ltj123 Loc: NW Wisconsin

So funny! Mirrorless is just up coming popular format providing in many cases a less weight advantage and the rage nowadays sparking sales for peoples desires to be on the cutting edge of this technology. DSLR will be around and poplar for years to come.
What's really coming is Cellphone technology that is already for many replacing both DSLR or Mirrorless, just read an article on current and coming advances here.
I've used both DLSR and Cellphone often for same subject and even used Cellphone images that for some purposes are just as good as my DSLR's..

camerapapi Loc: Miami, Fl.

"My question is this - is there any significant performance difference between a camera using an APS-C 24 megapixel sensor, and a full frame camera using 24 megapixel sensor?" Each of us will have a different opinion on this. Noise performance has been significantly improved with the APS sensor. Image quality, using the same lens, is identical.

"For a given reproduction size, the smaller the sensor, the more magnification is required. The greater the magnification, the more the image quality is degraded." Not entirely in agreement with this. If you talk about p&s I will be in agreement but if we compare modern M43 (micro fourth thirds) sensors to APS and Full frame we can see that the smaller sensor is as good as the others when it comes to quality of the photograph, more obvious with good glass.

I use APS and full frame sensors (Nikon D7000 and D610) and although the full frame has more Mp I cannot see the difference in image quality. My Olympus mirrorless are simply awesome when it comes to image quality, especially with their Pro lenses.

lamiaceae Loc: San Luis Obispo County, CA

To really see differences you need to print your images. Say to 13x17". Does your 55" UHDTV have 300 or 600 ppi?

dsmeltz Loc: Philadelphia

The answer is situation specific. You have laid out your situation rather well (something that cannot be said for all posts.) Basically you seem to be doing landscapes in daylight. This negates (to a large extent) the (actually significant) low light advantage of the larger pixels on FF. The advantage of an APS-C 24MP sensor for you is the length (and therefore costs) of lenses to fill your frame with a shot. But you will still do better using the highest quality lens you can afford.

If you fill your frame with the shot you want using a 100mm lens on and APS-C camera and do the same using a 150mm lens on a FF camera and both sensors are 24MP, you will have about the same enlargement capabilities assuming the daylight scenario you have indicated.

You will then experience the first three of the advantages you mentioned. However the 4th I do not agree with "Zoom lenses designed to cover the smaller sensor are lighter, cheaper and usually sharper" With the exception of a couple APS-C zoom lenses by Sigma, most APS-C specific zooms are not as high quality as the FF counterparts. However, there is an advantage to using FF zoom lenses on APS-C sensors. You end up using the sweet spot of the what the lens provides. Especially, there is less vignetting to correct in post.

kymarto Loc: Portland OR and Milan Italy

I had an a6000 and now have an A7RII. The sensor on the FF is better than that on the a6000, in the sense of having much better low light performance, higher dynamic range and a better color depth. Will you ever see that? Perhaps if you just shoot normal subjects in good light and do not do any post processing, you won't notice much difference. But if and when you start pushing the envelope the difference will be more than apparent. Another point is that if you are into bokeh photography, or you like to use shallow depth of field to isolate the subject from the background, the FF is much superior as it gives you 1.5x the angle of view with the same DOF.

But is the a6000 a good camera capable of high quality images? Yes, absolutely. Another thing worth mentioning is that the A7R series have a crop frame mode, that give you a respectable 18 Mpx, so that you can use all your crop lenses on an A7R body.

MT Shooter Loc: Montana

You will get the APS-C fans claiming their cameras are as good as FF cameras.
You will get the FF purists who claim the APS-C cameras are toys.
And then you'll always have the M4/3's fans who claim their tiny sensors are better than either of the bigger brothers.
Truth is, FF is definitely the king of resolution, but many do not NEED that much resolution so smaller sensors will fill their needs just fine. And at a lower cost for the camera and crop sensor sized lenses.
The only thing that matter is what does the job for YOU!

selmslie Loc: Fernandina Beach, FL, USA

"Image quality" is a broad statement but it includes both apparent noise (larger pixels control noise better) and resolution.

Resolution is not always a primary consideration unless you are shooting landscapes where nearly the entire image is expected to be sharp.

I will create a separate thread on this question because it needs a fairly detailed answer.

The bottom line is that, if you print a DX and FX 24 MP image to the same size using the same lens, the FX image will appear to be nearly 1.5. times as sharp, mainly because of the magnification.

But if the print is not large enough or you don't pixel-peep the full image, you are unlikely to see the difference.

Wanderer2 Loc: Colorado Rocky Mountains

<<I do understand there is a modest improvement in low light performance using the larger sensor. But then I do mostly scenics so that advantage is of little value to me. Smaller, lighter and cheaper do mean something to me. What are the advantages to using cameras with the full frame format?>>

I do landscape photography almost exclusively and have used both aps-c and full frame dslrs for that purpose (as well as 35mm, 120, and 4X5 back in the old days). Put simply, I find superior IQ with full frame, and not just low light performance but in sharpness, dynamic range, depth of field, with a particular advantage for large prints. I've never regretted moving from aps-c to FF.

OTOH, if for your purposes you are completely happy with what you have, and appreciate the aps-c advantages, why change?

Clapperboard

selmslie "APS-C magnifies the shortcomings of a lens 1.5x more than full frame." Are you sure?? A crop sensor uses the more central part of a lens. The part with better resolving power.

imagemeister Loc: mid east Florida

Your thinking is well grounded and correct !

As mentioned, 24MP FF will give greater low light/noise performance - but that is about it. As a practical matter, this allows you to hand hold in lower light or photograph action in lower light and it will also give smoother tonal graduations and color fidelity - all part of the composite "image quality"

But 36MP + FF will allow you (more resolution) to effectively use Sony's Clear Image Zoom - or crop your images ( I call it crop gain) - but you begin to loose the ISO advantage of the larger pixels. This crop gain/clear image zoom can be very important !

..

chrisg-optical Loc: New York, NY

Depending on the subjects you shoot the answer may be "both". If you're a specialist - for example a landscape or wedding photographer, then you more than likely want FF for HDR/ low light shooting. The crop sensor is an advantage for wildlife, nature, and macro shooting. But if you shoot at low ISOs it really doesn't matter too much. If you want a comparison go to DxOmark and compare a D8xx/D7xx to a D500/D7200 under the 18% grey S/N ratio tab (graph) you will see about a 1.25 - 1.5 stop difference in equivalent noise levels.

If you're an all around enthusiast then having both is an advantage. If you get a D850, for example, you will have the benefits of both - the DX mode is about 19 MP, which is greater than many cameras not too long ago.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

Not if the lens is a DX or APS-C format. Then you use all of the image circle, just like a full frame lens on a full frame camera. What you said only applies when you use a full frame lens on a cropped sensor camera.

hawleyrw Loc: Dayton, OH

I've been using APS-C since I started with my first Canon DSLR (20D). Personally, I've never liked APS-C. I finally this last year (when they went on sale, just before the MKII came out), purchased a Canon D6. This way, I'm getting the 'normal' focal length as depicted on the lens, rather than doing the conversion and losing the wider angle that the lenses automatically provide. Much happier now. One bonus...the D6 FF takes in lower light than my current previous one 7D.

gvarner Loc: Central Oregon Coast

I've read that bigger sensors are better in low light ability because it's pixels are bigger in order to cover the entire surface area. But I may be wrong. 😜

selmslie Loc: Fernandina Beach, FL, USA

That's only true if you shoot wide open. Once you stop the lens down (as you would with a landscape to get more DOF) that difference is almost gone.