RF and EF extenders on the EF 600/4L IS II

#41
Thanks for this! have just acquired a 600mm F4 IS II and want to get as much out of it as I can. Right now I have the EF 1.4 and 2X converters and am shooting with an R5.

I really appreciate the "real world" test where you can see the effects of the magnification.

Post some photos in the field when you have a chance.
 
Upvote 0
#42
Nice writeup, I'm a fan of TCs when they can save you money. I can't afford any big white lenses at present so I'm using the Sigma EF TCs with the Samyang EF 135/2 adapted to the R bodies when I want larger apertures than the RF 100-400 has.

This is a relatively cheap setup that allows the following fast telephoto options.

135 2.0 - FF
189 2.8 - FF
216 2.0 - Crop
270 4.0 - FF
302 2.8 - Crop
432 4.0 - Crop
 
Last edited:
Upvote 0
#43
Thanks for putting this together. I have all but the RF 2x, and I don't think I'll be in any hurry to get one now. It's interesting how the EF2x+RF1.4x preserves the line width of the text, while the EF1.4x+RF2x slims it down, so the former wins for me. I don't see any real benefit to going with the EF2x+RF2x over that (maybe a little less color aliasing, but I'll take double the shutter speed at that FL).

I have tested the RF 1.4x against the EF 1.4x III on the EF 600/4 II using MTF Mapper. I could not see any difference, except in the extreme corners the RF 1.4x was less sharp in my test. Across the rest of the frame, my 1200 dpi test chart was probably limiting.

BTW, I use the CommLite CM-EF-EOSR ARC adapter (with the control ring, but without the foot) because it only needs relatively minor surgery to fit the RF extender:

20220109-653A9903-3.jpg
 
Upvote 0
#44
I just ordered an RF 2x and one of the Commlite adapters to try this mod myself. This definitely increases the appeal of certain EF lenses, since EF are the only ones you can effectively double stack TCs without extension tubes using this method. For example, if this works for me I will probably pick up the Sigma 150-600 again. Having a 600-2400 lens sounds pretty good.
 
Upvote 0
#45
Johnw said:
I just ordered an RF 2x and one of the Commlite adapters to try this mod myself. This definitely increases the appeal of certain EF lenses, since EF are the only ones you can effectively double stack TCs without extension tubes using this method. For example, if this works for me I will probably pick up the Sigma 150-600 again. Having a 600-2400 lens sounds pretty good.
Click to expand...
2400mm f/25 isn’t going to resolve significantly more than 1200mm f/12.6 by the time increased optical aberration and diffraction have kicked in, and will be horrible to handle. You would do just as well by buying Topaz Gigipixel and upresolving 2x.
 
Upvote 0
#46
AlanF said:
2400mm f/25 isn’t going to resolve significantly more than 1200mm f/12.6 by the time increased optical aberration and diffraction have kicked in, and will be horrible to handle. You would do just as well by buying Topaz Gigipixel and upresolving 2x.
Click to expand...
Agree that 2400mm f/25 is not useful on a modern high-resolution body. You should consider that the 150-600mm zooms essentially have a 1.4x TC built-in to get from 400mm to 600mm, so just putting a TC on it is essentially stacking TCs (not exactly, but close enough to practical reality).

But I disagree that AI upscale with Topaz Gigipixel (or equivalent), is a panacea. Aside from the technical problems it can create, there are ethical issues as well. Unless the viewer expects the image to be artistically interpreted, then using AI in a photo that could reasonably be expected to be in documentary form is not kosher. But I don't mean to send this thread off in another direction, so I won't say more on that here.

Also, I didn't mention that the R5 can see both the EF & RF TC when stacked, and calls them both out in the EXIF, but it doesn't multiply the TC factors to get the total extension factor and effective focal length right. So that could affect AF and IBIS.
 
Upvote 0
#47
mandog said:
Agree that 2400mm f/25 is not useful on a modern high-resolution body. You should consider that the 150-600mm zooms essentially have a 1.4x TC built-in to get from 400mm to 600mm, so just putting a TC on it is essentially stacking TCs (not exactly, but close enough to practical reality).

But I disagree that AI upscale with Topaz Gigipixel (or equivalent), is a panacea. Aside from the technical problems it can create, there are ethical issues as well. Unless the viewer expects the image to be artistically interpreted, then using AI in a photo that could reasonably be expected to be in documentary form is not kosher. But I don't mean to send this thread off in another direction, so I won't say more on that here.

Also, I didn't mention that the R5 can see both the EF & RF TC when stacked, and calls them both out in the EXIF, but it doesn't multiply the TC factors to get the total extension factor and effective focal length right. So that could affect AF and IBIS.
Click to expand...
What I was getting at was that if you double up again the focal length of 150-600mm f/6.3 with a 2x TC on it already at 1200mm f/12.6, you increase the number of pixels by a factor of 4 but you hardly improve the resolution with a high resolution sensor and may even make it worse as TCs do degrade images to greater or lesser extents. So, you might just as well increase the number of pixels in post processing by using decent software like Topaz Gigapixel. I don't understand what you mean about ethical issues. Topaz Gigapixel doesn't do anything to alter the image artistically. All it does is to upresolve the image without making it softer. How is that unethical - it's no different from downresolving an image or sharpening it using software, and AI software does it better?
 
Upvote 0
#48
AlanF said:
What I was getting at was that if you double up again the focal length of 150-600mm f/6.3 with a 2x TC on it already at 1200mm f/12.6, you increase the number of pixels by a factor of 4 but you hardly improve the resolution with a high resolution sensor and may even make it worse as TCs do degrade images to greater or lesser extents. So, you might just as well increase the number of pixels in post processing by using decent software like Topaz Gigapixel. I don't understand what you mean about ethical issues. Topaz Gigapixel doesn't do anything to alter the image artistically. All it does is to upresolve the image without making it softer. How is that unethical - it's no different from downresolving an image or sharpening it using software, and AI software does it better?
Click to expand...
AI doesn't up-resolve the image--that's not possible. The original scene micro-detail is irretrievably lost when it is down-sampled through the Bayer matrix filter on the sensor. AI takes cues from images in a training set, and applies them to the image to simulate a higher resolution, creating false (but believable) detail. It effectively creates a photo-composite, only at the pixel level. So if you use it on a photo with a bird as the primary subject, it will use feather detail from birds in its training set to produce feather detail that "looks" good. If your bird photo is presented as abstract art, that's fine. But if you are presenting the photo as an accurate representation of that bird in the wild, it's not. If that's too abstract, consider whether it would be ethical to use AI to up-resolve a crime scene photo used in court.
 
  • Like
Reactions: 1 user
Upvote 0
#49
mandog said:
AI doesn't up-resolve the image--that's not possible. The original scene micro-detail is irretrievably lost when it is down-sampled through the Bayer matrix filter on the sensor. AI takes cues from images in a training set, and applies them to the image to simulate a higher resolution, creating false (but believable) detail. It effectively creates a photo-composite, only at the pixel level. So if you use it on a photo with a bird as the primary subject, it will use feather detail from birds in its training set to produce feather detail that "looks" good. If your bird photo is presented as abstract art, that's fine. But if you are presenting the photo as an accurate representation of that bird in the wild, it's not. If that's too abstract, consider whether it would be ethical to use AI to up-resolve a crime scene photo used in court.
Click to expand...
What is your evidence that it is using training on a set of birds to create detail? Do you know what the neural networks are trained on? Are they just working from local general patterns? I can see in the patterns from the Topaz AI sharpening that they are doing a local geometric based sharpening and not reconstructing real feather detail.
 
Upvote 0
#50
AlanF said:
What is your evidence that it is using training on a set of birds to create detail? Do you know what the neural networks are trained on? Are they just working from local general patterns? I can see in the patterns from the Topaz AI sharpening that they are doing a local geometric based sharpening and not reconstructing real feather detail.
Click to expand...
From the Topaz web site: "Gigapixel AI’s neural networks are continuously trained on a wide variety of sample images to understand how photorealistic detail looks. After learning from millions of images, our AI image upscaler can now believably increase resolution on a wide variety of different subjects..." There probably are some feathers in those millions of images. Also note that they say it's "believably" increasing resolution. That's telling.
 
  • Like
Reactions: 1 user
Upvote 0
#51
mandog said:
From the Topaz web site: "Gigapixel AI’s neural networks are continuously trained on a wide variety of sample images to understand how photorealistic detail looks. After learning from millions of images, our AI image upscaler can now believably increase resolution on a wide variety of different subjects..." There probably are some feathers in those millions of images. Also note that they say it's "believably" increasing resolution. That's telling.
Click to expand...
What AI is particularly good at is seeing patterns. If there are hidden patterns in interpolating pixels that it detects from say comparing low resolution images with high resolution then it can predict with some credence the best interpolation in various circumstances and not necessary using a database of say feathers. I think that Topaz doesn’t use accurate preset libraries of details as it makes a real mess of introducing artefacts when the settings are too high.
 
Upvote 0
#52
AlanF said:
That's not a job for the fainthearted!
Click to expand...

I used a manual file on mine but the job was pretty easy, took less than an hour. I also had to take off enough to expose the lower electronics so I covered that with a piece of tape to finish it off. I love this mod because now I can use the RF TCs with any EF lens, even ones that did not support TCs originally. With the ones that did, they can be double stacked.

AlanF said:
2400mm f/25 isn’t going to resolve significantly more than 1200mm f/12.6 by the time increased optical aberration and diffraction have kicked in, and will be horrible to handle. You would do just as well by buying Topaz Gigipixel and upresolving 2x.
Click to expand...

The utility would be limited of course. I'm mainly thinking of brightly lit astro targets like the moon or Venus, and using a tripod or equatorial mount. No hand holding at 2400. There is actually some decent close up footage of the moon at f/25 on youtube, mainly just lacking adequate stabilization to make it better.
 
Last edited:
Upvote 0
#53
Johnw said:
I love this mod because now I can use the RF TCs with any EF lens, even ones that did not support TCs originally. With the ones that did, they can be double stacked.
Click to expand...
On my list of things to try is the RF 1.4x behind the EF 85/1.4L IS for a 120mm f/2. That's really about the only non TC-compatible EF lens I still have worth putting a TC behind. Double-stacking might be fun with the MP-E 65, I don't see a need for it with the TS-E 17 or 24.
 
Upvote 0
#54
neuroanatomist said:
On my list of things to try is the RF 1.4x behind the EF 85/1.4L IS for a 120mm f/2. That's really about the only non TC-compatible EF lens I still have worth putting a TC behind. Double-stacking might be fun with the MP-E 65, I don't see a need for it with the TS-E 17 or 24.
Click to expand...
As far as I'm concerned even the first TC is too much for MP-E ... with R7. With low res FF bodies 1.4x would be usable, but I seriously doubt 2x would help compared to 1.4x. The effective aperture is just too small especially as most MP-E:s tend too need some stopping down for max sharpness.
 
Upvote 0
#55
JKT said:
As far as I'm concerned even the first TC is too much for MP-E ... with R7. With low res FF bodies 1.4x would be usable, but I seriously doubt 2x would help compared to 1.4x. The effective aperture is just too small especially as most MP-E:s tend too need some stopping down for max sharpness.
Click to expand...
I would agree with that, though I haven't ever tested a 1.4x TC with the MP-E 65mm. The EF 2xIII TC adds some real resolution to images with the 1D X, but not with the smaller pixels of the EOS M. Nor do the smaller pixels of the EOS M add spatial resolution at 5x or 10x (but the smaller pixels do add spatial resolution up to 2x). That's all based on empirical testing at f/11, so wide open might be a little better but as you state the MP-E is not at its best wide open.

Here are the comparisons of the 1D X and EOS M with the MP-E at 5x on top and at 10x with the 2x TC on the bottom. Images are 100% crops (they appear same size because they're both 18 MP, which made comparisons between those cameras quite convenient; I can now do the same with my R3 and EOS M6 since both are 24 MP).

1D X:
EOS 1D X.png

EOS M:
EOS M.png

The above images are small crops from a NIST/NBS 1010A resolution target intended for use with research microscopes, below is a shot of the target with the 1D X and 100L at 1:1, so it's a 24x36mm region of the 1x3" glass microscope slide, with the region shown above marked.

Test region.png
 
Upvote 0
#56
Did I understand correctly: nominal f/11? I didn't mean quite that much.

The sharpest aperture at 5x is in my case f/3.5 or f/4. Naturally that is mostly useful only with stacking. Even then the effective aperture with nominal f/4 at 5x is about f/27.5 and when you add TC to that,..

If you want to see resolution changes, a reshoot with f/4 might be interesting.

Another thing about TC:s on MP-E: they also magnify the CA nicely. I wonder if the small aperture is the reason it isn't really visible in your images ... or is it just that they are from center of the frame?
 
Upvote 0
#57
JKT said:
If you want to see resolution changes, a reshoot with f/4 might be interesting.
Click to expand...
I may do that at some point...those were from about 10 years ago.

JKT said:
Another thing about TC:s on MP-E: they also magnify the CA nicely. I wonder if the small aperture is the reason it isn't really visible in your images ... or is it just that they are from center of the frame?
Click to expand...
Would have to be the small aperture, here's the entire image of the EOS M at 10x, the ROI above is at the bottom edge.
M 10x.png
 
Upvote 0
#58
Here's a compilation of crops from IC images with MP-E and RP. Columns are different positions in the image and rows different apertures starting from f/2.8 at the top and changing by 1/3 of stop at each line. These images have been stacked even though MP-E is pretty close to planar. The CA is clear. The best aperture is not quite as clear and depends somewhat on location. A resolution target would be nice, but that I don't have.
Kaikki 2.jpg
I have a similar set with EF 1.4x II, but there's no point in showing that as it adds horrible barrel distortion and its own CA too. EF 1.4x III doesn't.
 
Upvote 0
#59
mandog said:
Thanks for putting this together. I have all but the RF 2x, and I don't think I'll be in any hurry to get one now. It's interesting how the EF2x+RF1.4x preserves the line width of the text, while the EF1.4x+RF2x slims it down, so the former wins for me. I don't see any real benefit to going with the EF2x+RF2x over that (maybe a little less color aliasing, but I'll take double the shutter speed at that FL).

I have tested the RF 1.4x against the EF 1.4x III on the EF 600/4 II using MTF Mapper. I could not see any difference, except in the extreme corners the RF 1.4x was less sharp in my test. Across the rest of the frame, my 1200 dpi test chart was probably limiting.

BTW, I use the CommLite CM-EF-EOSR ARC adapter (with the control ring, but without the foot) because it only needs relatively minor surgery to fit the RF extender:

View attachment 203175
Click to expand...
I di this with the Commlite but I had to take off more plastic than that to get it to mount and it exposed the circuit board underneath but still worked ok! I'm wondering now if it had something to do with the foot being mounted on mine?
 
Upvote 0
#60
dcweather said:
I di this with the Commlite but I had to take off more plastic than that to get it to mount and it exposed the circuit board underneath but still worked ok! I'm wondering now if it had something to do with the foot being mounted on mine?
Click to expand...
Looks like he used the control ring version of the adapter, did you use that one or the vanilla one? I used the vanilla one and like you, I had to trim it back sufficiently to expose the PCB (see this post from earlier in the thread). I did cover the opening with electrical tape.
 
Upvote 0
You must log in or register to reply here.

Similar threads

TexPhoto
1000mm, 2x Extender on the 100-500mm
Replies
4
Views
449
kaihp
K
C
Is this Canon EF 600mm f/4L IS USM a Buy? Advice pls!
Replies
8
Views
2K
EricN
EricN
Canon Rumors
Report: The RF 200-500mm f/4L IS USM is delayed until 2025
Replies
46
Views
4K
upallnight
U
L
RF extenders with EF lenses
Replies
8
Views
4K
neuroanatomist
neuroanatomist
Canon Rumors
Is Meike gearing up to offer autofocus lenses for the RF mount?
Replies
10
Views
1K
bn5fg
B
Top Bottom
Back
Home
Forums
Media
Menu