25mm Biogon - which hood?

[Terao]

I see that there are two hood options for the 25 - either the rectangular 21/25 hood or the circular 25/28 hood. I'm not likely to own either the 21 or 28 so which out of the two do you recommend? This is for use on an R-D1, Bessa T, and potentially an M8 (or that mythical Ikon Digital 🙂 )
Portability is important, I'm not too bothered about viewfinder blocking...
Would be handy to see what both hoods look like mounted.

 

[back alley]

i use the square one, it works fine and i think is a bit smaller than the round one.

 

[sepiareverb]

I have the square one as well, looking to trade for the round one. While getting the lenscap on is nice and easy with the square hood, I find it protrudes into the frame a bit more than I like.

 

[jgeenen]

The effect of the 21/25 hood on a 25 Biogon must be minimal (it has to cover the 21mm angle).

If you'd like to use a hood for it's original purpose (banning out-of-area light), you should take the 25/28 hood. Even more important when you switch to digital cameras with a cropping factor. This even more reduces the angle of view - a 35mm hood (if it would fit) would be the best.

The 21/25 hood on a 25mm lens is just a (bad) compromise.

 

[back alley]

yet it works for me...never a problem with flare.

 

[sepiareverb]

I have had some tiny bits of flare in both the 25 & the 28- usually in the corners, a small flame of flare can appear. Only in a few negs.

 

[AusDLK]

Round one. Fits nicely, looks right.

 

[MichaelM7]

No hood!
I think for such a short focal length and such a lens design, a hood is hardly necessary at all.
If you have a bright light within your field of view (FoV), the hood is needless anyway. If you have a bright light well outside your FoV, the hood is not needed either.
Only if you have a light just outside your FoV, a hood could help you. However, due to the number of lenses within your lens, and the (assumed but well proven) high workmanship of Zeiss in blackening the outer diameter of each glass element, any optical ray will most probably hit a blackened outer diameter of a glass element within the lens itself. That means, the risk of having a flared image is probably minimal. This is even more true, if you use a smaller than 35mm digital sensor, i.e. on the M8
I for one prefer the more compact outfit without the hood.

 

[Terao]

Hadn't considered the no hood option 🙂
Its partly there for lens protection as well, I hate using protection filters.
Anyway, have ordered the 25/28 hood from Robert White...

 

[abumac]

I have the round one. Works well and looks nice.

 

[sepiareverb]

No takers on a trade for the much more flash square hood?