Correction: Canon is bringing us an RF 24-105mm f/4-7.1 IS STM Macro

koenkooi

EOS 5D Mark IV
CR Pro
Feb 25, 2015
1,605
1,461
It really is difficult to understand. The lens itself is an f4; but imagine, you mount an EF-S lens on a Full Frame body, you will get heavy vignetting. This is because the lens is designed for a smaller sensor. The focal length compared to what the sensor sees from the same spot is also different.
If you look at the amount of light hitting the sensor while shooting the same picture (with different sensor sizes), than an MFT sensor needs a 2 stops better aperture for the same amount of light hitting the sensor.

Same absolute amount, yes. Same brightness, no. In the "There's an interesting bear/lion/eagle half a mile away" case both the exposure and DoF would be the same for the same f-stop, since it's the same as cropping the FF image in post to match the MFT crop.
 

ahsanford

Particular Member
Aug 16, 2012
8,617
1,642
Same absolute amount, yes. Same brightness, no. In the "There's an interesting bear/lion/eagle half a mile away" case both the exposure and DoF would be the same for the same f-stop, since it's the same as cropping the FF image in post to match the MFT crop.


I (truly) love that the Godwin's Law of CR Forums is sensor/FL equivalence and not Hitler. :)

- A
 

TMACIOSZEK

Canon EOS R
Dec 11, 2019
76
68
Central Florida
pix.tmac.cc
There are always things we would rather want. The real question for me is: what are the alternatives? You can't look at something in isolation and say it is good or bad. It may be a bad lens in comparison to others. But the only fair comparison would be zoom lenses with a similar range and price tag (< 500) and weight (< 400). Since clearly, those are the properties this lens was designed for: affordable and compact.

I can't think of any alternative right away, but I don't have a great overview on FF zoom lenses anyway. Are there other lenses with such parameters? In which regards are they better?

Well you're in luck. All you need is a handy EF to RF converter (often provided free with the cameras now) and your world has just exploded with lens opportunities. The introduction of this lens, in my humble opinion, is for rubes that don't know better and think they're getting a bargain.
 

Sdiver2489

EOS M50
Apr 17, 2013
28
5
1) Depth of field is not a property of the lens alone, it's a property of the lens and sensor size combined.

2) The Olympus lens is also brand new, announced today, in fact that was the whole point of the comparison.


That is also wrong. If we use the Samsung S10's main rear camera as an example of a decent smartphone camera, it has a full frame equivalent of about f/9, so our f/7.1 RF lens is only 2/3 stop better. **BUT** the RF lens is 105 mm, and magnification caused by the narrower field of view contributes greatly to the background blur and therefore subject isolation. So no, all those buyers who you imagine might upgrade for this one facet of performance won't be disappointed.

1) Actually sensor size does not directly affect DOF. Focal length does and aperture. The reason why we often refer to sensor size affecting DOF is because we frame lenses differently when they are affected by their crop factor. If you frame a picture the same on a crop camera, then the DOF is exactly identical.

And in regards to your second comment about the S10, you aren't taking into account computational photography. Smartphone users can simulate much smaller DOF than a F7.1 lens on their smartphone even though the FF equivalent may be less. You and I may not be satisfied with simulated DOF, but the more average consumer likely is and in order to differentiate itself, Canon has to give a compelling reason for people to carry around a dedicated camera and IMO this lens does not give them one.
 

Sdiver2489

EOS M50
Apr 17, 2013
28
5
It really is difficult to understand. The lens itself is an f4; but imagine, you mount an EF-S lens on a Full Frame body, you will get heavy vignetting. This is because the lens is designed for a smaller sensor. The focal length compared to what the sensor sees from the same spot is also different.
If you look at the amount of light hitting the sensor while shooting the same picture (with different sensor sizes), than an MFT sensor needs a 2 stops better aperture for the same amount of light hitting the sensor.

I've heard this argument and I just don't see eye to eye with it. I will agree that different sensors have different noise performance. However, just because a lens is designed for a smaller sensor does not make the exposure properties different. If I take a MFT camera and set it to F4, 1/250 ISO 100 and a Medium format camera and set it to F4, 1/250, ISO 100, I am going to get the same exposure. In fact sometimes the smaller sensor might be brighter due to the fact that lenses designer for larger sensors tend to have higher vignetting.

Yes, if you did a sum total of the light collected over the sensor area, the FF sensor will be higher because there is more area with the same amount of light. But it does not affect exposure. I've seen a number of people post thinking that on a crop camera they need a larger aperture to get the same exposure as a FF camera and arguments like these contribute to these mistakes IMO.
 
  • Like
Reactions: Travel_Photographer

ahsanford

Particular Member
Aug 16, 2012
8,617
1,642
And in regards to your second comment about the S10, you aren't taking into account computational photography. Smartphone users can simulate much smaller DOF than a F7.1 lens on their smartphone even though the FF equivalent may be less. You and I may not be satisfied with simulated DOF, but the more average consumer likely is and in order to differentiate itself, Canon has to give a compelling reason for people to carry around a dedicated camera and IMO this lens does not give them one.


We do take into account computational photography. It's a neat trick, I admit, but it really looks sub-par compared to basic wide open shooting on a large sensored rig. You don't need to print out those portrait mode cell phone shots and stand a foot away to see the bounding profiles between in field and out of field with the software. I (and I presume many here) prefer capturing subject isolation optically with quick glass and a large sensor.

Your premise appears to be that photography is all about subject isolation, and if a lens can't deliver that, it shouldn't be offered. That is farcical. Each lens Canon offers does not have justify the existence / utility / purpose of the camera it is attached to. Were that the case, we'd only carry lead pickle jars for extreme bokeh or ultra-specialized glass for wildlife or macro.

Some of us just want to take a snap of our vaca. Sometimes we want small and light. That doesn't mean buying the camera was a waste of time, or that we'll never put a fast prime on it.

- A
 

Act444

EOS R
May 4, 2011
1,129
201
1) Depth of field is not a property of the lens alone, it's a property of the lens and sensor size combined.

Is this the case though? My understanding is that sensor size actually has no effect on DOF - rather, the reason larger sensors appear to produce shallower DOF than smaller ones is the necessity for longer focal length lenses to approximate the same field of view. Longer FL = less DOF. Also, for a given focal length, with a larger sensor camera you have to get closer to your subject to get the same framing. Lesser distance to subject = less DOF. Right?
 

Steve Balcombe

Too much gear
Aug 1, 2014
262
181
We do take into account computational photography. It's a neat trick, I admit, but it really looks sub-par compared to basic wide open shooting on a large sensored rig.
Absolutely we do, yes it is, and yes it does. I will freely admit that an awful lot of people really wouldn't notice the difference, but my assumption would be that those are not the people who are potentially upgrading to FF mirrorless, because they're happy with their phones.

The depth of field / subject isolation thing needs a more complicated reply which I can't do right now, but I'll try to come back with something in the fullness of time.
 
  • Like
Reactions: ahsanford

Sdiver2489

EOS M50
Apr 17, 2013
28
5
We do take into account computational photography. It's a neat trick, I admit, but it really looks sub-par compared to basic wide open shooting on a large sensored rig. You don't need to print out those portrait mode cell phone shots and stand a foot away to see the bounding profiles between in field and out of field with the software. I (and I presume many here) prefer capturing subject isolation optically with quick glass and a large sensor.

Your premise appears to be that photography is all about subject isolation, and if a lens can't deliver that, it shouldn't be offered. That is farcical. Each lens Canon offers does not have justify the existence / utility / purpose of the camera it is attached to. Were that the case, we'd only carry lead pickle jars for extreme bokeh or ultra-specialized glass for wildlife or macro.

Some of us just want to take a snap of our vaca. Sometimes we want small and light. That doesn't mean buying the camera was a waste of time, or that we'll never put a fast prime on it.

- A

Camera manufacturers are facing a shrinking market from smart phones that are becoming more and more competitive with mirrorless cameras. One of the features that was always a major differentiator was the fact that small sensors were not capable of subject isolation. That is lost when you develop a F7.1 lens. That is my point. I never said no one should ever use F7.1. I said you lost one of the main benefits of large sensor cameras...one that people will notice.

Obviously there are different purposes for each lens, what I have been expressing is my opinion. I would never buy a F4-F7.1 lens. If you would...great. But I can buy constant F4 lenses readily available. I would never go less than this. If you would...more power to you!
 
Last edited:
  • Like
Reactions: ahsanford

Kit.

EOS 5D Mark IV
Apr 25, 2011
2,096
1,435
1) Depth of field is not a property of the lens alone, it's a property of the lens and sensor size combined.
Let me put it this way:

All the parameters of the image, except for:
1. the particular placing of the plane of focus,
2. optical aberrations, and
3. vignetting
- are already predetermined by how the light crosses the entrance pupil of the lens. Sensor size does not affect them.
 

SecureGSM

2 x 5D IV
Feb 26, 2017
2,376
1,246
Promotional vid here -- wow are they leaning into the 24mm end of the macro!


- A
I get it. Perfect for a consumer grade product photography. Use cases: eBay listings, Craigslist, Gumtree, etc. INC social networking. Sure. For traveling however.... this one here. Any day...

 

Shellbo6901

EOS M50
Jan 16, 2015
39
8
besides the macro and the pricepoint... maybe the weight, why would one want this VS the other 24-105 RF's available? seems dumb IMO, even for the RP.
 

aj1575

EOS RP
Dec 15, 2010
202
0
Yes, if you did a sum total of the light collected over the sensor area, the FF sensor will be higher because there is more area with the same amount of light. But it does not affect exposure. I've seen a number of people post thinking that on a crop camera they need a larger aperture to get the same exposure as a FF camera and arguments like these contribute to these mistakes IMO.
Difficult it is... (I had to look it up myself to understand it better)

Let's say you shoot with an MFT (crop factor 2) with a 50mm f1.4. To get the same angle of view (the same frame) with a FF you need a 100mm lens. The aperture size (f-number) is calculated by the focal-length divided by the diameter of the aperture; same diameter means same amount of light. The 50mm has a diameter of 35.7mm at f1.4 (50/1.4). For the 100mm we get an aperture of 100mm/35.7mm = 2.8. So 50mm f1.4 on a MFT equals 100mm f2.8 on a FF, in terms of amount of light. But the FF sensor has 4 times the area of an MFT sensor. This means the amount of light per area is 4 times smaller on a FF sensor. On the other hand, with the same pixel count, the light per pixel would be the same.

I'm using APS-C, and think about switching to FF. My feeling is, that consumer lenses on a FF will be sharper than semi pro lenses on APS-C, because the pixel on the FF are bigger. I will have to do some internet research on that when the time comes for a new camera.
 

Eimajm

EOS M6 Mark II
Oct 10, 2011
51
1
Macro shooters: could this lens replace other lenses in your kit, or is the magnification
Actually I use wide apertures for macro, but I have a VERY specific use case in mind. I readily acknowledge my situation is unusual.

If f/7.1 works for people, then this sounds like a good thing!
For me I need 1x magnification, so this lens can’t replace a true macro lens
Yup should be called pseudomacro lens Also won't be optimised for close focus like dedicated macros.
 

Random Orbits

EOS 5D Mark IV
Mar 14, 2012
2,439
309
besides the macro and the pricepoint... maybe the weight, why would one want this VS the other 24-105 RF's available? seems dumb IMO, even for the RP.

Price is king. It's initial price is 400, which is a lot lower than the RF 24-105L. Just wait a couple years after the lens price falls. Something like the RP and this 24-105 lens for less than $1000. That is the target market.

Canon was criticized for leading with L-glass because there weren't enough consumer-grade options, and now that consumer grade options are coming it, it's not good enough...
 
<-- start Taboola -->