gain FOV. They can also do this by decreasing aperture by going from f/1.2 to a f/1.0 lens as an example. This is what Pulsar did in the last versions. The only other choice with the lens is to go smaller in diameter. However, when you go smaller, the thermals tend to struggle more with humidity and other environmental factors, so it is a balancing act as a 18mm lens will not cut through environmental factors as well as a 50mm.
Thermal companies have two additional variables they can use to get to a desired FOV/magnification. It is the sensor micron size and the resolution. The smaller the micron size, the less FOV and higher the base magnification.
Case in point, Bering Optics had the Hogster 25 and 35. However, they were getting lots of customer feedback saying customers wanted a scope around 3x base mag. I was one of them as I wanted a longer-range coyote scope for open-plains hunting. Based on the discussion, they had two main options increase lens size or decrease microns. They wanted to keep the Super Hogster reasonably priced, so they decided to go from 17 to 12 microns and keep everything else the same. This moved them from 2x base mag to almost 3x.
The higher the resolution, the larger the FOV and the lower the base magnification. So, to answer the original question, if thermals stay at 12 microns, moving from 640x512 to 1280x1024 will make a difference. By increasing resolution and keeping everything else the same, they can use the same other parameters and get a wider FOV and less magnification if they choose to do so. However, every hunting situation is different. Many PM members want wide FOV, while the next person in Europe is shooting foxes at 300m and needs a lot of clarity at long distances. As resolution hopefully continues to increase, you will eventually see a combination of larger lens options that start with a lower base mag, and allows the thermal to be digitally zoomed many times and still retain decent image quality.
Why The Big Drop In Thermal Prices The Last 10 Years? One of the many reasons price drops have occurred in the last 10+ years to thermals, is the invention of smaller micron sensors/detectors has allowed thermal vendors to not have to use large diameter lenses (75-100mm) to get magnification.
Hopefully, we will see the trend eventually move back to lower base magnification/wider FOV. This could be a reality as the higher resolutions could mean companies could produce a greater range of magnification/FOV and still retain decent thermal image quality even under digital zoom.
Why Is This So Confusing? It is all a juggling act with these parameters to try to get a combination of elements that provide what a hunter needs. In some ways, ATN may have it right. They tend to market their scopes like an ATN 1-4x, 2-8x, 4-16x, etc. Bottom line is the lens size, aperture, and/or resolution is changing in these models. I like this approach because the FOV and magnification should be a major part of every thermal purchase and should be based on terrain and min/average/max distance needs of the shooter.
Whenever I speak with a person about thermals, my first questions are what are you using it for, what is your terrain, what is your min/average/max shot distances, and what is your budget. A good thermal dealer with this type of information should be able to help guide a person to what model or models would be the best fit.
