Greetings, Hogs! I turned traitor and recently purchased a 5D Mark III (my trusty Nikon D200 will be relegated for macro work). I want to purchase a general purpose flash for the 5D with the following characteristics:

- compact
- tiltable
- TTL
- good guide number
- good battery life

Yup! I want it all, but know I will have to settle.

I want compact as I travel a lot and don't believe in bringing too much photo gear (1 long lens and my point and shoot only). I see many flashes on the market and some with my requirements but looking to tap into the hog experience base to help me further sort through my list.

Thanks very much for your help. RAR_man

for years now, I have been traveling with my Nikon 80-400mm, Sigma 28-300mm and a Lumix waterproof point-and-shoot. Sometimes I leave the Sigma at home. Its amazing how useful the very long lens is even for landscapes. I am more the wildlife photographer, thus the long lens. On the other hand, the long lens lets me shoot architectural detail otherwise lost to a short lens. It also affords me close up shots of locals without getting in their faces or disturbing the spontaneity of the moment. It is a little heavy but a good sling or padded strap helps that. I have been traveling that way for years. Have fun and don't over-pack. Leave most of your camera gear home and take only what you think you really need. Have a great time!

I suspect if someone from Nikon, Canon or other lens maker were watching this exchange, they would say that at the factory lens are cleaned with solvents. Back when I was working in an optics factory, final cleaning was often done with de-ionized water, ethanol, methanol and a host of other solvents as needed. Granted I have been away from optics coating for some years now, but I can't imagine that things have changed much. Most optics standards include a list of solvents that the coatings must be impervious to.

That being said, I use breath most of the time and soft lens cloth or better yet, disposable lens tissue.

Still no data. There are many lens cleaning products containing alcohols and other organic solvents these days. BTW, detergent will leave residues unless rinsed off. I am a chemist and have also worked in the thin film coating industry (A/R coatings, etc.) and aware of basic specs for optics. I'd be surprised if the standards I used were any different for the commercial camera lens industry. Enlightnen me/us. Not saying you are wrong, it is just counter-intuitive to me, so looking for data.

I was surprised to read no IPA as generally optical coatings are spec'd to survive alcohol, heat/humidity and a small list of solvents. Any data on why IPA is not recommended?