This converter was just what I needed. Would buy again!

It worked right away. I had tried other converter. I gotta say this one worked awesomely!!!

You don't even need to power the converter even though you have the option to.

Great lens for the price! I had a little trouble fitting the 2x converter onto the lens. I sent an email to Big Mike's Electronic's and they responded promptly. I spoke with one of their support reps and he was very helpful. After I attached the 2x converter I took some shots and they are fantastic. This lens is the way to go if you are on a limited budget. Amazon great, check. Lens great, check. Big Mike's Electronic's great, check. Overall a great deal and fantastic customer support.

Decided to try this lens out and ordered it on Sunday afternoon around 3pm and it was delivered at 8pm the same day. Already looking good! Well packaged and Big Mike's Electronics added a 7 page typewritten FAQ and instruction sheet. Looking better. I've used T-Mount lenses in the past, so it was easy to assemble the camera mount to the lens. I chose to not install the 2X converter at this time (more about that later). I mounted the lens to my camera (Canon EOS R6 mirrorless) and set the camera menu to allow picture taking with no lens attached (as this lens is totally manual with no electronic contacts the camera doesn't know its there--you need to do this with any fully manual lens, not just this one). Turned the camera on and voila--it worked. As the minimum focusing distance with a 500mm lens is around 35 feet, I couldn't really take many photos in the house, and it was already dark outside. So I had to wait until this morning to really try it out.Finally got a chance to take some photos (through my window). I mounted it on my tripod--this is a 500mm lens, it magnifies camera/hand shake tremendously, use a tripod!. Focused on some things down the street, made some photos (attached). Sat down to write this review.If you are used to auto-focus lenses with an aperture that lets you focus wide open and automatically stops down when you take the photo you are going to have to learn new ways of working. Focus is manual. If your camera allows for Live View focusing on the back screen, use that, and magnify it if you can. If you want to work at f/8 (the maximum aperture on this lens) you are all set. If you want to stop down for more depth of field there are two steps after focusing. First note that there are two adjustable rings on the lens. One sets the aperture (F/16 in the attached photo) and the other (marked O/C for Open or Closed) actually adjusts the aperture. Set it to Open to focus wide open letting in as much light as it can. Then twist it to Closed to actually stop down to the desired aperture before taking the photo.About the 2x converter. I have not tried that yet as any 2x will lose two stops of light, making the lens a 1000mm f/16 lens. Need a really bright day or high ISO for that. I will test that another day. My issue with the converter, before using it, is that you need to remove the camera T-mount adapter from the lens and attach it to the converter and then attach the converter to the lens. That's a lot to go through if you are out in the field and it requires the use of a very small screwdriver for the three setscrews that hold it all together. If you want to be able to use the converter and take it on and off more quickly, I would suggest getting a second t-mount adapter for your camera so both the lens and the converter have it permanently attached. Then you just need to unscrew the lens from the adapter and screw the converter onto the lens.Bottom line, a good value for the cost. Not quite the image quality of a Canon 500mm lens. And no image stabilization or auto-focus. But the Canon 500mm lens sells for $9,000. For the number of times I will need a long lens like this, I can accept the image quality and get a photo that I otherwise wouldn't get.

Fits in the old clamp on mount from my last fluorescent one that died...love the LED...a really good light! Thanks!UPDATE!!!Today...the usb converter is almost too hot to touch....this is WAY underpowered and for sure a fail/fire equation...needs better higher rated converter or be 110 volt powered. Going back.....too HOT!

Purchased with a 1/4 male female converter. Using to mount this on a normal camera tripod to hold a flashlight or laser point for nighttime pictures. This is a good quality product. Little expensive, but I like it.

Worked great!! Took this shot without the 2x converter within 30 minutes of getting the lens. I did use a tripod and a wireless remote to reduce all shaking before taking shot.