I will be brutally honest, the second one is not very nice at all, text looks too squashed and ''fitted'' the DR is also too, typewriter and does not at all fit with the text.
Your first iterations are fine, the logo and text works and personally i would go against what gemini said and leave the 'lens'' effect as it is, its nice not to see a perfectly crafted lens and shows a bit of creativity, the D and R i do agree on however, this can easily be sorted in illustrator just tweaking the D's width without loosing or squashing anything as you have done in the second iteration.
I hope you don't mind but as image editing was turned on;
i have attached here what i would do, as the logo will be used on its own a lot in photo's / websites etc if not then i would get rid of it, logo's generally come into play (like IBM best example) when you no longer need the name attached but clients / company's know who you are, of course text can accompany it if you wish but there's no inherent need for it.
so what i would do with text;

IMAGE LINK: http://s1224.photobucket.com …ia/DRphotography.jpg.html
just a subtle but useful way to project your logo, not very un-common.
IMAGE LINK: http://s1224.photobucket.com …Drixar/media/dr2.jpg.html
could always do something like this aswell so you could always have both.
there is multiple things you can do with this to make it work and flow nicer, while being a designer i would not give these two as finished products to my clients as i would call it the first iteration of many some with small some with major variations, just thought i would quickly whip these up while on lunch.
edit: while my brain whirls i just keep changing things, so before i get back off lunch just another variation, it does change your logo a bit though but then the whole instance becomes your logo, again infinite possibilites, but your basic design and idea works absolutely fine, personally if i was designing a photographers logo i wouldnt use any lens or camera bits, its used a lot however if they are dead set on a lens part (or camera part) to be included then i personally would make sure its unique, different and stands out like a saw thumb (in a good way)
IMAGE LINK: http://s1224.photobucket.com …Drixar/media/dr3.jpg.html
Canon 400D(Rebel XTi) | 15-55mm kit lens | 50mm 1.8 MII |Raynox 250 macro conversion | Cheap Extension Tubes | 55-250 IS II.
Note; I am able to Design logo's upon request.
My Razzi