R7 vs R5. Balancing low light performance and reach.

[batmn319]

I've been shooting with the R7 and RF100-500L for a couple of months and find it to be a potent combination for birds/wildlife in many situations. Not surprisingly, the low light sensitivity of the APS-C sensor is limiting at times...

I'm a knowledgeable novice and am interested in insight/perspective/resources on how to think about sensor sensitivity, lens speed, and resolution. I realize those may not all fit into the same category, but here's what I'm trying to solve for - 

1. Can I overcome the R7's low-light performance with a faster lens (like an EF 500 F4 mkii)? Or would I have better results with an R5 and my current RF100-500L. 

2. I've read that the R7's 33mp crop sensor is the equivalent of 79mp full frame (or something crazy like that). If I were to swap the R7 for an R5 can I make up for the loss of effective focal length with cropping and still maintain IQ for large prints? 

3. Or should I wait for an R5 mk ii with the rumored higher res senor....?

Thanks so much. Hope these aren't super redundant questions, but I imagine they might be. I did some searching and came up empty. 

[rs-eos]

Better low-light performance comes from:

• Larger individual sensor sites.  This is why full-frame sensors tend to do much better since there's more physical real-estate to work with.  However, as resolution increases, low-light performance will decrease (since sensor sites are now smaller).
• Better/newer sensor tech.
• Lenses with wide apertures.  Though one con here is that sometimes working with shallower depth-of-field can be challenging.  Or, not desired.

Given that both the R7 and R5 are fairly new, the second point is covered pretty well.  The first and third will amount to balancing tradeoffs.

Having said all that, if you're finding you're pushing your gear to their current limits and have to raise ISO to very high levels, I would first recommend using faster lenses as they can allow you to work with lower ISO values.

In terms of cropping images captured on full-frame cameras, yes you'll lose resolution.  But it will depend upon how large of a print you'd need.

e.g., my EOS 5D IV captures 30 MP images.  Cropping an image to that of an APS-C field-of-view, this would lead to roughly 12 MP (4200 x 2800).  At 300 dpi, that's 14 x 9 inches (or 28 x 18 at 150 dpi).

[shadowsports]

All that Ricky said is true.  There's not much else to be said that he hasn't covered.  The faster lens route is going to yield the most noticeable results between these two body's.  The DR performance are closely matched with the trade off's being the size and number of available sensor sites.  More light gathering capability and shallower depth of field vs. an increase in DR and color rendition.  Its going to be fairly close, so I do not feel swapping body's is the way to go.  To gain something, you will be giving something up.  So once again, I believe Ricky's lens suggestion is a better way to go in the case of longer focal lengths.  

[FloridaDrafter]

One thing to keep in mind with the EF 500L prime is that, to me, it isn't as versatile as your zoom. By that I mean, you will lose the MFD you are used to and the ability to pull back to 100mm and other variations. That may sound trivial to most, but like you, I shoot nature. From birds to flowers to insects and just about anything that catches my eye. I need a zoom and close focusing abilities 🙂

I've used the EF 500L II on my 5D mark IV and 7D mark II and also own the EF 100-400mmL II. I used the 100-400 the most because of the abovementioned versatility of a zoom and MFD for my particular needs. I shoot a lot in and below heavy forest canopy and thick brush, and generally don't like swapping out glass when I'm sneaking through the forest.

I've long since sold the EF 500mmL II so I don't have any real world experience with it on my R5. But I do use the RF 100-500 on it and have pushed both camera and lens to their limits, and trust me, they are quite high and this combo never ceases to amaze me. My prints are usually under 20", depending on the birds which are sometimes only 3" long, and distance to subject. Low light and cropping just aren't a problem for me with the R5 and RF 100-500L. Admittedly, I may be a rare case and I'm not pushing the R5 over a brighter lens, just my experience shooting wildlife with the R5 and RF 100-500.

Newton

[johnrmoyer]

The previous advice is good. I hope some of this might also be helpful.

I have an EOS R5 and often use it in 1.6x crop mode for far away small birds. In crop mode, it has only a few less pixels on the bird than does my EOS 80D. Your EOS R7 has many more pixels on the bird. The advantage of the EOS R5 for me is that I can use it as full frame for landscape as well as cropping for birds.

Before buying a new camera, I suggest with your current camera try using these steps to emulate what you would get with the full frame camera:

1. in Canon DPP no sharpening except maybe Canon Digital Lens Optimizer until artifacts just start to appear around noise
2. Maybe no noise reduction if you will use other software later, else the noise reduction in DPP at a level that the camera would have chosen
3. set white balance and brightness in DPP
4. increase dynamic range in DPP until no clipped highlights
5. export 16 bit TIFF
6. in your favorite other software (gimp with GMIC plugin for me) noise reduction, maybe median filter
7. resample to the lower resolution you would have had at the same distance with the same lens and a full frame camera (I use graphicsmagick command line for this)
8. unsharp mask with a radius to match the blur from the median filter if such blur still exists after resample or if noise still exists then radius should be large enough to not sharpen noise

These steps will get you about the same thing you get with a full frame camera where the larger photo sites on the full frame sensor would do the equivalent of mean or median filter. It will have the additional advantage that the smaller photo sites on the EOS R7 sensor will be sampling the data at a higher frequency resulting in better raw data to work with. The Canon DPP DLO removes much of the small aperture diffraction blur, or Richarson/Lucy deconvolution in other softare before unsharp mask.

1/60 sec., ISO 4000, Canon EF 100-400mm f/4.5-5.6L IS II USM + 1.4x, cropped