Cropping for larger depth of field

[Frank_GH]

Hi,

Moving away from a subject, and then cropping the picture is a way of taking advantage of a wide aperture (in dark situations) while keeping the DOF a little larger. In a 24 megapixel photo (6000x4000 pixels), the 1/3 of the picture has 2000x1333, which is okay for a 1920x1080 screen. But from my experiments, the quality of the image is much worse than if I crop half a 3936x2624 picture (getting 1968x1312 pixels, which is also fine for a 1080p screen).

Is there such a limit to cropping ability (other than the number of pixels, which is not a problem in both examples above)?

In case it's relevant, I'm using the Sony a7iii.

 

[ThrillaMozilla]

Well, this is a topic that most of us don't think about much. This was an opportunity to solidify the concepts in our heads too. I could have used the information this weekend. Thanks for your good attitude.

 

[Christof21]

Hello,

Here is a graph comparing the 2 different strategies.

It is the size of the airy disc (the degree of blur) depending on the distance behind the subject

• Original picture (1):

focussed at 1 meter, focal = 35mm f/4

• Taken from further away (2)

focussed at 2 meters, focal = 35mmf/4, cropped x2

Or equivalently: focal=70mm f/8 uncropped

• Stopped down (3):

focussed at 1 meter focal=35mm f/8

You see the degree of blur. The unit for absciss is meter, the ordonate is millimeter.



The red line corresponds to the FF CoC, this means that the part below this line is considered to be sharp.

Conclusions:

The shot taken from further away does increase dof compared to the original shot (it becomes more blurry sooner). The background blur at infinity tends to the same limit

The shot taken stopped down has the same dof than shot further away. You see that the orange and green curve have the same slope around 0, so the part below the red line is roughly the same. At infinity, the background will be less blurry.

Remark: the strategy

Hope this helps,

Chris

 

[Frank_GH]

Hello,

Here is a graph comparing the 2 different strategies.

It is the size of the airy disc (the degree of blur) depending on the distance behind the subject

• Original picture (1):

focussed at 1 meter, focal = 35mm f/4

• Taken from further away (2)

focussed at 2 meters, focal = 35mmf/4, cropped x2

Or equivalently: focal=70mm f/8 uncropped

• Stopped down (3):

focussed at 1 meter focal=35mm f/8

You see the degree of blur. The unit for absciss is meter, the ordonate is millimeter.



The red line corresponds to the FF CoC, this means that the part below this line is considered to be sharp.

Conclusions:

The shot taken from further away does increase dof compared to the original shot (it becomes more blurry sooner). The background blur at infinity tends to the same limit

The shot taken stopped down has the same dof than shot further away. You see that the orange and green curve have the same slope around 0, so the part below the red line is roughly the same. At infinity, the background will be less blurry.

I really appreciate this, since I'm a visual learner. Thanks

Remark: the strategy

?

Hope this helps,

Chris

 

[Tom Axford]

To summarise:

Your method of moving further away and cropping to compensate (while keeping the camera and lens at the same settings otherwise) is a good method for increasing the depth of field. The depth of field increases in proportion to the distance from your subject. So, if you double the distance and crop by a factor of 2 (so you get one quarter as many pixels), the depth of field is doubled.

But, and it is a big but, this method works only if the final image quality is acceptable. Cropping always reduces image quality (measured relative to the size of the image). You need to decide how much cropping is acceptable for your camera and lens and the quality you expect in the final image. Cropping by a factor of 2 may be acceptable, but a factor of 3 may lead to too much loss of quality.

It all depends on the circumstances; particularly the camera, lens, aperture setting, and how much final image quality you want. You really need to decide on the maximum level of cropping that works for you.

 

[ThrillaMozilla]

To summarise:

Your method of moving further away and cropping to compensate (while keeping the camera and lens at the same settings otherwise) is a good method for increasing the depth of field.

No it isn't. It's better to stop down and either increase the exposure time or the ISO setting.

The depth of field increases in proportion to the distance from your subject. So, if you double the distance and crop by a factor of 2 (so you get one quarter as many pixels), the depth of field is doubled.

But, and it is a big but, this method works only if the final image quality is acceptable. Cropping always reduces image quality (measured relative to the size of the image). You need to decide how much cropping is acceptable for your camera and lens and the quality you expect in the final image. Cropping by a factor of 2 may be acceptable, but a factor of 3 may lead to too much loss of quality.

Choose the distance based on composition or perspective, but not on the basis of depth of field.

It all depends on the circumstances; particularly the camera, lens, aperture setting, and how much final image quality you want. You really need to decide on the maximum level of cropping that works for you.

No it doesn't. There is always an image-quality penalty.

 

[Tom Axford]

To summarise:

Your method of moving further away and cropping to compensate (while keeping the camera and lens at the same settings otherwise) is a good method for increasing the depth of field.

No it isn't. It's better to stop down and either increase the exposure time or the ISO setting.

You are being very contrary!

The OP implied that he wished to maintain the camera settings. If that is the case, moving further away and cropping works perfectly well subject to the proviso made later about image quality. I have used it many times myself.

The depth of field increases in proportion to the distance from your subject. So, if you double the distance and crop by a factor of 2 (so you get one quarter as many pixels), the depth of field is doubled.

But, and it is a big but, this method works only if the final image quality is acceptable. Cropping always reduces image quality (measured relative to the size of the image). You need to decide how much cropping is acceptable for your camera and lens and the quality you expect in the final image. Cropping by a factor of 2 may be acceptable, but a factor of 3 may lead to too much loss of quality.

Choose the distance based on composition or perspective, but not on the basis of depth of field.

Are you suggesting that that is some fundamental rule of photography? Frankly, you are talking nonsense.

It all depends on the circumstances; particularly the camera, lens, aperture setting, and how much final image quality you want. You really need to decide on the maximum level of cropping that works for you.

No it doesn't. There is always an image-quality penalty.

So what? If the image quality is fully acceptable, there is no benefit in improving it further.

That is just being pragmatic and using common sense.

 

[Christof21]

To summarise:

Your method of moving further away and cropping to compensate (while keeping the camera and lens at the same settings otherwise) is a good method for increasing the depth of field.

No it isn't. It's better to stop down and either increase the exposure time or the ISO setting.

You are being very contrary!

The OP implied that he wished to maintain the camera settings

I think the question is more if he has only a fixed focal lens that he wants to use absolutely or a zoom.

It is better to use a longer FL than cropping unless again he has not the choice.

 

[Tom Axford]

To summarise:

Your method of moving further away and cropping to compensate (while keeping the camera and lens at the same settings otherwise) is a good method for increasing the depth of field.

No it isn't. It's better to stop down and either increase the exposure time or the ISO setting.

You are being very contrary!

The OP implied that he wished to maintain the camera settings

I think the question is more if he has only a fixed focal lens that he wants to use absolutely or a zoom.

It is better to use a longer FL than cropping unless again he has not the choice.

Hopefully, the OP will tell us what he wishes to do and why. I may have read something into his OP that wasn't intended.

 

[ThrillaMozilla]

To summarise:

Your method of moving further away and cropping to compensate (while keeping the camera and lens at the same settings otherwise) is a good method for increasing the depth of field.

No it isn't. It's better to stop down and either increase the exposure time or the ISO setting.

You are being very contrary!

No, I'm just telling you the best way to do it. *

Sorry, I was going to edit that post to take the edge off, but it was too late.

The OP implied that he wished to maintain the camera settings.

That was just an assumption. He was actually trying to increase the depth of field and maintain image quality. His goal wasn't to maintain camera settings.

If that is the case, moving further away and cropping works perfectly well subject to the proviso made later about image quality. I have used it many times myself.

That's an old holdover from the film era. It works -- sort of -- but now there's a better way. *

The depth of field increases in proportion to the distance from your subject. So, if you double the distance and crop by a factor of 2 (so you get one quarter as many pixels), the depth of field is doubled.

But, and it is a big but, this method works only if the final image quality is acceptable. Cropping always reduces image quality (measured relative to the size of the image). You need to decide how much cropping is acceptable for your camera and lens and the quality you expect in the final image. Cropping by a factor of 2 may be acceptable, but a factor of 3 may lead to too much loss of quality.

Choose the distance based on composition or perspective, but not on the basis of depth of field.

Are you suggesting that that is some fundamental rule of photography? Frankly, you are talking nonsense.

It's a darned good suggestion, based on fundamental laws of optics. What do you think this topic is about?

It all depends on the circumstances; particularly the camera, lens, aperture setting, and how much final image quality you want. You really need to decide on the maximum level of cropping that works for you.

No it doesn't. There is always an image-quality penalty.

So what? If the image quality is fully acceptable, there is no benefit in improving it further.

That is just being pragmatic and using common sense.

Let's see, double the depth of field, 1/4 the number of pixels. That's the tradeoff. You can do it, but I wouldn't.

*********

* Footnote. I'll give you this. There's are two little exceptions I can think of, why on rare occasions you might not want to stop down. If you can't increase the exposure time, you are using an ISO-variant camera, and an increase in the ISO setting leads to an unacceptable loss of dynamic range, then you might consider stepping back. But this is a second-order consideration, for experts, and this is the beginner's forum. It takes so much careful consideration to use well that I doubt that I would ever be able to use it to good advantage in the field.

The second exception is with film, if you can't increase the exposure time and you can't switch to a faster film.

 

[Frank_GH]

To summarise:

Your method of moving further away and cropping to compensate (while keeping the camera and lens at the same settings otherwise) is a good method for increasing the depth of field.

No it isn't. It's better to stop down and either increase the exposure time or the ISO setting.

You are being very contrary!

The OP implied that he wished to maintain the camera settings

I think the question is more if he has only a fixed focal lens that he wants to use absolutely or a zoom.

It is better to use a longer FL than cropping unless again he has not the choice.

Hopefully, the OP will tell us what he wishes to do and why. I may have read something into his OP that wasn't intended.

Good point. I could've described my goal more precisely. I was thinking of a hypothetical situation where the room would be so dark that, even at very wide aperture and SS 1/60, ISO would be around 12000 (which, from what I was told and from my own limited experience, is a number that preferably shouldn't be exceeded). The subject could be people dancing, for example, so people not still and not at the same distance from the camera (hence the need for a wider DOF). No flash or other lighting allowed. In other words, I was thinking that I had no other option, I'd step back and crop, but from what I've understood here, I'd still be better off stopping down. I would have more pixels to try to make it look good in post production.

BTW, I only have the a7iii kit lens (FE28-70) and the FE 50mm f/1.8. I mainly use the prime lens. I know it's low end, and I'll probably buy a better one at some point to get a better resolution. But concerning low-light conditions, am I right to say that for a given aperture and SS, putting a better 50-mm lens on the same camera will result in the same ISO? In other words, it wouldn't particularly help for low-light conditions?

 

[Tom Axford]

Good point. I could've described my goal more precisely. I was thinking of a hypothetical situation where the room would be so dark that, even at very wide aperture and SS 1/60, ISO would be around 12000 (which, from what I was told and from my own limited experience, is a number that preferably shouldn't be exceeded). The subject could be people dancing, for example, so people not still and not at the same distance from the camera (hence the need for a wider DOF). No flash or other lighting allowed. In other words, I was thinking that I had no other option, I'd step back and crop, but from what I've understood here, I'd still be better off stopping down. I would have more pixels to try to make it look good in post production.

OK, I did misunderstand what you were trying to do. Thrillamozilla is right in saying that you will always be worse off by cropping if you want the best quality.

BTW, I only have the a7iii kit lens (FE28-70) and the FE 50mm f/1.8. I mainly use the prime lens. I know it's low end, and I'll probably buy a better one at some point to get a better resolution. But concerning low-light conditions, am I right to say that for a given aperture and SS, putting a better 50-mm lens on the same camera will result in the same ISO? In other words, it wouldn't particularly help for low-light conditions?

Again, I am not sure what you are really asking here.

Using a 50mm f/1.8 lens is only going to be a significant advantage over using 50mm on your kit zoom if you want to use f/1.8 or similar apertures. If you want to use say f/16 for large DoF, then it will not make any noticeable difference using f/16 on the 50mm lens or using 50mm f/16 on the zoom lens.

Is that what you are asking or have I misunderstood again?

 

[Great Bustard]

To summarise:

Your method of moving further away and cropping to compensate (while keeping the camera and lens at the same settings otherwise) is a good method for increasing the depth of field. The depth of field increases in proportion to the distance from your subject. So, if you double the distance and crop by a factor of 2 (so you get one quarter as many pixels), the depth of field is doubled.

But, and it is a big but, this method works only if the final image quality is acceptable. Cropping always reduces image quality (measured relative to the size of the image). You need to decide how much cropping is acceptable for your camera and lens and the quality you expect in the final image. Cropping by a factor of 2 may be acceptable, but a factor of 3 may lead to too much loss of quality.

It all depends on the circumstances; particularly the camera, lens, aperture setting, and how much final image quality you want. You really need to decide on the maximum level of cropping that works for you.

Under what circumstances does stepping back and cropping (or framing wider in place and cropping, if using a zoom) result in a photo that is better than merely stopping down, given that one can still use the same exposure time when stopped down (usually in conjunction with a concomitantly higher ISO setting, concomitantly longer exposure time, or some combination thereof)?

Even if the speed of getting the photo is a factor, I'm pretty sure that, for example, changing to a two stop higher f-number and two stop higher ISO setting is faster than stepping back twice as far and then taking the shot.

However, since stepping back and cropping *necessarily* changes the perspective, then the only situation in which stepping back and cropping may be a superior solution is if the perspective from further back is more desirable and one is using a prime lens.

In addition, if light is so low that one has "run out of ISO" when shooting OOC jpgs, then one may find that stopping down while maintaining the same exposure time is not possible. However, in such a situation, the photo would be so noisy, anyway, that I find it hard to believe that the deeper DOF would be preferable to a more shallow DOF that is significantly less noisy.

I would be interesting in what situation(s) you consider stepping back and cropping is a superior solution, and why they represent a superior solution.

 

[ThrillaMozilla]

I was thinking of a hypothetical situation where the room would be so dark that, even at very wide aperture and SS 1/60, ISO would be around 12000 (which, from what I was told and from my own limited experience, is a number that preferably shouldn't be exceeded).

Wow, this is pushing some limits, and way outside the range of conditions on your test photos. But I just took a nice landscape photo at ISO 12800 with a very modest camera. Even I am astonished by the quality, and you have better equipment.

The subject could be people dancing, for example, so people not still and not at the same distance from the camera (hence the need for a wider DOF). No flash or other lighting allowed. In other words, I was thinking that I had no other option, I'd step back and crop, but from what I've understood here, I'd still be better off stopping down. I would have more pixels to try to make it look good in post production.

That's a tall order. Most of us assumed more ordinary conditions, but I still think you will be better off stopping down, unless perhaps you find the dynamic range to be the limiting factor. Sometimes with complex image questions, there's no substitute for just trying it and evaluating results visually.

BTW, I only have the a7iii kit lens (FE28-70) and the FE 50mm f/1.8. I mainly use the prime lens. I know it's low end, and I'll probably buy a better one at some point to get a better resolution. But concerning low-light conditions, am I right to say that for a given aperture and SS, putting a better 50-mm lens on the same camera will result in the same ISO? In other words, it wouldn't particularly help for low-light conditions?

I don't see what good a better lens would do. I believe your problem is lack of light, not lens quality.

 

[ThrillaMozilla]

...However, since stepping back and cropping *necessarily* changes the perspective, then the only situation in which stepping back and cropping may be a superior solution is if the perspective from further back is more desirable and one is using a prime lens.

Or if you are being chased by lions.

In addition, if light is so low that one has "run out of ISO" when shooting OOC jpgs, then one may find that stopping down while maintaining the same exposure time is not possible. However, in such a situation, the photo would be so noisy, anyway, that I find it hard to believe that the deeper DOF would be preferable to a more shallow DOF that is significantly less noisy.

Good point. I didn't realize that this was the complex image quality at the edge forum.

 

[Tom Axford]

To summarise:

Your method of moving further away and cropping to compensate (while keeping the camera and lens at the same settings otherwise) is a good method for increasing the depth of field. The depth of field increases in proportion to the distance from your subject. So, if you double the distance and crop by a factor of 2 (so you get one quarter as many pixels), the depth of field is doubled.

But, and it is a big but, this method works only if the final image quality is acceptable. Cropping always reduces image quality (measured relative to the size of the image). You need to decide how much cropping is acceptable for your camera and lens and the quality you expect in the final image. Cropping by a factor of 2 may be acceptable, but a factor of 3 may lead to too much loss of quality.

It all depends on the circumstances; particularly the camera, lens, aperture setting, and how much final image quality you want. You really need to decide on the maximum level of cropping that works for you.

Under what circumstances does stepping back and cropping (or framing wider in place and cropping, if using a zoom) result in a photo that is better than merely stopping down, given that one can still use the same exposure time when stopped down (usually in conjunction with a concomitantly higher ISO setting, concomitantly longer exposure time, or some combination thereof)?

I was assuming that the OP was wanting to keep the same camera settings for whatever reason (maybe at minimum aperture already or at maximum ISO).

If stopping down is acceptable, then I agree it should be as good or better than stepping back and cropping.

Even if the speed of getting the photo is a factor, I'm pretty sure that, for example, changing to a two stop higher f-number and two stop higher ISO setting is faster than stepping back twice as far and then taking the shot.

However, since stepping back and cropping *necessarily* changes the perspective, then the only situation in which stepping back and cropping may be a superior solution is if the perspective from further back is more desirable and one is using a prime lens.

In addition, if light is so low that one has "run out of ISO" when shooting OOC jpgs, then one may find that stopping down while maintaining the same exposure time is not possible. However, in such a situation, the photo would be so noisy, anyway, that I find it hard to believe that the deeper DOF would be preferable to a more shallow DOF that is significantly less noisy.

I would be interesting in what situation(s) you consider stepping back and cropping is a superior solution, and why they represent a superior solution.

I have used stepping back and cropping if I know that the image quality after cropping will still be acceptable. I would not claim that it is the best way to increase DoF, but it is a particularly quick and easy way of increasing DoF without having to change any other camera settings, e.g. when used in macro-photography. However, it is acceptable only if the loss of image quality through cropping is not a problem (e.g. for images that are to be shared with others via mobile phone or other small display devices). As a photographer, I find there are many situations in which achieving the highest possible resolution is not my top priority.

 

[Christof21]

Hello,

Here is a graph comparing the 2 different strategies.

It is the size of the airy disc (the degree of blur) depending on the distance behind the subject

• Original picture (1):

focussed at 1 meter, focal = 35mm f/4

• Taken from further away (2)

focussed at 2 meters, focal = 35mmf/4, cropped x2

Or equivalently: focal=70mm f/8 uncropped

• Stopped down (3):

focussed at 1 meter focal=35mm f/8

You see the degree of blur. The unit for absciss is meter, the ordonate is millimeter.



The red line corresponds to the FF CoC, this means that the part below this line is considered to be sharp.

Conclusions:

The shot taken from further away does increase dof compared to the original shot (it becomes more blurry sooner). The background blur at infinity tends to the same limit

The shot taken stopped down has the same dof than shot further away. You see that the orange and green curve have the same slope around 0, so the part below the red line is roughly the same. At infinity, the background will be less blurry.

I really appreciate this, since I'm a visual learner. Thanks

Your welcome.

In my opinion, stepping back, other than changing perspective, can be used to change to change the dof + background blur.

You can perfectly for instance increase dof and increase background blur, this is not contradictory.

I tend to consider that the maximum aperture size is a kind of indication of separation power between subject and background

For instance a 80mm f/4 has more separation power than a 25mm f/1.8. So if you shoo the same portrait at ma aperture with both lenses, of course further away for the 80mm, uou will have a larger part of the face in focus and the background at infinity will be blurrier.

This gives you more creativity. But you should consider first, most of the time, the perspective you want. That said, I have seen many times photographers who take "easy" pictures, they shoot people at the beach for instance. They take a long FL lens, the dof is enough to have all the face in focus as explained above and the background can be very blurry. They sell pictures like this, no need to be a good photographer in fact.

Separation power is not an official terminology, take it with a grain of salt, but I hope you get the idea.

For a given framing, f# controls dof while aperture size controls background blur.

 

[Frank_GH]

Hello,

Here is a graph comparing the 2 different strategies.

It is the size of the airy disc (the degree of blur) depending on the distance behind the subject

• Original picture (1):

focussed at 1 meter, focal = 35mm f/4

• Taken from further away (2)

focussed at 2 meters, focal = 35mmf/4, cropped x2

Or equivalently: focal=70mm f/8 uncropped

• Stopped down (3):

focussed at 1 meter focal=35mm f/8

You see the degree of blur. The unit for absciss is meter, the ordonate is millimeter.



The red line corresponds to the FF CoC, this means that the part below this line is considered to be sharp.

Conclusions:

The shot taken from further away does increase dof compared to the original shot (it becomes more blurry sooner). The background blur at infinity tends to the same limit

The shot taken stopped down has the same dof than shot further away. You see that the orange and green curve have the same slope around 0, so the part below the red line is roughly the same. At infinity, the background will be less blurry.

I really appreciate this, since I'm a visual learner. Thanks

Your welcome.

In my opinion, stepping back, other than changing perspective, can be used to change to change the dof + background blur.

You can perfectly for instance increase dof and increase background blur, this is not contradictory.

I tend to consider that the maximum aperture size is a kind of indication of separation power between subject and background

For instance a 80mm f/4 has more separation power than a 25mm f/1.8. So if you shoo the same portrait at ma aperture with both lenses, of course further away for the 80mm, uou will have a larger part of the face in focus and the background at infinity will be blurrier.

Interesting. When I shoot portraits with my 28-70mm, I usually set it at 50 mm because people say it is close to what the human sees, but I might get nicer results at 70 mm. I'll give it a try. I wonder what focal distance most photographers use for portraits.

This gives you more creativity. But you should consider first, most of the time, the perspective you want. That said, I have seen many times photographers who take "easy" pictures, they shoot people at the beach for instance. They take a long FL lens, the dof is enough to have all the face in focus as explained above and the background can be very blurry. They sell pictures like this, no need to be a good photographer in fact.

Separation power is not an official terminology, take it with a grain of salt, but I hope you get the idea.

For a given framing, f# controls dof while aperture size controls background blur.

 

[Frank_GH]

Good point. I could've described my goal more precisely. I was thinking of a hypothetical situation where the room would be so dark that, even at very wide aperture and SS 1/60, ISO would be around 12000 (which, from what I was told and from my own limited experience, is a number that preferably shouldn't be exceeded). The subject could be people dancing, for example, so people not still and not at the same distance from the camera (hence the need for a wider DOF). No flash or other lighting allowed. In other words, I was thinking that I had no other option, I'd step back and crop, but from what I've understood here, I'd still be better off stopping down. I would have more pixels to try to make it look good in post production.

OK, I did misunderstand what you were trying to do. Thrillamozilla is right in saying that you will always be worse off by cropping if you want the best quality.

BTW, I only have the a7iii kit lens (FE28-70) and the FE 50mm f/1.8. I mainly use the prime lens. I know it's low end, and I'll probably buy a better one at some point to get a better resolution. But concerning low-light conditions, am I right to say that for a given aperture and SS, putting a better 50-mm lens on the same camera will result in the same ISO? In other words, it wouldn't particularly help for low-light conditions?

Again, I am not sure what you are really asking here.

Using a 50mm f/1.8 lens is only going to be a significant advantage over using 50mm on your kit zoom if you want to use f/1.8 or similar apertures. If you want to use say f/16 for large DoF, then it will not make any noticeable difference using f/16 on the 50mm lens or using 50mm f/16 on the zoom lens.

You are confirming what I was suspecting. That's one of questions I was asking myself.

Is that what you are asking or have I misunderstood again?

 

[Dem Bell]

To summarise:

Your method of moving further away and cropping to compensate (while keeping the camera and lens at the same settings otherwise) is a good method for increasing the depth of field. The depth of field increases in proportion to the distance from your subject. So, if you double the distance and crop by a factor of 2 (so you get one quarter as many pixels), the depth of field is doubled.

But, and it is a big but, this method works only if the final image quality is acceptable. Cropping always reduces image quality (measured relative to the size of the image). You need to decide how much cropping is acceptable for your camera and lens and the quality you expect in the final image. Cropping by a factor of 2 may be acceptable, but a factor of 3 may lead to too much loss of quality.

It all depends on the circumstances; particularly the camera, lens, aperture setting, and how much final image quality you want. You really need to decide on the maximum level of cropping that works for you.

Under what circumstances does stepping back and cropping (or framing wider in place and cropping, if using a zoom) result in a photo that is better than merely stopping down, given that one can still use the same exposure time when stopped down (usually in conjunction with a concomitantly higher ISO setting, concomitantly longer exposure time, or some combination thereof)?

Macro/close up. When you are already shooting at f/22 equivalent and cannot stop down anymore or the lights are low and you need to keep the shutter speed up. It is not "better" but trading some resolution for DOF might be preferable.

Even if the speed of getting the photo is a factor, I'm pretty sure that, for example, changing to a two stop higher f-number and two stop higher ISO setting is faster than stepping back twice as far and then taking the shot.

The difference in focus distance might be a few inches.

However, since stepping back and cropping *necessarily* changes the perspective, then the only situation in which stepping back and cropping may be a superior solution is if the perspective from further back is more desirable and one is using a prime lens.

Or you want more DOF and are prepared to lose some resolution.

In addition, if light is so low that one has "run out of ISO" when shooting OOC jpgs, then one may find that stopping down while maintaining the same exposure time is not possible. However, in such a situation, the photo would be so noisy, anyway, that I find it hard to believe that the deeper DOF would be preferable to a more shallow DOF that is significantly less noisy.

That's why people tend to use flash with macro.

I would be interesting in what situation(s) you consider stepping back and cropping is a superior solution, and why they represent a superior solution.

So not just the bee but most of the flower is also in focus.