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Author Topic: Major IQ advantage of FF?  (Read 9800 times)

AprilForever

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Re: Major IQ advantage of FF?
« Reply #30 on: November 07, 2013, 10:14:50 PM »
I know that you get a more shallow DOF and better high ISO performance with a full frame over a crop, but with good lenses on either is there really much of an IQ difference all other things being equal.  I do get great results with my T1i, but I do see some ultra-great results out there that my camera just isn't capable of.  The sensible option is to remain with my crop-inspired lenses and maybe go to a 70D or the next Rebel, but the 6D seems pretty cool. 
I agonize over this stuff because I'm the opposite of a gear-hound.  I'm a minimalist who tries to do the most with the least so it's quality over quantity.  Thank you in advance for your wisdom.

All else being equal, a photosite is a photosite. A FF camera has a larger area, BUT...

Costs more
Has shallower depth of field (NOT always a good thing, ESPECIALLY with long lenses)
Wide angle lenses are WAY more expensive (there are superb crop lenses Tokin 11-16 for example)
lenses are not as long...
Heavier
Bulkier camera
Bulkier lenses

There are a lot of people jumping on the Micro four thirds bandwagon. check out Natureandphotography.com
The author there has ditched FF for smaller, far more usable gear. A camera is useless which is too bulky to use. If you ever feel like not picking up your camera because it is too heavy, consider the true price of FF...
What is truth?

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Re: Major IQ advantage of FF?
« Reply #30 on: November 07, 2013, 10:14:50 PM »

takesome1

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Re: Major IQ advantage of FF?
« Reply #31 on: November 07, 2013, 10:37:01 PM »
I know that you get a more shallow DOF and better high ISO performance with a full frame over a crop, but with good lenses on either is there really much of an IQ difference all other things being equal.

I'm a minimalist who tries to do the most with the least so it's quality over quantity.  Thank you in advance for your wisdom.

Shallow DOF and better high ISO performance improves IQ. Unless you hold to the thought that lens sharpness is the test of IQ. Both of these reasons are big positives to go with a FF body.

With equally framed identical FOV pictures with the same lens the IQ will be better out of the FF. The FF will put more pixels and larger pixels on the target than a crop body will. Larger pixels will take a larger sampling of available light. You will be closer to the subject in this situation and that will improve your IQ as well.

Only in those situations where you focal length limited would the crop body have an advantage. An example would be shooting distant objects with the longest lens you own.

So quality over quantity IMO would be to own a 6D with a 24-70mm f/2.8 II, instead of owning a t4i and a half dozen average lenses.

abcde12345

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Re: Major IQ advantage of FF?
« Reply #32 on: November 07, 2013, 11:47:24 PM »
To be honest I've always been skeptical about the difference, but today after editing some of the pictures from a 6D I borrowed from someone, the IQ difference is amazing! I used the same lens for 6D and 550D, and I must say the sharpness, crisp, dynamic range, colour and "wow" effect is something I've never seen in my 550D. Given that it might be a skill thing, I am convinced now that the sensors do matter, and IQ will be the same if the same sensor is used in APS-C and FF cameras (I guess?), but the issue is that FF generally uses a different sensor, hence the difference.

Pi

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Re: Major IQ advantage of FF?
« Reply #33 on: November 07, 2013, 11:57:39 PM »
A FF camera has a larger area, BUT...
[...]
Has shallower depth of field (NOT always a good thing, ESPECIALLY with long lenses)

This is a misconception. FF does not have shallower DOF. It only has the option for less DOF when needed.

AprilForever

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Re: Major IQ advantage of FF?
« Reply #34 on: November 08, 2013, 12:23:00 AM »
A FF camera has a larger area, BUT...
[...]
Has shallower depth of field (NOT always a good thing, ESPECIALLY with long lenses)

This is a misconception. FF does not have shallower DOF. It only has the option for less DOF when needed.

Sure it has shallower depth of field 50mm at f4 on a 7D is roughly equivalent to 30mm f2.5 on a 5D. Same framing, shallower depth of field. When shooting birds in flight, I need usually f8 on a 7D to get the bird at least mostly in focus. On full frame? That's f13. To maintain shutter speed, that means ever rising ISO's.

Yes. The Hi ISO advantage disappears.

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Pi

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Re: Major IQ advantage of FF?
« Reply #35 on: November 08, 2013, 12:39:11 AM »
This is a misconception. FF does not have shallower DOF. It only has the option for less DOF when needed.
When shooting birds in flight, I need usually f8 on a 7D to get the bird at least mostly in focus. On full frame? That's f13. To maintain shutter speed, that means ever rising ISO's.

Yes. The Hi ISO advantage disappears.

And the "shallow DOF disadvantage" disappears, too. There is a reason those are called equivalent settings.

J.R.

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Re: Major IQ advantage of FF?
« Reply #36 on: November 08, 2013, 12:52:51 AM »
A FF camera has a larger area, BUT...
[...]
Has shallower depth of field (NOT always a good thing, ESPECIALLY with long lenses)

This is a misconception. FF does not have shallower DOF. It only has the option for less DOF when needed.

Sure it has shallower depth of field 50mm at f4 on a 7D is roughly equivalent to 30mm f2.5 on a 5D. Same framing, shallower depth of field. When shooting birds in flight, I need usually f8 on a 7D to get the bird at least mostly in focus. On full frame? That's f13. To maintain shutter speed, that means ever rising ISO's.

Yes. The Hi ISO advantage disappears.



And that is just plain BS you are talking. Assuming that you are taking a photograph of a bird with a 400mm lens 50 feet away. Let's see how the DOF works out at f/8 with the 5D3 and the 7D -

7D: Total DOF is 1.41 feet
5D3: Total DOF is 2.23 feet
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Re: Major IQ advantage of FF?
« Reply #36 on: November 08, 2013, 12:52:51 AM »

Hillsilly

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Re: Major IQ advantage of FF?
« Reply #37 on: November 08, 2013, 01:51:28 AM »
I enter monthly club photo competitions.  When you view the entries, you have no idea what type of camera was used, the settings, the lens etc.  Yet I know that other photos are taken with a mixture of FF and APS-C cameras.  There's even the occasional film camera and P & S.  But usually its almost impossible to tell what type of camera was used.  And in 100% of cases, from a viewer's perspective, it is irrelevant, because you are only interested in the final result.  You're more concerned with impact, emotion, etc.

But from the photographers perspective, choice of camera is very relevant.  If your final result relates to an image in low light, fast action, taken in the rain, needs particular lenses, etc then things are so much easier if you are using the right tool for the job.  Given that FF cameras have traditionally been more feature packed, apart from IQ, there are a lot of other reasons why they might be the best choice for someone.  Just as in many situations, a crop camera is the best choice.

In summary - when viewing the final result, nobody cares what camera you used.  But choosing the right camera makes it easier to get the best final result.
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AlanF

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Re: Major IQ advantage of FF?
« Reply #38 on: November 08, 2013, 02:23:22 AM »
A FF camera has a larger area, BUT...
[...]
Has shallower depth of field (NOT always a good thing, ESPECIALLY with long lenses)

This is a misconception. FF does not have shallower DOF. It only has the option for less DOF when needed.

Sure it has shallower depth of field 50mm at f4 on a 7D is roughly equivalent to 30mm f2.5 on a 5D. Same framing, shallower depth of field. When shooting birds in flight, I need usually f8 on a 7D to get the bird at least mostly in focus. On full frame? That's f13. To maintain shutter speed, that means ever rising ISO's.

Yes. The Hi ISO advantage disappears.



And that is just plain BS you are talking. Assuming that you are taking a photograph of a bird with a 400mm lens 50 feet away. Let's see how the DOF works out at f/8 with the 5D3 and the 7D -

7D: Total DOF is 1.41 feet
5D3: Total DOF is 2.23 feet

I think that there are circles of confusion here! It seems pretty obvious that if you have the same lens it gives the same size image on crop and FF sensors, and if the two images are viewed at the same size on a screen or print they will have exactly the same depth of field. If they are not enlarged, but the FF is viewed at a smaller size, it will only appear to have a greater depth of field.

The arithmetic from the DOF calculator proves that the images have the same depth of field when viewed at the same size. The depth of field is calculated from the size of the circle of confusion. For the 5DIII it is 0.03 mm, for the 1.6x crop 7D it is 0.019. And 0.03/0.019 = 1.6. So, when you enlarge the FF image 1.6x to get the same size image as the crop, you exactly compensate for the difference in circles of confusion.

Similarly, look at the ratios of total DOF of the 5D3 to 7D. It equals 2.23/1.41 = 1.6. The image from FF has to be enlarged 1.6x to give the same size print as the crop, and in doing so you multiply the out of focus regions 1.6x and so reduce the depth of field 1.6x. 

Edit: to avoid confusion - what I am talking about is taking. say, a photo of a bird in flight, and cropping the bird in flight on the FF to be the same size as that taken directly on the crop. Then, they should have the same depth of field.
« Last Edit: November 08, 2013, 02:54:25 AM by AlanF »
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Zlyden

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Re: Major IQ advantage of FF?
« Reply #39 on: November 08, 2013, 02:33:52 AM »
And that is just plain BS you are talking. Assuming that you are taking a photograph of a bird with a 400mm lens 50 feet away. Let's see how the DOF works out at f/8 with the 5D3 and the 7D -

7D: Total DOF is 1.41 feet
5D3: Total DOF is 2.23 feet

Yes (as someone else probably already mentioned), you should count in crop factor of x1.6 and compare "Focal length (mm): 400 mm" on cropped 7D with "Focal length (mm): ~ 640 mm" on FF 5Ds.

After that you will see that to get "equivalent" DOF, you need to stop 5D down to f/13...
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Re: Major IQ advantage of FF?
« Reply #40 on: November 08, 2013, 02:42:09 AM »
And that is just plain BS you are talking. Assuming that you are taking a photograph of a bird with a 400mm lens 50 feet away. Let's see how the DOF works out at f/8 with the 5D3 and the 7D -

7D: Total DOF is 1.41 feet
5D3: Total DOF is 2.23 feet

Yes (as someone else probably already mentioned), you should count in crop factor of x1.6 and compare "Focal length (mm): 400 mm" on cropped 7D with "Focal length (mm): ~ 640 mm" on FF 5Ds.

After that you will see that to get "equivalent" DOF, you need to stop 5D down to f/13...

AprilForever wasn't talking about equivalence so I guess you missed the point. In fact, while doing the IQ comparisons, it is almost always assumed that you need to crop the FF image to make it equivalent to the APS-C image ... If that is mandatory, why buy a FF in the first place?
« Last Edit: November 08, 2013, 03:08:23 AM by J.R. »
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J.R.

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Re: Major IQ advantage of FF?
« Reply #41 on: November 08, 2013, 02:49:16 AM »
A FF camera has a larger area, BUT...
[...]
Has shallower depth of field (NOT always a good thing, ESPECIALLY with long lenses)

This is a misconception. FF does not have shallower DOF. It only has the option for less DOF when needed.

Sure it has shallower depth of field 50mm at f4 on a 7D is roughly equivalent to 30mm f2.5 on a 5D. Same framing, shallower depth of field. When shooting birds in flight, I need usually f8 on a 7D to get the bird at least mostly in focus. On full frame? That's f13. To maintain shutter speed, that means ever rising ISO's.

Yes. The Hi ISO advantage disappears.



And that is just plain BS you are talking. Assuming that you are taking a photograph of a bird with a 400mm lens 50 feet away. Let's see how the DOF works out at f/8 with the 5D3 and the 7D -

7D: Total DOF is 1.41 feet
5D3: Total DOF is 2.23 feet

I think that there are circles of confusion here! It seems pretty obvious that if you have the same lens it gives the same size image on crop and FF sensors, and if the two images are viewed at the same size on a screen or print they will have exactly the same depth of field. If they are not enlarged, but the FF is viewed at a smaller size, it will only appear to have a greater depth of field.

The arithmetic from the DOF calculator proves that the images have the same depth of field when viewed at the same size. The depth of field is calculated from the size of the circle of confusion. For the 5DIII it is 0.03 mm, for the 1.6x crop 7D it is 0.019. And 0.03/0.019 = 1.6. So, when you enlarge the FF image 1.6x to get the same size image as the crop, you exactly compensate for the difference in circles of confusion.

Similarly, look at the ratios of total DOF of the 5D3 to 7D. It equals 2.23/1.41 = 1.6. The image from FF has to be enlarged 1.6x to give the same size print as the crop, and in doing so you multiply the out of focus regions 1.6x and so reduce the depth of field 1.6x.

If talking in terms of equivalence, yes.
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Zlyden

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Re: Major IQ advantage of FF?
« Reply #42 on: November 08, 2013, 03:23:40 AM »
AprilForever wasn't talking about equivalence so I guess you missed the point.

Maybe.

As I understand the meaning was:

"To get the similar image of some bird on FF body, you will need a longer lens and smaller aperture value, that makes higher ISO advantage less obvious"
(close enough?)

And this is really one the things crop-to-FF switcher should take into account (or at least -- not forget about).

PS: I did myself made a switch from old 400D to 6D about a month ago ;D) (that should explain my interest to the topic).

So far I'm quite happy with 6D -- it's amazing how the lenses I used to play with for 4-6 years on 400D (24-105, 70-300, 50/1.8II) started to make very different pictures. It really adds new level of fun to amateurish hobby (one of the things that makes the switch "worth it" for those who did not have FF bodies before). I would avoid using phrases like "Major IQ advantage".

But, I'm not sure yet if I'm happy with 17-40 that I had to get to replace cropped 10-22...
« Last Edit: November 08, 2013, 03:25:28 AM by Zlyden »
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Re: Major IQ advantage of FF?
« Reply #42 on: November 08, 2013, 03:23:40 AM »

AlanF

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Re: Major IQ advantage of FF?
« Reply #43 on: November 08, 2013, 03:53:31 AM »
A FF camera has a larger area, BUT...
[...]
Has shallower depth of field (NOT always a good thing, ESPECIALLY with long lenses)

This is a misconception. FF does not have shallower DOF. It only has the option for less DOF when needed.

Sure it has shallower depth of field 50mm at f4 on a 7D is roughly equivalent to 30mm f2.5 on a 5D. Same framing, shallower depth of field. When shooting birds in flight, I need usually f8 on a 7D to get the bird at least mostly in focus. On full frame? That's f13. To maintain shutter speed, that means ever rising ISO's.

Yes. The Hi ISO advantage disappears.



And that is just plain BS you are talking. Assuming that you are taking a photograph of a bird with a 400mm lens 50 feet away. Let's see how the DOF works out at f/8 with the 5D3 and the 7D -

7D: Total DOF is 1.41 feet
5D3: Total DOF is 2.23 feet

I think that there are circles of confusion here! It seems pretty obvious that if you have the same lens it gives the same size image on crop and FF sensors, and if the two images are viewed at the same size on a screen or print they will have exactly the same depth of field. If they are not enlarged, but the FF is viewed at a smaller size, it will only appear to have a greater depth of field.

The arithmetic from the DOF calculator proves that the images have the same depth of field when viewed at the same size. The depth of field is calculated from the size of the circle of confusion. For the 5DIII it is 0.03 mm, for the 1.6x crop 7D it is 0.019. And 0.03/0.019 = 1.6. So, when you enlarge the FF image 1.6x to get the same size image as the crop, you exactly compensate for the difference in circles of confusion.

Similarly, look at the ratios of total DOF of the 5D3 to 7D. It equals 2.23/1.41 = 1.6. The image from FF has to be enlarged 1.6x to give the same size print as the crop, and in doing so you multiply the out of focus regions 1.6x and so reduce the depth of field 1.6x.

If talking in terms of equivalence, yes.

I am not sure that he is talking "plain BS". If you obtain the same field of view on the FF as on the 1.6x crop by either standing 1.6x closer with the FF or use a 1.6x longer lens, the crop has 1.6x greater DOF (calculated on the DOF calculator you used). If, as we have agreed, you crop the FF from the same distance with the same lens, 1.6x, then the cropped FF has the same DOF as the crop sensor.
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aj1575

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Re: Major IQ advantage of FF?
« Reply #44 on: November 08, 2013, 04:38:19 AM »
  The sensible option is to remain with my crop-inspired lenses and maybe go to a 70D or the next Rebel, but the 6D seems pretty cool. 
There are mainly two questions you need to answer. First, and most important; how much money do you like to spend on a tool you do not need to make a living out of. I think you know this, since the 70D and the 6D are not so far appart on the price scale.
The second qustion is, what you like to do with the camera and the file; are you an allround shooter, or do specialize in something; do you need/like to make large prints, or do you almost only make smaller prints.

FF (the 6D) will give an advantage in IQ; you will see this especially at high ISO and in large prints. With smaller prints and at lower ISO the difference is rather small. On the screen APS-C pictures can look quite nasty when zommed to 100% (my 70D files at high ISO do so), but at 20MP the resolution is so high, that it does not really matter in normal prints.
On the other hand, the 70D has a very nice AF-system, a cool touch screen (this is no toy, it really improves the handling), the higher frame rate, and other nice features.

If you are a landscape or architecture photograph, then I would go for the 6D. The IQ is great, but it is not a "fast" camera. The 70D is more of an allround package, with a little disadvantage in IQ; which is okay when you do not need large prints.

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Re: Major IQ advantage of FF?
« Reply #44 on: November 08, 2013, 04:38:19 AM »