[TwoUptons]

Someone in one of the CP+ translations suggested it was going to be lightweight and compact.

To me that suggests different optics from the 60-250, the Tokina, or the Tamron, as none of those are ‘lightweight’ , never mind the differences in focal length.

-Eric

[Socrateeze]

To do the modification I have to suggest not the forum thread but this article: Modifying the DA* 60-250mm F4 for Full Frame - Introduction - In-Depth Articles
What I did:

1. Remove the rear baffle
2. With a Dremel cut the circular border (I used the sand paper tool)
3. Paint the area with this: BLACK 2.0 - The world?s mattest, flattest, black art material by Stuar ? Culture Hustle
4. Reassemble

Now I have a spectacular 60-250 f/4.0...it is my most used lens that works also with film era cameras.

Very impressive photos, Andrea.

I want to ask a question fully recognizing that it is probably a very dumb question. ... If removing the baffle on the 60-250mm effectively lets a wider usable image through to be captured by the FF sensor (and doesn't it do that?), does this effectively make the focal range closer to 40-165mm in 35mm terms?

[Kunzite]

I want to ask a question fully recognizing that it is probably a very dumb question. ... If removing the baffle on the 60-250mm effectively lets a wider usable image through to be captured by the FF sensor (and doesn't it do that?), does this effectively make the focal range closer to 40-165mm in 35mm terms?

Ouch. Another "equivalence" victim.

There is no "focal range in 35mm terms".
You don't change a lens' focal length/range by putting it on a camera or another. You don't make a lens' focal length disappear by removing it from a camera.
You don't change a lens' focal length/range by removing a baffle. You simply remove a restriction, in effect reducing the vignetting presumably well enough in this case to successfully use the 60-250 without crop, on the K-1.
If you're asking about the field of view, it will be unchanged after this operation.

[Socrateeze]

Ouch. Another "equivalence" victim.

There is no "focal range in 35mm terms".
You don't change a lens' focal length/range by putting it on a camera or another. You don't make a lens' focal length disappear by removing it from a camera.
You don't change a lens' focal length/range by removing a baffle. You simply remove a restriction, in effect reducing the vignetting presumably well enough in this case to successfully use the 60-250 without crop, on the K-1.
If you're asking about the field of view, it will be unchanged after this operation.

I do realize that the optical or real focal length of a lens does not change when putting it on a different camera or when removing a baffle. However, as you obviously realize, a lens of a given focal length will not produce the same field of view when cast onto a different sized sensor, and the field of view is frequently or even typically expressed in terms of a proxy: in terms of a focal length on a FF sensor - hence "in 35mm terms". So an *optically* 18mm lens on an APS-C sensor camera will give a field of view roughly equivalent to an *optically* 28mm lens on a FF sensor, and so on. This is what I take to be meant and understood by saying something like "an 18mm lens on an APS-C camera is [equivalent to] a 28mm lens in FF/35mm terms". If interpreted pedantically, this would be incorrect, but, as with language generally, I take it that what really matters is whether we understand each other. So long as others understand this way of talking, there is no problem. What we care about and communicate concerns the field of view, but we communicate in terms of the focal lengths of lenses with a FF sensor. C'est la vie.

In any case, I'm not asking whether the field of view changes after the operation. I fully understand that all that the modification does is remove the vignetting that would be seen with a FF sensor. This, however, presumably increases the *usable* field of view - which is what I and I'm guessing most people really care about. What I am asking concerns whether the lens gives a *usable* field of view with a FF sensor that is greater than the *usable* field with an APS-C sensor. I ask this in part because B&H says of this lens "equivalent to an 90-375mm f/4.0 lens upon 35mm SLR cameras".

[monochrome]

Very impressive photos, Andrea.

I want to ask a question fully recognizing that it is probably a very dumb question. ... If removing the baffle on the 60-250mm effectively lets a wider usable image through to be captured by the FF sensor (and doesn't it do that?), does this effectively make the focal range closer to 40-165mm in 35mm terms?

On an APSc the 60-250 behaves as a 90-375 would on FF. On FF the 60-250 behaves as a 60–250 would on FF.

[Socrateeze]

On an APSc the 60-250 behaves as a 90-375 would on FF. On FF the 60-250 behaves as a 60–250 would on FF.

Thank you very much.

[Kunzite]

I do realize that the optical or real focal length of a lens does not change when putting it on a different camera or when removing a baffle. However, as you obviously realize, a lens of a given focal length will not produce the same field of view when cast onto a different sized sensor, and the field of view is frequently or even typically expressed in terms of a proxy: in terms of a focal length on a FF sensor - hence "in 35mm terms". So an *optically* 18mm lens on an APS-C sensor camera will give a field of view roughly equivalent to an *optically* 28mm lens on a FF sensor, and so on. This is what I take to be meant and understood by saying something like "an 18mm lens on an APS-C camera is [equivalent to] a 28mm lens in FF/35mm terms". If interpreted pedantically, this would be incorrect, but, as with language generally, I take it that what really matters is whether we understand each other. So long as others understand this way of talking, there is no problem. What we care about and communicate concerns the field of view, but we communicate in terms of the focal lengths of lenses with a FF sensor. C'est la vie.

In any case, I'm not asking whether the field of view changes after the operation. I fully understand that all that the modification does is remove the vignetting that would be seen with a FF sensor. This, however, presumably increases the *usable* field of view - which is what I and I'm guessing most people really care about. What I am asking concerns whether the lens gives a *usable* field of view with a FF sensor that is greater than the *usable* field with an APS-C sensor. I ask this in part because B&H says of this lens "equivalent to an 90-375mm f/4.0 lens upon 35mm SLR cameras".

Yet due to the theory's sheer - and undeserved - popularity, you're tricked into thinking about it. You try to apply it when you really shouldn't. You're reading and quoting the nonsense B&H wrote.

The 60-250mm is a 60-250mm, period; and removing a baffle does nothing to its angle of view on any specific format.
What it does, is increasing the lens' coverage. I never did that to my own 60-250 (preferring to replace it with the 150-450) but I've seen samples in which vignetting was minimal to negligible. Image quality outside of the APS-C area is another thing.

---------- Post added 10-03-19 at 12:13 PM ----------

On an APSc the 60-250 behaves as a 90-375 would on FF.

For an extremely narrow and twisted definition of "behaves" - making it refer only to the angle of view.

[repaap]

Yet due to the theory's sheer - and undeserved - popularity, you're tricked into thinking about it. You try to apply it when you really shouldn't. You're reading and quoting the nonsense B&H wrote.

The 60-250mm is a 60-250mm, period; and removing a baffle does nothing to its angle of view on any specific format.
What it does, is increasing the lens' coverage. I never did that to my own 60-250 (preferring to replace it with the 150-450) but I've seen samples in which vignetting was minimal to negligible. Image quality outside of the APS-C area is another thing.

---------- Post added 10-03-19 at 12:13 PM ----------


For an extremely narrow and twisted definition of "behaves" - making it refer only to the angle of view.

Oh, behave

[nocturnal]

It always amazes me how many photographers do not understand the crop factor...

A 50mm lens is a 50mm lens on both FF and APSC. On APSC the sensor can only see 2/3 of the FF image.

It is like zooming in 'cropping' in Lightroom. The 50mm lens does not behave like a 75mm lens, it behaves as a 50mm lens and we zoom in 1.5x to give 'only a FF equivalent field of view of 75mm' .

The 60-250 on APS-C 'only' has an equivalent Field Of View of 90-375mm on FF. It is not the same as using a 90-375mm on FF. A 90-375mm lens would obviously have more reach.

One advantage of APSC, say a 24MP is that is has smaller pixel density (this is a disadvantage too regarding dynamic range) so the FF equivalent would need to be 24MP x 2.25 = 54MP FF to achieve the same advantage regarding the crop sensor.

[Rondec]

There are plenty of threads out there that deal with equivalence. Big Mack had one not too long ago if anyone wants to go back down that rabbit hole. Suffice to say that some lenses cover a full frame sensor and some don't (most of the wide angle DA lenses don't). If they do and you mount the lens on a K-1 it will "see" a wider angle of view compare to when you mount it on a crop camera.

In this particular case, the 60-250 is close to being full frame compatible and after surgery mentioned earlier in this thread, the corners improve when it is shot on a K-1 or K-1 II.

[nocturnal]

There are plenty of threads out there that deal with equivalence. Big Mack had one not too long ago if anyone wants to go back down that rabbit hole. Suffice to say that some lenses cover a full frame sensor and some don't (most of the wide angle DA lenses don't). If they do and you mount the lens on a K-1 it will "see" a wider angle of view compare to when you mount it on a crop camera.

In this particular case, the 60-250 is close to being full frame compatible and after surgery mentioned earlier in this thread, the corners improve when it is shot on a K-1 or K-1 II.

No more rabbits, the info exists elsewhere.

What do you mean by improved corners on a K1? I thought DA lens corrections did not work on FF.

I have the 60-250 but not K1.

[Kunzite]

It can only mean less mechanical vignetting.

[Rondec]

No more rabbits, the info exists elsewhere.

What do you mean by improved corners on a K1? I thought DA lens corrections did not work on FF.

I have the 60-250 but not K1.

What Kunzite said. Less vignetting, maybe more sharpness. Nothing to do with lens corrections.

[nocturnal]

What Kunzite said. Less vignetting, maybe more sharpness. Nothing to do with lens corrections.

Ah right you mean the baffle mod. I'd love to see good photos with a K1 60-250, I'll need to have a look

TBH I am delighted it works as a FF lens if I ever get one that is, still to this day don't feel the need despite being a landscape photographer.

Snowing/sleeting/thunder lightning outside maybe that is why

[lytrytyr]

If you are going to do conversions, you could say that it functions the same as a 90-375 f5.6 full frame lens would when mounted on a crop camera. But I'm not sure we want to go there.

Ricoh does!

Fact-checking our thread's misinformation yesterday, I came across this gem:

"It provides a zoom ratio of approximately 2.9 times to cover a telephoto range from 107mm to 307mm in the 35mm format."

HD PENTAX-D FA?70-200mmF2.8ED DC AW / Telephoto Lenses / K-mount Lenses / Lenses / Products | RICOH IMAGING

And this in the specs for a full-frame lens!