Talk me out of it PLEASE

[Doormat]

For some stupid reason I’ve suddenly decided I “need“ a EF 300mm F4L IS !!
I already have all 4 versions of the EF 70-300mm ( L, Nano, IS & DO)
Plus the 100-400Lii.

I’ve got this idea in my head that the 300f4 with speedbooster on my M bodies will suddenly become an amazing 300/2.8L

I’m wrong aren’t I ?

Convince me why.
Also have a RP so again I’m imagining images that my current lenses can’t deliver.

Fun fact - I did buy the 300/4L IS a few years back but the clunk of the IS drove me insane. Hence sold it and bought the 100-400Lii

But now I’m questioning myself was it really that bad?

C’mon chaps, give me the brutal truth before I hit the buy it now button.

 

[AlanF]

For some stupid reason I’ve suddenly decided I “ need “ a EF 300mm F4L is !!
I already have all 4 versions of the EF 70-300mm ( L, nano, IS & DO)
Plus the 100-400Lii.

I’ve got this idea in my head that the 300f4 with speedbooster on my M bodies will suddenly become an amazing 300/2.8L

I’m wrong aren’t I ?

Convince me why.
Also have a RP so again I’m imagining images that my current lenses can’t deliver.

Fun fact - I did buy the 300/4Lis a few years back but the clunk of the IS drove me insane. Hence sold it and bought the 100-400Lii

But now I’m questioning myself was it really that bad?

C’mon chaps, give me the brutal truth before I hit the buy it now button.

It will become a 210/2.8 - the speed booster changes the focal length and f-number in parallel.

 

[neuroanatomist]

It will become a 210/2.8 - the speed booster changes the focal length and f-number in parallel.

The 200/2.8L II is a pretty nice lens, although the EF 70-200/2.8 II is better and the RF version better still (and although bulkier, it’s shorter than the adapted EF prime).

I wouldn’t recommend a 300/4 plus speedbooster over any of them, though.

 

[Doormat]

It will become a 210/2.8 - the speed booster changes the focal length and f-number in parallel.

Are you sure?
M6ii is a aps c
300 x 1.6 x .71 = 340
So wouldn’t it be a 340/2.8 with IS?

 

[Doormat]

The 200/2.8L II is a pretty nice lens, although the EF 70-200/2.8 II is better and the RF version better still (and although bulkier, it’s shorter than the adapted EF prime).

I wouldn’t recommend a 300/4 plus speedbooster over any of them, though.

I’ve got the 200/2.8ii & 70-200/2.8 is (V1)
But I’ve often wondered if the 300/4 on the M6ii with speedbooster could be a poor man’s 300/2.8

 

[AlanF]

Are you sure?
M6ii is a aps c
300 x 1.6 x .71 = 340
So wouldn’t it be a 340/2.8 with IS?

A 210mm lens is a 210mm lens whatever body it is on. You might argue that if it is on an APS-C body it has the field of view of a 340mm lens on FF. But, then you have to accept its f-number also effectively increases by 1.6x in terms of depth of field, S/N from sensor etc and is equivalent to f/4.5. on FF. So, it’s either a real man’s 210/2.8 or a poor man’s 340/4.5.

 

[neuroanatomist]

Are you sure?
M6ii is a aps c
300 x 1.6 x .71 = 340
So wouldn’t it be a 340/2.8 with IS?

If that is how you choose to interpret it, then simply mounting a 200/2.8 (via a regular mount adapter) on the M6II gives you a 320/2.8.

But I’ve often wondered if the 300/4 on the M6ii with speedbooster could be a poor man’s 300/2.8

It’s not. A crop sensor doesn’t magically increase focal length. It just captures a smaller area of the image circle, with a correspondingly narrower angle of view.

A speedboosted 300/4 gives you a 213/2.8 lens, which is not significantly different than a 200/2.8 lens. And you already have two of those. If you want to have a 3rd, well…it’s your money.

 

[Doormat]

If that is how you choose to interpret it, then simply mounting a 200/2.8 (via a regular mount adapter) on the M6II gives you a 320/2.8.


It’s not. A crop sensor doesn’t magically increase focal length. It just captures a smaller area of the image circle, with a correspondingly narrower angle of view.

A speedboosted 300/4 gives you a 213/2.8 lens, which is not significantly different than a 200/2.8 lens. And you already have two of those. If you want to have a 3rd, well…it’s your money.

Gotcha

Thank you

So am I right thinking the 200/2.8 will be optically better than the 300 + speedbooster?

 

[neuroanatomist]

So am I right thinking the 200/2.8 will be optically better than the 300 + speedbooster?

Most likely, yes. Adding optics between camera and lens (TC, speedbooster, adapter with optics) does not yield better optics than the bare lens, though it may not be much worse depending on the combination. Since the 300/4L IS, 200/2.8L, and 70-200/2.8L IS (MkI) deliver similar optical quality as bare lenses, the speedboosted 300/4 would not be better. It would have IS, but so does your 70-200.

 

[Doormat]

Most likely, yes. Adding optics between camera and lens (TC, speedbooster, adapter with optics) does not yield better optics than the bare lens, though it may not be much worse depending on the combination. Since the 300/4L IS, 200/2.8L, and 70-200/2.8L IS (MkI) deliver similar optical quality as bare lenses, the speedboosted 300/4 would not be better. It would have IS, but so does your 70-200.

Speaking of my 70-200
I’ve never been impressed with it wide open on either my 5diii or 6d/6dii
But, oh boy on the RP it’s a different lens, 2.8 is now totally useable.

 

[neuroanatomist]

Speaking of my 70-200
I’ve never been impressed with it wide open on either my 5diii or 6d/6dii
But, oh boy on the RP it’s a different lens, 2.8 is now totally useable.

The RP and 6DII share the same sensor. The likely reason IQ would be better on the RP is because the mirrorless cameras use the image sensor for AF, while DSLRs do not. Did you perform AF microadjustment on you lenses when you shot with DSLRs? With shallow DoF (as you’d get at 200/2.8 with a close subject), a bit of front- or back-focus can be a big problem.

 

[Longtermer]

The RP and 6DII share the same sensor. The likely reason IQ would be better on the RP is because the mirrorless cameras use the image sensor for AF, while DSLRs do not. Did you perform AF microadjustment on you lenses when you shot with DSLRs? With shallow DoF (as you’d get at 200/2.8 with a close subject), a bit of front- or back-focus can be a big problem.

Any general tips on doing that sort of microadjustment? I've never tried, but had it in the back of my mind that I really should ...

 

[neuroanatomist]

Any general tips on doing that sort of microadjustment? I've never tried, but had it in the back of my mind that I really should ...

Maybe a tip or two.

AF Microadjustment Tips

AF Microadjustment Tips

www.the-digital-picture.com

I wrote that a decade ago, prior to the existence of Reikan FoCal software that automates the process, which I used for several years prior to switching fully to mirrorless. I highly recommend Reikan FoCal.

 

[Longtermer]

Maybe a tip or two.

AF Microadjustment Tips

AF Microadjustment Tips

www.the-digital-picture.com

I wrote that a decade ago, prior to the existence of Reikan FoCal software that automates the process, which I used for several years prior to switching fully to mirrorless. I highly recommend Reikan FoCal.

Thank you! I'll read with interest - including re the software.

 

[Doormat]

The RP and 6DII share the same sensor. The likely reason IQ would be better on the RP is because the mirrorless cameras use the image sensor for AF, while DSLRs do not. Did you perform AF microadjustment on you lenses when you shot with DSLRs? With shallow DoF (as you’d get at 200/2.8 with a close subject), a bit of front- or back-focus can be a big problem.

No, I have several (more actually) bodies that I use rotationally. Be it Full Frame ( 5diii, 6d/6dii) for shallow depth of field, Crop (7d/7dii,80d/70d) to extend the reach. Smaller Crop (100d/200d) for lighter carry. Vintage DSLR,s (40d, 50d, 5dc, 1div) for their sensor interpretations.
More recently the M bodies and lastly the RP.
The thought of micro adjusting all for a single lens choice never appealed. Hence the arrival of the RP due in part of its full frame, EVF and AF off the sensor.
As much as I’m enjoying mirrorless I can’t give up my DSLR’s.
I adore the look of the files from the 1div. It’s currently paired with the sigma 30mm EX 1.4. The colours are just gorgeous and I cannot replicate with either the 24mm stm on crop or the 40mm on full frame both those lenses give the approximate view as the 1div/30mm combo.