The Gregory Packs Optic 58 is an ultralight backpack with a ventilated frame that helps evaporate back sweat and keep your shirt dry when hiking. Weighing 40-45 ounces, the Optic is a fully featured backpack with a lightweight wire frame, large hip belt pockets, an optional speed lid, front mesh pocket, and a max recommended load of 35 pounds. A women’s version of this lightweight backpack is also available called the Gregory Octal 55.
If you’re looking at the Osprey Exos or Levity backpacks because they have ventilated frames, I’d encourage you to compare them against the Gregory Optic 58. While it has a more conventional appearance, the Optic carries heavier loads closer to your back and core than the Exos or Levity, making it much more responsive when scrambling or hiking uphill, in addition to having hip belt pockets and a comfortable hip belt.
Specs at a Glance
- Volume (L): 58 (size large, tested)
- Weight with speed lid, no top lid, no rain cover: 40 oz.
- Weight with top lid, no speed lid, no rain cover: 41.95
- Weight with top lid, rain cover: 45.35 oz.
- (Large:) Torso: 20″-22″; Hipbelt: 32″-53″ – tested
- (Medium:) Torso: 18″-20″; Hipbelt: 28″-48″
- (Small:) Torso: 16″-18″; Hipbelt: 26″-45″
- Frame: Perimeter Wire, Ventilated with Mesh
- Fabric: 100 denier nylon, 210 denier nylon bottom
- Max Recommended Load (lbs): 35
- Gender: Men’s (the Gregory Octal 55 is the Optic’s female variant)
Backpack Organization and Storage
The Optic 58 is a conventional top loading backpack that closes with a drawstring. It has a top lid with two pockets, one external and one under the lid for storing small items like gloves, maps, and keys. The top lid can be replaced with a speed lid that does not have pockets, but covers the drawstring opening to block out rain or dust. While the top lid is technically a floating lid, it has very short straps which make it less suitable for compressing bulky gear against the top of the main compartment, which is how floating lids are normally used.
The pack has a front stretch mesh pocket which is good for storing layers or wet items and two mesh side water bottle pockets. The bottom of the side pockets is not reinforced with solid fabric and I’d expect them to get torn up pretty quickly with backcountry use. The side bottle pockets are large enough to fit two 1L Smartwater bottles, but they have holster-style front cutouts so I’d be careful about what you put in them, lest it fall out. While you can pull a bottle stored in the side pocket out through the holster-hole, you need to take the pack off to get it back into the side pocket. If you prefer to use a hydration system, there is a large hydration pocket in the main compartment and a central hang loop to keep it vertical.
The hip belt has two large zippered solid pockets with large zipper pulls, so you can open them when wearing gloves. The pockets are large enough to store cell phones, a point and shoot camera, or snack bars. There are no pockets on the shoulder straps.
External Attachment Points and Compression
The Optic 58 has side compression straps on each side of the pack – a top strap and a bottom one – threaded in a diagonal pattern. They work “ok” as compression straps, but the diagonal pattern and the lack of side release buckles makes it difficult to use them for holding snowshoes and other larger items along the sides of the pack. This is less of an issue for three season use and more of a winter backpacking concern.
It’s possible to attach a sleeping pad or tent to the bottom/back of the pack with accessory webbing. This is a nice feature to have on a backpacking pack and one that’s often missing on 60 liter backpacks. The bottom side compression strap is threaded to come out the bottom and back of the side compression pocket and has enough slack in it to hold a pad or tent, as shown here.
The pack also comes with a pair of ice axe loops that can also be used as trekking pole holders. Two adjustable elastic shaft/pole holders are included along the sides of the front mesh pocket, another feature that’s left off many packs.
If you want to rig up your own external attachment points there are four webbing loops on the corners of the front mesh pocket for this purpose. Just tie some elastic cord between them, add a cord lock to help tension it, and you can attach snowshoes or wet clothing to the back of the pack with ease. There are additional webbing loops on the top lid that can also be used to hang a solar panel when hiking someplace with sustained sunlight
Backpack Frame and Suspension
The Gregory Optic 58 is a ventilated “trampoline-style” backpack that’s optimized for effective airflow behind your back. Breathable mesh is suspended in front of the back panel creating a large ventilated space behind your back that’s designed to evaporate sweat before it can soak your shirt. The mesh is tightly stretched across the aluminum frame, hence the name, trampoline, which also serves to anchor the hip belt and load lifters. While many backpacks claim to provide foam air channels to facilitate ventilation, you really need a deep cavity behind shoulder straps to keep your back and shirt perspiration free.
The Optic 58 has a lightweight wire frame with horizontal reinforcements that help stiffen it up. The mesh trampoline is suspended from it, with a cavity that’s 1 to 2 inches deep behind it to facilitate air flow. You can feel the mesh on your back, but there’s no noticeable backwards pull to throw you off-balance when the pack is heavily loaded, and load transfer to the hip belt is really superb. Load lifters are included and anchored to the wire frame for maximum effectiveness.
The hip belt has beefy hip belt pockets and is pre-curved to wrap around your hip bones. It’s covered with wicking mesh and has a slight lumbar pad at the rear, that’s well cushioned and hardly noticeable. The hip belt also has a pull forward cinch system that’s easy to tighten.
|Make / Model||Price||Weight (oz)||Type|
|Gossamer Gear Silverback 55||$325||43.4||Roll top, Top lid|
|Gossamer Gear Mariposa 60||$270||30.5||Speed flap|
|Granite Gear Crown 2 - 60L||$200||36.7||Roll top, Top lid|
|Granite Gear Blaze 60||$270||48||Roll top, Top lid|
|Hyperlite Mountain Gear SW 3400||$345||32.11||Roll top|
|Osprey Exos 58||$220||43||Top lid, speed flap|
|Gregory Optic 58||$210||43.35||Top lid, speed flap|
|Zpacks Arc Blast 55||$325||21||Roll top|
|Mountain Laurel Designs Exodus 57||$215||18||Roll top|
|Mountainsmith Scream 55||$160||45||Roll top|
|Seek Outside Gila 3500 (57L)||$339||47||Roll top, side zipper|
|Sierra Designs Flex Capacitor||$200||41.2||Top lid|
|Elemental Horizons Kalais||$270||37||Roll top|
The Gregory Optic 58 is a fully featured ultralight ventilated backpack with several optional components that weighs 40-45.35 oz, depending on how you have it configured. Ventilated, trampoline style backpacks are desirable because they help reduce perspiration and keep your shirt dry when backpacking. Some ventilated frames can throw you off-balance because they shift your center of gravity behind your hips. That’s not the case with the Optic 58, which sits closer to your hips and core muscles where it can be carried more comfortably and efficiently.
Gregory has done a really nice job with the Optic 58 and demonstrated that you can make a fully featured, ventilated backpack that weighs close to 2 and 1/2 pounds. If you prefer a more conventional top-loading backpack but have been looking for one that’s under 3 pounds, I’d encourage you to put the Gregory Packs Optic 58 on your short list for serious consideration. I’m pretty impressed with this pack and thank the reader who encouraged me to review it.
Disclosure: The author purchased this pack with his own funds.
- Osprey Exos 58 (2018) Backpack Review
- Osprey Atmos 50 AG Backpack Review
- History of Ventilated Backpack Frames
Written 2018.Editor's note: Help support this site by making your next gear purchase through one of the links above. Click a link, buy what you need, and the seller will contribute a portion of the purchase price to support SectionHiker's unsponsored gear reviews, articles, and hiking guides.
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