more questions about FF versus DX

[coastalconn]

I have to say I agree with Sleist.. Feel free to waste your money, but you would be better served by learning what the limitations of your current gear is. To want a 35mm lens just to have a 35mm FOV seems sorta goofy. Maybe you should consider the new sigma 18-35 f1.8... just take a sharpie and cover up the 18-35 part and use the lens to get proper framing and not worry about FOV?

buy a D600 to replace my D7100

If you insist on wasting money, just send it to me instead.
If your photos suck on a D7100, then they will still suck on a D600.

Don't be suckered by the camera companies. (and the forum gear-head idiots)

Saw some truly excellent landscapes today on p.net.
Shot on a D5100 and the 18-55mm kit lens ....

Just sayin'

 

[Murray Bloom]

The only real improvement you'll obtain by increasing sensor size is better low-light performance, since FF sensors are, by their nature, less noisy. However, in anything resembling normal light levels, the DX sensors do just fine.

Forget about the math. Just understand that a 'normal' focal length for a FF camera is about 42mm; DX is about 28mm; and for comparison, 4x5 is 163mm. They're just numbers. The important thing is the reproduction ratio, which determines the telephoto or wide-angle effect at any given focal length.

I agree that bokeh is subjective and not finite. It depends on a lot of factors, such as a lens's optical configuration, the position of the diaphragm in the lens, the number of diaphragm blades and their shape.

Finally, a FF sensor will produce shallower depth of field than a DX lens. This assumes that the focal length of the lenses used are proportional to the sensor sizes, yielding similar angles of view. It may seem counterintuitive, but you have to remember that even though all the optical aspects can be proportional (focal length, lens element diameter, maximum lens opening, aperture, etc., there's always one element in the picture that doesn't scale - the subject. This upsets the balance, and is responsible for why crop sensor cameras have better DOF at any given f-stop.

 

[Derrel]

Murray's last sentence is important, when he writes, "crop sensor cameras have better DOF at any given f-stop." By better depth of field he means more depth of field. Greater depth of field.

At each picture angle, the smaller the sensor, the more depth of field there is. The issues underlying depth of field are somewhat complicated. Too complicated to go into in a forum post. But suffice it to say, crop-sensor cameras yield MORE depth of field than do FX cameras, at the same picture angle.

One of the main REAL benefits of FX cameras is the full,complete range of lenses NIkon offers. No holes in the FX lens lineup, unlike the DX lineup, which is skimpier in terms of lenses offered.

FX works better, in my opinion, for people work, because it allows you to shoot "people pictures" and control the background depth of field more easily. Case in point. With an 85mm prime lens, 8.5 foot tall field of view is obtained at 20 feet with an FX camera. With a DX-format Nikon,m that same 8.5 foot tall angle of view is obtained at 33 feet. So, to take a proper portrait of a standing person, with the FX camera, you can be just 20 feet distant; with a DX Nikon, you need to move wayyyyyyy back, to 33 feet. That means people and objects can be in the line of sight; and the depth of field BEHIND the subject at such a long working distance is much greater. Depth of field, and the degree of "out-of-focusness", what the OP is referring to as bokeh, is something that numbers do not really explain. A good example is in studio shooting, when using a crop-sensor camera, there is usually so much depth of field that in a group shot, it becomes a significant challenge to render the background well and truly out of focus.

In "REAL" living rooms, and with "real" 9-foot-wide background papers, DX bodies force the shooter to move wayyyyyyyy back, OR to resort to really short focal lengths to get the whole of the group or people into the frame...due to the smaller sensor, and the shorter focal lengths, and the greater distances, this adds up to MORE DEPTH OF FIELD for each picture angle when shooting to a DX sensor camera. And more depth of field is often not what people want to see.

 

[djacobox372]

KmH was dead on regarding bokeh, it is about quality, not quantity. As I understand it, there is no difference in DOF between the two when using the same lens and setting. The lens is producing a circular image at the sensor plane, how much of that image is captured is based on the size of the sensor. The crop sensor is simply cropping a certain percentage off the edges. If I am wrong there, someone please explain and correct me.

You're mistaken, a full frame camera will produce a significantly shallower dof when using the same f stop and focal length due to the ability to shoot closer to the subject. With a crop sensor you have to increase distance or decrease focal length to frame the same shot, both of which widen the dof--putting the background in sharper focus.

If sensor size didn't matter to "bokeh" than why not just use a phone camera or a point and shoot?

 

[Murray Bloom]

Derrel is correct, but I have one issue with what he says. It involves working distance. He doesn't consider that most shooters will have lenses proportional to the sensor being used.

For example, with an FF sensor D800, my general purpose lens is 24-70mm f2.8, while with a crop sensor D300, it's a 17-55mm f2.8. The focal length range is proportional to the sensor size, and for the same subject, working distance is about the same. Both are very good lenses.

Having a mix of sensor sizes has an advantage. The larger sensor needs a lens line-up like 14-24mm, 24-70mm, and 70-200mm, all fast, heavy lenses. However, this would allow me to use the relatively light 18-200mm VR on the D300 as a very versatile walkaround lens and backup to the larger, heavier FF. I can also keep my 10.5mm fisheye for the DX camera and use the 60mm micro on either body. It sounds confusing, but works out very well in practice.

 

[sashbar]

Are you sure you understand why you need an FX camera?? You say you want to see a true 35 mm frame... Do you have many years of shooting with a film SLR got used to a FF frame and now are annoyed but the cropped sensor? Looking at you pictures I doubt it. You want a professional quality, but it comes with what is behind the viewfinder, not with a new camera, especially if you already have D7100. And as far as I see you are not involved in a photography that makes you stretch your camera to its limits. No low light action etc here that I can see. IMHO at this stage buying a FF would be an epic waste of money. You need 'more bokeh' for your portraits? Just buy a good fast prime and there will be bokeh and DoF so shallow you will be struggling to keep a face in focus... Do not be fooled by the D600 price. Buying an FF is all about good FX glass. And good FX glass costs a lot. In my opinion it would be much wiser to hold your fire and keep learning. There is of course the difference in IQ but it is really important to know what is the MEANINGFUL difference for your own work. I see a lot of amateurs who are unable to see and compose a decent picture and yet they keep talking about bokeh, color rendition, skin tones and other technical stuff. Then they go an shoot their cats and dogs. This is a photographic cul-de-sac. I am not saying that you are there, but it I'd always worth bearing in mind.

 

[astroNikon]

......In my opinion it would be much wiser to hold your fire and keep learning. There is of course the difference in IQ but it is really important to know what is the MEANINGFUL difference for your own work. I see a lot of amateurs who are unable to see and compose a decent picture and yet they keep talking about bokeh, color rendition, skin tones and other technical stuff. Then they go an shoot their cats and dogs. This is a photographic cul-de-sac. I am not saying that you are there, but it I'd always worth bearing in mind.

I totally agree about learning as much as possible on your camera body. Though I consider myself a newbie I ran across a green newbie who bought a D7100. Had sent it in the shop to get it fixed because it would not take pictures when he pressed the shutter. So after it was "fixed" and returned it still didn't work. He sold it and jumped to Canon. I'm sure he had his AP-C and AP-S default settings to FOCUS instead of Release, and he was too close to the subject to focus properly -- I remember those initial days as I did the same thing

 

[JTPhotography]

KmH was dead on regarding bokeh, it is about quality, not quantity. As I understand it, there is no difference in DOF between the two when using the same lens and setting. The lens is producing a circular image at the sensor plane, how much of that image is captured is based on the size of the sensor. The crop sensor is simply cropping a certain percentage off the edges. If I am wrong there, someone please explain and correct me.

You're mistaken, a full frame camera will produce a significantly shallower dof when using the same f stop and focal length due to the ability to shoot closer to the subject. With a crop sensor you have to increase distance or decrease focal length to frame the same shot, both of which widen the dof--putting the background in sharper focus.

If sensor size didn't matter to "bokeh" than why not just use a phone camera or a point and shoot?

Yes, I agree. But I am talking about two identical shots, all things being equal including distance from the subject. In that case DOF would be identical. If you move closer or farther away of course it would change, but then you are talking about two different shots. The difference in the sensors is two dimensional. Changes in the third dimension come from lenses and camera position.

 

[sleist]

If sensor size didn't matter to "bokeh" than why not just use a phone camera or a point and shoot?

Sensor size impacts DOF. Bokeh is the "quality" of out of focus areas and is a characteristic of the lens.
The two interact, but are not the same.

A lens with good bokeh characteristics has pleasing out of focus rendering on my DX as well as my FX camera despite the difference in minimum DOF.
There is a point where DOF becomes so large to reduce the amount of out of focus regions (as in your cell phone example), but since we are discussing FX vs. DX, your argument is pointless.

 

[shadowlands]

For me, I was getting frustrated in low-light situations... kids basketball game (indoors), Baptism's, etc...
ISO 3200 on my former D300 was not real pretty at times.
So I finally swapped for a D700, and I can shoot those very events at ISO 6400 now.
So for me, it was worth switching. But outside of those lowlight situations, my former D300 was awesome.

 

[sashbar]

FX works better, in my opinion, for people work, because it allows you to shoot "people pictures" and control the background depth of field more easily.

That is unless you are into environmental portraits or street shooting.

 

[supercool2]

UPDATE:
A few people who replied seemed to be stuck on telling me that I am not gaining better pictures. I know that,and I know that its about the operator,not the gear/camera. My reasoning was *not* for getting better pictures.

I wanted the field of view,as silly as that may sound to some . Since it's also a bigger sensor, it was worth it to me. I am already quite familiar with the limitations/menu/features of the D7100/D600 even though i haven't used every feature yet. I want to feel like its still well beyond good enough for more than a year from now,if not more. And wanted something I can also take a while to grow into with some of the more advanced features and not have a camera that was without those, later on down the RD when I decide to use those (like internal focusing motor, bracketing, and maybe one other thing).

I did go ahead and get a D600. It came today and I tested it out outside a little before it got dark. I already like that I can get more in the picture, compared to the crop. For example at the distance i was sitting away from my daughter, I could get more of the environment around her. When switched the same lens(85mm) on the DX body, the framing was so tight, if i got any closer, part of her head would have been chopped off.
For now I will just be keeping both camera's and using either/or depending on my current needs. For example I might use the D7100 for macro stuff like bugs (later when i get the right lenses for that). And the D600 for most of the portraits, and some landscape,or every day walk around pictures. If I find that I am not using one of them hardly at all, I will know to just sell it already, and get something less expensive as my 'back up" . But Right now I will be keeping both. For what I paid for both combined, that was not too much over my budget for a camera in the first place. When you include the lenses I bought,yes it did bring me over but what's done is done,and I'm happy with my decisions .

 

[djacobox372]

Yes, I agree. But I am talking about two identical shots, all things being equal including distance from the subject. In that case DOF would be identical. If you move closer or farther away of course it would change, but then you are talking about two different shots. The difference in the sensors is two dimensional. Changes in the third dimension come from lenses and camera position.

Lol your only correct if u consider a close-up of a nose and a photo of a face "identical shots."

Why is subject framing unimportant to your calculations? It only happens to be the single most important consideration in photography.

 

[krystalynnephoto]

I just upgraded from the D7000 to the D600 two days ago. For what you're shooting and the reasons you're wanting to upgrade to FF, I just can't justify it. The D7100 is a highly capable camera and sounds like it would be plenty of technology for you. The image quality is superb on a D7000, so I would imagine it to be even better on the D7100. I would keep the extra money and go for the 7100, but that's just my opinion, and I'm not the one spending the money.

 

[supercool2]

Well it's worth it to me,and that is all that matters ;-) I can't go buy a new camera every few years. So the ones I have will have to work for a very very long time.