The lens was used gif s short birding break to Spain. It was coupled to a new Lumix G9 Ii. Availability of any long lenses gif MFT are limited and will hold the brands back because of it. However, this was available and I hired it for the week. It’s heavy and relatively slow although I was already aware of that. It’s quite well made apart from the nasty cheap hood. The lens is too stiff to zoom making it difficult to follow quick birds or pick them up at 100mm and zoom in as the focus is grabbed. The throw between 100 and 400mm is ridiculously long. You have to dislocate your wrist to not let go. The stiffness doesn’t allow you to ginger the zoom round as it does on other lenses. Using it for video was virtually impossible for the same reasons. It’s a poorly thought ... MoreThe lens was used gif s short birding break to Spain. It was coupled to a new Lumix G9 Ii. Availability of any long lenses gif MFT are limited and will hold the brands back because of it. However, this was available and I hired it for the week. It’s heavy and relatively slow although I was already aware of that. It’s quite well made apart from the nasty cheap hood. The lens is too stiff to zoom making it difficult to follow quick birds or pick them up at 100mm and zoom in as the focus is grabbed. The throw between 100 and 400mm is ridiculously long. You have to dislocate your wrist to not let go. The stiffness doesn’t allow you to ginger the zoom round as it does on other lenses. Using it for video was virtually impossible for the same reasons. It’s a poorly thought out lens thst potentially could be s decent performer. If your subjects aren’t moving much, it’s fine. When it does and at speed… it’s too difficult to use.

A formidable contender for budget

A formidable contender for budget supertelelphoto lenses - great versatility and good image quality.Pros- 2× crop factor on micro four-thirds sensor gives effective focal length of 200-800mm that can be held in hand.- Fully functional with 1.4× and 2× teleconverters, giving effective focal lengths of 280-1,120mm and 400-1,600mm.- Capable option for butterfly and dragonfly photography with minimum focus distance of 1.3m + 0.57× magnification at 400mm.Cons- Largely plastic exterior, though solidly constructed and weather-sealed.- Focus ring could be easier to rotate.- Base aperture of f/9.0 and f/13.0 when using 1.4× and 2× teleconverters at 400mm.- Zoom lock only works when lens barrel is unextended.

Big improvement over the 75-300 II

I've been shooting birds & insects with the Oly 75-300 II for 9 years and the Oly 100-400 is a huge improvement for me. I've had a lot of great shots from the 75-300 II, but it has several weaknesses. It has a tendency to give washed-out images from light bouncing around in the lens. Also distant birds etc. usually give disappointing results. Also (not sure if this is due to a few drops over the years), I started to notice major image flaws (smeared edges on one side of each twig, etc.), so I bought the 100-400. After 2 days with the 100-400 (actually from the first few photos) I'm seeing a huge difference. Images are so much higher in contrast, no more washed out images. Also, some nice surprises. The focus is so freakishly fast and accurate, I can aim at a little ... MoreI've been shooting birds & insects with the Oly 75-300 II for 9 years and the Oly 100-400 is a huge improvement for me. I've had a lot of great shots from the 75-300 II, but it has several weaknesses. It has a tendency to give washed-out images from light bouncing around in the lens. Also distant birds etc. usually give disappointing results. Also (not sure if this is due to a few drops over the years), I started to notice major image flaws (smeared edges on one side of each twig, etc.), so I bought the 100-400. After 2 days with the 100-400 (actually from the first few photos) I'm seeing a huge difference. Images are so much higher in contrast, no more washed out images. Also, some nice surprises. The focus is so freakishly fast and accurate, I can aim at a little blob on a waving grass blade and get a nice crisp photo of an insect. Focus is so much better than the 75-300 II, and I never realized what a different it could make. Also, AF seems much better at choosing the subject, rather than the background. Also, the in-lens IS really works! I got a bunch of keepers using 1/100 to 1/200 sec at 400mm. IBIS never really did much for the 75-300 II and I always had to use much faster exposures. Bulkier size of the 100-400 definitely demands a slightly larger bag, but I'm loving this lens and it's absolutely worth it.

Decent lens, but super-heavy for the quality

This is a very heavy lens. I was hoping that the high-quality glass and internal image stabilization would make for super-sharp images, but even with a sturdy tripod and shutter delay, the resulting images just didn't look all that much better than my other lighter (and much cheaper) lenses. Don't get me wrong: the images were sharp and very good quality. They just weren't significantly better, enough to justify carrying around such a heavy lens.

Great Lens

I used this lens with the OM -1 for 3 weeks in Peru shooting a lot of birds from 75-100 yards out... and some quite small. this is a great lens in that it's lightweight and when paired with the OM-1 micro 4/3'd it extends the lens from 100-400 to 200-800. So it gets right out there. Hand held is good. The only thing you need to remember is to pre-focus where you anticipate the shot to be as it is slow to focus quickly when stretched that far.Otherwise it's a great lightweight lens with great reach.

Great lens and outstanding customer service

I researched for months whether to switch from Olympus to Sony, Canon or Nikon. Having sold my old Canon gear years ago for the lighter micro 4/3 system I was intrigued by the recent developments pertaining to full frame mirrorless. Another reason was that I took up bird photography and was looking for more reach, and therefore maybe back to APSC sensors. After going though all options I decided to rent the Olympus 100-400 for the immense reach on my OMD5 III. I didn’t expect it to be as outstanding as it turned out. One of the sharpest lenses I ever owned, sharper than my 40-150 pro. Fast focusing, even though branches. Yes, the aperture is not that bright, but if you want a constant f4 it will be heavier and more expensive, like the Olympus 150-400, f4.5 for ... MoreI researched for months whether to switch from Olympus to Sony, Canon or Nikon. Having sold my old Canon gear years ago for the lighter micro 4/3 system I was intrigued by the recent developments pertaining to full frame mirrorless. Another reason was that I took up bird photography and was looking for more reach, and therefore maybe back to APSC sensors. After going though all options I decided to rent the Olympus 100-400 for the immense reach on my OMD5 III. I didn’t expect it to be as outstanding as it turned out. One of the sharpest lenses I ever owned, sharper than my 40-150 pro. Fast focusing, even though branches. Yes, the aperture is not that bright, but if you want a constant f4 it will be heavier and more expensive, like the Olympus 150-400, f4.5 for 7500.00. I am sure it is a great lens for somebody who is willing to spend the money. So until I win the lottery the 100-400 is a compromise, but a good one. The dilemma of quality, weight and price will not go away, especially for wildlife photographers. Until somebody comes up with the perfect solution the Olympus 100-400 is an outstanding option. The customer service from Lensrentals is far above outstanding. The support they provided to this confused person getting crazy about optimizing the right strategy was incredible.

High-quality and excellent build quality

I bought this with an OM-1 after using the combination of camera and lens for two weeks in Costa Rica (see my OM1 review for more detail). It's hard to review the lens in isolation, but a couple of observations are in order:1. Lens design is constrained by physics, primarily fundamental optics. Performance, light weight, quality - choose two. This lens is not equal to its big brother, the $7500 150-400 pro lens, but then again, it is 1/5 the price. It's also hard to beliee that it is not a better lens than, for example, a light-weight Canon 100-400 that costs half as much.2. IMage quality has been outstanding. Hard to distinguish from $1500-2800 equivalent Canon and Sony lenses.3. Build quality and ergonomics are excellent. Feels precise, zoom and focus are ... MoreI bought this with an OM-1 after using the combination of camera and lens for two weeks in Costa Rica (see my OM1 review for more detail). It's hard to review the lens in isolation, but a couple of observations are in order:1. Lens design is constrained by physics, primarily fundamental optics. Performance, light weight, quality - choose two. This lens is not equal to its big brother, the $7500 150-400 pro lens, but then again, it is 1/5 the price. It's also hard to beliee that it is not a better lens than, for example, a light-weight Canon 100-400 that costs half as much.2. IMage quality has been outstanding. Hard to distinguish from $1500-2800 equivalent Canon and Sony lenses.3. Build quality and ergonomics are excellent. Feels precise, zoom and focus are smooth. Weather-sealing is a major plus. If I was being really picky I might want the focus to be a little quicker and the zoom to be a tiny bit smoother and less stiff, but it's better than other lenses I have handled. The $7,500 version is probably better:)Would not hesitate to buy this again, strongly recommend with the OM1.

Incredible reach

If you need to get close to things that are very far away, especially birds, it's hard to beat this lens for the reach.However, it is a lens with a slow aperture, and that can create issues with image quality and noise given the fast shutter speeds necessary for photographing wildlife at this distance.It even works with the MC-14 and MC-20 teleconverters for even more insane reach, but you really need a tripod if you're going to use the MC-20...not to mention the risk of diffraction. I would stick to the MC-14 with this lens if you really need a teleconverter. Even without a teleconverter, an 800mm full frame equivalent is a lot of reach.This lens is incredibly sharp, which is the most important criterion when considering it. Just know that you may be battling ... MoreIf you need to get close to things that are very far away, especially birds, it's hard to beat this lens for the reach.However, it is a lens with a slow aperture, and that can create issues with image quality and noise given the fast shutter speeds necessary for photographing wildlife at this distance.It even works with the MC-14 and MC-20 teleconverters for even more insane reach, but you really need a tripod if you're going to use the MC-20...not to mention the risk of diffraction. I would stick to the MC-14 with this lens if you really need a teleconverter. Even without a teleconverter, an 800mm full frame equivalent is a lot of reach.This lens is incredibly sharp, which is the most important criterion when considering it. Just know that you may be battling noise.I think I'll save up a bit more for the 300mm f4 PRO lens, but this is a very legitimate choice as well. There's also the amazing 150-400mm f4.5 PRO lens, but that is extremely expensive.

Ultimate enthusiast wildlife lens

I would say this is the ultimate enthusiast wildlife lens. It's relatively affordable, is sharp, has ridiculous range for the size and weight, the IS works well, even though it doesn't have the sync IS of the much more expensive pro 150-400mm lens. It just generally feels great to use. You do start to get tired (or at least I do. If you're strong in the arms you may not) after a while of hand holding it, but compared to a full-frame equivalent lens, this is very portable and won't require you to use a monopod to take the weight off in anywhere near the same way. Most people will have no issue with walking around with this all day hand holding it. Especially if you're taking it in and out of a backpack to give yourself short breaks.

great and versatile lens for wildlife and birding

This is simply a great and versatile lens for wildlife and birding. What you get is a 200mm to 800mm full-frame equivalent lens. I mostly use it at f/7.1 or f/8 and find it to be very sharp. It’s not a pro lens, but it has all the features of one. In fact, it’s much better than any third-party lens I’ve used with APS-C and full-frame bodies. The lens stabilization is good but could be improved a bit, especially for faster lock on subject and better compatibility with in-body stabilization. Additionally, I wish it could be lighter. For optimal use, consider pairing it with an external grip on an OM-5 body. (note: files are not jpg from OM-5 but processed with exteranl software)Highly recommended – 5 stars