[plcleung]

Is 420 EX compatible with EOS 1000D ?
Is 420 EX or 550 EX outdated now ?

Is Sigma DG 500 (old version) more suitable in EOS 1000D ?

[Obi-Wan]

ALL flash with EX can use ETTL on ALL recent canon DSLR including 1000D. I am using both 420EX & 550EX on my 20D, 50D & 5D mk2 with all the functions including wireless flash etc.

don't have any idea for Sigma DG500

[DeltaTeam]

420EX & 550EX are for E-TTL (First generation) DC only,

DO NOT BUY THE OLD THINGS!

430EX & 580EX (580EXII) are for ETTL- II DC and before DC(E-TTL)
since 350D .

SIGMA EF-500 DG SUPER also have E-TTL version and
E-TTL II version(Mentioned at the Flash Body)

Now EF-530DG SUPER is E-TTL II version.

[Obi-Wan]

DeltaTeam
brother, can u explain what is the difference between ETTL(I) & (II) in details?

I am using two 420EX & TWO 550EX with 5Dmk2 & 50D (also 350D, 400D, 20D) without any problem in ANY auto modes!

I repeatedly pointed out many many times:
"ALL CANON flash with the extension EX can be used in ALL recent camera with at least E-TTL"

for readers who do not know ETTL(I) & (II), please go read
http://photonotes.org/articles/eos-flash/

[DeltaTeam]

Ha Ha!, I am not Skywalker.

Just remind the user do not buy the 2nd hand old flash
for his EOS1000D!

[Obi-Wan]

2nd hand flash is not that good unless u know how many flashes has been fired, but for a cheap cheap 420EX under $900, it can't be wrong.

If have used Sigma in bounce flash, u will know the difference between original CANON flashes & other brand flashes.

Buy any 220EX, 380EX, 420EX or 550EX because they can 100% support the E-TTL-(II) as the new ones

[plcleung]

Thank for C Hing advice. I know 420EX & 550 EX can suport E-TTL (I)
& (II).
The old model flash has a little problem. Its automatic zoom range cannot take into account of the 1.6X crop factor. For example, if I zoom the lens to 24mm, the angle of the picture is only 38.4mm wide. But the old model flash might zoom to exactly 24mm wide. However, this might be good to prevent dark corner of the picture more effectively. But the amount of light fall on the object might reduce. This may render the object a little bit underexposed.

[Obi-Wan]

plcleung

"But the amount of light fall on the object might reduce. This may render the object a little bit underexposed. " <===== NO NO!

My two 420EX & two 550EX has PERFECT exposure on 20D to 50D, really no problem!