Ray Hennessy: Are Teleconverters Necessary for Wildlife Photography

[Woodyg3]

I think it's probably got to do with the fact that there is this silly and extremely misleading convention, even among people who fully understand how it really works, of talking about DX/APS-C bodies as having "more reach." Lots of people who are inexperienced or less knowledgeable about photography see discussions all the time where people talk about DX having "more reach" and even people who don't like the usage just go with it and don't say anything because it's so ubiquitous that there's no point in trying to "correct" it every time you see it.

when I have used the term “more reach” I simply mean that a crop sensor body results in an image with a narrower field of view than with a full sensor camera with the same focal length lens. Nothing else implied like magic or voodoo. I think that most people who use the term mean the same thing.I also think that most people who use the term are fully aware that crop sensor cameras do not use sorcery, just a smaller sensor.

 

[Archibald]

when I have used the term “more reach” I simply mean that a crop sensor body results in an image with a narrower field of view than with a full sensor camera with the same focal length lens. Nothing else implied like magic or voodoo. I think that most people who use the term mean the same thing.I also think that most people who use the term are fully aware that crop sensor cameras do not use sorcery, just a smaller sensor.

For me, more reach is more pixels on the subject, and that is quite different from your definition.

 

[EricKlees]

For me, more reach is more pixels on the subject, and that is quite different from your definition.

I agree. When i talk about crop or using an APS-C body. A 500mm doesn't magically become a 750mm lens. It's still 500mm.

The way i explain or describe it to people is using a crop mode or crop body is it give the FOV equivalent of a 750mm lens but it's still 500mm. It adds no pixels, resolution or increases the resolving power of the lens. Physics is physics

 

[Woodyg3]

For me, more reach is more pixels on the subject, and that is quite different from your defIt Is.

For me, more reach is more pixels on the subject, and that is quite different from your definition.

Interesting. For me “reach” has always meant field of view, whether on any particular size of film or sensor. By your definition, two full frame cameras, one 24 MP and one a 45MP have different “reach” because one has more pixels on the subject even though the field of view is the same. That’s fine, I’ve just never thought of it that way.

I agree. When i talk about crop or using an APS-C body. A 500mm doesn't magically become a 750mm lens. It's still 500mm.

The way i explain or describe it to people is using a crop mode or crop body is it give the FOV equivalent of a 750mm lens but it's still 500mm. It adds no pixels, resolution or increases the resolving power of the lens. Physics is physics

I think most people understand that and are just using the term”reach” in place of field of view or angle of view.

I really think this is a matter of semantics and that the vast majority of serious photographers understand pixel density and field of view. This is probably a good reminder to use more exact terms so there is less misunderstanding.

 

[Anjin San]

I'd really love to one day understand why people think switching to dx mode is any different than cropping in post (wrt image quality) to the same size.

For me…the only reason to go to DX is if AF needs a little assist by making the subject bigger..otherwise you’re right.

 

[Archibald]

Interesting. For me “reach” has always meant field of view, whether on any particular size of film or sensor. By your definition, two full frame cameras, one 24 MP and one a 45MP have different “reach” because one has more pixels on the subject even though the field of view is the same. That’s fine, I’ve just never thought of it that way.

I think most people understand that and are just using the term”reach” in place of field of view or angle of view.

I really think this is a matter of semantics and that the vast majority of serious photographers understand pixel density and field of view. This is probably a good reminder to use more exact terms so there is less misunderstanding.

You make good points. We need to be mindful that some may have different definitions of terms, and it is good to mention what is meant.

There was a time in digital photography when all cameras, FF and crop, had similar megapixels. In those years, reach = field of view, roughly. But then some very high MPx cameras came along, and that changed things. High MPx cameras give a higher resolution of distant subjects. And that is what some of us call "reach".

 

[EricKlees]

Interesting. For me “reach” has always meant field of view, whether on any particular size of film or sensor. By your definition, two full frame cameras, one 24 MP and one a 45MP have different “reach” because one has more pixels on the subject even though the field of view is the same. That’s fine, I’ve just never thought of it that way.



I think most people understand that and are just using the term”reach” in place of field of view or angle of view.

I really think this is a matter of semantics and that the vast majority of serious photographers understand pixel density and field of view. This is probably a good reminder to use more exact terms so there is less misunderstanding.

A lot of people with mid to high end gear that I've met out on the field over the last 4 or 5 years do NOT understand this. I'd even say most didn't grasp this which is why i explain it like i mentioned so it makes them ask me to explain. The term "equivalent field of view" is what piques their interest

 

[Woodyg3]

A lot of people with mid to high end gear that I've met out on the field over the last 4 or 5 years do NOT understand this. I'd even say most didn't grasp this which is why i explain it like i mentioned so it makes them ask me to explain. The term "equivalent field of view" is what piques their interest

Surprising.

 

[fcotterill]

There is no escaping the laws of physics, as illustrated in the video on DoF by Cinematographer John Hess. There is no concept of Reach in optical theory, although it's used widely on wildlife photography forums.

Keeping all other variables the same, cropping tightens the field of view only so it "removes pixels". A longer focal length lens, or adding a Teleconverter magnifies the image: effectively increasing Pixels/Duck
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[fcotterill]

These threads might not have been cited in posts above. They cover much of what's been revisited above

DX Mode Versus Teleconverter?

Good day. My question is, what are the differences between using a 1.5 teleconverter vs. dx mode? A 500mm lens = 750mm in both incidences. Is there a good reason as to why people buy one, rather than use the DX camera mode? I would do the experiment to find out the result(s) but I do not own...

bcgforums.com

The 400mm f 2.8 S lens

Hey Photographers! I need some advice. I just received my Z9 and its my first mirorless camera. I have 3 DSLR body camera and some F mounted lenses: 500mm F4, 300mm F2.8, 70-200 mm f2.8 and macro and wide angle. I am thinking to sell all my lenses and my DSLR except the 300 mm F2.8 and my...

bcgforums.com

How does crop mode or cropping in post impact subject isolation/DOF?

So I think I know the answer to this question, or at least have an opinion, but I find it interesting. If you shoot in crop mode, or even crop in post, for depth of field purposes do you have to divide your f number by the crop factor?

bcgforums.com

 

[Andeye]

Take a look. Here is several examples with TC vs cropping. TC is providing more detail vs cropping.

 

[Thern]

I think Ray is correct.

However with “current state of the” art one can push a lot in PP and more skilled photogs with good skills in PP can diminish the negative impact by cropping on IQ.

The labtests here above are only showing that a TC will have very little or neglectable impact on sharpness at MFD and nearby subjects. (Where the use of a TC shines, but also won’t be any better than cropping)
I’d love to see this labtests done at a distance of let’s say 25 meters, 50 and 100 meters where astigmatism, monochromatic abberation and even sensitivity for lens-flare will be progressively impact resolution.

Like others said before there’s a penalty for using TC’s depending on the quality of the lens in use regarding AF, FOV and resolving power but if used correctly with a high resolving lens it can be a beneficial add on in the right circumstances with the correct use.

Personally I never use a TC nowadays but (very) occasionally for static subjects. (Where I still prefer the foot-zoom, if possible)

 

[arbitrage]

I'm not sure if this is the case with with other camera brand not this works for the Z9 and Z8. Likely due to the fact the 2 camera pulls the AF works directly off the EVF with the dual pipe tech. The larger the subject in the EVF, the easier the subject detection can recognize the subject and the eye.

I've found that this is the case for the Canon R series cameras. It is also the case for the latest Sony cameras that have the dedicated AI chip like A7RV and A9III.
However, it is the exact opposite for all the previous Sony cameras I've owned like A9II, A7RIV and A1. For whatever reason, that I've never understood, those cameras are more likely to recognize the subject and put a nice tiny box on the eye if in FF mode and often lose the eye in APS-C mode. I would assume that a camera would either have no difference in APS-C vs FF or would show the behaviour of Nikon Z and Canon R. But it is what it is, I've tested it countless times on the A1. On the A9III it was showing behaviour similar to Z9 and R5 which were the other cameras I've owned and tested.

 

[bleirer]

I think the common acceptance of the informal term reach has to do with field of view/angle of view as mentioned earlier. Field of view is defined by sensor size and focal length. As I see it the effective sensor size is altered by cropping in post or crop mode in camera. To me pixels per duck relates pixel pitch or density, so pixels per duck doesn't change with cropping, so no change in field of view/reach.

 

[SCoombs]

Interesting. For me “reach” has always meant field of view, whether on any particular size of film or sensor. By your definition, two full frame cameras, one 24 MP and one a 45MP have different “reach” because one has more pixels on the subject even though the field of view is the same. That’s fine, I’ve just never thought of it that way.



I think most people understand that and are just using the term”reach” in place of field of view or angle of view.

I really think this is a matter of semantics and that the vast majority of serious photographers understand pixel density and field of view. This is probably a good reminder to use more exact terms so there is less misunderstanding.

I think most very experienced people understand this and it's why the terminology has stuck, but many, many others don't.

Here's the thing: I don't think it's at all intuitive or even necessarily logical to talk about field of view by using the term "reach."

If I cover up one eye, I've narrowed my field of view considerably, but I can't suddenly see farther. If I put on swim goggles, my field of vision narrows, but I can't see more distant objects. A person experiencing a loss of peripheral vision has a narrower FOV, but doesn't from that gain better vision at distance.

A narrowing of the field of view is a consequence of reaching further optically, but reaching further optically is not a consequence of narrowing one's field of vision. That's why I think "more reach" is misleading, even if a lot of people who use the term understand what it really means, and why a lot of people hear it and get the wrong idea: because there is a relationship between reach and field of vision, but the convention is to use the word describing one aspect of this relationship when we're really talking about situations where only the other aspect is present.

All extra reach will narrow the field of view, but not all narrowing of the field of view will result in more reach. It's like how all squares are rectangles but not all rectangles are squares, but as if we developed a convention to use the word "squares" as shorthand when we're talking about quadrilaterals with unequal sides.

 

[bleirer]

I'm not sure how this relates, but I think it sorta does because photography also uses a flat plane to try to show relative distance to the viewer. In other visual arts one main factor in perceived distance has to do with how the object relates with the edges of the frame/format shape. Paint a house 8 inches wide in a 9 by 12 frame and we say the house is near. Paint the same 8 inch house in a 36 by 48 frame and we say it is far. Same with field of view, in my view.

Of course there are other factors to the feeling of distance, as mentioned in previous posts. 12 factors by one count. For example paint something with less detail we say it is farther away. If it overlaps another object we say it is closer, etc.

 

[SCoombs]

I'm not sure how this relates, but I think it sorta does because photography also uses a flat plane to try to show relative distance to the viewer. In other visual arts one main factor in perceived distance has to do with how the object relates with the edges of the frame/format shape. Paint a house 8 inches wide in a 9 by 12 frame and we say the house is near. Paint the same 8 inch house in a 36 by 48 frame and we say it is far. Same with field of view, in my view.

Of course there are other factors to the feeling of distance, as mentioned in previous posts. 12 factors by one count. For example paint something with less detail we say it is farther away. If it overlaps another object we say it is closer, etc.

I think you hit on a key factor that explains some of the different perspectives people have on this.

I have observed over the years that some people regard detail as the most important thing in a photo... not necessarily fine, perfect detail, as though we need to see every distinct feather on a bird's head all the time, but detail nonetheless. Others care more about the overall "context" of a photo. Others have other foci.

So for instance, I was recently in a craft store and saw some inexpensive oil paints and I've been wanting to try the Bob Ross thing for a while so I picked them up. I got a small 5x7 canvas because I just wanted to mess around and didn't intend or expect to produce anything all that great, never having painted before. I painted this:

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Some people would step back a few feet and say that this is pretty good. It's definitely lacking in detail - partly because of my skill, partly because I think based on some research that I need a different type of pil paint for the style, and partly because of the limits posed by the small canvas size - BUT for such a small canvas we have an expansive scene which some may argue doesn't require a lot of detail to be good.

Others would argue that even for the small size we'd Ike to see more detail.

I think this kind of difference in perspective lies behind a lot of disagreements over the quality of a new lens, or the preference for cropping vs teleconverters, or the question of "reach" as greater resolution vs narrower field of view vs both.

 

[nmerc_photos]

it's not a one or the other situation

often times it's a TC + cropping

 

[Woodpecker]

I cureently have the Z 400 f4.5, and the reports are that the 1.4x tele perform well with this lens.

Although I don't have one, after all I hear and read you are right. Of course you pay the price for physics and loose some resolution with the TC - as every lens does - but ending up with a 560mm 1:6.3 is on par with something lieke the 180-600 in terms of light and it's also pretty close in terms of resoltion, and after @Steve has tested both this should be a sufficient signal to go for it . The reason why I don't have the 400 1:4.5 is because I prefer zoom flexibility for going light whereever possible and I have an old big prime for the things beyond 500mm when working more stationary. IMHO getting a TC 1,4x is a no brainer for anybody having tele primes that are not too slow already if used naked. Even if you - like me - are dreaming of a Z 400 f2.8 TC it makes sense to have it. My friend is using it with this TC to be able to flip between 560 and 800 with the internal TC rather than using the TC 2.0 and he really loves it. BTW, the guys mentioned above actually tested it like this and found out that the combination of external TC and internal TC acutally rendered slighlty better results than using the TC 2.0.

There must be a reason why TC's seem to belong to the most value stable items on the second hand market .