A tricky challenge from Monk.
But enjoyable as ever. And a pangram to boot. Thank you Monk!

ACROSS
8. Shooting pioneer from Germany before a Napoleonic war? (8)
DAGUERRE
D (Germany) before A + GUERRE (Napoleonic war?, i.e. in French)
Shooting in the sense of a camera
9. Press plugs French articles, those offering an expanded view? (6)
LOUPES
OUP (press) plugs LES (French articles)
OUP = Oxford University Press
10. Samsung finally takes recycled packing material (6)
GASKET
[Samsun]G (finally) + TAKES* (*recycled)
11. Spreadsheet item perhaps checks new private overseas asset (8)
TANGIBLE
TABLE (spreadsheet item perhaps) check N (new) + G.I. (private overseas)
12. Undersized jumper in raffle artefacts (4)
FLEA
[raf]FLE A[rtefacts] (in)
13. Assembly of plant components is in 24 hours transforming China (5,5)
DAISY CHAIN
IS in DAY (24 hours) + CHINA* (*transforming)
15. Solemn, like a member of Parliament (6)
OWLISH
Cryptic definition
From the collective noun: a parliament of owls
17. Note singer delivered (6)
TENNER
“TENOR” (singer, “delivered”)
20. Incidental series of changes including epitaph by that woman (10)
PERIPHERAL
PEAL (series of changes) including (R.I.P. (epitaph) by HER (that woman))
‘Ringing the changes’ refers to traditional English bell ringing
23. Tedious course associated with hard old book (4)
RUTH
RUT (tedious course) associated with H (heard)
Ruth from the Old Testament of the Bible
24. Wager on dominant basic principles (8)
ALPHABET
BET (wager) on ALPHA (dominant)
26. Writer’s answer is about films being cut by 50pc (6)
ASIMOV
A (answer) + IS< (<about) + MOV[ies] (films, being cut by 50%)
27. Dishonest amusement park opening late (6)
UNFAIR
[f]UNFAIR (amusement park, opening late)
28. Displaying loss of communication, desperate Appalachians without plan (8)
APHASIAC
A[p]P[al]ACHIA[n]S* (*desperate, without PLAN)
DOWN
1. Belt spread by a big starter of linguine and a crumbly dessert (10)
ZABAGLIONE
ZONE (belt) spread by (A BIG L[inguine] (starter of) and A)* (*crumbly)
2. Unsolicited correspondence from naked hunky male in prison (4,4)
JUNK MAIL
([h]UNK[y] (naked) + M (male)) in JAIL (prison)
3. Graphic extra disturbed duke (1-5)
X-RATED
EXTRA* (*disturbed) + D (duke)
4. Bohemian family turning up after “blow” (7)
BEATNIK
KIN< (family, <turned up) after BEAT (blow)
5. Patience of a sort shown by poor donkey supporting King Log’s head (8)
KLONDYKE
DONKEY* (*poor) supporting K (king) + L[og] (‘s head)
Klondyke is a form of the game of patience/solitaire
6. Tiny bird, mostly cold, standing on hot drinking cup (6)
QUAICH
QUAI[l] (tiny bird, mostly) + C (cold) standing on H (hot)
7. Grain alcohol cleared out after case of misadventure (4)
MEAL
A[lcoho]L (cleared out) after M[isadventur]E (case of)
14. Absurd old tax collectors, extremely artful, limiting allowance (10)
IRRATIONAL
IR (old tax collectors) + A[rtfu]L (extremely) limiting RATION (allowance)
Inland Revenue preceded the current HMRC in the UK
16. Composer butchers works (8)
SCHUBERT
18. I so managed to be upset about small flowers (8)
NARCISSI
(I + SIC (so, Latin) + RAN (managed))< (to be upset) about S (small)
19. Female picked up ne’er-do-well, one having fine teeth? (7)
FRETSAW
F (female) + WASTER< (ne’er-do-well, <picked up)
21. Goddess of Wrath, simmering, somewhat shown up (6)
ISHTAR
[w]RATH SI[mmering]< (somewhat, <shown up)
22. Very porous clay he pounded (6)
LEACHY
25. Covers of instruction books essentially bearing large print (4)
LINO
IN[struction] (covers of) + [bo]O[ks] (essentially) bearing L (large)
Hmm yes quite a bit of bung and pray in this one. I’ve been examined through loupe glasses but dnk what they’re called. And tangible as noun, is that businessspeak? For 28ac, always thought the adjective was aphasic. And 5 and 6 down were guesses too. Enjoyed it ntl, thanks Monk and Oriel.
This was tricky. I managed all but QUAITCH and it was then that I realized that the 26 letters of the 24A were neatly arranged around the perimeter.
Liked DAGUERRE for the surface, ZABAGLIONE and DAISY CHAIN.
Thanks to Monk and Oriel.
Thanks Monk and Oriel. I was lucky to spot the Nina early on. As Diane@2 has already said, the pangram is not just in the grid as a whole, but in its perimeter.
9ac: I hesitated before entering this one, but eventually decided that LES can refer to multiple occurrences of the French article LE.
28ac: Chambers 2016 p 66 allows aphasiac as noun and adjective, and aphasic just as an adjective.
Not a simple pangram – a perimeter pangram. Beautifully done – thanks Monk.
Mitz@#4, you might even say a 20ac 24ac 🙂