A little while back, we had a chance to look at the Bering Optics Hogster Stimulus. The Stimulus is no doubt the best value for the money in thermal optics. But that doesn’t necessarily mean it is the best USE of money in thermal optics. What do we mean by that? The Stimulus is no question fantastic for the dollar if you are on a very limited budget. At $1599, you would be hard-pressed to find something that will hang with it as far as capabilities go. But what if you have a little more in the tank? To answer that question, we took a look at the Stimulus side by side with Hogster R-35.
The price difference is significant. While the Stimulus is most often found at $1599, the R-35 is around $2600. (No MSRP is set, there seems to be some wiggle room among dealers.) That is about 60% more expensive, and not that far off double. Which in this economy is nothing to sneeze at. So is it double as effective? Well, yes and no. The Stimulus is like the truck with 2-wheel drive and a small engine, while the R-35 has 4×4 and a big engine. (That makes the Super Yoter the Raptor, which is a discussion for another day.) Is the R-35 better? Well, only if you need it to be. In which case, yes. A lot.
The Stimulus was intentionally cut down to make a certain price point. There is actually a step in between our two test models, but it was determined to be too close to the Stimulus to accurately compare features. The R-35 is full throttle with all the bells and whistles, at least as far as the sub $3000 market is concerned.
To start with, the R-35 has a bigger objective lens system. Is bigger always better? That is a debate for the science nerds. But in this case, yes. Similar to light gathering on a daylight scope, the larger lens array seems to be more capable of seeing heat. The Stimulus is 19mm, while the R-35 is 35mm. That is a lot of mm’s.
You will note that the Stimulus comes in at a more powerful base magnification (2.3) than the R-35 we tested (1.4). That can be deceptive, so let me craft my words carefully here. Both test units have a base magnification (optical/lenses) and a digital zoom feature. This is not totally unheard of in digital optics. But it can throw you off in this case. The Stimulus has only a 2x zoom, for a total of 4.3x magnification. The R-35 has 4x digitial zoom, for 5.6x top end magnification. But, that also isn’t the entire story.
Digital zoom, much like “enhanced photos”, isn’t quite the same as real lens magnification. Also, the larger objective lens, as well as electronics, play a role here. Looking at them side by side, I find the image from the R-35 with NO zoom (1.4 power) to be more clear and usable than the Stimulus at 2x digital zoom, ie 4.6 power. Granted, the image is smaller. But it is so much more clear that I still give it the edge. Perhaps conditions exist where that would not be true, I will grant. But in all my testing, I would stand by it.
The R-35 then absolutely blows its doors off when using 2x or 3x zoom. I would think this is a function of processing power in the unit as well, along with a big one we will talk about shortly. The R-35 gets a bit pixelated at 4x, you can tell you are really pushing the limits of the unit. But for smaller game like jackrabbits, this would still be a handy feature.
The elephant in the room difference is the refresh rate on the R-35. The Stimulus has a 30 Hz refresh rate, while the R-35 has a 50 Hz. For those of us that haven’t read white papers on thermal imaging theory, that probably doesn’t mean much. I know going into this it didn’t to me, besides “more = more gooder.” Yes, that is true. But real world, it packs a major difference when it comes to moving targets.
To test against a reliable and predictable moving object, I took both out to a relatively busy county road. (No weapons were involved, I’m not insane. Both units were handheld.) The speed limit is 45, which granted outpaces pretty much any animal. But it did offer a very good analysis of capability. It was also daylight so that I could see out of both eyes. The Stimulus just could not refresh fast enough to track something moving like that. Both eyes open, and you could really see the lag. The R-35 was close enough to real-time as to be indistinguishable. Impressive, considering the computer has to make an image for your eye. The lag in the Stimulus is roughly equivalent to the Syonix night vision camera we reviewed. It isn’t something you can’t overcome, but it is a weakness compared to bigger budget options.
And the whiz-bang leather seat goodies for the R-35 are no joke either. Like a picture in picture mode, with 2x magnification on the top image. The ability to record to a video device. And the upgraded core, which no doubt has an effect on image quality as well.
The detection range difference was really hard to judge. Much of that is going to depend on you, and how well you know your device. As well as, the numbers look weaker on paper than they do in the field. We used a coyote as the range estimate on the Stimulus, calling it detection at 700-800 and identification/shooting solution at 150-200 yards. For the R-35? Detection is better, but not that much better. I would say 900 yards is not unreasonable in the right conditions. And an ID/ shooting solution at 300. However, it will do it much clearer and cleaner. The Stimulus is amazing when you haven’t touched a thermal in a while, but feels like a serious downgrade when you have the R-35 on hand too.
The R-35, overall, is a very good value for the money as well. If you can possibly afford to buy it over the Stimulus, you will know where that money went. If you are going to be out every week blasting hogs, it is 100% worth saving up a few more months. I would say the R-35 is the first step for the serious hunter if the Stimulus is the best of the entry-level options. Which one is best for you? Speed costs money, how fast do you want to go?