Do I need more megapixels, a lens or what

I am a crop maniac. When I take a group pictures, I do a virtual copy in Lightroom of the pictures, then I crop avery faces. But I tend to run into a problem that some crops are not sharp, this one was in low ligh.
D3100 50mm(1.8 D) 1/100, 2.8, ISO 400.
Do I need a better camera with more mega pixels - because I crop alot, lens or VR, or higher ISO or S?
Thanks.

Shooting a group @ f/2.8 and expecting individual faces to be sharp in crop is unrealistic. Try stopping down to at least f/5.6 and see if things get sharper. Maybe you need a little faster shutter speed. Are you shooting RAW? What do you do with the cropped head shots that they need to be sharp?

IMHO, if you want a portrait, shoot a portrait, if you want a group shot, shoot a group shot. Cropping is going to degrade the IQ and the more extreme the crop, the more degradation you get. You could get D810 and have lots of megapixels for cropping, but that's big $$$.

Short answer, maybe.

More mega pixels to begin with will give you more latitude in cropping.

The AF-D does not autofocus on a D3100 so you are focusing manually - which is wonderful if you have mastered that skill. But it does introduce a margin of error if you move after focusing. And depending on the aperture your depth of field will mean some will be in better focus than others. If you know you are going to crop shoot at a higher aperture so front row and back row are both in your focus plain - F2.8 is great for low light and that loverly blurry background. But not for mega cropping.

But before you go out and buy a more expensive body for more pixels and a AF-S lens, Jim's post above makes an excellent point. If you want a single person shot - shoot that person. Cropping is always going to cost you in IQ. There are times when you have to and it is a tool in your bag, but use it when it is needed.

Some of the newer, upgraded bodies offer the ability to calibrate your lenses for AF. Not sure if it starts with the D5x00 bodies so if you go with a different body, please keep that in mind. But because your 50mm 1/8D lens doesn't have a focus motor, you wouldn't be able to do the AF calibration until the D7x00 series anyway.

As singlerosa mentioned, the D810 has a very high number of pixels so it would be one of the best bodies for cropping. However, it if you are doing mega-crops, the images might still suffer. Better to do individual portraits rather than group shots with cropping.

Tito,
A couple of things come to mind is to get a good handle on what you are trying to achieve: Depth of Field. In olden days before digital all lenses came with little marks on the lens barrel these could be used for depth of field or hyper focal distance; both are similar but not the same. The lens manufactures used to pack a card that gave the DOF at each lens opening at a certain distance. As the manufactures tried to make photography easier by "dumbing down" they actually made it difficult. Most of us have smart phones so you may be able to download a DOF app.

A couple of links to help you out, if you haven't done so.

Understanding Depth of Field in Photography
A Flexible Depth of Field Calculator

I showed in a class that I recently taught that a kit lens such as a 55-200mm and a 70-200mm can actually perform a similar DOF but at two different distances because the kit lens at 200mm was F/5.6 and the background had to be farther back and the better lens was at F/2.8 to get that out of focus background.

Hope this helps.

Lou Cioccio

Quit cropping that much. The D3100 is just not the camera for cropping.
f2.8 needs to be F8 or better to get the DOF you need
D810 or possibly a D750 would be better suited but only then if you go with high quality lens and proper techniques. I would not think about cropping this way even with my D750.
Shoot the group then before the leave shoot a face shot of each person if that is what you want.

I think I may have missing the point with your original question. You ask if you need a new lens or better body.

Of course you do. We all need new lenses, and better bodies. Nikon needs us to need them.


It all depends on how you define 'need'. I need them to satisfy my lens lust and treat my bad case of N.A.S. .


I keep telling my wife "I need a ________ lens" and "A new DXXX would be a good addition to my camera collection"

Fortunately my wife's definition of "need" and mine differ as my definition would bankrupt us.

Having said that looking at my signature shows I tend to ignore her wise words anyway and just keep adding.

At the moment I feel a real need for a fast wide prime, and I need to get one of those Siggy Artsy lenses because I don't have one and I should upgrade to a real fisheye (mine does not even autofocus). And I need to get that DF body because it just looks so dang cool.


:unconscious: said with tongue firmly planted in cheek :unconscious:

Thanks everyone.

titoPhoto said:

Thanks everyone.

Click to expand...

Very good advice in the above posts, give it a try next time your taking a few shots, and post back with the results.

If you are trying to use a 10mm on a DX then you need a 14mm on an FX (D810) if you want sharp.
If you are doing landscapes you want an D810