Hi All,

I've found these forums exceptionally helpful to the new DSLR user, and so I'm posting a question that I'd like your opinions on.

I have a Nikon D-40 and am very happy with it. I haven't yet bought an external flash, but since I mostly take travel photos, I was thinking of the SB-400, due to it's small size. Now I find myself headed off to a cave photography class in a few weeks, and am wondering if the SB-400 will be sufficient, or should I just deal with the larger size of an SB-600 and go that route? It seems that monetary difference between 400 and 600 is about 80 dollars, so I'm less worried about price and more interested if the 600 would be overkill for my applications? (In some cases the cave ceilings may be low enough to bounce light off, in other case, maybe not. For my travel photos, I take pictures of everything: monuments, buildings, people, landscapes, etc..)

Also, would you guys recommend picking up a diffuser?

Thanks!

For $80 I would go with the SB-600. You can always dial down the power if you need to. I have 2 600's, and an 800 as well.

The 600 comes with a built in flip-down diffuser, and I don't use mine that often.

I chose the SB600 because it was close to the power of the SB800 and the price was much cheaper. In my opinion you can never have too much power. Having more power just give you more options when taking pictures. I liked the amount of flashes you get with the SB600 and the recycle time was quick. With the money I saved from not getting the SB800 I purchased the Nikon 50mm 1.8 lens.

With my SB600 being a little taller and farther away from the lens I haven't had any red eye problems. Don't know if you do with the 400 or not. Hope this helps, Jeff

Only five things the SB800 will do that the SB600 wont't do:
1) Act as a 'commander' in the 'Nikon wireless mode' (CLS).
2) Sense it's own feedback lighting from a scene, so it can be used in 'Auto Flash' mode
on other cameras.
3) Has a pc connection.
4) Is 1/3 F/stop more powerful
5) May have built-in be optical trigger. (I'm not sure about this).

The SB400 needs to be in "manual mode' on the D40.

The SB's works very well with 'light modifiers' like the Gary Fong and Demb units.
Indoors:
Camera Mode = Manual 1/80th at f3.5, EV comp = 0, and ISO = 400
Flash Mode = TTL, and EV comp = -.3 to -.7

Outdoors:
Camera Mode = 'P', EV comp = 0, and ISO 200
Flash Mode = TTL BL, and EV comp -1.0 to -1.7

http://www.dembflashproducts.com/

http://www.garyfong.com/ ( Note: A lot of negative reviews for
the 'Puffer'.)

http://abetterbouncecard.com/

I bought myself the sb-800 just before christmas, with my work bonus money, so in a fact it was free, great speedlight for my nikon d50, i have learned a bit about bouncing light and learning the proper color temperature with the gell's in relation to the white balance, also just recently purchased the cord sc-29, that can be still sync'd with the camera as for distance and be handheld or tripod mounted, with the 5'th battery the recycle time is really great,with more education on its many diverse uses i will have my hands full.

The SB400 needs to be in "manual mode' on the D40.

Actually, unless I'm reading you wrong, this isn't entirely correct :p

The D40 and D40x are the *only* cameras that support manual mode on the SB-400 via camera menu control (as far as I know they are the only ones, the D3/D300 may have this too but I no longer have the 400 to check)

They do, however, support the i-TTL automatic flash system when attached to the cameras.

Thank you everyone for the input. I've decided on the SB-600.