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Canon R5 + RF 28-70mm Tips + Tubes

Started 3 weeks ago | Questions
Ephemeris
Ephemeris Senior Member • Posts: 1,186
Canon R5 + RF 28-70mm Tips + Tubes

Hi folks

Any tips or help for the use of this lens appreciated. It will replace an older EF 100 F2.8 lens and also an RF 28-105 F4 lens (I don't really like this lens - the EF was doing as much work for us).

The lack of IS is making me a little nervous and also that I can't use a TC.

Do any of you use this lens with extension tubes/rings? Is the AF still usable?

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Canon EOS R5
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Sittatunga Veteran Member • Posts: 5,406
Re: Canon R5 + RF 28-70mm Tips + Tubes
2

Ephemeris wrote:

Hi folks

Any tips or help for the use of this lens appreciated. It will replace an older EF 100 F2.8 lens and also an RF 28-105 F4 lens (I don't really like this lens - the EF was doing as much work for us).

The lack of IS is making me a little nervous and also that I can't use a TC.

It's a 28-70mm f/2, so the IBIS of your R5 should be sufficient, especially as that lens will give you two stops of speed over your EF 24-105mm.

Apart from perspective control lenses I can't see the point of putting a teleconverter behind any lens shorter than 135mm, maybe that's my lack of imagination. I'd rather put an R7 behind that lens than a TC, even if a TC were possible.

Canon don't do RF mount extension tubes yet and it's not compatible with EF tubes. The shortest third-party (11mm) tube I can find will probably focus impossibly close at 28mm and to, at most, a couple of feet from the sensor at 70mm, so it's not a lens I would use with extension tubes. The AF should still be usable, but there's really no point. That lens does focus a couple of inches (50mm) closer than the EF 24-105mm L lenses though.

Do any of you use this lens with extension tubes/rings? Is the AF still usable?

Ephemeris
OP Ephemeris Senior Member • Posts: 1,186
Re: Canon R5 + RF 28-70mm Tips + Tubes

Sittatunga wrote:

Ephemeris wrote:

Hi folks

Any tips or help for the use of this lens appreciated. It will replace an older EF 100 F2.8 lens and also an RF 28-105 F4 lens (I don't really like this lens - the EF was doing as much work for us).

The lack of IS is making me a little nervous and also that I can't use a TC.

It's a 28-70mm f/2, so the IBIS of your R5 should be sufficient, especially as that lens will give you two stops of speed over your EF 24-105mm.

The shouldnt is the logical concept but I'm still nervous.

It's an RF 24-205 and screwed up because of my 28 typo, sorry about that but can edit it.

Apart from perspective control lenses I can't see the point of putting a teleconverter behind any lens shorter than 135mm, maybe that's my lack of imagination. I'd rather put an R7 behind that lens than a TC, even if a TC were possible.

We have two R5 bodies and not an R7 (after much reading I don't think it would help us)

With a TC 1.4 we are very close to 100mm which would help to have a similar viewing angle to the EF100mm but as I understand it's not possible

Being able to put a TC on can be helpful. We use it a lot on EF 70-200 and why we can't use the RF.

Canon don't do RF mount extension tubes yet and it's not compatible with EF tubes. The shortest third-party (11mm) tube I can find will probably focus impossibly close at 28mm and to, at most, a couple of feet from the sensor at 70mm, so it's not a lens I would use with extension tubes. The AF should still be usable, but there's really no point. That lens does focus a couple of inches (50mm) closer than the EF 24-105mm L lenses though

I use tubes a lot with the EF100 and EF70-200. When trying to maximise the frame size of a failed bolt they are golden, use them everyday.

I thought the minimum focus is 39cm which is at the wide end I'm not sure at the long end.

Kenko appear to have some but this is just two tubes (not sure why not 3).

https://www.speedgraphic.co.uk/extension_tubes__adapters/kenko_dg_extension_tube_set_canon_rf/29453_p.html

Do any of you use this lens with extension tubes/rings? Is the AF still usable?

Sittatunga Veteran Member • Posts: 5,406
Re: Canon R5 + RF 28-70mm Tips + Tubes

Ephemeris wrote:

Sittatunga wrote:

Ephemeris wrote:

Hi folks

Any tips or help for the use of this lens appreciated. It will replace an older EF 100 F2.8 lens and also an RF 28-105 F4 lens (I don't really like this lens - the EF was doing as much work for us).

The lack of IS is making me a little nervous and also that I can't use a TC.

It's a 28-70mm f/2, so the IBIS of your R5 should be sufficient, especially as that lens will give you two stops of speed over your EF 24-105mm.

The shouldnt is the logical concept but I'm still nervous.

It's an RF 24-205 and screwed up because of my 28 typo, sorry about that but can edit it.

The title said 28-70mm, not 24-105mm.  There isn't an RF 24-205mm, the RF 24-240mm IS is a different class of lens, and the RF 24-70mm has IS. The only other ways you'll get native RF 100mm are with the macro lens (with adjustable spherical aberration but nobody seems to have made that feature work for portraiture), either RF 70-200mm lens (neither of which can take teleconverters), the 100-400mm f/5.6-8 or the 100-500mm f/4.5-7.1 (which can't take a TC if it's set to shorter than 300mm).

Apart from perspective control lenses I can't see the point of putting a teleconverter behind any lens shorter than 135mm, maybe that's my lack of imagination. I'd rather put an R7 behind that lens than a TC, even if a TC were possible.

We have two R5 bodies and not an R7 (after much reading I don't think it would help us)

32Mpx, IBIS, self leveling horizon and effective 45-110mm f/3.2 or 40-110mm f/4.5 sounds reasonably close to what you would achieve with a TC behind a standard zoom were that possible, and I'd have thought it would give better image quality.

With a TC 1.4 we are very close to 100mm which would help to have a similar viewing angle to the EF100mm but as I understand it's not possible

Being able to put a TC on can be helpful. We use it a lot on EF 70-200 and why we can't use the RF.

Canon don't do RF mount extension tubes yet and it's not compatible with EF tubes. The shortest third-party (11mm) tube I can find will probably focus impossibly close at 28mm and to, at most, a couple of feet from the sensor at 70mm, so it's not a lens I would use with extension tubes. The AF should still be usable, but there's really no point. That lens does focus a couple of inches (50mm) closer than the EF 24-105mm L lenses though

I use tubes a lot with the EF100 and EF70-200. When trying to maximise the frame size of a failed bolt they are golden, use them everyday.

11mm is about the shortest you can buy with electrical contacts. It makes sense with 70mm (about ⅙ life size) but not with a standard zoom. You'll just be too close to light a failed bolt using a standard zoom with extension tubes,

I thought the minimum focus is 39cm which is at the wide end I'm not sure at the long end.

Kenko appear to have some but this is just two tubes (not sure why not 3).

https://www.speedgraphic.co.uk/extension_tubes__adapters/kenko_dg_extension_tube_set_canon_rf/29453_p.html

Do any of you use this lens with extension tubes/rings? Is the AF still usable?

Ephemeris
OP Ephemeris Senior Member • Posts: 1,186
Re: Canon R5 + RF 28-70mm Tips + Tubes

Sittatunga wrote:

Ephemeris wrote:

Sittatunga wrote:

Ephemeris wrote:

Hi folks

Any tips or help for the use of this lens appreciated. It will replace an older EF 100 F2.8 lens and also an RF 28-105 F4 lens (I don't really like this lens - the EF was doing as much work for us).

The lack of IS is making me a little nervous and also that I can't use a TC.

It's a 28-70mm f/2, so the IBIS of your R5 should be sufficient, especially as that lens will give you two stops of speed over your EF 24-105mm.

The shouldnt is the logical concept but I'm still nervous.

It's an RF 24-205 and screwed up because of my 28 typo, sorry about that but can edit it.

The title said 28-70mm, not 24-105mm.

The title is correct.

I also mentioned our EF100 and RF 28-105 (typo for 24 - 105).

I've not mentioned a 24-205.

There isn't an RF 24-205mm, the RF 24-240mm IS is a different class of lens, and the RF 24-70mm has IS.

The 28-70 (F2) as in the title doesn't ha s IS.

Thehe only other ways you'll get native RF 100mm are with the macro lens (with adjustable spherical aberration but nobody seems to have made that feature work for portraiture),

The RF 100mm f2.8 doesn't seem to offer very much over the EF we have and won't accept a TC.

either RF 70-200mm lens (neither of which can take teleconverters),

Yes I made that point as a reason we won't buy one.

the 100-400mm f/5.6-8 or the 100-500mm f/4.5-7.1 (which can't take a TC if it's set to shorter than 300mm).

Apart from perspective control lenses I can't see the point of putting a teleconverter behind any lens shorter than 135mm, maybe that's my lack of imagination. I'd rather put an R7 behind that lens than a TC, even if a TC were possible.

We have two R5 bodies and not an R7 (after much reading I don't think it would help us)

32Mpx, IBIS, self leveling horizon and effective 45-110mm f/3.2 or 40-110mm f/4.5 sounds reasonably close to what you would achieve with a TC behind a standard zoom were that possible, and I'd have thought it would give better image quality.

We only have two R5 full frame bodies and the R7 isn't a consideration after discussion, reading and investigation. The solution must be for full frame.

With a TC 1.4 we are very close to 100mm which would help to have a similar viewing angle to the EF100mm but as I understand it's not possible

Being able to put a TC on can be helpful. We use it a lot on EF 70-200 and why we can't use the RF.

Canon don't do RF mount extension tubes yet and it's not compatible with EF tubes. The shortest third-party (11mm) tube I can find will probably focus impossibly close at 28mm and to, at most, a couple of feet from the sensor at 70mm, so it's not a lens I would use with extension tubes. The AF should still be usable, but there's really no point. That lens does focus a couple of inches (50mm) closer than the EF 24-105mm L lenses though

I use tubes a lot with the EF100 and EF70-200. When trying to maximise the frame size of a failed bolt they are golden, use them everyday.

11mm is about the shortest you can buy with electrical contacts. It makes sense with 70mm (about ⅙ life size) but not with a standard zoom. You'll just be too close to light a failed bolt using a standard zoom with extension tubes,

It's more that it is only 2 tubes not 3 tubes so the maximum length is limited rather than minimum.

We use all 3 tubes in the EF100 regularly for day to day work.

I thought the minimum focus is 39cm which is at the wide end I'm not sure at the long end.

Kenko appear to have some but this is just two tubes (not sure why not 3).

https://www.speedgraphic.co.uk/extension_tubes__adapters/kenko_dg_extension_tube_set_canon_rf/29453_p.html

Do any of you use this lens with extension tubes/rings? Is the AF still usable?

Sittatunga Veteran Member • Posts: 5,406
Re: Canon R5 + RF 28-70mm Tips + Tubes

Ephemeris wrote:

Sittatunga wrote:

Ephemeris wrote:

Sittatunga wrote:

Ephemeris wrote:

Hi folks

Any tips or help for the use of this lens appreciated. It will replace an older EF 100 F2.8 lens and also an RF 28-105 F4 lens (I don't really like this lens - the EF was doing as much work for us).

The lack of IS is making me a little nervous and also that I can't use a TC.

It's a 28-70mm f/2, so the IBIS of your R5 should be sufficient, especially as that lens will give you two stops of speed over your EF 24-105mm.

The shouldnt is the logical concept but I'm still nervous.

It's an RF 24-205 and screwed up because of my 28 typo, sorry about that but can edit it.

The title said 28-70mm, not 24-105mm.

The title is correct.

I also mentioned our EF100 and RF 28-105 (typo for 24 - 105).

I've not mentioned a 24-205.

You did when you said

It's an RF 24-205 and screwed up because of my 28 typo, sorry about that but can edit it.

There isn't an RF 24-205mm, the RF 24-240mm IS is a different class of lens, and the RF 24-70mm has IS.

The 28-70 (F2) as in the title doesn't ha s IS.

I know, but the R5 has up to 5 stops of IBIS, which is why I don't think there will be a problem with a lens which is two stops faster than your EF 24-105.

The only other ways you'll get native RF 100mm are with the macro lens (with adjustable spherical aberration but nobody seems to have made that feature work for portraiture),

The RF 100mm f2.8 doesn't seem to offer very much over the EF we have and won't accept a TC.

It offers 1.4x macro, which would be equivalent to either of the EF 100mm macros set to 1:1 with  40mm of extension tubes behind it (if either were still actually 100mm focal length when set to 1:1). Neither of the EF 100mm macros are supported by the Series III EF Extenders (teleconverters) either.

either RF 70-200mm lens (neither of which can take teleconverters),

Yes I made that point as a reason we won't buy one.

the 100-400mm f/5.6-8 or the 100-500mm f/4.5-7.1 (which can't take a TC if it's set to shorter than 300mm).

Apart from perspective control lenses I can't see the point of putting a teleconverter behind any lens shorter than 135mm, maybe that's my lack of imagination. I'd rather put an R7 behind that lens than a TC, even if a TC were possible.

We have two R5 bodies and not an R7 (after much reading I don't think it would help us)

32Mpx, IBIS, self levelling horizon and effective 45-110mm f/3.2 or 40-110mm f/4.5 sounds reasonably close to what you would achieve with a TC behind a standard zoom were that possible, and I'd have thought it would give better image quality.

We only have two R5 full frame bodies and the R7 isn't a consideration after discussion, reading and investigation. The solution must be for full frame.

In that case I would suggest you continue to use your EF 100mm macro for photographing broken bolts.  Or buy an EF mount Canon MP-E 65mm f/2.8 1-5x Macro, but that's manual focus and just over £1000 new, so you might want a focussing rail as well.  A TC behind a standard zoom isn't a solution to your requirements.

With a TC 1.4 we are very close to 100mm which would help to have a similar viewing angle to the EF100mm but as I understand it's not possible

Being able to put a TC on can be helpful. We use it a lot on EF 70-200 and why we can't use the RF.

Canon don't do RF mount extension tubes yet and it's not compatible with EF tubes. The shortest third-party (11mm) tube I can find will probably focus impossibly close at 28mm and to, at most, a couple of feet from the sensor at 70mm, so it's not a lens I would use with extension tubes. The AF should still be usable, but there's really no point. That lens does focus a couple of inches (50mm) closer than the EF 24-105mm L lenses though

I use tubes a lot with the EF100 and EF70-200. When trying to maximise the frame size of a failed bolt they are golden, use them everyday.

11mm is about the shortest you can buy with electrical contacts. It makes sense with 70mm (about ⅙ life size) but not with a standard zoom. You'll just be too close to light a failed bolt using a standard zoom with extension tubes,

It's more that it is only 2 tubes not 3 tubes so the maximum length is limited rather than minimum.

We use all 3 tubes in the EF100 regularly for day to day work.

A standard zoom is definitely not the tool for the job if you need that much magnification, and I would have thought a focussing rail was more use than AF for that case.

I thought the minimum focus is 39cm which is at the wide end I'm not sure at the long end.

Kenko appear to have some but this is just two tubes (not sure why not 3).

https://www.speedgraphic.co.uk/extension_tubes__adapters/kenko_dg_extension_tube_set_canon_rf/29453_p.html

Do any of you use this lens with extension tubes/rings? Is the AF still usable?

Ephemeris
OP Ephemeris Senior Member • Posts: 1,186
Re: Canon R5 + RF 28-70mm Tips + Tubes

Sittatunga wrote:

Ephemeris wrote:

Sittatunga wrote:

Ephemeris wrote:

Sittatunga wrote:

Ephemeris wrote:

Hi folks

Any tips or help for the use of this lens appreciated. It will replace an older EF 100 F2.8 lens and also an RF 28-105 F4 lens (I don't really like this lens - the EF was doing as much work for us).

The lack of IS is making me a little nervous and also that I can't use a TC.

It's a 28-70mm f/2, so the IBIS of your R5 should be sufficient, especially as that lens will give you two stops of speed over your EF 24-105mm.

The shouldnt is the logical concept but I'm still nervous.

It's an RF 24-205 and screwed up because of my 28 typo, sorry about that but can edit it.

The title said 28-70mm, not 24-105mm.

The title is correct.

I also mentioned our EF100 and RF 28-105 (typo for 24 - 105).

I've not mentioned a 24-205.

You did when you said

It's an RF 24-205 and screwed up because of my 28 typo, sorry about that but can edit it.

There isn't an RF 24-205mm, the RF 24-240mm IS is a different class of lens, and the RF 24-70mm has IS.

Hopefully you are clear which lenses I am referring to now?

The 28-70 (F2) as in the title doesn't ha s IS.

I know, but the R5 has up to 5 stops of IBIS, which is why I don't think there will be a problem with a lens which is two stops faster than your EF 24-105.

It is but it's one stop faster than my EF 70-200 to which I don't switch it off at 70mm. Many have said it's not a problem but I haven't seen very many dynamic situation users. The 24-70 2.8 has IS for example.

I'm not saying your wrong but nervous.

The only other ways you'll get native RF 100mm are with the macro lens (with adjustable spherical aberration but nobody seems to have made that feature work for portraiture),

The RF 100mm f2.8 doesn't seem to offer very much over the EF we have and won't accept a TC.

It offers 1.4x macro, which would be equivalent to either of the EF 100mm macros set to 1:1 with 40mm of extension tubes behind it (if either were still actually 100mm focal length when set to 1:1). Neither of the EF 100mm macros are supported by the Series III EF Extenders (teleconverters) either.

https://www.dpreview.com/forums/thread/2040941

Fairly sure we don't have a problem.  The EF we have is the USM Macro (no IS).

either RF 70-200mm lens (neither of which can take teleconverters),

Yes I made that point as a reason we won't buy one.

the 100-400mm f/5.6-8 or the 100-500mm f/4.5-7.1 (which can't take a TC if it's set to shorter than 300mm).

Apart from perspective control lenses I can't see the point of putting a teleconverter behind any lens shorter than 135mm, maybe that's my lack of imagination. I'd rather put an R7 behind that lens than a TC, even if a TC were possible.

We have two R5 bodies and not an R7 (after much reading I don't think it would help us)

32Mpx, IBIS, self levelling horizon and effective 45-110mm f/3.2 or 40-110mm f/4.5 sounds reasonably close to what you would achieve with a TC behind a standard zoom were that possible, and I'd have thought it would give better image quality.

We only have two R5 full frame bodies and the R7 isn't a consideration after discussion, reading and investigation. The solution must be for full frame.

In that case I would suggest you continue to use your EF 100mm macro for photographing broken bolts. Or buy an EF mount Canon MP-E 65mm f/2.8 1-5x Macro, but that's manual focus and just over £1000 new, so you might want a focussing rail as well. A TC behind a standard zoom isn't a solution to your requirements.

The MPE-E isn't something I can sensibly use in the field, especially without AF. My question was how well the AF would continue to work using tubes. This is what we do now, day in, day out.

I also use a 1.4x on a 70-200 and a 100-400 so why wouldn't I use a TC on a zoom? What are those people taking images of wildlife using them for?

With a TC 1.4 we are very close to 100mm which would help to have a similar viewing angle to the EF100mm but as I understand it's not possible

Being able to put a TC on can be helpful. We use it a lot on EF 70-200 and why we can't use the RF.

Canon don't do RF mount extension tubes yet and it's not compatible with EF tubes. The shortest third-party (11mm) tube I can find will probably focus impossibly close at 28mm and to, at most, a couple of feet from the sensor at 70mm, so it's not a lens I would use with extension tubes. The AF should still be usable, but there's really no point. That lens does focus a couple of inches (50mm) closer than the EF 24-105mm L lenses though

I use tubes a lot with the EF100 and EF70-200. When trying to maximise the frame size of a failed bolt they are golden, use them everyday.

11mm is about the shortest you can buy with electrical contacts. It makes sense with 70mm (about ⅙ life size) but not with a standard zoom. You'll just be too close to light a failed bolt using a standard zoom with extension tubes,

It's more that it is only 2 tubes not 3 tubes so the maximum length is limited rather than minimum.

We use all 3 tubes in the EF100 regularly for day to day work.

A standard zoom is definitely not the tool for the job if you need that much magnification, and I would have thought a focussing rail was more use than AF for that case.

I thought the minimum focus is 39cm which is at the wide end I'm not sure at the long end.

Kenko appear to have some but this is just two tubes (not sure why not 3).

https://www.speedgraphic.co.uk/extension_tubes__adapters/kenko_dg_extension_tube_set_canon_rf/29453_p.html

Do any of you use this lens with extension tubes/rings? Is the AF still usable?

Sittatunga Veteran Member • Posts: 5,406
Re: Canon R5 + RF 28-70mm Tips + Tubes
1

Ephemeris wrote:

Hi folks

Any tips or help for the use of this lens appreciated. It will replace an older EF 100 F2.8 lens and also an RF 28-105 F4 lens (I don't really like this lens - the EF was doing as much work for us).

The lack of IS is making me a little nervous and also that I can't use a TC.

Do any of you use this lens with extension tubes/rings? Is the AF still usable?

What size objects are you trying to photograph in the field?  Your current macro lens will AF down to a field of view of just over 36x24mm without tubes, while the RF macro will go to just over 22x15mm without tubes.  Neither will work with a Canon Extender (TC) without an extension tube between lens and TC, because the TCs penetrate further into the lens mount than the rear elements are recessed.  The RF macro has the advantage that its IS is designed to work in conjunction with your camera's IBIS; the EF 100mm L macro's wasn't, because IBIS wasn't a consideration for Canon when it was introduced in 2009.

First, a 28-70mm standard zoom is definitely not a replacement for a macro lens.  You can't use it with an RF mount teleconverter, because Canon's teleconverters penetrate something like 17mm inside the lens' mount and the rear element is only recessed about 4mm.  It would work if you mounted it on a 16mm extension tube, but then the maximum focusable distance would range from less than 300mm from the front of the lens at 70mm to  somewhere within the filter threads at the wide end.  The lens would work with extension tubes, but a standard zoom lens is a bit of a nightmare with extension tubes and almost impossible to calculate tube length and focus in the field because of its length.

Even if somebody were to produce an RF mount TC without protruding front elements, a 1.4x would turn it into a 40-100mm f/2.8  with probably noticeably worse performance than the RF 24-105mm f/4 and certainly more than twice the weight. A 2x TC would give you a heavy (1kg heavier than the RF 70-200mm f/4)  56-140mm f/4.  I'm sure an R7 would give better quality with this lens than an R5 + a third-party TC. TCs have their place with long lenses if you're trying to get more reach, but they don't really work with standard lenses.

Ephemeris
OP Ephemeris Senior Member • Posts: 1,186
Re: Canon R5 + RF 28-70mm Tips + Tubes

Sittatunga wrote:

Ephemeris wrote:

Hi folks

Any tips or help for the use of this lens appreciated. It will replace an older EF 100 F2.8 lens and also an RF 28-105 F4 lens (I don't really like this lens - the EF was doing as much work for us).

The lack of IS is making me a little nervous and also that I can't use a TC.

Do any of you use this lens with extension tubes/rings? Is the AF still usable?

What size objects are you trying to photograph in the field?

It depends. It can be the pintle of an injector, a foreign object within a conformal coat or an entire active suspension corner.

I did pass you a link regarding TCs in the 100mm EF. We certainly use a TC with it (I have said this already).

So from tubes to TCs and just natural.

Your current macro lens will AF down to a field of view of just over 36x24mm without tubes, while the RF macro will go to just over 22x15mm without tubes. Neither will work with a Canon Extender (TC) without an extension tube between lens and TC, because the TCs penetrate further into the lens mount than the rear elements are recessed.

I've coved the TC above and previously passed a DPReview link on the topic.

The RF macro has the advantage that its IS is designed to work in conjunction with your camera's IBIS; the EF 100mm L macro's wasn't, because IBIS wasn't a consideration for Canon when it was introduced in 2009.

The RF macro won't allow a TC which is a mallace.

The 1.5x magnification is certainly a bonus, a big one for us.

The likely improved AF speed a bonus.

The likely improved image stability via the IS and IBIS a bonus.

However. The EF100 would be sold, the RF 24-105 sold (we are not a fan at all of this lens) to provide some funds.

First, a 28-70mm standard zoom is definitely not a replacement for a macro lens.

I'm not trying to replace it but some of its function will be covered by the new lens.

You can't use it with an RF mount teleconverter,

Agreed but I covered this.

because Canon's teleconverters penetrate something like 17mm inside the lens' mount and the rear element is only recessed about 4mm.

It would work if you mounted it on a 16mm extension tube, but then the maximum focusable distance would range from less than 300mm from the front of the lens at 70mm to somewhere within the filter threads at the wide end.

I hadn't considered adding a tube but we don't have an RF TC so that may be why I hadn't given it a thought. Helpful information tbought. Nice to have some fresh thoughts.

The lens would work with extension tubes, but a standard zoom lens is a bit of a nightmare with extension tubes and almost impossible to calculate tube length and focus in the field because of its length.

Do I need to calculate it? Let's say a 16mm tube is added then I can assess if it's helpful or not.

The question is how it may affect the AF.

Even if somebody were to produce an RF mount TC without protruding front elements, a 1.4x would turn it into a 40-100mm f/2.8 with probably noticeably worse performance than the RF 24-105mm f/4 and certainly more than twice the weight.

Sometimes slightly better, slightly worse isn't the throught process it's about can it, will it to allow me the opportunity.

The opportunity is king here.

Weight - well EF-100 400, TC, R5 and grip, flask, laptop etc. Just have to bite my lip and moan.

A 2x TC would give you a heavy (1kg heavier than the RF 70-200mm f/4) 56-140mm f/4.

Having the close to 100mm field of view would be the need for the 1.4x TC. But I could cover it with the EF-70 200 so that's probably the logical way to go

I'm sure an R7 would give better quality with this lens than an R5 + a third-party TC.

An R7 isn't going to be on the cards. Investigated to death. Just not the machine for us.

R5II or better still something with a big jump in resolution. Whichever it will cause a lot of process changes and validation so I won't be in a hurry to spend as soon as it arrives. If it needs a different grip for instance then that's a bit more of a head scratcher.

All that said I would think you are right. But it's back to opportunity - we have one thing not the other.

TCs have their place with long lenses if you're trying to get more reach, but they don't really work with standard lenses.

I appreciate what your saying. We currently use a TC1.4 and from what I am reading from you it's likely not always the best optical decision.

Appreciate all the effort you have gone to at a weekend to help me. If you are ever at a loose end in West Yorkshire I'm sure we would benefit from you knowledge.

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