bf said:
I'm looking for a light bag-pack to put these on for short day hiking:
One M series body
2 lenses + filters + batteries
1LB Tripod
Water (would consider a hydration pack)
Fruit, trail mix etc
Cellphone+Wallet etc
A light jacket etc
What's your suggestion?
Define short (hours, distance, elevation gain). What weather might you might experience throughout the year? Are the trails well traveled or seldom used. Are you beyond cell range? Is water available along the trail? Are you hiking solo or in a group?
There can be quite a bit of variance in these answers. I often hike solo so I'm carrying some extra gear, just in case. My day hikes range from 6 to 16 hours. Sometimes I'll be the only person on the trail that day and often without cell coverage. And I might just be snowshoeing above 10k feet in the dead of winter here in Colorado. Or above tree line where water is seldom available so I must carry it all in. One pack is not sufficient in my case.
I prefer inserts with a pack designed for hiking over any camera bag. A single insert allows me to extract all the camera gear at once to make a change or to set aside when getting lunch or setting up camp. Slings are a no go with any amount of weight on a trail. Might as well drop the pack and rest for a minute while changing lenses - less likelihood of something going wrong. This approach gives a lot of flexibility to balance the amount of camera gear you wish to carry versus other gear needed for the conditions. And I get to reuse the bags I've already got - both camera and hiking. Visit your local outdoor store and get fitted for a pack to see the difference, especially with a load in it.
For my M camera kit I typically use a 7 liter Gura Gear insert. I have the 11 liter insert also if I want to carry a larger lens. I sometimes use my Think Tank Mirrorless Mover 10 (2.5 liter) or 20 (4 liter) as inserts (sans straps) when I want something smaller. The 7 liter might be a bit large for your needs.
The insert goes in an 18, 30 (normal), or 45 liter day pack or overnight pack for a day hike depending on the season and weather. The Peak Design Capture Pro allows me to carry the M on my strap if I want it available on the go.
On a short stroll with my wife I carry the 18 liter with a TT MM and the PD Capture Pro on the strap. She won't be carrying much other than a water bottle.
Here's a look at the 7 liter insert in my 45 liter pack (below) on a day hike up to tree line for some photos of the fresh snow from the day before on the forest and peaks. I carried the M3, 4 lenses and some accessories. The weather was cold and iffy so I was carrying some extra gear in the larger pack.
On a 4 day group trip with a 65 liter pack in late September I needed to minimize my camera load so I could squeeze in a bear canister and group equipment. I carried the M3 and 2 lenses in the TT MM 20 with the PD Capture Pro on the strap. On a solo overnight trip I carry the 65 liter with the 7 liter insert so I have more camera/lens options.
Have fun.