RF 100mm f/2.8L IS Macro lens on an R7 camera body

[rickbb]

Hi, I understand the geometry associated with the use of a FF lens on an APS-C camera body and a previous thread thoroughly explores that subject. My question: what is the effect on photo quality, if any, using a FF lens with a small sensor?
Thanks!

[Anonymous · Accepted solution]

I think that using a FF lens on an APS-C camera would result in somewhat better image quality as the full image circle of the lens would not be used. The center area of the lens usually has the best image quality, while the edges of the image field are not as clear. Since less of the edges and more of the center area is used, better clarity and focus is achieved in the image.

[shadowsports · Accepted solution]

I just purchased this lens, but am using on a FF sensor.  I agree with Bob.  The magnification and MFD will remain the same.  I purchased this lens for both stills and video.  The R5 C's recent FW update has a magnification feature in Cinema OS that I really liked.  I'm not into bugs but the cricket and butterfly videos I saw with 2 and 3x mag were very life like.  Delicate and beautiful.  I'm sure images taken with an R7 will be striking.    

[Anonymous · Accepted solution]

I think that using a FF lens on an APS-C camera would result in somewhat better image quality as the full image circle of the lens would not be used. The center area of the lens usually has the best image quality, while the edges of the image field are not as clear. Since less of the edges and more of the center area is used, better clarity and focus is achieved in the image.

[shadowsports · Accepted solution]

I just purchased this lens, but am using on a FF sensor.  I agree with Bob.  The magnification and MFD will remain the same.  I purchased this lens for both stills and video.  The R5 C's recent FW update has a magnification feature in Cinema OS that I really liked.  I'm not into bugs but the cricket and butterfly videos I saw with 2 and 3x mag were very life like.  Delicate and beautiful.  I'm sure images taken with an R7 will be striking.    

[ebiggs1]

"My question: what is the effect on photo quality, if any, using a FF lens with a small sensor?"

The question is too open ended as compared to what? Unless the two cameras used to do the comparison are identical except for sensor size you really can't compare them. Lets say they are. The center of either image taken from either camera will be the same. The edges if there is any distortion is generally not of significant importance in most cases. Meaning people generally concentrate on the center most important part of any photograph. In the case of a pixel peeper there might be but is there in general? I really doubt it.

[ebiggs1 · Accepted solution]

You know years ago in the early days of crop sensor cameras people often suggested using FF lenses on the smaller sensor bodies. But was what they were seeing as sensor advantage due to FF lenses? Or, are FF lenses generally better quality and nothing to due with the sensor. When you are talking FF lenses most are going to be L quality which is Canon's best effort. There are no "L" level crop lenses.

It is akin to the telephoto advantage of a crop sensor vs FF. Is it better to use a crop sensor or to us a FF and crop the photo in Photoshop to the same size. In my own test again remember there are no equivalent crop vs FF camera bodies, I can see no real meaningful difference. Bottom line is a better camera and a better lens will always preform better. So my advice is buy the best you can afford and move on.

[krahe]

Given a FF vs. crop sensor of the same resolution, there is more glass covering each pixel of the FF sensor. That gives the FF an edge in low-light performance. It can also make the FF less susceptible to being affected by imperfections in the glass. Of course, the FF is also collecting less detail from a given region of the view, because it's taking in a wider FoV.

[FloridaDrafter]

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@rickbb wrote:My question: what is the effect on photo quality, if any, using a FF lens with a small sensor?

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I agree with EB. It's hard to say, in general, and depends on the lens/camera. However, I have used the subject lens RF 100mm f/2.8L IS USM Macro on my FF cameras (R5, R6, R6II) for a couple of years and it is sharp from corner to corner so there will be no effect, good or bad, e.g., "center being sharper". I have also used (and still do) its predecessor the EF 100mm f/2.8L IS USM on various croppers from the XSi to the 7DII and the FF 5D mark IV. The only time I ran into a problem using the EF version on a cropper was when shooting subjects that were to large to be captured by the smaller sensor at MFD, which caused me to have to pull back from 1:1. Granted, this was rare, but it happened on occasion. An example would be something like a medium sized rose or focus stacking larger subjects where I wanted to start at 1:1. FF did the job.

Sticking to the lens of topic, true macro lenses ("true" to me is 1:1 or smaller) are designed differently to account for the various problems of close focusing. I'm not so sure Canon has applied the same standards to the cheaper entry level 0.5 or 1:2 "macro" lenses they have released. I would have to use one, but my guess would be they aren't equal to a true macro like the EF and RF 100mm f/2.8L Macro or the EF 180mm Macro. BUT, I could be wrong, LOL!

Newton

[FloridaDrafter]

I figured I would post an example of where I would not be able to get the full 1:1 magnification, or in the case of the RF 100mm Macro 1.4:1 mag., at MFD with a cropper.

This is a 60ish shot stack of a rose that's been dipped in acrylic or something using the RF 100mm macro and an EOS R5 then processed in DPP 4. This is the full frame then reduced for posting. I used a macro rail to get MFD, which was the closest point on the rose. As you can see from this example, I should have taken 20 more shots in the stack as the back is OOF 🙂

Newton

[ebiggs1]

" It's hard to say, in general, and depends on the lens/camera."

The problem is people are comparing the old apples to oranges in other words apophenia. A common phenomenon we all suffer form now and again.