Losing weight

My landscape kit comprises a K1 and the f2.8 FF lenses 15-30mm, 24-70mm and 70-200mm, plus the Lee Filters SW150 system and assorted polarisers. And a tripod. Whilst in a backpack this lot is manageable the weight makes it not particularly enjoyable and limited to short walks. However I love using the K1 and the quality of full frame images so I am looking to reduce the weight of the lenses. The 24-70mm gets used 75% of the time so that can stay, but at around 2kg the 70-200mm is too much. There is an f4 version due next year but as I have a trip planned in November I am looking at the Samyang f2 135mm at around 800g to cover typical telephoto landscape use. Next up would be an Irix 15mm Firefly to replace the 15-30mm and a bonus would be using the screw-on Lee Filters adapter which fits the other lenses so saving the special mount. A bit more cash would buy the Blackstone which is weatherproof but at a weight penalty. Both these are manual focus which is a disadvantage but reports are that both render excellent sharp images with minimal distortion.

Sorry to ramble on a bit but I would be interested to hear your views, especially if anyone has used either of these budget primes.

Pentax Fa 20-35mm if you can find one, may well be a better replacement for the 15-30mm than the Irix, you would lose the F2.8 though, that may or may not be an issue for you, but you retain some zoom. Lennybloke has one and rates it highly,
Review here
https://www.pentaxforums.com/lensreviews/SMC-Pentax-FA-20-35mm-F4-Zoom-Lens.html

I have the samyang 135mm f2 and can tell you that it is one sharp lens, even wide open, solidly built, smooth focusing, hard to fault it really.
A few shots, just trying out mine
https://flic.kr/s/aHsmh85Cnb

Review here
https://www.pentaxforums.com/userreviews/samyang-135mm-f20-ed-umc.html

This is not rambling at all Rob..!! For Pentax users it is an issue I feel.. I am in the process of setting up a Landscape kit myself. But I'm having similar issues .. Though in the really wide angle lens dept. I havint yet made the purchase. After looking at cheaper Samyang and Irix offerings.. I had decided it was better to bite the bullet and fork out for the 15-30. As i thought at the end of the day it would return better images overall and was auto focus.. (Well its only money....lol) But I too have concerns over the weight issue and carrying it all day.
Personally, I use the Kase range of glass filters. (82mm and 100 x 150) So getting the 15-30 would also mean more expense in the 150mm lens filter conversion and larger filters.. (About a further £500. My present 82mm ND filters wont fit )
I own the Pentax 24-70 and the 70-200.. But usually leave the 70-200 behind in favour of the 55-300.. Usually find speed isnt an issue and a little editing in photoshop usually keeps the images from the K1 satisfactory.
Maybe its cheaper to buy a KP and use the Sigma 10-20 I aleady own..!!

I also have tripod issue's..!! And ask the more experienced landscapers for advice on this issue.. Years ago when I made my tridod purchase. I plumped for the Manfrotto 055. It great n sturdy but too large and heavy to strap to a bag..!! I thought I'd try carbon but hear you have to weight these down at arrival to stop wind vibration..? I could use some suggestions in this dept.. Though lets not hijack Rob's thread..

The DA 200mm 2.8 is top quality and less than half the weight of the 70-200. Completely full frame compatible as far as I can see. Less versatile but I suspect that the 70-200 is mainly carried for use at the long end.

Thanks all, I am encouraged Derek by your recommendation of the Samyang 135mm. Smudge, I thought about the DA 200 and made a point last week of seeing what setting I was using most on the 70-200 and concluded it is a bit long for landscape. Stub, you are right about the 15-30mm it is a great lens but for landscape I find myself framing more often at the 24-30mm end which is covered by the 24-70mm. Don’t get me wrong, I will be keeping these lenses and taking them if I have something specific in mind. My main concern is when I look at my manual focus efforts on the computer they are rarely as sharp as an autofocus one which I put down to my ageing eyesight, so more practise needed!

The Lee Filters lens match on their website is helpful and it appears that any lens around 15mm needs the SW 150 system; I had hoped to swop for the SW 100 which the likes of Thomas Heaton use on a 21mm prime but that is the widest the system will accommodate.

Stub, I use the Manfrotto 055 tripod, managed to get a carbon fibre one in a Black Friday deal and chose the 3 section one as it’s more rigid. It is bulky but I just carry it rather than strapping to the backpack. As I am always getting it wet when the tide comes in I have thought about the waterproof Sirui, which is more compact but I doubt it is as rigid.