While the reviews for the lenses I've read have been good, all have mentioned something like, "good for what I paid".
I've looked at my photos and have compiled a list.
1) I need a much longer lens. There have been so many times where I wish I had more than 55mm. Such as at the Mets game this past Sunday, while I was on the bottom section of the stadium and only seven rows up, most of my crops haven't come out looking too crisp.
Try the amazing 80-200mm f/2.8, which is only $430 used at adorama. That is a steal. If I shot Nikon, I'd buy it right now.
2) I want to get into HDR photography. The D40 doesn't feature auto-bracketing, which I've heard makes doing HDR a nightmare when you have to switch the settings in Aperture Priority everytime you take one.
Yes. This is why you should use Manual mode, not aperture priority/auto bracketing for HDR. Auto bracketing only gives you 3 exposures to work with, anyway, which isn't really enough for anything great. The best HDR images out there are 6-9 individual images with the same DoF (aperture) and varying E.V. values (shutter speed).
3) We just moved to a different apartment in NYC, and our walls are pretty barren right now. I'd like to make some big prints to hang up, but I don't think 6 megapixels will be enough for to have crisp and clear prints upwards of/around 20''.
First off, you can always use genuine fractal or bicubic image resampling in photoshop to enlarge prints. Secondly, the more pixel dense a sensor is, the more noise it will have. This is not a good thing. Considering that big prints are usually viewed from a moderate distance, they don't need immense resolution. You can print 20" wide images at 150dpi (not too bad) from your D40 without any upscaling. With some PS action, these sorts of prints should be no problem.
4) Not exactly sure about this one, but if the D80 spits out more pixels, doesn't that mean that the image will be crisper?
Nope. The best way to a sharper picture is a steady tripod, shutter remote, and use of mirror lock-up function. After this, pro lenses make the biggest difference.
I've pretty much given up the Tamron lenses now and I'm looking at the D80 kit with the Nikkor 18-135mm lens.
EEEK! If you care at all about image quality, you should know that the longer a zoom's range is, the worse it tends to be in terms of sharpness, saturation, and such. The 18-200VR and Sigma 50-500 are commonly accepted as exceptions to this theory. Think about something in the 17-50 range and something else for the 70-200 range.
Right now I'm more of a hobbyist photographer, but I'm hoping to get more serious with it.
The way to get more serious is by shooting a lot and working on photo skills. I looked at your flickr page and really liked your images, but feel like I should mention that a relatively inexpensive photo course at a local art center does a lot more good in the long run than expensive equipment.
