Will I get better results from a full-frame camera if the only full-frame lens I have is a "nifty-fifty" 50mm f/1.8?

Question

Currently I'm using a 700D (T5i) for a few years and I'm thinking of buying a new body - given current prices of the 6D this might be my only chance of getting into FF.

I do mostly architecture / travel photography (sometimes street photography for which I will still be using my 700D) and my main concern is to improve image quality, even in broad daylight full frame photos seem to be sharper, more clean and rich than from a crop. Apart from selling pictures on microstock sites I'm not a professional, so this means spending significant money, currently I only have the 50 1.8 STM (and 3 EF-S lenses) but I can buy other FF lenses later on. I might as well buy the 80D at about the same price, but I consider photography a serious hobby, and the full frame image quality is the standard I'd like to enter. So would you buy the 6D having only the nifty-fifty lens?

Answer 1

Boiling it down, FF sensors will offer gains in DoF and in lesser noise, especially as ISO increases.

That being said, sensor tech seems to make leaps and bounds and it would also be accurate to say that a new APS-C will perform better than an old FF. Since you're really going with old -> old, I think you'll find that the 6D is an upgrade over your 700D.

That being said, you have to ask, what if I bought newer tech? And now we're back into a conundrum.

Your question is doubly difficult because you've outfit yourself with EF-S lenses - which you'd have to sell secondhand and replace with EF lenses. If you cannot do this right away, and if you spend good time using your other lenses, then I think you will find yourself very unhappy about the decision to move to FF (at least, until you can replace parts of your kit).

Is FF worth it? To me, it absolutely was. Then again, I spend most of my time shooting film and didn't have to sell off my lenses to get a FF (I also chose to buy a 5Dmk2 - considerably old by today's standard).

Will it be worth it to you? Personally, I think you need to look really hard at those gains and decide. If your main goal is the nebulous "Image Quality" then I think that you should not make this decision - as it could be other factors about your shooting that would help you improve your IQ...like lighting, technique, lens choice, etc.

Generally speaking - until you can accurately and finitely describe a problem that is a show stopper in your current gear, and that is only solved with a new camera/lens/whatever...then you are not actually going to find the upgrade beneficial to your photography.

Answer 2

Forgive, I'm going to be rearranging quotes from your question.

So would you buy the 6D having only the nifty-fifty lens?

together with:

... given current prices of the 6D this might be my only chance of getting into FF.

No, I would not buy the 6D, not if cost is an overriding factor, and I'm already having trouble putting together the budget to purchase a used 6D body. The 6D is low-cost because the 6DMkII is out. How much lower will it be when the 6DMkIII is released? Go look at the prices on the 5D "Classic" (Mark I) or 5D Mark II. This is far from being the only opportunity or choice for an affordable full frame body.

And in the meantime, you have to save up for glass.

... but I can buy other FF lenses later on.

Yes, you can, but have you looked at the prices? The kit lens for a dRebel is the EF-S 18-55 lens, roughly $250 new, but sub $100 used. The kit lens for a 6DMkII is the 24-105L. Which is roughly $1000 new, and around $700 used.

Full frame glass requires more glass. And will typically be higher-end than crop glass, because who wants low-end glass on a full-frame body? :) The full-frame lenses you're likely to look at are all going to be more expensive than their EF-S counterparts. That 10-18's FF equivalent is a EF 17-40/4L or EF 16-35/2.8L. The full-frame kit lens is a 24-105 (L or STM). The 55-250 IS's equivalent is the 100-400L.

Remember, all your glass gets 1.6x shorter in the move. To get the FoV equivalence of 250mm on crop, you need a 400mm lens on full frame. And that 50/1.8 STM of yours? It's gonna look a lot like a 35mm does now on your 700D. You may want to replace it with an 85/1.8 USM for something closer to what you're used to with the 50/1.8 STM now.

Every lens you have can change in usage when you switch format, just because of the crop factor.

... even in broad daylight full frame photos seem to be sharper, more clean and rich than from a crop.

Consider that folks who spend thousands on a new full frame bodies may also be the kind of folks who spend thousands on L lenses, and have the experience, talent, creativity, and exposure and post-processing capabilities to make the most of any scene they capture. Not to mention the sheer-minded bloody determination to buy airline tickets, scale mountains, and get up at 4am to hike miles to the best vantage point in the best season to get a stunning landscape shot. It's not just the sensor size that may be different.

Are you shooting RAW and using Photoshop or Lightroom? Are you shooting with L glass? Are you off-camera lighting? If not, I'd say pursue those before a full-frame sensor, not only because they can be much cheaper, but will include improvements and purchases that will travel with you if/when you make the full-frame leap while being great with your 700D right now.

Answer 3

The points in this answer from inkista and this one from Corey are all certainly valid. There are many other factors that affect image quality apart from sensor size.

That being said, every EF lens should perform better on a FF camera than on a crop body, at least in the center 2/3 of the frame. The main two reasons for this are the size of the pixel wells for any particular resolution and the need to enlarge the image from the smaller sensor more to view at the same display size.

At the same number of pixels, a lens needs to be able to resolve fewer lines per millimeter to get the same resolution with a FF sensor than with an APS-C sensor if the output from both are enlarged to the same size. If the pixels are the same size on both the FF and APS-C cameras, the FF camera will have more than twice the number of pixels as the APS-C camera will.

Assuming the resolution of the lens rather than the resolution of the sensor is the limiting factor, larger sensors do tend to give higher resolution with the same lens because the larger sensor means less enlargement for the same display size compared to an APS-C camera. But it also means you need a longer focal length to get the same field of view. That can work in your favor for wide angle lenses, it can work against you for longer focal length lenses.

For more about the resolution advantage of larger sensors compared to smaller sensors when using the same lens, please see: Why is FF sharper than crop body for the same framing of the same object?