D90 vs D3100
 

I know this is not apples to apples comparison but which is better for low light shots?

I just thought I would ask since I would like the remote capability of the D90 but do not want to sacrifice image quality.

The D3100 will likely be better...newer sensor, newer technology. This area moves forward with each new generation. That being said, the D90 is very good in low light, and there is no reason to believe you will get noticeably worse images. If the D90 has the features you need, go ahead and get it. There is also the new D7k, which should be available in stores now.

I agree with rjseeney, with one caveate. Most of the low light lenses don't have their own autofocus motors, and so won't autofocus on the D3100 but will on the D90. If you can find the lenses you need that will autofocus on the D3100, that's the camera for you. Otherwise, you might be better off with the D90 to get the lenses you need.

This brings up a good point. You are better off attacking low light situations with lenses than camera bodies. Yes, higher available iso's help but if you're stuck at f5.6 because of your lens, then you are forced to use higher Iso's which will result in lower image quality. You're better off with a wide aperture which allows a lower corresponding iso and gives you an even higher ceiling and more latitude. The differences in IQ in bodies are minuscule when compared to the flexibility you get with wide aperture lenses.

I still don't understand why would one use very high iso (esp 3200 and 6400) instead of using flash :confused:

Shooting at 1600 on my Alpha 300 + stock lens resulting to very poor IQ at 100% magnification :( Is it only because of my cheap lens?

Another question, Most of the low light lenses don't have their own autofocus motors, and so won't autofocus on the D3100 same for D7000?

There are lots of reasons not to use flash, but many of them come down to personal preference. And it's not just Flash vs. High ISO. There are different variables that can be adjusted individually or in combination that would allow someone to shoot in low light without a flash.

Not necessarily. While the 18-70 kit lens that came with the A300 wasn't great, it wasn't terrible either. What it was was dim. A lens with a larger aperture would have allowed you to take essentially the same photo with a lower ISO setting which may have improved IQ.

This is a distiction that is unique to Nikon. After decades of putting autofocus motors in their SLR and dSLR bodies, Nikon started leaving them out of their entry level dSLRs (starting with the D40.) That meant that only lenses that had their own motors could autofocus on those dSLR bodies. At that time, there weren't a lot of lenses that had their own motors, and while the situation is improving, there are still only a few large aperture lenses with their own motors, and thus can AF on those entry level bodies. That makes low-light photography with entry level Nikon dSLRs challenging. While the D3100 is challenged in this respect, the D90 and D7000, which are not entry level dSLRs and have their own AF motors, are not.

Thank you TCav. It seems I made the right choice to get a D90.

[QUOTE=LGWGM;1157816]I still don't understand why would one use very high iso (esp 3200 and 6400) instead of using flash :confused:

I use flash a lot. However, I also shoot indoor sports (volleyball and Basketball) and you cannot use flash in the gyms I shoot in. I've got no choice but to use my f2.8 lenses and high iso's. I get very good results with my D300 and 3200 iso. There are many places that don't allow flash (indoor exhibits at zoos, churches to name a few) so you have no choice but to use high iso's

It can be a challenge and a lot of fun taking low light action photos where no flash is allowed. I recently was able to take photos of a speech contest WHILE the contestants were giving their speech. While photography is prohibited by rule during the contest, I was the exception waiving the rule with the concurence of the contestants. Yes, I used high ISO on the D90 as I don't have fast glass. In situations like that where you don't want to be distracting...manual focus. That eliminates the IR autofocus light.

One lesson learned. Save the interior white balance for post. I initially set camera up for lighting, then threw a flash on for the awards presentation. Not good.

Or shoot in RAW...in low light you can squeeze out some even better resolution and dynamic range as well as adjust white balance in post processing. Down side is that you get fewer images per card and your burst rate may be slower which could be problematic if you are shooting sports.