Osprey Atmos 50

Priced: $159.19 - $210.00 Rated:   - 4 stars out of 5 by 45 reviews.
Osprey Atmos 50
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Color: Oxide Red
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Osprey Atmos 50 -
The Atmos 50 backpack from Osprey is perfect for light backpacking adventures. The LightWire alloy frame gives a semi rigid structure to move with you and have enough flex to give support to make this your back's best friend. Featuring a tensioned 3D mesh back panel, a thermoformed perforate waffle foam hipbelt with compression straps for a easier time with heavy loads, Stow-on-the-Go™ trekking pole attachment, and additional tool straps. Perfect for any outdoor adventures, lightweight and comfortable, ventilation to keep you nice and cool. The Osprey Atmos 50 backpack is the perfect companion to hit the trail with confidence.

Support and Cushioning:

  • Shoulder harness adjusts over a 3 in. range for fine-tuned fit; new pad design with spacer-mesh contact surfaces and ventilated foam provides breathable, supportive cushioning


  • Detachable lid lets you slim down for side trips


  • Airspeed Suspension with LightWire Alloy frame
  • LightWire alloy frame allows room for air to circulate without destabilizing the load


  • Gender-specific harnesses available in three sizes
  • Updated Airspeed suspension lets you adjust the torso length 3 inches and and hip-belt 6 inches


  • Zippered sleeping bag compartment with removable divider
  • Dual vertical zip front pockets allow for easy gear organization


  • Multiple pockets, including convenient front stretch and hip-belt pockets, organize your gear and put it in easy reach
  • Floating top lid features a large pocket and an under-the-lid mesh pocket
  • The floating top pocket with under lid mesh pocket can be easily removed
  • Side stretch mesh pockets with InsideOut compression


  • Lightweight nylon fabrics resists abrasion and stand up to years of use
  • Made with 210D high tenacity twill nylon, 100D high tenacity mini-ripstop nylon
  • The Osprey Atmos 50 pack is made with a lightweight yet strong 210- and 100-denier fabric set that offers excellent durability and less trail weight than heavier fabrics
  • Zippered fabric hipbelt pockets for storing a trail snack
  • Front stretch woven pocket, side stretch-mesh pockets, zippered hipbelt pockets and 2 large front zippered pockets help organize gear for quick, convenient access
  • Zippered fabric hipbelt pockets provide secure, accessible storage


  • Hook and loop adjustable over 3"/7.5 cm range to allow fine tuned fit
  • Hipbelt uses dual-density foam for improved support and spacer mesh for breathability; exclusive adjustment system lets you customize the fit while wearing the pack
  • Three frame sizes each for Atmos and Aura provide precise fit


  • Pads able to extend 3"/7.5 cm each side for 6"/15 cm total adjustment range
  • Removable sleeping pad straps add a level of performance versatility
  • Pack exterior features removable sleeping pad straps, Stow-on-the-Go™ quick stash trekking pole attachment system and dual ice axe loops with bungee tie-offs


  • Scalloped side openings for enhanced cross ventilation
  • LightWire™ alloy frame creates low-profile air space, optimizing balance and ventilation; 3D tensioned mesh back panel ensures excellent breathability and supportive fit


  • Large main compartment with hydration sleeve and reservoir clip
  • All Atmos/Aura series packs are hydration compatible with tube exit ports on both sides of the pack

Size and Dimensions:

  • Dimensions are 29 in length (height) x 17 in width x 14 in depth. (Medium)


  • Side compression straps stabilize your load
  • Slide adjustable sternum strap


  • Torso adjustable/interchangeable shoulder harness
  • Trekking pole and multiple gear attachment points let you stow items externally
  • Tool Attachment
  • Each Atmos/Aura Series pack features dual ice tool loops and bungee tool tieoffs
The Atmos 50 provides the ideal volume for your next superlight backpacking experience. At 3000 cubic inches and with an average weight of just over 3 lbs / 1.5 kg, you can carry your superlight essentials with ease and comfort. A traditional floating top pocket/top load design and twin front pockets with welded water resistant zips makes loading easy. Other features include an internal hydration sleeve, zippered mesh pockets on the adjustable hipbelt and removable sleeping pad straps.

• AirSpeed suspension.
• Volume Cubic Inches: (S) 2868 cu in, (M) 3051 cu in, (L) 3234 cu in.
• Volume Liters: (S) 47L, (M) 50L, (L) 53L
• Weight: (S) 3lbs 1oz, (M) 3lbs 2oz, (L) 3lbs 4oz / (1.39, 1.42, 1.48 kg)
• Dimensions: 29 x 17 x 14 in. (74 x 42 x 36 cm)
• Recommended Use: Thru-hiking/Overnight to extended trips. 35-50lb load.

You probably won't even know it's on your back when you take that hike with the Atmos 50 - 2012 by Osprey®.
Adjustable torso harness allows 3 in / 7.5 cm of adjustment for a fine-tuned fit.
New pad design with spacer mesh and ventilated foam provide a breathable and supportive cushion.
AirSpeed™ suspension with LightWire™ frame and 3D tensioned breathable mesh backpanel provides optimized pack balance, ventilation and support.
Fit-On-The-Fly™ hipbelt design uses dual density foam for improved support and spacer mesh for breathability.
Adjustable system allows the belt to be custom fitted with a 6 in / 15 cm total adjustment range.
Hydration compatible with tube exit ports on both sides of the pack.
for added versatility.
with under lid mesh pocket can be easily removed.
Spacious main compartment for all your gear.
Dual ice tool loops and bungee tool tieoffs.
allow for easy gear organization.
Ajustable shoulder straps with sliding sternum strap for added load management.
Hipbelt features zip pockets for added storage on the go.
Osprey will repair for any reason, free of charge, any damage or defect in their product − whether it was purchased in 1974 or yesterday. If they are unable to perform a functional repair on your pack, Osprey will happily replace it.
FEATURES of the Osprey Atmos 50 Pack.
SPECIFICATIONS of the Osprey Atmos 50 Pack.

Even though the Atmos 50 Backpack already won Outside Magazine’s Gear of the Year Award, Osprey updated it with a new low-profile back panel. This Airspeed design places the pack closer to your back for better support and greater long-distance comfort, without sacrificing breathability. Several pockets and a large front flap help you keep everything well organized.

Appalachain Outdoors
The Atmos 50 Backpack from Osprey is superlight so you'll experience comfort while experiencing the great outdoors. This 3000 cu in pack is loaded with features you'll love.
Eastern Mountain Sports (EMS)
The Osprey Atmos 50 L defines the lightweight hiking pack with a custom ventilated fit that lets you tick away the trail miles in comfort. With a radically updated AirSpeed suspension systems, new fabrics and a lighter trail weight.
Backcountry Edge

A long-time favorite among AT thru-hikers and fast-and-light backpackers, the Atmos 50 combines both durability and lightweight performance. A redesigned harness and adjustable hipbelt now provide even better comfort and fit.


The Osprey Atmos 50 pack redefines expectations for weight, ventilation and comfort. An updated suspension provides a customized fit for greater comfort than ever on the trail.



The series that redefined expectations about weight, ventilation, and comfort in backpacking, is about to do it again. The radically updated AirSpeed™ suspension of Osprey’s Atmos now provides customized fit, with fully adjustable torso length, interchangeable harnesses, and adjustable hipbelt fit. It all adds up to an even better fit and greater comfort on the trail.

Mountain Gear
Lightweight versatility at it's finest.
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Average Price History: Price History
Review RatingNumber of Reviews
Access:Top Loading
Access Type :5003
Adjustable torso:Lightweight backpack
Backpack Features:Sleeping Bag Compartment, Top Loader
Backpack Style:Multi-Day Pack
Bottom Width:15 in
Capacity:(S) 2868cu.in, 47L, (M) 3051cu.in, 50L (L) 3234cu.in, 53L
Custom Fit Options:Adjustable harness, Fit-On-The-Fly™ hipbelt
Depth:10 in
Detachable Daypack:No
Detachable Pack:no
Dimension:(H x W x D)
Dimensions:29 x 17 x 14 in (74 x 42 x 36cm)
Features:Removable sleeping pad straps, Removable top pocket, Vertical zip pocket
Fits Torso:Medium: 18"-20.5" Large: >20"
Fits Waist:Medium: 30"-34" Large: >33"
Fits waist/hips:No
Frame material:47 liters
Frame type:Backpacking
Gear capacity (L):Internal
Gear capacity (cu. in.):Internal
Handle Drop:3 in
Handle Length:8 in
Height:25 in
Helmet Carrier:no
Hydration Bladder Included:Not Included
Hydration Compatible:Yes, Hydration sleeve
Ice Axe Loops:yes
Item Weight:Medium: 3 lb 5 oz Large: 3 lb 8 oz
Key Fabrics:210D high tenacity twill nylon; 100D high tenacity mini-ripstop nylon
Laptop Sleeve:None
Load Range:Comfort Weight: 40 lbs ; Maximum Weight: 50-60 lbs
Material:210D high tenacity twill nylon / 100D high tenacity mini-ripstop nylon
Maximum Weight:40 lbs
Middle Width:10 in
Number of Pockets:4
Number of exterior pockets:3,234 cubic inches
Number of stays:50 liters
Optimal Load Range:25-40 lb
Organization Pocket:no
Pack Capacity:47 L
Pack Fabric (Primary):210D nylon100D mini-ripstop nylon
Pack Size:3000-3999 cu in
Pack access:3,051 cubic inches
Pack loading:2,868 cubic inches
Primary Access:Top Access
Raincover included:3 lbs. 2 oz.
Recommended Use:Multi-Day Lightweight Backpacking
Shovel Pocket:yes
Ski / Snowboard Carrier:no
Sleeping Bag Compartment :No
Sternum Strap:Yes; Adjustable Position
Strap Drop:15 in
Strap Length:36 in
Suspended mesh back panel:53 liters
Suspension:AirSpeed™ suspension
Top Width:10 1⁄2 in
Torso Adjustment:Yes
Torso Fit :Standard
Torso Length:S <18.5 in.M 18-20.5 in.L >20 in.
Trekking Pole Loops:yes
Trip Length:Extended Trip (>3 nights)
Type:Internal Frame Backpack
Use :Camping, Hiking
Volume:[S]: 2868 cu in (47L) ; [M]: 3051 cu in (50L) ; [L]: 3234 cu in (53L)
Volume Range:46-59 liters
Weight:[S]: 3 lbs 1 oz (1.39kg) ; [M]: 3 lbs 2 oz (1.42kg) ; [L:]: 3 lbs 4 oz (1.48kg)
Weight - metric:Lightweight backpack
Weight Capacity:30-50 lb.
•LG:3 lbs 4 oz / 1.48 kg.
•MD:3 lbs 2 oz / 1.42 kg.
•SM:3 lbs 1 oz / 1.39 kg.
Compare specifications to related products.

Subcategories of Backpacks, Daypacks & Bags:

Osprey Atmos 50 Reviews:

Positive Reviews:

Osprey got it right - eventually

I wrote a review of this pack maybe 4 or 5 years ago, when the first version originally appeared, and pretty well trashed the suspension: the padding was too flimsy, the frame rubbed on my shoulders, and the pack bounced around; I called it an updated external frame pack.

When Osprey added the adjustable shoulder straps this year, a friend convinced me to give it another look. While it may, technically, still be an external frame (it has a trampoline backband, and a perimeter frame to which the bag is attached), this isn't the old Kelty pack we all remember. (Well, some of us remember it.) I've had it on a few weekend trips so far, and it is the most comfortable pack I've ever owned.

Osprey has taken the best features of the internal frame pack (well-designed pack bag, frame just barely buried in the pack bag) and combined them with the best features of an external frame pack (ventilation and load carrying comfort) to acheive something that is truly a hybrid - I'm not sure you can really put it in either the internal or external classification, and I'm not sure that it matters anyhow.

I was using a Kestrel 48 pack, which is also adjustable. I could get the right shoulder strap length, but the frame itself was too short. That meant that the point at which the load lifters connected to the frame was too low to give the necessary angle (usually 30-45 degrees) to let you take the load off your shoulders. In my case, with the shoulder straps correctly adjusted, I would get a zero (or even negative) angle, and end up with tired shoulders at the end of the day. (Not painful, but tired.)

The Atmos has a slightly longer frame, and the load lifter angle is perfect - I can move the load completely to my hips, if I choose. The extra frame length also solves the problem that I had with the original version: the frame rubbed my shoulders badly. On the current, adjustable version, the frame doesn't touch me anywhere.

The tensioned, trampoline backband is incredibly comfortable, and considerably cooler than a true internal frame back pad. You'll still get a wet back on a hot, humid day, but at least some air can get to your back. You would think that the tensioned pad would hold the load too far away from your back, but the sculpted packbag (which others describe as annoying to pack) allows the load to snuggle up to you, just like an internal frame pack does. The result is that the load doesn't bounce, or move in the opposite direction when you turn (like the old-style externals did.)

The bag itself is a clean, uncluttered design: two side pockets that will hold a 1-liter platypus bottle well, leaving only about an inch or so of the bottle above the top of the pocket. (On other packs, the pockets were too short, leaving half the bag exposed and causing it to flop over when half empty.) The shove-it pocket on the front (back? I'm never sure what to call it) is roomy and very functional. But my favorite feature is the long zippered pockets on the front, under the shove-it pocket. They are perfect for my rain gear and (in cold weather) a warm jacket - things you want to get at easily during the day. The interior of the pack is plenty roomy; since I don't use a stuff sack for my down bag, and don't use a hydration system, I don't have the loading issues others mention.

The lid pocket is roomy and functional, fully floating, and detachable (great for minimalist summer trips.) The mesh pocket on the underside allowed me to eliminate the small stuff sack my first aid and repair kit used to occupy.

The hipbelt and shoulder straps are much stiffer than the original version of the pack, and very comfortable and supportive (the hipbelt doesn't collapse, like the initial version used to.) The hipbelt pockets are a bit small, but OK. The ability to adjust the length of the padding on the hipbelt is really nice; the belt fits well regardless of your waist size.

The only complaint I have is that the nylon webbing (the moving part) on the shoulder straps and hipbelt is way too long. I could easily cut a foot off each and still have plenty of adjustability.

I'd very much recommend that you look at this pack if you're in the market - and that we start leaving our pre-conceived notions about internal versus external frames at the door.
Glenn at REI on 06/06/2013

Love, love, love this pack!

I recently completed a six day hike on Isle Royale and this pack performed awesomely! I have been steadily lightening up my load and tried a Go-lite Jam to save even more weight but I just missed all of the creature comforts of a full-featured pack. I cannot believe how many features Osprey has jammed into this pack while still keeping it extremely light. For me it is well worth the extra pound or so to have places for all of my stuff. As for the suspension, it truly is amazing. I started with about 35 lbs total and I could barely tell it was there. I will say the hip belt was a little stiff at first. I have about a 31" waist and 35" hips so I could use more of a taper in the hip belt but it loosened up after a few days and didn't bother me any more. (One word of warning, if you are a stockier build the suspension might not work well for you. My nephew (football player build) tried this pack on and the corners of the frame were setting on his hips instead of being off to the sides like they are for me.) I was with a scout troop on Isle Royale and we had a few injuries and equipment failures so I ended up packing some extra equipment for a couple of days. I would estimate that I had between 45 and 50 pounds at one point which really pushed the limits of this pack but I can't say it got any more uncomfortable than any other pack would with that much weight. I also did not use a hydration bladder so I did not have the loading issues that some other reviewers have mentioned. I just used a couple of 1 liter Powerade bottles that I threw in the top of my pack and then some 20 oz Gatorade bottles in the side pockets. The side pockets are amazing! They have both a top and side opening so you can put small bottles in them and pull them out on the go. And the stow-n-go feature is absolutely great for holding trekking poles when you need your hands free. And the stretchy back pocket just keeps on stretching and is a great place for all of the miscellaneous stuff you need access to on an extended outing. Sorry to go on and on but I really can't say enough good things about this pack. I looked at and tried out several other packs in the process of deciding on this pack and I am extremely satisfied with my decision. Thanks Osprey for a great piece of gear!
ezycheez at REI on 08/08/2012

Decent bag for the Camino de Santiago

I bought this specifically for use on the Camino de Santiago in September/ October 2013. I wore it many times while training prior to going on the trip. The pack is easily adjusted and very comfortable. I especially liked the waist belt. When it is properly packed, it really floats on your waist! Many have said it is hard to pack due to the rounded shape of the back, and I somewhat agree. It is a little bit awkward, but not so much that it is something to worry about. I used lightweight packing cubes, which I felt made it very easy to pack.

My shoulders do not have a lot of mobility when reaching backward, so for me personally, it was hard to use the outer pockets on the sides of the pack (where most would keep their water bottles).

There was more than enough room in my pack for this trip. Since I had a hard time reaching bottles on the side of my pack, I instead bought a bladder and put it in the top pocket behind my head. It worked like a charm, and was easier than using the dedicated water bladder pocket inside the pack.

I added some small outer pockets to the straps for my camera, music, and snack. I also used lots of carabiners on the back to attach things like sandals, etc.

I strapped my sleeping bag to the outside of the backpack instead of putting it inside the pack. Keep that in mind if you get a rain cover for this backpack!

Overall, I thought this pack was great. I saw more of these packs on the Camino than any other brand/ style. Many (most?) people probably would not have the problem that I had reaching the back pockets, because I think that is just due to my quirky body. Try one on in the store and see how it works for you.
rorygentry at REI on 11/11/2013

Comfortable with a heavy load

I use the pack to carry my gear when performing trail work for the USFS. I carry heavy, dense items like tools and fuel in addition to safety gear, food and extra clothing. When shopping for a pack I am not looking for volume but for the ability to correctly carry a load. Frequently I perform trail work swinging tools or clearing debris while wearing the pack.
This is a great pack that distributes the load through a series of easily adjustable points. It has one of the best hip belts I have ever owned. The pack does not overly restrict movement or chafe my neck. The comfort is probably due to the correct size frame for my body in addition to the assistance in getting the correct size. Take the time to do it right. The form of the pack body keeps the pack free of my back and promotes air flow. Its not perfect but its much better then other packs I have tried.
The pack is a bit on the heavy side as it has a full suite of compartments. For me this is a small price to pay for the ability to keep the 2 stroke fuel separate from my lunch and my felling wedges separate from my hydration bladder.

Cant say much about the durability of the pack as this is my first season with the pack but I can say that the Osprey Kestrel I retired when I purchased the Atmos held up for 10 years doing the same duty. I note that it wasn't the stitching that finally gave up the ghost but the fabric lost both its coating and its ability to hold shape At the end it was basically a ruck sack. I look forward to 10 years with the Atmos
arc2arc at REI on 07/07/2013

Hits the Sweet Spot

I finally found the pack that works best for me. I have many packs, from a large capacity external framed pack to a minimalist pack that weighs about 1.5 pounds. I prefer the open air and back dryness of an external framed pack but until I got the Osprey Atmos 50 I could not find an internal framed pack that carried like an external. This pack is right-sized for 3-season multi-day excusions if you pack light (without going to extremes). I actually found it to be roomier than my 62 liter pack.

The key to going with a pack of this size is to get a down sleeping bag and a small shelter. Together with a lightweight camp stove everything fits inside quite easily. Lots of room for clothes, food, water bladder, fiter, etc. Once you get down to this size and weight you won't go back. And this pack, although a little heavier than the lightest ultra light packs, puts its extra ounces to good use. The suspension easily carries loads to 35 - 40 pounds in comfort. Something that most ultra lights cannot do.

Very good build quality and it is way more adjustable than anything else I have owned or used. I am 6'1" and weigh 175 pounds, and the large size fit me well (at its shortest setting).

It has only one place to load from (the top) but I don't find that to be a significant inconvenience. The pack is small enough that you can get to anything you really need quite quickly.

I have four good backpacks, but this is the one I will be using most often.
PTetreault at REI on 10/10/2013

4 night backpacking

I broke this backpack in during my first solo backpacking experience for four nights in south western Iceland. The back is extremely comfortable and fits very well. Overall I was very pleased and surprised with 50 liters I had enough space to get through four nights traveling alone. The many compartments on this bag make things accessible and easy to get to (except for the lowermost part of the bag).

The comfort of this pack is incredible. Aside from normal fatigue one would feel traveling four four days the pack hugs you. It doesn't feel like you're carrying a pack but rather the weight just sits on you. It made hiking up steep inclines very easy and manageable.

However here were some issues I ran into:
The bus driver must have laid my backpack with the straps up on the bus because when I received it back after a five hour bus ride the front elastic pocket had a finger sized hole in it. It's something that can be easily fixed though. Because of my improper backing, the zipper to the right side of the back busted, but was easily fixed by using a fingernail to straighten out the teeth. I think these issues could have been easily prevented, but I just wanted to share my experiences with this pack.

Overall I thought this pack was EXTREMELY comfortable, lightweight, and well worth the investment. Had I not jumped the gun I would gave probably bought the larger 65 liter Atmos, but I do not regret this purchase.

Happy hiking!
Thom Washington DC at REI on 08/08/2012

Best Pack I've ever owned!

I have only used this pack once (that's my disclaimer). That said, it was the most comfortable pack I have ever used. And I've owned a lot of packs over the years. I think I currently have 6 packs? I've never been compelled to write a review for any other pack.

I steer towards the light and fast / minimalist style of backpacking. With this pack I don't sacrifice comfort in an effort to save weight. It's so comfortable and lightweight. Its a little bigger than many other packs I have used and seems to just swallow up the gear. Its easy breezy to pack.

There are these two use outer pockets. In one pocket I put my tent (Big Agnes Fly Creek UL2) and in the other pocket I put my shell, a beanie and water filter. This constricts the inside of the pack some, however I place my sleeping bag at the bottom and food in the middle. As I consume my food I am able to tighten the outer compression straps, pulling my tent / rain jacket closer to my back. This was a super awesome way of packing.

It was raining and snowing during the four days I was out with this pack, and not having to dig through my backpack to pull out the tent was really convenient. Also, having the water filter and a jacket so readily at hand really sped up our transitions so we were able to cover more ground.

Buy this backpack, the competition doesn't compare!
J-Jay at REI on 06/06/2012

My first and only pack so far..

Disclaimer: This was my first bag and until recently my only bag.. (I got a much larger Arcteryx bag for longer journeys.

I've taken this thing with me all over the place in the past year, Colorado for 3 months of backpacking, Yosemite, Yellowstone twice, Grand Tetons twice, Banff NP, Glacier NP, All over Norway, all over Montana, Idaho, Wyoming, etc etc. All I can say is that I'm extremely surprised it still works flawlessly. The fabric seemed so soft and flexible when I first got it, I didnt think it would last. But after over 400 miles of trails, here it is, still in great shape, no stuck zippers, no tears, no rips.. Nothing.

I think the pack is darn near perfect.

I use this thing for shorter trips like 3-5 days max.. After that I want more comfort and that require a bigger pack for more food, extra stuff. If you pack it for 3-5 days you will realize that you have to put sleeping bag in first before you put the filled hydration bladder in it, or else it won't fit thru. This is just part of owning the pack, I dont see it as a downside.
Albert Manduca at REI on 04/04/2013

So far so good

I'm just getting into this so I don't feel qualified to give 5 stars yet. That being said, this is a great pack. Very comfortable, and more than enough room for my gear. My gear is pretty descent (small pack size) stuff so I'd suggest taking this pack home and sticking your gear in it before deciding that it's big enough for you. However, once you get a feel for the pack there's lots of room to be had than appears at first glance.

One tip is to pack the inside cavity first. That will give you enough room to pack the outside pockets without overfilling. I wouldn't put small objects in the side pouches, they have a hole for strap access that could lead to small things falling out of it if you don't strap it down tight. They are better for a towel or something bulky enough to not fit through the hole.

I don't plan on doing too much winter backpacking (yet ;) so 50L is enough for me, but if you're in the market for a 50L bag, You can't go wrong with this one.
Brendan from VA at REI on 05/05/2012

Used this pack the entire length of the AT in 2012 and loved it the whole way. I have 2 other Osprey packs (Argon 85 and Aether 60) and this one fits the best. I have the previous model, but several of my firends had this newer version and not much has changed. In fact, I will say that about 80% of the hiker class from 2012 had some model of Osprey pack. The Atmos and Exos were the most popular, but did see a few Talon 44's and Kestrel models. The girl I hiked with had a Gregory and wished she'd bought an Osprey after hearing such rave reviews by fellow hikers. 2184.2 miles equals a well tested product and high approval rating! If you are planning to thru-hikeor just looking for a great pack for short trips, do yourself a favor and buy this pack!
In addition, I'm 5'9" and have a 31" waist. I bought a Medium and was a perfect fit.

Christopher Hood at Backcountry.com on 02/09/2013

Negative Reviews:

I was hoping this pack would be my pack for doing a long thru-hike this summer. Supposedly Osprey revamped this pack from previous years to allow for more weight carrying. Their website indicates max loads from 35 to 45 lbs. Backcountry.com indicates up to 35 lbs. I gave the pack a few trial runs with up to 35 lbs and anticipated going higher.. At first the pack seemed great, but when I went for a 16 miler one day with 35 lbs, the hip belt became unreasonably uncomfortable after about 5 hours. The hip belt design on this pack seems to be a total afterthought in comparison to the rest of the Airspeed suspension design. The hip belt design creates pressure points where the hip belt meets the back of the pack. Otherwise the Airspeed suspension system worked great at minmizing back sweat. The rest of the pack seemed great, but unfortunately for me the pack ended up ebing uncomfortable, maybe because my bodytype is very thin. YMMV

A-Bomb at Backcountry.com on 02/15/2012

Osprey 50

. . . item not compatible with Camelback water carrier, as are previous models id'ing themselves as Osprey Atmos 50.
REI Junk at REI on 09/09/2013

Neutral Reviews:

Decent, but not as great as I'd hoped

I had been waiting for Osprey to update the Atmos line so when they did I finally purchased this one in early 2012.

The good: I love the packbag design with stretch side pockets, front pocket, and dual-zppered front pockets. I can easily get a week's worth of gear and food inside, with pretty good organization. I really like the back panel that offers good ventilation, and Osprey is smart to keep exposed thread/stitching to a very minimum. In my experience, exposed thread lines (especially on the backpanel and straps) get full of sweat and trail dust, then get abraded until they fall apart. The hipbelt is comfy and nicely adjustable, and the pockets are a nice size and easy to get into.

The 'could be better': As a former long-distance hiker, I never use the top lid. Took that off right away and am really disappointed there is no strap to tighten down over the top of the storm collar. This is a real pain not to be able to cinch that down, bring the weight closer to your back and keep things up there from wobbling. Every pack I've ever owned has had one of these but for some reason Osprey left it off this one. Major minus.
Also, when the pack is fully stuffed and I go to cinch the side compression straps, often times it pulls apart the zipper on the dual front pockets. I have to be real careful about how tight I cinch them so that the zippers don't pull open as I'm hiking down the trail and have everything fall out.

Other than that it's pretty well made. I appreciate that Osprey uses higher stitch-counts than most pack manufacturers nowadays. That really helps hold everything together over the long haul. I'd hoped to keep this one awhile but am keeping my eye out for possible replacements due to the issues above.
JPhO at REI on 08/08/2013

I had been waiting for Osprey to update the Atmos line so when they did I finally purchased this one in early 2012.
The good: I love the packbag design with stretch side pockets, front pocket, and dual-zppered front pockets. I can easily get a week's worth of gear and food inside, with pretty good organization. I really like the back panel that offers good ventilation, and Osprey is smart to keep exposed thread/stitching to a very minimum. In my experience, exposed thread lines (especially on the backpanel and straps) get full of sweat and trail dust, then get abraded until they fall apart. The hipbelt is comfy and nicely adjustable, and the pockets are a nice size and easy to get into.
The 'could be better': As a former long-distance hiker, I never use the top lid. Took that off right away and am really disappointed there is no strap to tighten down over the top of the storm collar. This is a real pain not to be able to cinch that down, bring the weight closer to your back and keep things up there from wobbling. Every pack I've ever owned has had one of these but for some reason Osprey left it off this one. Major minus.
Also, when the pack is fully stuffed and I go to cinch the side compression straps, often times it pulls apart the zipper on the top of the dual front pockets. I have to be real careful about how tight I cinch them so that the zippers don't pull open as I'm hiking down the trail and have everything fall out.
Other than that it's pretty well made. I appreciate that Osprey uses higher stitch-counts than most pack manufacturers nowadays. That really helps hold everything together over the long haul. I'd hoped to keep this one awhile but am keeping my eye out for possible replacements due to the issues above.

JPhO at Backcountry.com on 08/19/2013

Less than expected

I bought this pack for a three day hike on a portion of the NCT and used it on 30 miles of practice hikes with 50 lbs of weight. It seemed to hold up well and was comfortable.

The hip belt pockets are too small for even a Clif bar. The "easy access" storage pockets on each side of the main pack are too small for a standard 750 ml water bottle. The hour glass shape of the frame makes loading bulky items (e.g., sleeping bag) difficult to push to the bottom. And even though the pack size was technically too large for me the frame seemed too small at the hips.

When I was starting to load the pack with the items I plan to take on the hike one of the side zippers slit and I couldn't get it back together.

I returned the pack to REI and got a REI Crestrail 70.
t-rex22 at REI on 08/08/2013

Not so great

I purchased the Osprey Atmos 50 because of the Osprey guarantee and my experience with their hydration pack. Overall, it's a good pack; lots of attachment points, good compression straps and very nice padding.

Unfortunately, the pack is shaped in an "hour-glass" and it is "difficult" to push items to the bottom. Also, the side pockets are pretty useless, too small.

Another issue I had was that even though the pack itself fit properly, the frame at the hips did not fit well (it was too large).

The final straw was that while I was packing for my trip one of the zippers on a side pocket came unthreaded. I do not believe I over-stuffed the pocket.
t-rex22 at REI on 08/08/2013
I took this pack to Zion National Park in Utah. The pack has a steel wire frame around the perimeter for support. An aluminum ferrule holds the ends together at the bottom. The wire digs into your buttocks just below the belt line. After 20 miles you want to throw it off a cliff. When I got it home I tried to flex the wire away from the sore spots and broke the ferrule. I sent it to Osprey who fixed it right away. Good company but this one is a bad design. Whatever you buy, try it on with weight in it first. Kelty is pretty bombproof. I have many packs but nothing so far can beat my Kelty Agile.
Anonymous - customer at Zappos.com on 08/13/2011

Osprey atmost

This is one of the most stylish, practical, and functional bags Osprey offers. it has a metal spine, which evenly distributes the load across your shoulders and hips and protects your lower back from excess weight. Unfortunately this metal spine is also the bags greatest flaw. The spine digs into your hips under any load greater than 25lbs and is more than a thorn in your side after the 4th mile. As much as I loved the style and practicality of this pack, it is far too uncomfortable to wear on extended hikes and I would NEVER consider using it for overnight camping.
Dan at Eastern Mountain Sports (EMS) on 11/11/2013