August 22, 2014, 08:01:21 PM

Author Topic: Major IQ advantage of FF?  (Read 9819 times)

sanj

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Re: Major IQ advantage of FF?
« Reply #15 on: November 07, 2013, 01:40:33 AM »
Of course full frame is better.

Why would you not shoot full frame? If you do not go overboard and limit yourself to say a 6D and a decent lens what would be the cost difference between this and crop? Not enough to matter in the long run.

gmrza

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Re: Major IQ advantage of FF?
« Reply #16 on: November 07, 2013, 01:49:49 AM »

Good examples! While they are somewhat close the 5D3 image has way more pop. :)

Therein lies part of the problem of my comparison - a good part of that "pop" is due to the 24-70 f/2.8II.  Pay more attention to shadow detail and noise, which is less due to the lens.

The 24-70 f/2.8 II is much better in this respect than the 50mm f/1.4 in terms of contrast and colour rendition.
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Nishi Drew

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Re: Major IQ advantage of FF?
« Reply #17 on: November 07, 2013, 03:45:08 AM »
Of course full frame is better.

Why would you not shoot full frame? If you do not go overboard and limit yourself to say a 6D and a decent lens what would be the cost difference between this and crop? Not enough to matter in the long run.

However, better lenses are required, though shooting F/2 on APS-C is close to shooting F/2.8 on FF, which means the stopped down performance advantage with equal DOF is there with FF, but lenses tend to perform better on APS-C in regards to taking the good center IQ of a lens. I've compared shots with my 5DII + Sigma 35mm and a friend's X100, the images come so close to performance with image quality and ISO performance, my lens was sharper wide open and of course, I could go twice as shallow, but the colors and overall picture the X100 can put out with plain Jpegs are just marvelous, this made me reconsider the relevance of full frame for a while...
But, I'm comparing an FF from 2008 and a crop from 2010, so, smaller sensor cameras will outperform older larger sensor cameras, but in terms of latest tech the bigger sensor will outperform the smaller in ISO performance, color depth, DR etc. but it's all an eventual catch up game I believe

Marsu42

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Re: Major IQ advantage of FF?
« Reply #18 on: November 07, 2013, 05:38:51 AM »
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 recently added a 6d to my 60d, so I would say that next to intensive research I know both sides pretty well by now, so here's my general take: It is true that it is very hard to tell a unprocessed shot from a crop at low iso from a ff (at the same dof of course), and iso noise doesn't matter if you are shooting for key chain holder print size. *But* there are hidden aspects:

* ff has more leverage for postprocessing, this is what matters the most to me. If you try to raise one color channel on a gradient (say lessen or intensify blue on a partly cloudy sky) the crop shot will immediately fall apart while the bigger ff pixels allow for more postprocessing creativity or fixing. Also the ff has less problems on the red color channel on plain surfaces, a known issue with Canon sensors, try shooting a red mushroom if you don't know what I'm talking about.

* The recent ff models like 6d have virtually no banding (well, I've never seen it), quite unlike the 60d, not to speak of the older 7d - I don't know if this has gotten any better with the 70d. Banding after raising shadows is what kills your shot while you can reduce the film-like iso noise on the recent ff models a lot esp. with newer algorithms like DxO PRIME. In reality, I find the ff has a 2-3 stop advantage over crop because with crop iso800 is the highest "safe" setting while with the 6d it's iso6400, and truth to be told I'd still prefer the latter if the dr is low.

* Crop is equal to ff with good lenses, but you really have look out for them or use ef-s - my midrange 17-40L and 70-300L are much sharper wide open on ff, though the tele zoom has a radial bokeh on the outside that you can like (or not) that is cut away by crop.

* Noise: I'd like to advise not to underestimate the freedom this gives you, it's not just for very large prints nobody will really do but with crop you constantly have to trade shutter speed vs. iso noise as crop @iso800 is already problematic. Unless the dr is very high with ff you can just use a higher shutter which results in much more keepers, less headaches about tech but more thought about composition.

* If you use Magic Lantern: with ff you can boost your dynamic range to 14ev with a dual_iso 100/800 shot with virtually no drawback because noise doesn't matter at these settings - with crop iso800 already has noise so it's getting awkward. Also to get a thinner dof with crop you have to carry much more bulk, with ff my compact 70-300L @f4 is "thin enough" for me.

* Viewfinder: Not directly sensor-iq related and last, but not least - the more expensive crop cameras have an somewhat ok vf, but with ff you see more of what you're shooting due to the larger mirror which is a reason for ff on its own as in "iq for your eye".

I keep using my 60d because it's better for macro (deeper dof, larger working range) and tripod (swivel screen) as the 100L and 17-40L (@f8+) is sharp enough for crop - and of course for tele shots with 300mm * 1.6x crop factor which makes a decisive difference for wildlife. So I ended up where Canon wants you to end up - buying two cameras :-p

dtaylor

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Re: Major IQ advantage of FF?
« Reply #19 on: November 07, 2013, 06:16:43 AM »
3) FF gives less distortion with wide angles while crop gives more pixels on target for distant objects.

First part is false. Distortion is the same for the FoV (assuming equal lens IQ).

Quote
4) FF is more forgiving of lens limitations than crop. (Kit lenses on a crop camera give poor sharpness, but a quality lens is good on FF and crop)

FF is more forgiving of lens sharpness, but less forgiving of side and corner performance.

dtaylor

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Re: Major IQ advantage of FF?
« Reply #20 on: November 07, 2013, 06:24:51 AM »
* ff has more leverage for postprocessing, this is what matters the most to me. If you try to raise one color channel on a gradient (say lessen or intensify blue on a partly cloudy sky) the crop shot will immediately fall apart while the bigger ff pixels allow for more postprocessing creativity or fixing.

This is true but an exaggeration. Crop images do not 'immediately fall apart.' You have to push to see the difference.

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Also the ff has less problems on the red color channel on plain surfaces, a known issue with Canon sensors, try shooting a red mushroom if you don't know what I'm talking about.

This is true at anything other then the lowest ISOs. But it's true for most (all?) crop sensors, and even the FF ones as the ISOs climb. You just have more ISOs where red doesn't suck on FF.

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In reality, I find the ff has a 2-3 stop advantage over crop because with crop iso800 is the highest "safe" setting while with the 6d it's iso6400, and truth to be told I'd still prefer the latter if the dr is low.

The crop sensors are fine to about 3200, though I agree that Canon's FF sensors are 2+ stops better at high ISO.

Quote
* Viewfinder: Not directly sensor-iq related and last, but not least - the more expensive crop cameras have an somewhat ok vf, but with ff you see more of what you're shooting due to the larger mirror which is a reason for ff on its own as in "iq for your eye".

I don't notice a significant difference vs. the 7D, though what you say is true for the other crop models.

Quote
and of course for tele shots with 300mm * 1.6x crop factor which makes a decisive difference for wildlife.

It's hard to beat a "built in" 1.6x teleconverter  :)

Cory

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Re: Major IQ advantage of FF?
« Reply #21 on: November 07, 2013, 06:35:53 AM »
Thanks for all the responses.  Here's my "best of" flickr stream if you like:

http://www.flickr.com/photos/corysteiner/

Sticking with what I have for now, but I can maybe replace the body with a 70D and see what happens or replace my body and normal lens with a 6D and 35 or 50 prime and see what happens (my telephoto lenses are the 100 2.0 and 200 2.8 ). 

 :o ??? :-* 8) ;D
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docsmith

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Re: Major IQ advantage of FF?
« Reply #22 on: November 07, 2013, 06:43:25 AM »
The "major" IQ advantage of FF is in high ISO noise.  There is an improvement of ~2 stops.  Which is to say, you get similar levels of noise at ISO 6400 on a current generation FF sensor as ISO 1600 on a current generation crop sensor. 

This past year I went from a 7D to a 5DIII.  I happily shot for years with the 7D.  It is a great camera.  I took many pictures that I proudly posted on the web and enlarged to 16x20 in prints.  People still come into my office and stop and stare at some of the pictures before they talk with me.  Crop sensors are very capable.

I upgraded for a couple of reasons.  First, the higher ISO performance.  I didn't want to use a flash as often as I was.  But I have also seen improvements, IMO, in color rendition, fine detail, highlight performance, and out-of focus blur (bokeh) using the same or similar lenses.  Regarding detail, I sometimes get shots that are so sharp, I could print them at 100% and they'd look good.  That was almost never true on the 7D.

So, P&S camera sensors are better than camera phones, crop sensors are much better than P&S cameras (2/3 sensors), FF is better than cropped sensors, and medium format gives even better images than FF.  So, phone>P&S>APS-C>FF>MF. 

You just need to pick where in that range your budget allows and you want to be...

sanj

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Re: Major IQ advantage of FF?
« Reply #23 on: November 07, 2013, 06:56:23 AM »
Of course full frame is better.

Why would you not shoot full frame? If you do not go overboard and limit yourself to say a 6D and a decent lens what would be the cost difference between this and crop? Not enough to matter in the long run.

However, better lenses are required, though shooting F/2 on APS-C is close to shooting F/2.8 on FF, which means the stopped down performance advantage with equal DOF is there with FF, but lenses tend to perform better on APS-C in regards to taking the good center IQ of a lens. I've compared shots with my 5DII + Sigma 35mm and a friend's X100, the images come so close to performance with image quality and ISO performance, my lens was sharper wide open and of course, I could go twice as shallow, but the colors and overall picture the X100 can put out with plain Jpegs are just marvelous, this made me reconsider the relevance of full frame for a while...
But, I'm comparing an FF from 2008 and a crop from 2010, so, smaller sensor cameras will outperform older larger sensor cameras, but in terms of latest tech the bigger sensor will outperform the smaller in ISO performance, color depth, DR etc. but it's all an eventual catch up game I believe

"All things being equal" implies we compare same manufactures, current sensors, lenses etc. Bottom line: Full frame is better.

Pi

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Re: Major IQ advantage of FF?
« Reply #24 on: November 07, 2013, 08:00:23 AM »
Unless you are FL (and cash) limited, FF provides much better IQ. Some people would not care, and that is OK. But if you do, you immediately notice:

  • Much richer colors. This is a Canon thing. To be competitive in benchmark tests, they put weaker color filters in the crop cameras.
  • Much better base ISO files. Again, on small monitors and/or for people who do not care, base ISO is the same. But once you start pp your file, you will notice better tonality, more "elastic" RAWs, etc. This is related to the better color separation and the lower noise at base ISO.
  • Much better resolution at equivalent apertures at large apertures (low f-numbers), and still better resolution at f/11 or so.
  • DOF, but you knew that.
  • A lot of excellent lenses designed for FF.
  • AF is generally better at equivalent apertures.

Here is a graph with DXO data: the Canon 50/1.4 on the 7D (green) vs. the Canon 85/1.8 on the 5D2 (red), in equivalent apertures, center:


You see that the advantage is more noticeable near wide open, where the weakest resolution is. BTW, I was sloppy, and did not make the effort to draw better interpolated curves. The peaks of both curves are flattened.

Another comparison: the 135L on the 5DII vs. the 85L (twice the price!) on the 50D, in the center, using photozone.de data. The 70D would perform better, of course but not so much wide open - the limiting factor is the lens here. Again, equivalent apertures. The shorter green curve is the 85/1.8 on the 50D. 


And here: http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=397&Camera=736&Sample=0&FLI=0&API=0&LensComp=108&CameraComp=0&FLIComp=0&APIComp=0 is a visual evidence (crop camera: 60D). This picture is much more telling since you see the effect of the LoCA as well.

BTW, I used to have crop cameras, so I am speaking of experience, as well. You can follow the link in my profile for some 50D/5D2 comparisons (cameras of the same generation). You can see there some equivalent comparisons, and also how the 35L compares wide open on both (not equivalent shots, of course).

BTW, the theory that crop cameras use the better part of the lens is a myth, mostly. They do but they penalize you everywhere by the extra enlargement needed. That penalty is compensated a bit but the higher pixel density but this factor is not enough, most of the time. EF lenses do offer more uniform performance on crop than EF-S lenses but at the expense of some resolution.
« Last Edit: November 07, 2013, 08:09:27 AM by Pi »

Ruined

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Re: Major IQ advantage of FF?
« Reply #25 on: November 07, 2013, 08:07:35 AM »
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.

In most cases, you will get better quality for full frame, but there are cases crop is better too.

If you are trying to frame something really far away and it fails to fill the frame of your full frame camera due to lack of reach, the crop camera will likely have better quality on said target as its reach will be better due to the crop factor & more pixels on the far away item.

Crop is also better in terms of lightness and cost, meaning you may not always want to take something as heavy and costly as full frame with you everywhere.

But, for most other situations full frame will produce a significantly better picture.  Consider though that for full frame its not just the cost of a 6D, but also the replacement zoom lenses that run $1000+ for quality ones, and $2000+ for really high quality ones.  So whether the improved picture is personally worth it will only likely be found with experimentation.

Personally, I'd advocate having both a full frame and a crop camera and using them for different scenarios.

Marsu42

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Re: Major IQ advantage of FF?
« Reply #26 on: November 07, 2013, 09:14:07 AM »
* ff has more leverage for postprocessing, this is what matters the most to me. If you try to raise one color channel on a gradient (say lessen or intensify blue on a partly cloudy sky) the crop shot will immediately fall apart while the bigger ff pixels allow for more postprocessing creativity or fixing.
This is true but an exaggeration. Crop images do not 'immediately fall apart.' You have to push to see the difference.

Not to be misunderstood: The "immediately" is concerning color channel operation like pushing or reducing blue sky or green grass - otherwise of course you can do a lot of pp with crop shots unless you're drowning in iso noise.

Quote
In reality, I find the ff has a 2-3 stop advantage over crop because with crop iso800 is the highest "safe" setting while with the 6d it's iso6400, and truth to be told I'd still prefer the latter if the dr is low.
The crop sensors are fine to about 3200

This has been discussed to death, so no need to re-open pandora's box :-p but to clarify: I find iso800 the max. setting which doesn't make that much of a difference @100% crop if properly exposed, otherwise it's up to the specific subject, print/display size and subjective feeling when nr+sharpening results in too much of a plastic look.

bdunbar79

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Re: Major IQ advantage of FF?
« Reply #27 on: November 07, 2013, 03:45:37 PM »
Ok, I know we're talking APS-C here, but have you ever shot at ISO 3200 and ISO 6400 with the 1D Mark IV?  Completely useable, if not underexposed.  I think this more speaks to Canon's flagship line manufacturing though, vs. the general category of APS-H sensors.  I have a lot of night football game shots at ISO 3200 with that camera that are probably not much different than the 1Dx shots at that ISO, same situation.  This is where I think a 1D4 with 300 f/2.8 might be a better choice than a 1Dx 300 f/2.8 but with cropping in post.  I could be wrong.
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gmrza

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Re: Major IQ advantage of FF?
« Reply #28 on: November 07, 2013, 04:45:31 PM »

  • A lot of excellent lenses designed for FF.


This is especially apparent if you want to shoot at the shorter end of the focal length range.  You have better options available to you if shooting full frame than crop.  That said, I have still shot some decent landscapes with the 7D.

One good example is the 24-105 f/4 - being a full frame lens, it delivers best in terms of its overall flexibility on a full frame body.  On crop, you effectively lose out on the wide end, and you cannot shoot exposures as long hand-held as on full frame.  I have successfully shot 0.3s exposures with the 5DII and 24-105 f/4L IS USM hand-held.  I would not like my chances of achieving the same with the 7D.
If you were to move to the 17-55 f/2.8 IS USM on crop, you would lose the long end and the weather sealing.

Currently, if I want to shoot something quickly, I just pull the 7D out of the cupboard.  If I want to put more care into the shot, I reach for the 5DII or 5DIII.

Maybe on the weekend I can convince my son or daughter to pose and let me shoot with the 5DIII and 7D in the same light, using the same lens.  That would be a more valid comparison.  It would probably need to be in studio to guarantee the same lighting.
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Cory

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Re: Major IQ advantage of FF?
« Reply #29 on: November 07, 2013, 07:53:22 PM »
Thanks again.  I think my options are:
- 70D with my current set of 17-55, 100 2.0 and 200 2.8II  or
- 6D (or used 5D Mk II) with (sell my 17-55 for) 35 2.0 IS, 100 2.0 and 200 2.8II
My main duty is indoor volleyball, but I also do a lot of street, landscape, travel, family, nature, etc.

 :-*
« Last Edit: November 07, 2013, 08:26:40 PM by Cory »
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