At what point does the Canon 5D Mark IV's high-ISO performance give it higher real resolution than the 5DS (R)?

Question

I want the sharpest images with the most detail possible.

• Resolution increases detail (to a limit)
• Noise decreases sharpness

Therefore, I have a dilemma. I am looking to purchase a new DSLR: either the Canon 5DS (R) or the 5D Mark IV.

The 5DS (R) has increased resolution (50MP), therefore increasing detail (to a limit). It does, however, have smaller pixels due to this increased resolution, meaning it has more noise in low light, thus decreasing sharpness.

The 5D Mark IV is the opposite. It performs better in low light, thus increasing sharpness, but it has fewer MP, meaning it shows less detail.

My question is this: If I want the sharpest picture with the most detail (e.g. close-ups of wildlife), which DSLR should I choose? I currently struggle with my photographs because my shots are always ruined by noise (currently using the Canon 700D), making them look unsharp. I understand both cameras will perform better than the 700D, but I want to know which would perform best, and what the differences would be.

Thanks for your help.

I use the Canon 100-400mm MkII, so lens quality is not an issue. I understand a balance is required between resolution and low light performance, but what I'm really hoping for is a specific answer. E.g. "For an ISO less than 6400, the 5DS R would be sharper, but at higher ISOs the image would be sharper with the 5D MKIII because of the reduced noise"

Answer 1

The literal answer to your question is: it depends. If you know you're always going to be shooting in good light, the 5DS will do better. In low light, the 5D may be more competitive.

However, the actual answer to your question is: you're worrying about the wrong thing. Unless you're already shooting with the 200-400 and a bunch of big white primes, you want to be spending your money on lenses, not the body. Consider dropping down to something like an older 5D, or maybe even a 6D or 7D Mark II, and spend the savings getting the best lens you can afford.

Answer 2

Would agree with Philip. Unless you have good/great lens you are better upgrading your glass rather than your body.

I was shooting with a Nikon D90 until just over a year ago due to me having decent glass. It was only when I was needing to shoot in very low light (a wet and rainy Welsh forest in Nov, under the canopy of the trees) that I realised I'd hit the limit of my body.

As a highlight and picking random numbers, if you have £2k to spend you'd be better off spending £1500 on a lens and £500 on a body than the other way round.

I know this answer doesn't really help coupled with Philip's answer, but sadly they are very few hard and fast rules when it comes to questions about kit.

Answer 3

Some things to consider:

• You might be surprised by how little additional detail 50 megapixels affords you over 30 megapixels. The 5DS gives you 8688x5792 pixels, while the 5D4 gives you 6720x4480 pixels. This means you can crop in 1.3x tighter on the 5DS (given that your lens is even able to provide that level of detail), which doesn't seem all that much when you consider that it has almost twice the number of megapixels. This is because the number of pixels grows quadratically with respect to the linear resolution (width/height). Of course, this might give you just the edge that you need in a certain situation, so it could still be worth it.

• A camera with higher resolution and smaller pixels does not necessarily produce more noise than one with a lower resolution. Yes, there will be more noise at the pixel level, however, downscaling images from the high resolution camera will reduce noise in a similar way as capturing it at a low resolution in the first place does (neglecting gaps between the pixels). That being said, the 5D4 uses newer sensor technology than the 5DS and in the end does produce less noise at the same ISO (dpreview).

• The 5DS only goes up to ISO 6400 (ISO 12800 extended), while the 5D4 goes to ISO 32000 (ISO 102400 extended). That means that if you want to go really high ISO, you will simply hit that limitation on the 5DS.

I think it's hard to say at which point the added resolution of the 5DS loses its value due to noise. Maybe somewhere around ISO 1600 or ISO 3200, if you look at the dpreview comparison. It may also be a preference thing (how much noise do you tolerate in your photos?).

Common wisdom says that the 5DS is more of a specialized camera that is used mostly for studio work where you have control over the light and need the added resolution in order to make huge prints. In contrast, the 5D4 is supposed to be the all-rounder. However, if your shooting style involves good light and a lot of cropping, it may still be the right choice for you. Echoing other peoples' comments, it may also be a good idea to look at lenses. An aperture that is one stop faster (f/4 instead of f/5.6) will offset any potential noise disadvantage of the 5DS.

Answer 4

If I want the sharpest picture with the most detail (e.g. close-ups of wildlife), which DSLR should I choose?

1. You need to balance between low light capability and resolution. Depends on your shooting style and favorite subjects.
2. Besides camera, you will need excellent lenses, pretty good shooting technique and perhaps some other tools like solid tripod, solid tripod head, etc. So before spending everything on the highest res body, leave large part of your budget to satisfy these needs, too.
3. Consider if you really need the highest available resolution, I have a 24MP camera and no desire for more detail from the sensor - with pretty good lenses it is enough for 13x19" prints.

Answer 5

This is a great question and it really depends on the two cameras you are comparing since there are may factors that contribute to the sensor performance.

Take for example the 16 MP Pentax K-5 IIs and 24 MP K-3. At one point I bough the K-3 to replace my K-5 IIs since, well the K-5 IIs was already better than the K-5 before it, so I assumed I could get even better performance from the K-3. Turns out I did not and sold the K-3 at a substantial loss of money while still ended with better image quality overall. This is what one can see if we look at DxOMark scores where the K-5 IIs performs notably better than the K-3, particularly in terms of dynamic range. However this is just one measure of performance and reality is that there is a cross-over somewhere. If I were to only shoot below ISO 400 for example, the K-3 would have produced better large prints as noise is very minimal at low-ISO where added resolution would be advantages.

Unfortunately I have neither had a chance to review the Canon 5DS or 5D Mark IV but I suspect you will get very similar results. At low ISO the resolution advantage of the 5DS will allow much larger prints. As ISO increases, details will get destroyed faster than the 5D Mark IV at the same ISO and eventually the 5D Mark IV will produce cleaner images which will remain more usable. Keep in mind that noise is not the only determining factor for image-quality, the newer 5D Mark IV is known to have a sensor with high dynamic-range thanks to technological improvements.