Using a 2x lens adapter and a moon filter we had a great view of the full Moon and Lunar Eclipse! This was easy to set up and just as easy to learn to use. Well, I didn't do a Polar Alignment and we just blindly pointed at the objects we wanted to see. It worked out perfectly! :) I HIGHLY recommend this scope as a beginner scope and look forward to seeing what she can do once we are not under a street light.

Great value for money. Holds camera, a 150-700 lens and 2x adapter easily. I found it easy to adjust and to carry (I'm female in my sixties).

Definitely a good lens, probably use it more than telephoto lenses.

I'm giving this 4 stars - 5 stars for what it does, and 3 stars for the fiddly.I use a Panasonic Lumix G6 MFT camera, and use full-size DSLR lenses with adapters for telephoto along with the occasional adapter that doubles the focal length of the kit lens. Hey, I'm on a budget!The Booster absolutely performs as advertised. When I first got it, I noticed that it was, well, *plasticky* and didn't feel very strong. It came with two adapters for the hot shoe (which I promptly misplaced but found again), and full directions. It took a bit of fiddling with the shoe mounts to get it seated correctly on the camera. I found that the only way to get it to perform properly was with one of the shoe adapters. With an adapter and the Booster in place, miracles happen.Everybody knows that the pop-up flash that every camera comes with is pretty much crap. Well, this little item with the War of the Worlds looking fresnel lens solves a lot of the issues.This will not work with your regular kit lens. This is meant for telephoto distance shooting, and that's how it best performs. Anything shorter than telephoto means that you'll have a blown out white circle in the middle of your picture! Ask me how I know...The pros of this item are pretty simple: It gives your pathetic pop-up enough power to brighten telephoto pics. After the fiddly part is done, it works perfectly. And it's made in the USA. Boom.The cons are simple, too: Plasticky feel, but may be stronger than it seems. It works on telephoto and ONLY on telephoto. Wish that they'd make one for wide angle!So to sum it up, I'm completely happy with the device and like the way it works. I just wish that the fit and finish would give me a little more confidence in its longevity. If it lasts, I will update it to five stars.

I recently moved into the category of "serious impassioned amateur photographer" and, after a healthy dose of research, purchased the Canon 20D D-SLR (see my previous review of the camera and experience with it). As is necessary to all impassioned photographers, the lens selection(s) is tantamount to the best photo, as seen by the photographer's inner eye. As a result, when I decided to purchase the 20D, I wanted the broadest breadth of lens exposure possible in the fewest possible lenses.In large part, my search came to a rapid halt when I ran across this lens, the Canon EF 70mm-200mm f/2.8L IS USM Telephoto Zoom lens. While this lens is heavy in terms of weight (approximately 2.9lbs) and price, it is easily the best lens purchase I've made, hands down. I have paired this lens with the Canon EF 24-70mm f/2.8L USM Standard Zoom lens and a 2x telephoto extender, and I am set for most any shoot. I have read reviews regarding quality degradation when shooting with the 2x extender however, I've not experienced that (perhaps it is my inexperience...but my photos don't show it!). The 2x extender has provided me with exposure options from 24mm to 400mm, with the high quality expected from Canon "L" lenses.A few words about IS (image stabilization)...I love to take shots of the moon. First, to get really great shots, one must have a reasonably telephoto lens (that is, if you want to actually see the cheese). The next issue is simply, how do I keep the moon from looking blurry even though the night is totally clear? The answer is simple: get a tripod or get a Canon lens featuring image stabilization. The IS feature has allowed me to take my best moon shots yet, and yes, the cheese is quite visible and quite clear. IS is a must for those shooting without a tripod.All told, this lens is incredibly rich in features, handles well for a large telephoto, has a tripod bracket for easy attachment to a tripod, and is pretty much the nuts for those of us not fully versed in photographic knowledge. While not the most inexpensive lens around, the features and product results afforded by this lens is well worth the cost. I'd buy it again without hesitation.

I mainly bought this lens for the 2x extender. Being old, 84, and senile, I thought, "Why, I'll just put that 2x on my Canon 300mm and I will have a 600mm lens, great for most birding. I wanted the converter more than the lens. As soon as I opened the box, i realized I was thinking incorrectly. The 2x does not fit my 300 EF Cannon Lens. But I still wanted the extender. The 2x extender for the Canon is expensive but does not work well withEF extenders from reports here at Amazon. It is designed for you guys with $11,000.00 pro lenses.I called Mike's knowing from reports here that I would get answers to my questions and good service. Eli, whose parents migrated here some time back from Syria because of the persecution of the Jews, live in Brooklyn, answered my questions. He first went over the procedures for using the new 500X lens and 2X extender. I asked him if there was a 2X extender for my 300mm EF lens that actually works. He had one in stock which is supposed to autofocus. I had him send that to me along with another memory card and some filters.I have not tried the new lens but I will perhaps this afternoon. It is manual and I don't expect to be able to use Autofocus. I don't plan to use the 2X extender in my first test but I will see how the 500X does with a bunch of Eagles that spend the winter in a tree here, living on fish scraps from the local fish processing plants. The 500mm lens is well designed and has a mount for a tripod which is advised, especially if I use the extender. You can look at my present camera birding results at [...] I have a number of cameras as you will see.I'll let you know as soon as I check this lens out. I will tell you how the 2x works with the 300mm Canon EF when that gets here next week. I'll tell you how the 2x extender that comes with the 500mm lens works out using a tripod.John T. Jones, Ph.D.Buhl, ID

I am using this 2X extender with my 135L, and I must say that after a little micro adjustment of +5, this is incredible! I now have a 270mm f/4 lens, and the images are very, very nice. Wide open (f/4), there is a little softness or dreamy effect, but stopped down to f/5.6, images are extremely sharp and contrasty. Yes, this will enhance any flaw in your lens, but with higher quality lenses, should not be much of an issue. AF is fast, I have not had any problems with its speed or accuracy. Overall, I am extremely pleased with this extender.

It's my first telephoto lens, but the results look great.