
Re the Nikon D800, why are there two different memory card slots?
Looking at the Sandisk extreme pro 32G memory card and the same for the compact flash, but really don't understand what the purpose of having two are. Do I use them both simultaneously? Sorry for such a dumb question, but can anyone give some guidance?

I have a Nikon D300s, and want to invest in a macro lens for underwater photography & nature.

Which as Nikon D800 & Canon5d mark2 suggest in best studio & Wedding photography shoot image

Which camera is Nikon D800 & Canon5d mark2 suggest in best wedding, modleing, outdoor shoot image

I'm thinking about getting a new camera. I know I'm going to get one, I just don't know which one I should get. I'm leaning towards the nikon d600 and I have weighed out some pros and cons
Pros
Least expensive out of all of the cameras
High ISO looks better than the D700 to me
The resolution seems just right 24 megapixels
The photos out of this camera look awesome!
2 SD card slots
Cons
It doesn't feel as nice as the D700 in my hands
That damn AF Mode button is in the weirdest place, I hate it. I wish they kept it where it was on the D700. I use this button constantly
No CF card slot
Where is the best place to get the cheapest nikon d600 price? Thank you! Also, if you have any other comments about the nikon 600 please let me know

So I've been thinking about Selling my Nikon D700&D300 w/ accessories to buy a Nikon D600 & 70-200 VR II but I have my doubts about the D600 compared to the D700. My equipment right now doesn't get much usage because of school and I can't shoot on weekends because of a family situation.
Added (1). My plan was to sell both of my Current set ups to buy the D600 and 70-200 VR II
which would give me the D600 24-70 & 70-200 VR II as my Set up to use until I can afford a D800
My current set up is
D700+24-70+2xSB-700+MB-D10
D300+70-300+SB-600+MB-D10

Ok, so i'm new to SLR camera's but eager to start using one. I'm not rich so i'm going to buy used. I've narrowed it down to the older Nikon d200 or the newer Canon t3 1100d. Can anybody help me decide?

Why can Canon shoot faster than Nikon? (exposure, not drive speed)?
So last week I was shooting badminton with Canon 7D with 24-70mm f/2.8 and I could shoot at
1/400, f/2.8, ISO 1250
and the pictures are PROPERLY exposed.
and yesterday I shot at the SAME PLACE under the same lighting with a Nikon D300s and 24-70mm f/2.8 and I could only shoot at
1/320, f/2.8, ISO 1250 and the pictures are UNDEREXPOSED by -1/3 stop
Why?
Added (1). No. It's indoors, it's in the gym. And I know that it's underexposed by 1/3 stop because it's looks underexposed and the camera meter said so. With nikon, it's at 0EV, with canon, its at -0.3EV

Are there lenses to help the nikon d800 with low lighting?
I'm trying to decide if i want to get the canon 5d mark iii or the nikon d800. I know that the 5d is more versatile (being better with low lighting and aliasing) but the d800 has an overall better resolution (therefore better images). Also the footage of the d800 doesn't have to have a lot of post op work on it (5d needs it every time if you want your footage to look its best).so I'm partial to the d800, but are there lenses that can help with its low lighting or aliasing problems?

DSLR/NIKON D300/NIGHT SKY SHOTS?
When I try to use the night sky setting in my camera (nikon d3000), it doesn't take the picture, or says subject is too dark. I'm totally new to this so should I be doing something different? Thanks.
Added (1). It will not let me change the settings of the shutter speed, it says that it is not possible to change under the settings, even though i had everything else