RF100mm F2.8 L macro - Focus Shift is Fixed/Addressed

[homebodyMacro]

Hello all,

Honestly, I bought this lens back in March before seeing older reviews mentioning focus shift.

I've seen plenty of comments about how this lens is compromised, etc., and certainly I would agree that Canon should not have shipped this lens with focus shift and no software offset.

That said, at least from a brief search I couldn't find anything that noted whether or not this obvious software fix was implemented.

Per old reviews, focus shift was strictly between f/2.8 and f/11: https://www.the-digital-picture.com/Reviews/Canon-RF-100mm-F2.8-L-Macro-IS-USM-Lens.aspx

I had never noticed any issues in my usage prior to seeing this in reviews, so I wondered if I missed it somehow. From my testing awhile back, I couldn't tell from manual focus peaking off of AF that there was any difference for f/2.8 vs. the affected range.

I saw a comment on this again today, so decided to take a few test images. Roughly orthogonal to this textbook, AF photos are perfectly sharp to the point of seeing paper grains for f/2.8, f/5.0, and f/7.1 at the intended point of focus. Everything looks good and comparable with manual focus peaking off the AF. Nothing used in DPP4 for processing other than setting sharpness to 0 to try to remove any confounding effect of sharpening.

The focus point is in the center, the lower half of the 2nd l^2 (after "to") which is of note as the photos are not taken perfectly orthogonal to the page.



f/2.8 (AF)



f/5.0 (AF)



f/7.1 (AF)



A good "test" in the full size images above: in the 2nd l^2 (after "to") there's a little v-shaped gap in the printed tone. It is basically equivalent in all the images, perhaps the sharpest in the f/5.0 version (i.e. not the f/2.8 which was never affected by shift). This is not at all visible to the naked eye.

Here is a comparison of AF and a tiny nudge with manual focus for f/5.0, where yes, you can now clearly see softness which does not exist in any of the AF tests. It is very similar to the softness seen in the release-time lens tested in the review above, reference the "GRI" orthogonal-to-camera text images (i.e. f/2.8 is good: https://media.the-digital-picture.c...F2.8-L-Macro-IS-USM-Lens/Focus-Shift/f28.webp, vs. f/5.6 is soft: https://media.the-digital-picture.c...F2.8-L-Macro-IS-USM-Lens/Focus-Shift/f56.webp

In this case the focus point was the upper half-ish of the 2nd l^2, again of note as the text is not perfectly orthogonal to the axis of the lens.



f/5.0 again (AF), very sharp at point of focus



f/5.0 again (AF with tiny MF nudge, compare to focus shift in this review: https://media.the-digital-picture.c...F2.8-L-Macro-IS-USM-Lens/Focus-Shift/f56.webp )



The MF nudge was small, you might have to look at the full size to see it (i.e. it is even smaller than the shift in the review linked).

As such, unless I'm missing something this issue appears to have been addressed adequately at some point.

It's a real shame that Canon didn't tidy this up before shipping it, and it is doubly a shame if there is a widespread impression that this lens still has a focus shift issue. I love the lens personally, and AF even for high magnification works very well.

Anyhow, hopefully this helps someone out there looking at the lens and feeling uncertain about close-up focus for medium-low to medium apertures.

 

[charlyw64]

As such, unless I'm missing something this issue appears to have been addressed adequately at some point.

It would be interesting to see which reports about focus shift you are talking about. One thing that would make me weary about the validity of the problem is that they are reported at f/2.8.

 

[homebodyMacro]

As such, unless I'm missing something this issue appears to have been addressed adequately at some point.

It would be interesting to see which reports about focus shift you are talking about. One thing that would make me weary about the validity of the problem is that they are reported at f/2.8.

I'm a little confused. There's a technical review in my post above that I referenced at least 3 times with 4 related links.

That's the clearest illustration of the focus shift issue that I've seen (https://www.the-digital-picture.com/Reviews/Canon-RF-100mm-F2.8-L-Macro-IS-USM-Lens.aspx).

If you scroll about halfway down, there's an image of some letters "GRI" illustrating the issue. f/2.8 and f/11 are clear, and the focus shift issue exists in between. I have linked to images from this set above, i.e.:

f/2.8 clear: https://media.the-digital-picture.c...F2.8-L-Macro-IS-USM-Lens/Focus-Shift/f28.webp

f/5.6 quite soft: https://media.the-digital-picture.c...F2.8-L-Macro-IS-USM-Lens/Focus-Shift/f56.webp

The focus shift is indeed obvious at f/4.0, f/5.6, and f/8.0 in their images when looking at the full review.

Dustin Abbott mentions shift at f/5.6 in his technical review: https://dustinabbott.net/2021/11/canon-rf-100mm-f2-8l-macro-is-usm/.

I haven't seen any claims that it exists at f/2.8. My images used f/2.8 as a basis of comparison only.

The focus shift issue is the worst at close focus distances, hence my images were very close-range. The full height letters in the text I captured are 0.10" tall (2.54mm). The magnification in my images is around 1.0x, so shift *should* be quite obvious as it was in the "GRI" images in the "digital picture" site review, if the issue still exists on my 2024-purchased lens.

Given that I can see no indication whatsoever of softening at the point of focus in my images (and f/5.0 looks a little sharper than f/2.8 which can normally be expected), as opposed to the very obvious example in the review, I am left to conclude that the issue has been corrected for in software. Hopefully that clears up anything unclear in the original post.

For my images, here's a super-closeup of the 0.10" tall cursive "l" letters at the focus point:

f/2.8:



f/5.0, in my view clearly a bit sharper (it is subtle, and this is an extreme level of detail)

 

[homebodyMacro]

Here's a final sample set:

This time, I used the same subject, but with the camera as close to the 1.4x max. magnification as I could get it (becomes extraordinarily sensitive at that point to movement).

Again, RF 100 F/2.8 L macro, auto-focus, both @ 2500 ISO, sharpness set to "0" in DPP4.

f/2.8 @ ~1.4x magnification:



f/2.8 focus point:



f/6.3 @ ~1.4x magnification



f/6.3 focus point:



And here's the ultra-close crop of the l^2 that is closest to the focus point:

f/2.8:



f/6.3:



I think the f/6.3 is marginally sharper than the f/2.8 at the focus point.

Again, I am only left to conclude that the focus shift, which was quite clear and obvious in the "digital picture" review, has been fixed post-hoc.

f/6.3 at maximum magnification on text, which should be more or less the absolute worst case for the focus shift issue, is sharp even when looking at a 0.10" letter at an on-screen size of 20" (200x). I don't see how we could conclude otherwise.

Worth noting that all of these are taken with my R8, as you can see from the metadata; it was on EFCS mode for all these, not that it should matter. I took short bursts and picked the sharpest one for each focal length (generally wasn't much variation, but exposures were quite long for higher aperature values and can be affected by tiny movements at such low focus distance).

I do think this analysis is pretty conclusive, so as I said, I hope it is helpful to someone out there. I absolutely love this lens, and I'm happy that the focus shift seems to be fixed, as what the "digital picture" review showed was pretty bad. Shame on Canon for releasing it as such, as it is a great lens. I use it for a huge variety of shots; it's a great all-arounder.

 

[drsnoopy]

homebodyMacro wrote:
(truncated)

I think the f/6.3 is marginally sharper than the f/2.8 at the focus point.​

Again, I am only left to conclude that the focus shift, which was quite clear and obvious in the "digital picture" review, has been fixed post-hoc.

f/6.3 at maximum magnification on text, which should be more or less the absolute worst case for the focus shift issue, is sharp even when looking at a 0.10" letter at an on-screen size of 20" (200x). I don't see how we could conclude otherwise.

Worth noting that all of these are taken with my R8, as you can see from the metadata; it was on EFCS mode for all these, not that it should matter. I took short bursts and picked the sharpest one for each focal length (generally wasn't much variation, but exposures were quite long for higher aperature values and can be affected by tiny movements at such low focus distance).

I do think this analysis is pretty conclusive, so as I said, I hope it is helpful to someone out there. I absolutely love this lens, and I'm happy that the focus shift seems to be fixed, as what the "digital picture" review showed was pretty bad. Shame on Canon for releasing it as such, as it is a great lens. I use it for a huge variety of shots; it's a great all-arounder.

Interesting - I remember reading about this on TDP and thought it a fatal flaw in what should be a flagship lens.

My questions would be:

(1) was the original finding due to copy variation, and you simply have a good one?

(2) how have Canon fixed it? Has there been a lens firmware update? Has a camera firmware update addressed this specific lens? Or has there been a hardware fix implemented in later production copies?

 

[homebodyMacro]

Interesting - I remember reading about this on TDP and thought it a fatal flaw in what should be a flagship lens.

My questions would be:

(1) was the original finding due to copy variation, and you simply have a good one?

(2) how have Canon fixed it? Has there been a lens firmware update? Has a camera firmware update addressed this specific lens? Or has there been a hardware fix implemented in later production copies?

Regarding (1), I think this is extraordinarily unlikely for these reasons:

1. The TDP review tested multiple copies and had comparable results.

2. The TDP review got a statement from Canon that this is inherent to the optical design: "The response from Canon's optical engineers was to confirm that, due to its 1.4x magnification (1.4:1 reproduction ratio) capability, a magnification far exceeding 1.0x, the RF 100mm F2.8 L Macro IS Lens's optical design exhibits some focus shift."

3. I would have to have a lens that is somehow experiencing a high-dimensional optical manufacturing tolerance stackup that randomly (mfg variation is random) sums up to perfect focus at multiple distances for multiple aperatures tested in the affected range. This is "too good to be true". I don't want to say it is impossible since I don't have an empirically calibrated opinion on optical tolerance stackups, but given that shift should be a function of aperature and focus distance, I think the probability is very low.

I can't find the source at the moment, but I know I've seen a review that other manufacturers can and have addressed focus shift in firmware.

Indeed, if Canon commented that it is inherent to the optical design, whatever numerical/computational predictive modeling they have for optical performance could be used to fix the issue in software. I'm sure their modeling is highly empirically validated, though a fix could also be constructed empirically.

The Canon website doesn't show any firmware downloads for the RF100mm macro. That's the only thing that doesn't quite pass the sniff test. However, an official firmware fix also requires admitting to a significant issue which may have a level of liability they don't like. Maybe they consider it minor and didn't officially release it as a "fix". Corporations tend to be terrible, so this seems very possible. 1.0.0 is "completely new firmware"; mine shows as 1.1.1, and there are lenses that are still at 1.0.0 here: https://rfshooters.com/blog/lenses/

 

[drsnoopy]

1. homebodyMacro wrote:

Interesting - I remember reading about this on TDP and thought it a fatal flaw in what should be a flagship lens.

My questions would be:

(1) was the original finding due to copy variation, and you simply have a good one?

(2) how have Canon fixed it? Has there been a lens firmware update? Has a camera firmware update addressed this specific lens? Or has there been a hardware fix implemented in later production copies?

Regarding (1), I think this is extraordinarily unlikely for these reasons:

1. The TDP review tested multiple copies and had comparable results.

2. The TDP review got a statement from Canon that this is inherent to the optical design: "The response from Canon's optical engineers was to confirm that, due to its 1.4x magnification (1.4:1 reproduction ratio) capability, a magnification far exceeding 1.0x, the RF 100mm F2.8 L Macro IS Lens's optical design exhibits some focus shift."

3. I would have to have a lens that is somehow experiencing a high-dimensional optical manufacturing tolerance stackup that randomly (mfg variation is random) sums up to perfect focus at multiple distances for multiple aperatures tested in the affected range. This is "too good to be true". I don't want to say it is impossible since I don't have an empirically calibrated opinion on optical tolerance stackups, but given that shift should be a function of aperature and focus distance, I think the probability is very low.

I can't find the source at the moment, but I know I've seen a review that other manufacturers can and have addressed focus shift in firmware.

Indeed, if Canon commented that it is inherent to the optical design, whatever numerical/computational predictive modeling they have for optical performance could be used to fix the issue in software. I'm sure their modeling is highly empirically validated, though a fix could also be constructed empirically.

The Canon website doesn't show any firmware downloads for the RF100mm macro. That's the only thing that doesn't quite pass the sniff test. However, an official firmware fix also requires admitting to a significant issue which may have a level of liability they don't like. Maybe they consider it minor and didn't officially release it as a "fix". Corporations tend to be terrible, so this seems very possible. 1.0.0 is "completely new firmware"; mine shows as 1.1.1, and there are lenses that are still at 1.0.0 here: https://rfshooters.com/blog/lenses/

Yet yours is apparently fixed. The question is how? It’s possible to check which firmware version is installed. If this is still the original, the question remains unanswered.

 

[homebodyMacro]

Yet yours is apparently fixed. How?

Mine is at firmware 1.1.1. There are plenty of 1.0.X possibilities as you can see here: https://rfshooters.com/blog/lenses/

Canon clearly has a lot of internal firmware revisions, but only a very small fraction of them are released as product advisories, i.e. a "firmware notice" that actually gets put on their website. They give no information for firmware on RF lenses that have not had an advisory, from the look of it, which is intentionally opaque.

Unless RF100mm macro lenses with firmware 1.1.1 are shown to have the same focus shift issue that was very, very clear in the TDP review, I think the simplest explanation is that it simply did not meet their internal risk threshold for a product advisory.

For example, in that list of RF lenses and firmware versions, there are specific firmware versions for only some cases. We have a 1.0.0, a 1.0.3, 1.0.6, 1.0.8, 1.1.0, 1.1.1, etc., etc. The versions increase from the right i.e. 1.0.0 < 1.0.1 < 1.1.0 < 1.1.1, etc.

For the RF 24-105mm F4L IS USM, it is at 2.0.6 - yikes. But if we use a search engine, we see releases for only a few of these:

site:https://www.usa.canon.com/support/canon-product-advisories/ RF 24-105mm F4L IS USM

or this search, if you want to be broader:

site:https://www.usa.canon.com/support/ RF 24-105mm F4L IS USM "firmware"

Firmware update notices for this lens (24-105 F4L) appear only for versions 2.0.0, 2.0.1, 2.0.6. Their software engineers are not just generating random firmware/software version numbers (though that would be a bit funny at this point), so there are clearly many versions that are not publicly announced, including the entire 1.X.X series!!!

Given that this clearly seems to be possible, as opposed to a majestic mythical magical copy of the lens that I just happen to have that inverted the optical design intent over broad input conditions without seemingly any issues (at which point, wouldn't they have release this optical design instead? perhaps I can get a good price for my copy...), I would say it is much more likely.

That doesn't mean it is certain, I just don't see how any alternatives seem probable at this moment. Sherlock Holmes is completely wrong in his epistemology - whatever remains mustn't be true, unless one has enumerated the entire universe of possibilities (generally difficult or impossible).

 

[c h u n k]

Why not take the test shots at an angle going down a line of letters or of a ruler? So much easier to see what's happening. You are near flat with the page.

 

[Phylloxera]

I've got firmware 1.1.1 and tried that with a ruler on my heavy macro stage at mag. 1.4x and couldn't find any focus shift worth mentioning. Tested with AF and MF between F= 2.8 and 11.

Perhaps a more scientific test might still find some shift but for my demands I'm satisfied.

 

[homebodyMacro]

Why not take the test shots at an angle going down a line of letters or of a ruler? So much easier to see what's happening. You are near flat with the page.

This may just be my opinion, I suppose, but from the TDP review (mentioned numerous times above, ref.: https://www.the-digital-picture.com/Reviews/Canon-RF-100mm-F2.8-L-Macro-IS-USM-Lens.aspx ), I think the perpendicular-to-lens-axis photos are the nicest illustration of the issue.

In particular, I was very confident that my lens had no shift from prior testing (including a plane location estimation), so all that was needed was "go/no-go" type of test.

For the perpendicular shot, the text is either sharp or it is not, and it is easy to tell. I would recommend looking at the "GRI" text images in the TDP review, which are perpendicular-to-lens-axis shots with focus shift being abundantly clear. They're about halfway down the review, just scroll there and load the comparisons. Their tests are very clear and conclusive, in my opinion.

Given that the focus plane is a hypothetical plane bordered by a continuum of blurriness, which gets much wider and subtler with higher aperture values, I think the perpendicular shots are a better test to show equivalence, which was my goal. It is also relatively easy to see if a shot is sharp or not - we do that every time we take a picture.

I did a quick test of my same subject from before with an angle, and I still have the same opinion more or less that the perpendicular shots are a more precise illustration. I'm sure there could be better subjects, but meh, the planes look close enough to be equivalent, so it seems very clear still.

R8, EFCS, RF 100mm F/2.8 L macro, Firmware 1.1.1, ISO 2000, magnification somewhere near 1.2x, all AF)

f/2.8 (AF)



f/2.8 AF focus point:



f/6.3 (AF)



f/6.3 AF focus point:

 

[homebodyMacro]

I've got firmware 1.1.1 and tried that with a ruler on my heavy macro stage at mag. 1.4x and couldn't find any focus shift worth mentioning. Tested with AF and MF between F= 2.8 and 11.

Perhaps a more scientific test might still find some shift but for my demands I'm satisfied.

It would be very interesting to falsify my tentative (but seemingly very likely) hypothesis explanation here with a 1.1.1 firmware RF 100 macro that looks comparable to the TDP review. Thank you for sharing your findings!

That said, I think that's pretty unlikely, especially given that Canon seems to have an enormous number of firmware versions that they feel do not warrant a website notice/release (and they purposefully do not list firmware information otherwise).

A firmware update fixing the focus shift issue that falls short of a posted firmware notice/website download seems not just possible, but quite likely based on the state of the RF lineup on firmware (https://rfshooters.com/blog/lenses/ ).

 

[homebodyMacro]

It would be very interesting if other RF 100mm macro owners chimed in with their firmware version and presence or absence of focus shift.

I think we could likely determine where the change occurred if we had enough RF 100mm owners (probably a bit of a stretch with the size of the userbase).

Currently: firmware 1.1.1 is 2/2 with no focus shift.

 

[Cristi CC]

What focus shift are you talking about? How it has been fixed? There is a recent firmware update about that?

Ok, you made some test shots, and?

 

[Chris Wolfgram]

I'm sorry to ask such a novice (probably dumb) question, in a technical thread such as this...

But I am definitely a macro newbie.

So I rented the RF 100 F2.8 macro several months ago, and I freaking loved it Definitely a learning curve, but by the time I had to send it back, I felt like I was starting to get the hang of it.

Anyway, I was mostly using focus stacking of like 30 to 200 frames... And it mostly worked.

However, about 20 or 30% of the time, it just flat failed..... So if get a block of 30 to 200 shots, with every single one OOF.

Is this the issue your speaking of ?

 

[homebodyMacro]

What focus shift are you talking about? How it has been fixed? There is a recent firmware update about that?

Ok, you made some test shots, and?

Feel free to read the thread and come to your own conclusion, I guess? It is all discussed earlier in the thread, so I'm not going to repeat it here.

I'm sorry to ask such a novice (probably dumb) question, in a technical thread such as this...

But I am definitely a macro newbie.

So I rented the RF 100 F2.8 macro several months ago, and I freaking loved it Definitely a learning curve, but by the time I had to send it back, I felt like I was starting to get the hang of it.

Anyway, I was mostly using focus stacking of like 30 to 200 frames... And it mostly worked.

However, about 20 or 30% of the time, it just flat failed..... So if get a block of 30 to 200 shots, with every single one OOF.

Is this the issue your speaking of ?

Focus shift is where you try to autofocus on a given point, and the camera actually focuses behind or in front of the object.

If you want to focus on anything planar, like text on a page or elsewhere, this would make the whole thing blurry. If you are taking a shot with depth, the focus will simply be at the wrong depth (vs. what you intended and where the AF says it is focusing).

If you look at this review: https://www.the-digital-picture.com/Reviews/Canon-RF-100mm-F2.8-L-Macro-IS-USM-Lens.aspx

Search for the words "Focus shift, the plane of sharp focus moving forward or backward as the aperture is narrowed" and just keep reading until that section is done (i.e. at "Next, we'll look at a comparison showing...").

They have images in there that illustrate precisely what is happening.

For this lens in particular, the older review copies at the very least focused behind the intended point in the shot (i.e. if you had a page of text, it will focus underneath the page, if that makes sense).

...

Separately, regarding focus bracketing, this focus shift issue should not cause it to fail. I don't think I can enumerate all the ways that focus bracketing can fail, but I would imagine the number of shots you selected vs. the shift increment conflicted for it to have a failure. I would guess that is the main cause of a failure, but again can't give you anything definitive there.

I will say that 30-200 shots is almost certainly more shots than you need for almost any focus bracketing application. If you use a higher aperture number (i.e. farther from f/2.8), your depth of field is better and you don't need as many individual shots to get the whole scene in focus. That will save you a lot of storage and also processing time (if you process the RAWs).

 

[Chris Wolfgram]

What focus shift are you talking about? How it has been fixed? There is a recent firmware update about that?

Ok, you made some test shots, and?

Feel free to read the thread and come to your own conclusion, I guess? It is all discussed earlier in the thread, so I'm not going to repeat it here.

I'm sorry to ask such a novice (probably dumb) question, in a technical thread such as this...

But I am definitely a macro newbie.

So I rented the RF 100 F2.8 macro several months ago, and I freaking loved it Definitely a learning curve, but by the time I had to send it back, I felt like I was starting to get the hang of it.

Anyway, I was mostly using focus stacking of like 30 to 200 frames... And it mostly worked.

However, about 20 or 30% of the time, it just flat failed..... So if get a block of 30 to 200 shots, with every single one OOF.

Is this the issue your speaking of ?

Focus shift is where you try to autofocus on a given point, and the camera actually focuses behind or in front of the object.

If you want to focus on anything planar, like text on a page or elsewhere, this would make the whole thing blurry. If you are taking a shot with depth, the focus will simply be at the wrong depth (vs. what you intended and where the AF says it is focusing).

If you look at this review: https://www.the-digital-picture.com/Reviews/Canon-RF-100mm-F2.8-L-Macro-IS-USM-Lens.aspx

Search for the words "Focus shift, the plane of sharp focus moving forward or backward as the aperture is narrowed" and just keep reading until that section is done (i.e. at "Next, we'll look at a comparison showing...").

They have images in there that illustrate precisely what is happening.

For this lens in particular, the older review copies at the very least focused behind the intended point in the shot (i.e. if you had a page of text, it will focus underneath the page, if that makes sense).

...

Separately, regarding focus bracketing, this focus shift issue should not cause it to fail. I don't think I can enumerate all the ways that focus bracketing can fail, but I would imagine the number of shots you selected vs. the shift increment conflicted for it to have a failure.

Thank you. It totally could have been user error. In fact, I hope it was, because that would be easier to fix

And I still do want the lens...

I would guess that is the main cause of a failure, but again can't give you anything definitive there.

I will say that 30-200 shots is almost certainly more shots than you need for almost any focus bracketing application. If you use a higher aperture number (i.e. farther from f/2.8), your depth of field is better and you don't need as many individual shots to get the whole scene in focus. That will save you a lot of storage and also processing time (if you process the RAWs).

 

[homebodyMacro]

Thank you. It totally could have been user error. In fact, I hope it was, because that would be easier to fix

And I still do want the lens...

No problem!

And if you want it, I think there might be an Amazon sale right now if I'm not mistaken (you might have to have a Prime account or the credit card though, so can't promise anything). EDIT: more on the sale/deal here: https://www.canonrumors.com/10-prime-card-bonus-on-select-canon-gear/

I really can't recommend it enough. I do need to expand my lens collection a bit, but it's such a good lens that I rarely take it off. It's incredibly sharp for all applications, not just macro, and with f/2.8 it can shoot pretty fast.

This review has an image of the MTF chart if you scroll down ( https://dustinabbott.net/2021/11/canon-rf-100mm-f2-8l-macro-is-usm/ ). It's extremely good.

You can also use this tool to compare it to other lenses: https://www.the-digital-picture.com...meraComp=979&SampleComp=0&FLIComp=0&APIComp=2

The EF version of the lens is on the right in that comparison (the RF is a bit sharper and has up to 1.4x magnification vs. 1.0).

 

[Chris Wolfgram]

Thank you. It totally could have been user error. In fact, I hope it was, because that would be easier to fix

And I still do want the lens...

No problem!

And if you want it, I think there might be an Amazon sale right now if I'm not mistaken (you might have to have a Prime account or the credit card though, so can't promise anything). EDIT: more on the sale/deal here: https://www.canonrumors.com/10-prime-card-bonus-on-select-canon-gear/

I really can't recommend it enough. I do need to expand my lens collection a bit, but it's such a good lens that I rarely take it off. It's incredibly sharp for all applications, not just macro, and with f/2.8 it can shoot pretty fast.

This review has an image of the MTF chart if you scroll down ( https://dustinabbott.net/2021/11/canon-rf-100mm-f2-8l-macro-is-usm/ ). It's extremely good.

You can also use this tool to compare it to other lenses: https://www.the-digital-picture.com...meraComp=979&SampleComp=0&FLIComp=0&APIComp=2

The EF version of the lens is on the right in that comparison (the RF is a bit sharper and has up to 1.4x magnification vs. 1.0).

I have an Amazon Prime acct, but I just spent $1900 on the 200-800.... So as much as I'd love to, it might be a while before I can get another lens....

--
Every day in the field is a blessing. Nice photos, of beautiful birds and wildlife are just a bonus.
https://www.flickr.com/photos/161603079@N02/page1
No time or attention given for negativity or trolls.

 

[charlyw64]

I'm sorry to ask such a novice (probably dumb) question, in a technical thread such as this...

But I am definitely a macro newbie.

So then you should stay clear of focus stacking for the foreseeable future (or even forget that function even exists). It doesn't do anything worthwhile except fill your disk with unusable data masses.

Anyway, I was mostly using focus stacking of like 30 to 200 frames... And it mostly worked.

I bet it didn't. Because you - as a macro newbie - didn't know where to look.

However, about 20 or 30% of the time, it just flat failed..... So if get a block of 30 to 200 shots, with every single one OOF.

I am willing to bet that you tried to stack hand held. That doesn't work - ever! For a stack to be feasible you:

- must be using a sturdy tripod.

- your subject must not move.

- your camera must not be touched during the stacking process

- you need to have short exposure times (< 1/1000)

- your subject must not have hair

- your subject must not have legs or feelers that overlap

- your subject must be in front of a distant background

- your subject must not be located on a detail rich perch

- your subject must not overlap the perch in any way.

- your subject must not have reflective surfaces.

I could continue the list but by this point all except cone shaped matted stones have been excluded. And no, no software can remedy the physically unavoidable defects that each of those points I listed will incur.

Is this the issue your speaking of ?

Nope.