Why do you use a crop sensor body?

Part to put more pixels on a subject (part body dependent) and part for faster fps without bulk, weight and expense.

A 800/8100 in DX crop mode puts 15.36 MP on the subject, compared to 24 MP on a D7200. 50% more MP on the subject can be a big DX advantage with this comparison.

I can get 10 fps on my D500 - faster than on my D850 with a grip, big battery, a special charger.

D850 DX crop compared to D500 MP is about equal - little resolution advantage - but a big price difference.

In low light the DX 1 stop brighter than FX viewfinder can be useful.

Canons just announced DX (is it 1.5 or 1.6x?) with 32.5 MP is interesting if Nikon follow up with DX bodies with more MP.

seahawk said:

Not really imho. The few lenses that are 1:1 comparable are not showing much difference.

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AF-P 70-300 VR DX vs FX is an example (415gm vs 680 gm, 125mm vs 146mm long), 16-80 vs 24-120 is another (480 vs 710 gms, 85mm vs 103mm long) , and of course 10-20vr vs 16-35 vr (230gm vs 680gm).

Perhaps that doesn't mean much to you but it saves my back a lot of weight when needed. It's also a lot smaller to fit in my bag.

Leonard Shepherd said:

Part to put more pixels on a subject (part body dependent) and part for faster fps without bulk, weight and expense.

A 800/8100 in DX crop mode puts 15.36 MP on the subject, compared to 24 MP on a D7200. 50% more MP on the subject can be a big DX advantage with this comparison.

Click to expand...

I never thought about it that way, although I'm sure there are 10K threads discussing this I never mixed the bodies until I went to Hawaii last year to shoot golf courses out there. It was very interesting to see the resulting files. I was often lost as to which camera shot what! The added reach I got with my 70-200 on the D7500 was very helpful.

Leonard Shepherd said:

I can get 10 fps on my D500 - faster than on my D850 with a grip, big battery, a special charger.

D850 DX crop compared to D500 MP is about equal - little resolution advantage - but a big price difference.

Click to expand...

I see a lot of people here with those two bodies in their gear lists, as well as D7500s, etc.

Leonard Shepherd said:

In low light the DX 1 stop brighter than FX viewfinder can be useful.

Click to expand...

I never knew that.

romfordbluenose said:

AF-P 70-300 VR DX vs FX is an example (415gm vs 680 gm, 125mm vs 146mm long), 16-80 vs 24-120 is another (480 vs 710 gms, 85mm vs 103mm long) , and of course 10-20vr vs 16-35 vr (230gm vs 680gm).

Perhaps that doesn't mean much to you but it saves my back a lot of weight when needed. It's also a lot smaller to fit in my bag.

Click to expand...

Does using an FX lens, on the DX body, that has soft corners help, e.g., because the coverage is bigger? (Thus leaving the soft corners off the sensor, off-topic but your pointing out the differences above prompts me to ask

romfordbluenose said:

seahawk said:

Not really imho. The few lenses that are 1:1 comparable are not showing much difference.

Click to expand...

AF-P 70-300 VR DX vs FX is an example (415gm vs 680 gm, 125mm vs 146mm long), 16-80 vs 24-120 is another (480 vs 710 gms, 85mm vs 103mm long) , and of course 10-20vr vs 16-35 vr (230gm vs 680gm).

Perhaps that doesn't mean much to you but it saves my back a lot of weight when needed. It's also a lot smaller to fit in my bag.

Click to expand...

The AF-P 70-300 DX is 4.5-6.3 the FX is 4.5-5.6.

The 10-20 is a 4.5-5.6, the 16-35 is a constant 4.0 lens.

I give you the 16-80 compared to the 24-120 and an advantage in superzooms or starting at 16/18mm and having 5 times of more zoom.

Imho not the same and if you want the same depth of field you need a faster DX lens for the same effect.

Imho the DX sensor shines the most when paired with a 70-200 2.8, which I find too short on FX but a beautiful telezoom on DX.

You are quite right of course if taken from your point of view. The question was asked though about why we use dx. I gave you my reasons which are either reach or weight/size. You are welcome to use whatever FX lens you want on your cameras and yes the 70-200 is a wonderful lens on any camera it's just too big and heavy for me.

--
Please don't quote long posts, it just fills up the forum with repetitive information. Just replying to the poster or selectively quoting will make it all easier to read.

olindacat said:

I'm using a D810, know it has a crop mode, but for a second body went with a crop sensor instead of another D810. Why? Well, because I could buy the crop body for a lot less, and It becomes my 'extra-reach' go-to solution. Is this a fallacy? I'm not a camera guru, and make tons of mistakes, all of the time, but snagged a $215 2nd hand D3500 and while I dislike its form factor, can tell you it's resolution blows away my old $5K D2X, and at 5FPS bursts, I can use a cheesy AF-S (P as soon as I can dump this S) for some pretty good average IQ lightweight reach. Is anyone else thinking like this? (Not trolling here Is that even the right term? "Trolling?"

Click to expand...

I don't believe in "reach".

You can't reach through the atmosphere and eliminate atmospheric pollution with a longer focal length or a smaller sensor or smaller pixels.

You can't reach a closer 3D perspective with a lens; you have to move to a closer location.

From a given distance, you can't get any resolution beyond the lens' analog resolution no matter how small your sensor or how small your pixels, but smaller pixels will resolve the optics better.

Any benefit for distant subject detail from a sensor is going to come from pixel density, and pixel density alone, but it does not make things closer, like you "reached" them; you just get better resolution of a distant-looking scene.

A 100MP FF camera would do this better than any current APS-C sensor.

Back when my main body was a D810 (36MP and 16MP) in DX mode, buying a 24MP crop body made sense. So when the D7500 came out I bought the D7200 at reduced cost. I personally wouldn't buy a D3xxx series. But the D7200 is great.

I've now got a D850 and Z7. Those are 20MP in crop mode. So the difference between them and a 24MP crop camera is not so great.

John Sheehy said:

I don't believe in "reach".

You can't reach through the atmosphere and eliminate atmospheric pollution with a longer focal length or a smaller sensor or smaller pixels.

You can't reach a closer 3D perspective with a lens; you have to move to a closer location.

From a given distance, you can't get any resolution beyond the lens' analog resolution no matter how small your sensor or how small your pixels, but smaller pixels will resolve the optics better.

Any benefit for distant subject detail from a sensor is going to come from pixel density, and pixel density alone, but it does not make things closer, like you "reached" them; you just get better resolution of a distant-looking scene.

A 100MP FF camera would do this better than any current APS-C sensor.

Click to expand...

You are quite right, but I think the term "reach" is now common casual language to describe what you have said. Namely a 24mp DX sensor puts more pixels on a subject than a 24mp FX sensor at the same distance. This is why the D8xx series cameras can to a certain degree do away with a DX camera as a second camera as they can put sufficient pixels on a subject and crop to what you need.

Leonard Shepherd said:

D850 DX crop compared to D500 MP is about equal - little resolution advantage - but a big price difference.

Click to expand...

The D500 has about 1/3 stop less read noise at the pixel level, too, compared to the D850. To get less noise with the D850, you need to get closer and not crop, or use a lens with a larger entrance pupil (both options requiring shallower DOF).

--
John
http://www.pbase.com/image/55384958.jpg

John Sheehy said:

olindacat said:

I'm using a D810, know it has a crop mode, but for a second body went with a crop sensor instead of another D810. Why? Well, because I could buy the crop body for a lot less, and It becomes my 'extra-reach' go-to solution. Is this a fallacy? I'm not a camera guru, and make tons of mistakes, all of the time, but snagged a $215 2nd hand D3500 and while I dislike its form factor, can tell you it's resolution blows away my old $5K D2X, and at 5FPS bursts, I can use a cheesy AF-S (P as soon as I can dump this S) for some pretty good average IQ lightweight reach. Is anyone else thinking like this? (Not trolling here Is that even the right term? "Trolling?"

Click to expand...

I don't believe in "reach".

You can't reach through the atmosphere and eliminate atmospheric pollution with a longer focal length or a smaller sensor or smaller pixels.

You can't reach a closer 3D perspective with a lens; you have to move to a closer location.

From a given distance, you can't get any resolution beyond the lens' analog resolution no matter how small your sensor or how small your pixels, but smaller pixels will resolve the optics better.

Any benefit for distant subject detail from a sensor is going to come from pixel density, and pixel density alone, but it does not make things closer, like you "reached" them; you just get better resolution of a distant-looking scene.

A 100MP FF camera would do this better than any current APS-C sensor.

Click to expand...

That's why I said earlier that "reach" is basically just pixel density. Higher pixel-density sensors have a definite advantage over lower ones when you can't get close enough to the subject. Now that we have 45 and 60 MP FF cameras, the "reach" of DX is negated.

When you need to run faster than you would with FX! :-D

Iron Eagle said:

John Sheehy said:

I don't believe in "reach".

Click to expand...

Click to expand...

Iron Eagle said:

Iron Eagle said:

You can't reach through the atmosphere and eliminate atmospheric pollution with a longer focal length or a smaller sensor or smaller pixels.

You can't reach a closer 3D perspective with a lens; you have to move to a closer location.

From a given distance, you can't get any resolution beyond the lens' analog resolution no matter how small your sensor or how small your pixels, but smaller pixels will resolve the optics better.

Any benefit for distant subject detail from a sensor is going to come from pixel density, and pixel density alone, but it does not make things closer, like you "reached" them; you just get better resolution of a distant-looking scene.

A 100MP FF camera would do this better than any current APS-C sensor.

Click to expand...

That's why I said earlier that "reach" is basically just pixel density. Higher pixel-density sensors have a definite advantage over lower ones when you can't get close enough to the subject. Now that we have 45 and 60 MP FF cameras, the "reach" of DX is negated.

Click to expand...

My understanding of the science of optics, terminology, and even some basic geometry or physics, if they are even applicable, are wanting. I can only tell you that there were times when I'd be shooting a golf hole over a gulch. No way to hover myself through the air and get in tighter. The focal length of my glass never exceeded 200mm, except for odd times when I borrowed primes from my friend to shoot golf events.

The 200 wa 70-200 2.8 VR1. I used it on a D2X. Prior to that I used an Olympus E-10 and E-20. Those were fixed zooms. I don't remember what the crop fact was on my D2X but it was probably 1.5, like a DX. I used to have the 17-55 DX lens.

Anyway, as cameras evolved, I think it was the D800 that really changed my simple world. I was able to crop images and get details and closer looks at golf holes I could never get before. I used the term "reach" to describe what was correctly now explained as pixel density.

I think, but again I'm no scientist, or expert here, but the recent 24MP DX cameras seem to offer something my D810 wasn't able to. in that I could turn my 24-70 FX lens into a 35-105 on that body, and still have more file to work with than my old D2X.

My use of the term 'reach' clearly was wrong, but for me, getting the added whatever it's called has been very useful. I hope to use it to give me more of that when I buy longer tele zooms.

I first got a D5600 and soon after a D7500, which I got primarily for birding/BIFS. I liked the extra reach for that purpose. The crop cameras are much smaller (especially the D5600) and lighter, and work well with the larger, heavier telephotos. I don't like using my 100-400 lens on the D700 in crop mode (FX mode is fine). If I want to get the potential 600mm reach it's much nicer to use the crop camera.

Recently I got a D700 so I could play around with FX (I have a lot of legacy manual focus lenses) and now I love that for things other than than birding.

John Sheehy said:

Leonard Shepherd said:

D850 DX crop compared to D500 MP is about equal - little resolution advantage - but a big price difference.

Click to expand...

The D500 has about 1/3 stop less read noise at the pixel level, too, compared to the D850. To get less noise with the D850, you need to get closer and not crop, or use a lens with a larger entrance pupil (both options requiring shallower DOF).

Click to expand...

Can you, outside a laboratory, detect 1/3rd stop less read noise

You can usually open up DX to 1/3rd stop lower ISO without loosing DoF relative to FX to get the same read noise.

--
Leonard Shepherd
In lots of ways good photography is much more about how equipment is used rather than the equipment being used.

I wouldn't say you're wrong. Most people think of reach like you do. When you put a lens on a crop body, you multiply by the crop factor to get the effective FOV. So if you put a 200mm on a crop camera, it's 200 x 1.5, and the lens acts like a 300mm. Now, of course, it's still a 200mm lens, but the sensor is cropping off the edges.

Basically, a 200mm lens on a crop, gives you the same FOV you'd see with a 300mm on a FF camera. The pixel density part is important because as you crop, you lose pixels. If you have a lot of them to begin with, you still have a lot after cropping to give a nice, sharp image. If you can only get 50' from a bird, and use a D750 (FX) with 500mm lens, and do the same thing with a D7200, you're going to put more pixels on that bird with the D7200 since they are more tightly packed together on the sensor. This is one situation where a DX camera absolutely beats FX.

However, if you use a D850, the results are much closer, because the D850's pixels are also tightly packed, and you're putting nearly as many on the bird. IMO, if you have a high MP FX camera like the D850, you can crop down to DX size in post and get the same image as you would with a DX camera. If you have a low-res FX camera, you're better off using DX. The lens just does the cropping for you.

Here's a nice tutorial and video:

Iron Eagle said:

If you can only get 50' from a bird, and use a D750 (FX) with 500mm lens, and do the same thing with a D7200, you're going to put more pixels on that bird with the D7200 since they are more tightly packed together on the sensor. This is one situation where a DX camera absolutely beats FX.

Click to expand...

The difference between m D2X and D800E was a real game changer for me. I think that was about half the res of the D3500 I just snagged on CL for $215!

Iron Eagle said:

However, if you use a D850, the results are much closer, because the D850's pixels are also tightly packed, and you're putting nearly as many on the bird. IMO, if you have a high MP FX camera like the D850, you can crop down to DX size in post and get the same image as you would with a DX camera. If you have a low-res FX camera, you're better off using DX. The lens just does the cropping for you.

Click to expand...

Because I write and publish a magazine (this might be my last year doing so), being able to get images on pages to look better was my main goal. The D800 and D810 files are huge, pixel density as you say, which lets me start out using only 16% or 33%. Being able to enlarge it is very helpful. The 24MP DX, or the newer more dense 30+ MP APS-Cs like Fuji or I guess Canon now (?), are even more dense. I remember years ago the density usually equated to poor low light performance. Something to do with the photosites.

In any event, that magnification/illusion of the crop giving me that 'effective reach', terms I know upset some, are very helpful. I see a lot of action and bird people using the D500 for his reason, or so I thought. My friend, a pro on Maui, as two D500s which he uses more than his D850 for these (and other) reasons.

Iron Eagle said:

Here's a nice tutorial and video:

https://northrup.photo/gear-basics/camera-body-features/sensor-size-crop-factor/

Click to expand...

Thanks. The conversation sort of carried me into topics I have studied but forgotten about. I have a terrible memory for good stuff, and only remember the bad

Leonard Shepherd said:

John Sheehy said:

Leonard Shepherd said:

D850 DX crop compared to D500 MP is about equal - little resolution advantage - but a big price difference.

Click to expand...

The D500 has about 1/3 stop less read noise at the pixel level, too, compared to the D850. To get less noise with the D850, you need to get closer and not crop, or use a lens with a larger entrance pupil (both options requiring shallower DOF).

Click to expand...

Can you, outside a laboratory, detect 1/3rd stop less read noise

You can usually open up DX to 1/3rd stop lower ISO without loosing DoF relative to FX to get the same read noise.

Click to expand...

I'm finding a very high percentage of people looking at images are doing so on devices other than 27" iMacs or bigger, and am curious when "read noise" is something one can notice on them, and at what point, which is what I wonder is what you are asking, Leonard? (How's that for poor grammar?

(Still like your bike in snow shot.)

olindacat said:

(Still like your bike in snow shot.)

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Off topic we have not had a snow like that for 9 years.

65 years ago we got 3 snows like it most Januaries,

DeathArrow said:

...

For around 230 euros I can get an used D700, so if I'd ever need a backup camera or a camera to take with me in places I might be afraid it can be stolen, that would be the better option for me.

Click to expand...

For me D700 is the most enjoyable camera to use, for the above and other reasons. But this is not the point of this thread -- just the reason for my answer.

Given that I like D700 so much, I have no reason to get rid of my D200 and D300. They are so compatible -- the batteries, memory cards, button layout, button customising. Especially, the D300 serves me well when I need higher pixel density on the subject.

Logically/technically, my D810 replaces the combination of D700 + D300 in a single body and then some -- except for frames per second which I do not need. I guess I am so used to the D700 interface and simplicity that my D810 is often waiting for me at home.

Yes, I do use a DX format Fujifilm. But here, there is no FF option. And medium format is far too expensive for me.