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ULA Photon 35 Backpack Review

ULA Photon Pack Review

The ULA Photon is a 35L ultralight-style roll-top backpack with a base weight of 26.1 ounces in a size medium.  It’s basically a lower volume version of ULA’s CDT ultralight backpack (54L) ideal for day hikes, hut-to-hut overnights, commuting, or air travel because it’s smaller and more compact. Like ULA’s other backpacks, the Photon is available with male (J-shaped) or female-friendly (S-shaped) shoulder straps, multiple torso sizes, multiple hip belt sizes, colors, fabrics, and an unusually wide range of sizes. You don’t often find that degree of customization on a pack that’s this low volume.

ULA was acquired from the former owner last year. The new owners stripped out some of the extras that used to ship with ULAs packs, added a host of customization options including colors and new fabrics like Robic 400D, XPac, and Ultra, and modernized the ULA website. It’s been exciting to see them breathe new life into ULA, one of the mainstay backpack manufacturers in the ultralight backpacking market.

Specs at a Glance

  • Weight: 26.1 oz (size medium, Robic 400D fabric)
  • Volume:  35 Liters incl. extension collar and external pockets
  • Fabric: Robic 400D Nylon (also available in XPac)
  • Mfg. Rec’d Max Load: 25 lbs
  • Mfg. Rec’d Base Weight: 12 lbs or less
  • Torso Lengths: 15-18″, 18-21″, 21-24″, 24″+
  • Hip Belt Sizing: 26-30″, 30-34″, 34-38″, 38-40″, 42-47″, 47″+
  • Made in the USA
  • For complete specs, visit ULA’s Photon Product Page

Storage and Organization

The ULA Photon is laid out like a standard ultralight backpack with a rear mesh pocket, side water bottle pockets made with solid fabric, and a single tier of side compression straps. It’s a roll-top pack (without any snaps, velcro, or a stiffener) that can be secured to the sides of the pack with straps and buckles or clipped together on top. If the latter, the extra straps can be looped around the backpack to provide rear compression or act as an attachment point to lash gear to the outside of the front mesh pocket, which can be very handy.

The Photon is an ultralight-style roll-top backpack.
The Photon is an ultralight-style roll-top backpack.

The side water bottle pockets are easy to reach while wearing the backpack and you can get bottles in and out of the pockets. There is also elastic with a cord lock along the top of the pocket to secure taller bottles.

The rear mesh pocket is great for storing wet or loose layers you want easy access to, without having to open up the roll top.  The stretch mesh has a very tight weave and good durability for on-trail use, but I wouldn’t recommend taking the Photon on rugged bushwhacking trips if you want to keep the mesh intact.

The side bottle pockets have an opening along the side as well as on top because the shoulder straps terminate inside them. While this attachment point helps pull the pack closer to your back, small items can fall out of the side water bottle pockets and they shouldn’t be used for that type of storage.

There are two zippered pockets on the exterior of the hip belt, large enough to store a point-and-shoot camera, snacks, Aquamira bottles, bug dope, and such. The fronts of both pockets are hard-faced to prevent tearing with heavy-duty zippers for durability.

There are trekking pole holders on the sides of the mesh pocket.
There are trekking pole holders on the sides of the mesh pocket.

The hipbelt wings are sewn to the back of the pack, which helps with load transfer but they are not as modular or as wide as the removable hip belts on ULA’s higher volume backpacks. The hip belt also closes with one webbing strap, not the two found on ULA’s higher volume packs, and doesn’t conform as well to different hip shapes. I didn’t find the hip belt to be very effective at load transfer on this pack because it’s too stiff to provide a very good wrap over my hip bones. You can order the Photon without a hip belt, which might be a good option if you only plan to use it as a day pack with lighter loads.

The interior of the Photon is just a big sack. While it does have side hydration ports, there isn’t a hydration pocket. There are two webbing loops sewn into the top seam where you can hang a hydration sleeve, but it costs an additional $12 on top of the pack’s $200 price. I think they should just sew in a center hang loop in the base pack and call it a day, rather than charging extra for a feature that is usually standard on other backpacks.

The side pockets are tall enough to carry 1L bottles
The side pockets are tall enough to carry 1L bottles

External Attachment and Compression System

There’s one tier of compression straps on the Photon located above each side pocket. In addition to helping compress puffy gear stored inside the pack, they can also be used to secure long skinny items to the side of the pack like a Tenkara fishing rod tube or a trekking umbrella.

Like all ULA backpacks, the Photon’s shoulder straps provide plastic rings to hang gear like GPS receivers or a Garmin mini 2. The sternum strap slides up and down a piece of webbing sewn to the front of the shoulder straps and is easy to adjust (since it’s not sewn like a daisy chain).

The shoulder straps have plastic rings to suspend pockets or gear from
The shoulder straps have plastic rings to suspend pockets or gear from

There are seven gear loops sewn into the pack’s seams that circle its perimeter which hold a crisscrossed adjustable elastic cord good for lashing items to the pack, although you can easily rig up extra cords any way you please. The Photon also has a pair of trekking pole holders that run down the outside of the pockets.

Backpack Frame and Suspension System

The Photon comes with a simple foam pad that provides cushioning between the main compartment and your back. You’d have to be really generous to call it a frame. ULA recommends carrying up to 25 lbs with the Photon, which is what you can expect with a frameless backpack, any frameless backpack.

The hip belt pockets are generously sized.
The hip belt pockets are generously sized.

I’d even recommend going lighter than 25 lbs with the Photon because it does not take kindly to being packed tightly. For example, if you pack any hard-edged objects you’ll probably feel them through the foam unless you pad them out with softer objects. If you try to overstuff the Photon, the pack will barrel into your back so it’s best to pack items loosely instead.

The foam pad is held in place in the main compartment by elastic straps and is easily removable. If you want, you can replace it with a pad you cut down for that purpose, perhaps something like a Therm-a-Rest Zlite, that can double as sleeping insulation. Adding a stiffer or a thicker foam pad will also help add more structure to the storage and make it much more comfortable to carry.

The rolltop can be clipped to the sides or buckled on top.
The rolltop can be clipped to the sides or buckled on top.

Although the 35L Photon has a lower capacity than the 54L CDT backpack, the shoulder straps are the same with the same width and foam padding/mesh backing, providing a very comfortable carry. If you’re a woman or an athletically built man, the Photon is also available with female-friendly S-Shaped shoulder straps that won’t mash your breasts flat. Nearly 50% of ULA’s customer base is female because they’re one of the only cottage backpack makers to offer anatomically correct shoulder straps for women.


The 35L ULA Photon is an ultralight style rolltop backpack available in a wide range of colors and sizes, which makes the pack quite appealing because it’s not something you find that often with lower volume backpacks. There are also a number of customization options available that I did not get a chance to evaluate including the ability to add a real frame w/load lifters (+50$) and a pass thru hip belt (+50$), like the ones offered on ULA larger volume overnight packs. Based on my experience with ULA’s packs, I think those are good options to consider because they’ll prevent any barrelling when the pack is stuffed tightly and they’ll improve the fit of the hip belt, particularly if you carry gear near the pack’s max recommended load of 25 lbs. For lighter weight loads, I’d consider forgoing the hip belt altogether.

In terms of quality and durability, the sewing on the Photon is immaculate, which you’d expect on a pack that is still manufactured in the USA. The Robic 400D Nylon is also impressively tough stuff and while it’s not waterproof like XPac or Ultra, it’s extremely abrasion resistant and should hold up pretty much forever.  ULA has been using this grade of Robic for many years now and they have the track record to prove it.

Disclosure: ULA loaned the author a Photon Backpack for this review.

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  2. Overnight they went from 145 to 199…….sad.

  3. The Photon is not available in Ultra, yet. Just the framed packs at the moment.

  4. Great timing, I received my XL Royal Blue Robic Photon on Friday after much review of so many other packs. I plan to use it solely for day hikes and couldn’t find the right size in any other brand. I have a long torso and ULA offers the most customization.

    I chose the Photon without a hip belt, did add the internal storage pouch and one shoulder strap pocket. Dual side pockets for water bottles were a must.

    Everything about the ordering process was great. I had several interactions with ULA’s customer service to ask about actual pack lengths, shipping time, etc. They were very prompt and extremely helpful.

    The attachment of the shoulder strap pocket could be better. It tends to be a bit floppy with the clips they provided. I might sew on a Velcro strap to help hold it snuggly. (The Gossamer shoulder pockets use Velcro and I found they are very secure.)

    For the price, I’m extremely pleased. Quality, customization, customer service is hard to find.

    • Yeah I tried the ULA should pocket last year and prefer the more universal Gossamer gear pocket for the same reason. Good call on the hip belt. The sizing options are also really great.

    • I also do not like the ULA shoulder pocket. In addition to the floppiness, on the S straps it’s pretty difficult to find a good position for the pocket since they’re so curved (and I have a short torso so that probably complicates matters further). I bought an Etsy-made one from one of the shops Philip posted about recently and it attaches with double-sided velcro (that stuff is great, actually) and I like it much much better.

  5. I took your advice and ordered the Photon with a frame, load lifters and pass- thru adjustable hip belt. My backpack is a ULA Catalyst so I’m sure I’ll be really impressed by its performance. Can’t wait to try it out. My previous day pack was a Coulee 25?which was another stellar pack recommendation from you.

    • Hi Tim. Im curious how this pack is working for you. After alot of research, Ive ordered the Photon with a frame, lifters and pass-thru belt in ultra. Had a ULA circuit years ago and with new owners and customization options plus updated design tweaks, really looking forward to seeing how it performs in a few weeks.

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