Rab Women's Photon X Jacket Review

Filled with PrimaLoft Gold insulation under a Pertex shell, Rab markets this synthetic duvet as the 'definitive Scottish winter belay jacket'. It is described as being 'durable and exceptionally warm' and 'ready to take on everything from sub-zero temperatures to bitter, battering winds.' Having now used it for the first couple of months of the Scottish winter season, I've had a good chance to put the claims to the test.

An excellent winter belay jacket, so long as you're not hanging around on a belay for several hours
© Iain Small


For a winter belay jacket that is designed to be worn over other layers, I'd say the Photon X is relatively close-fitting. For this review I have the size 16 jacket which I've found a good fit when worn over multiple layers. I can move my arms freely in this size, both for keeping warm on belays and if seconding in the jacket. I originally tried the size 14 but found that this was too tight on my arms (especially around my biceps when bending my arms) and across my upper back. As a point of reference for other women I am 5'6" (so average height), 70kg and normally wear size 14 jackets as I have quite broad shoulders and back. Probably going up one size from what you would normally wear will give you the best fit over all of your other layers.

For women the Photon X is available in sizes 8 - 16, so anyone much larger than me might be out of luck. For men it comes in sizes S - XXL.

Thought has clearly gone into the fit; for instance I have appreciated having a belay jacket that covers my bum as this provides extra insulation on belays. I've had no significant hem lift when raising my arms. Meanwhile, down at the cuffs, there's plenty of room for fitting over bulky gloves.


Always a key feature on a belay jacket, the hood fits easily over a helmet. I find that some jackets can be tight around the mouth and chin when zipped up fully over multiple layers but this is not the case with the Photon X and it is easy to get food in your mouth when the zip is all the way up, as well- handy on a long belay.

Decent length in the back for better bum coverage  © Iain Small
Decent length in the back for better bum coverage
© Iain Small

Big glove friendly zip pulls and plenty of room for layering  © Iain Small
Big glove friendly zip pulls and plenty of room for layering
© Iain Small

The volume adjustment for the hood is a single drawcord on the back, located in the middle of your head. This is manageable with gloves on, but not as easy to use as the zips. There's no stiffened or wired peak of any sort, but I've found that when wearing a helmet the hood is very effective in high wind, with no billowing or flapping. I haven't tested it in windy conditions without a helmet, but I think that the snug fit would offset the lack of any wire structure in terms of the hood keeping its shape in stormy weather.


I have used the Photon X as my belay jacket on early season (November and December) Scottish winter routes this season. I haven't yet had an epic belay session in it but a few of the belays were of two hours or longer and on semi-hanging belays (Unicorn and Diedre of the Sorrows). Conditions in November and December were Alpine-like on many days and so the jacket has mostly been tested in dry and very cold (for Scotland) air temperatures, though it was also tested in an unexpected rain shower on Lochnagar.

I have worn the jacket when seconding some pitches and have carried it up pitches both in its stuffsac on the back of my harness and stuffed into my small seconding pack.

The hood fits well over a helmet
© Dave Almond


For winter climbing, the Photon X has well designed features. For instance, the zip baffle and chin guard prevent the metal of the zip from being directly against your skin. All of the zip pulls are substantial and easy to use when wearing gloves or mitts, too. Small features such as this make a big difference to comfort.

The jacket has a good selection of pockets for keeping snacks, spare gloves, headtorch etc - one Napoleon chest pocket, two zipped hand warmer pockets and two inside open mesh pockets. The chest pocket will take a medium sized pair of climbing gloves, for example Mountain Equipment Guide Gloves, but a bulky pair of belay mitts would be tight, so I'd call it medium rather than large. I tend to put spare gloves down my front so they are kept warm by being against my torso, and for this the inside zip-less mesh pockets are handy. One large glove/belay mitt comfortably fits in each of these mesh pockets, so they're a good size if you don't mind splitting the pair.

Outer fabric

The jacket has a Pertex Endurance outer. This is windproof and lightweight but is not the most durable of materials, as I discovered when I managed to rip a fairly large hole in the right arm when climbing, on only the second time of wearing the jacket. The material does patch up well and my repair has prevented the hole from becoming any larger.


The Photon X uses PrimaLoft Gold, one of the leading current synthetic fills in terms of warmth-for-weight and moisture management. Rab have put some thought into the distribution of this insulation, zoning it in different weights across the jacket to allow for more insulation where it's most needed and better freedom of movement (and less overheating when active) where thickness is less necessary. In the sides of the body and under the ams Rab have given you 133gsm of PrimaLoft Gold, while on the front of the body it's a hefty 193gsm; elsewhere you're getting 170gsm. For its thickness the Photon X packs down well, and it is a good weight jacket when it comes to climbing in it or carrying it. For its realtively light weight I have found this to be a warm belay jacket. In terms of weight, I make it 800g for a size 16, which definitiely puts this jacket in the warmer/ heavier category.

However, for the very toughest conditions or really epic belay sessions, I think a heavier weight of insulation still would be preferable. I haven't yet worn the jacket in any really testing conditions (i.e. constant precipitation, strong winds), but in this situation I am not confident that the Photon X would be substantial enough to keep me warm on a really long belay, i.e. one lasting three or more hours, especially if the opportunity for moving to keep warm on the belay was limited (i.e. on a hanging or particularly cramped belay). I don't expect any belay jacket to keep me completely warm on a belay such as this and there will always be a degree of becoming cold on a long belay in winter. However, during my longer stints in this jacket on semi-hanging belays I was definitely becoming colder than I would have done in my old heavier belay jacket. By way of comparison, the BD stance uses 180gsm of 'Thermolite' throughout, while the ME Citadel's PrimaLoft Gold fill is 200gsm in the body and 170gsm in the arms - so marginally warmer synthetic jackets than the Photon X are definitely available, though of course they're likely to be heavier and bulkier. We are all different though, and some others may find they run warmer and never feel the need for anything thicker than the Photon X.

I have only worn the jacket in wet conditions on one occasion so far, when there was an unexpected rain shower on Lochnagar. I found that the jacket, and cuffs in particular, quickly became damp. I'd say it is best saved for sub-zero conditions.

The verdict?

In my opinion this is an excellent belay jacket for easy to mid grade winter climbs, where its warmth for a modest weight is likely to be sufficient. Perhaps this is a bit of a niche concern, given that many people don't operate in the upper grades, but on hard mixed routes you'll often have some very long belay sessions, potentially on hanging or semi-hanging belays where the opportunity to move around to stay warm is going to be limited, and in this situation I would personally prefer a heavier, warmer belay jacket than the Photon X. It is very well designed though, with small features that add a lot to comfort and ease of use. It's a good fit (if you get the sizing right) and it packs down easily into a small seconding pack or into its own stuffsac. The outer material is not the most durable however, and I think that is something to be aware of when seconding in it.

Rab say:

Durable and exceptionally warm, our Photon X is your definitive Scottish winter belay jacket. Ready to take on everything from sub-zero temperatures to bitter, battering winds our Photon X provides shelter in the harshest conditions. Shrugging off rain and snow, the Pertex Endurance outer protects you from the elements while the zoned PrimaLoft Gold Insulation Active inner eliminates any cold spots even when wet.

With two large hand warmer pockets, a helmet-compatible hood that can be adjusted with one hand and zips that can be opened easily with large mitts, there is no better jacket for a baltic Scottish belay.

  • Price: £225
  • Weight: 800g (size 16 - our measure)
  • Sizes: 8 -16 (women) S-XXL (men)
  • Pertex® Endurance windproof and outer fabric with a 100% nylon breathable inner liner
  • Zoned insulation: 170g PrimaLoft® Gold Insulation Active throughout
  • 133g PrimaLoft® Gold Insulation Active in sides and underarms
  • 193g PrimaLoft® Gold Insulation Active in front torso
  • Helmet compatible hood with one-handed adjustment and insulated baffle in back neck
  • 2-way YKK® VISLON® front zip with insulated internal zip baffle with chin guard
  • 1 YKK® large, zipped Napoleon chest pocket, 2 YKK® zipped hand warmer pockets and 2 internal open mesh pockets
  • Glove compatible zip pulls
  • Part elasticated cuffs with anti-snag velcro adjustment
  • Hem drawcord
  • Stuffsac

For more info see rab.equipment

BUY NOW from:
logo£220.00. 15% discount off this price if you're booked with Jagged Globe.
See this product at the Jagged Globe shop
logoThis is our best-selling mega warm, synthetic belay jacket for women!
See this product at the Needle Sports shop

13 Feb, 2018

Good review Helen. Definitely agree it's a great well thought out winter belay jacket but do size up - I'm normally a Medium Men's in most stuff, found it a touch tight in the neck and arms so went for a large on this jacket. I'd diagree on the Pertex fabric, I think it's a good balance on weight saving an durability and similar to what most companies are using in anycase. I personally wouldn't want anything heavier. I really like the pocket configuration over other jackets on the market, the 2 big mesh pockets are great for gloves and I find 3 on the body fine for stashing other bits.

In terms of the warmth of the jacket, it's definitely not as warm as the heavier Mountain Equipment Citadel as you say, but it's a good bit warmer than the ME Fitzoy which is another popular belay jacket but I find it too cold for winter. I think it's a really good weight jacket for most folk in winter, top design and materials and good balance of warmth and weight.

I've not yet had any epic belay stints this season but will probably pack a thinner summer weight belay jacket to boost it up to Citadel levels of warmth on the odd day it's needed. It would be ace if Rab took the same design and did a heavier weight version of this jacket. It would be my go to jacket for long hard days belaying your mate whilst they crawl their way up their hardest ever lead!

15 Feb, 2018

I've been using the men's version for a few months now in winter conditions and it is the best synthetic jacket I have owned. And I have owned a few over the years.

It saved the day when I was camping up high. My down sleeping bag had got quite damp but wearing the jacket inside my bag sorted me out