Fuji X Lenses

[armand]

And before being accused I'm incomplete again  what I found for particular lens (200 mm F/2.8 ) focused at 100 meters (or feet) in APS-C you need to get closer to 82 meters (or feet) to get the same DOF on full frame.
I'm too lazy to calculate the differences in FOV when you get closer (plus it might change with the focus distance, not sure on this one as the percentages seem to stay the same).

[Slobodan Blagojevic]

Armand, it seems to me that you are challenging this concept:

You can't dream much about bokeh on an APS-C sensor

Are you saying that it isn't true? What Hulyss is saying, in a very broad-brush terms, is that cropped sensors have inherently deeper DOF, i.e., are less suitable if one is after a shallow DOF, which is one of the elements of a good bokeh (the other being the quality of rendering of OOF areas).

Now, it seems to me that you are saying that 56/1.2 Fuji lens would have the same DOF as 85/1.8 Nikon on a full-frame body? That would be correct, but only if Fuji is used one f/stop wider, e.g., f/1.2 vs. f/1.8. If the same f/stop is used for both lenses, a full frame sensor would deliver a better bokeh. Are we in agreement on that?

[armand]

Armand, it seems to me that you are challenging this concept:

Are you saying that it isn't true? What Hulyss is saying, in a very broad-brash terms, is that cropped sensors have inherently deeper DOF, i.e., are less suitable if one is after a shallow DOF, which is one of the elements of a good bokeh (the other being the quality of rendering of OOF areas).

Now, it seems to me that you are saying that 56/1.2 Fuji lens would have the same DOF as 85/1.8 Nikon on a full-frame body? That would be correct, but only if Fuji is used one f/stop wider, e.g., f/1.2 vs. f/1.8. If the same f/stop is used for both lenses, a full frame sensor would deliver a better bokeh. Are we in agreement on that?

Yes. If you cannot get enough DOF with the 56 at F/1.2 then you cannot get it with the full frame Nikon 85 at F/1.8 either as they are identical in FOV and DOF.

I do not challenge that the full frame has an inherent advantage in providing shallower DOF.

The second part though I would like to see somebody come with an explanation as I thought the same as you until I actually checked.

PS. The second part being what I posted with the DOF calculator

[Slobodan Blagojevic]

... The second part though I would like to see somebody come with an explanation as I thought the same as you until I actually checked.

PS. The second part being what I posted with the DOF calculator

Can you specifically formulate the issue you are referring to as "the second part"? There is too much confusion going back and forth what was said or implied in which post.

[David Sutton]

Armand, it seems to me that you are challenging this concept:

 If the same f/stop is used for both lenses, a full frame sensor would deliver a better bokeh. Are we in agreement on that?

No, I wouldn't agree based on using a 5DII and Fuji cameras. I just don't see in print that one or the other is better, just different.  Because we trying to compare camera systems not just lenses. Both full frame and APS-C can deliver stunning bokeh or make you feel frazzled.
What is really interesting is the quality of the gradient as the background goes out of focus.

[Slobodan Blagojevic]

No, I wouldn't agree... Both full frame and APS-C can deliver stunning bokeh or make you feel frazzled...

David, we are in agreement, but only if by "bokeh" we assume the quality of OOF area rendering. If, however, we add another element to the definition of bokeh, i.e., the amount of blur (which is then dependent of DOF), full frame sensors would have an advantage (at the same f/stop). While you can match a full-frame bokeh of a 1.8 lens with, say 1.2 lens on a cropped body, you can not match 1.4, 1.2, or 1.0 lens, unless you have a full stop wider lens on a cropped body.

[Hulyss]

Armand, it seems to me that you are challenging this concept:

Are you saying that it isn't true? What Hulyss is saying, in a very broad-brash terms, is that cropped sensors have inherently deeper DOF, i.e., are less suitable if one is after a shallow DOF, which is one of the elements of a good bokeh (the other being the quality of rendering of OOF areas).

Now, it seems to me that you are saying that 56/1.2 Fuji lens would have the same DOF as 85/1.8 Nikon on a full-frame body? That would be correct, but only if Fuji is used one f/stop wider, e.g., f/1.2 vs. f/1.8. If the same f/stop is used for both lenses, a full frame sensor would deliver a better bokeh. Are we in agreement on that?

Thank you Slobodan, I need to formulate better my phrases for a better understanding 

I would had that the bigger surface of a 24x36 sensor also help at better transition which have impact on final rendering (and bokeh). I'm tired of those comparisons

[David Sutton]

David, we are in agreement, but only if by "bokeh" we assume the quality of OOF area rendering. If, however, we add another element to the definition of bokeh, i.e., the amount of blur (which is then dependent of DOF), full frame sensors would have an advantage (at the same f/stop). While you can match a full-frame bokeh of a 1.8 lens with, say 1.2 lens on a cropped body, you can not match 1.4, 1.2, or 1.0 lens, unless you have a full stop wider lens on a cropped body.

Yes, I think we are in agreement.
But I would go a little further and argue that while a 1.2 on a full frame will in theory absolutely give more dof than a 1.2 on an APS-C (but not necessarily better quality), in real life you probably won't see it. My eye gets more distracted by the quality of the gradient and the busyness of the highlights in the background. We are always comparing apples with oranges if that makes sense.
Here's an example. I'm starting to find that my Fuji lenses that are sharp corner to corner (and give much sharper files than the 5DII printed large) are not always what I'm looking for in terms of bokeh. I plan on  getting some Rokinon/Samyang primes that are sharp in the middle 2/3 and then fall away at the edges.  I think wide open they will direct the viewer's eye in a way that can't be done satisfactorily in post. The bokeh from a sharp lens has a different quality from one that is going a little soft, and I think I may sometimes prefer the lens that is gradually going soft.
David

[armand]

Thank you Slobodan, I need to formulate better my phrases for a better understanding 

I would had that the bigger surface of a 24x36 sensor also help at better transition which have impact on final rendering (and bokeh). I'm tired of those comparisons

No, that's not what you said and I understood very well what you were trying to say.
You have something against APS-C (and Fuji in particular) and because of that you made the statement that APS-C cannot get good bokeh. This statement is inaccurate (partly because of its generalization).
The way I was trying to combat it was by giving an example where your statement was not correct: if the 56 at 1.2 cannot do that, than the 85 at 1.8 cannot do it either, which is not a commonly accepted fact.


Second clarification: we are talking here about DOF, not the quality of the bokeh which is much more subjective (incidentally with the exception of 35 F/1.4 I'm not that impressed in this regard by Fuji).

Third clarification: while full frame has an inherent advantage to give shallower DOF, on APS-C world there are means to get very shallow DOF without much effort, hence the affirmation that one can only "dream" about good bokeh is not accurate.


Fourth clarification: if you shoot a subject with the same lens at the same distance at the same aperture, the APS-C will have a narrower DOF (an interesting find, particularly for wildlife). This was not part of the original discussion but I found it's interesting as I thought otherwise.


Is it clearer for you now?

[Slobodan Blagojevic]

... Fourth clarification: if you shoot a subject with the same lens at the same distance at the same aperture, the APS-C will have a narrower DOF (an interesting find, particularly for wildlife). This was not part of the original discussion but I found it's interesting as I thought otherwise.

This is because of the difference in pixel density (or sensel size) and its impact on the circle of confusion. APS-C typically have smaller sensels (more pixels per square inch). "The depth of field can be based on when the circle of confusion becomes larger than the size of your digital camera's pixels" (source: Cambridge in Color).

So: smaller circle of confusion means that you are going to notice a drop in sharpness, used to determine DOF) sooner, making DOF shallower.

Clearer? Or we are still circling around confusion?

[barryfitzgerald]

I had hoped we would avoid this but there you go
There are 2 ways of looking at it if you don't move use the same focal length and aperture the DOF is the same (the image is cropped on the APS-C sensor thus a smaller field of view but the same DOF) For portraits you would adjust your position to "maintain the subject size" thus you are closer with the FF camera and further away with the crop body thus the distance to subject has changed so has the DOF ie less DOF on the FF camera

I think we can all grasp that. I shoot FF and APS-C though I am not unhappy with APS-C for shallow DOF subject to using the appropriate lens/aperture background distance etc

I'm interested in the quality of the rendering not how much DOF we have even a ho hum lens can product OK bokeh if the background is far enough away, likewise even a respected lens can in some cases product iffy rendering at times. Real world results count and yes it is subjective not everyone wants "super creamy smooth tastic" "bokeh". Some say aspherical elements can ruin "bokeh" though I have lenses that are quite good with these elements. Some of the older lenses I have with simpler designs do seem to be ahead here though.

Bokeh is more than aperture blades (again I have lenses with many some with less) more than elements I'm not an optical engineer but I do look at results. For some reason lenses can be great or average some even poor. The Fuji's I've used have been sharp though I have noticed an "edge" to outlines in out of focus areas on some, less so on others this can be quite subtle at times but it can be obvious too. There may be more to a lens than "bokeh" but there is likely more than just "sharp"

I don't think the XF50-140mm is bad for bokeh, but so far I've not seen it be amazing either conditions vary hugely in field use there are a lot of variations. Those samples didn't really convince if you were after creamy smooth transitions. Nikon even make a few DC specialist lenses for smoothness Sony have a re-badge Minolta STF that also does super creamy bokeh. I'm not a bokeh hard liner so I'm not rushing to get those lenses (they are undoubtedly top tier for that type of look) but rendering is important to some

[armand]

This is because of the difference in pixel density (or sensel size) and its impact on the circle of confusion. APS-C typically have smaller sensels (more pixels per square inch). "The depth of field can be based on when the circle of confusion becomes larger than the size of your digital camera's pixels" (source: Cambridge in Color).

So: smaller circle of confusion means that you are going to notice a drop in sharpness, used to determine DOF) sooner, making DOF shallower.

Clearer? Or we are still circling around confusion?

Aha, thanks! I did see the circle of confusion was changed but did not know why and what practical impact it has, if any. I would thinks this is valid for equal MP sensors?!

Either way, this just came out while I was looking for other things discussed earlier.

My bottom line on this is that while full frame has some advantages, it's not that clearly superior to APS-C as it is touted (and this comes from somebody who posted mostly D750 shots in the last month)

[Slobodan Blagojevic]

... while full frame has some advantages, it's not that clearly superior to APS-C as it is touted...

I recently acquired a full-frame body (Canon 6D and 24-105/4) and I was marveling about its ability to shoot reasonable portraits at ISO 16,000 in this post.

Then I realized that, had I shot the same scene with my other combo, 60D + 17-55/2.8, I would be having more or less the same DOF, but I could have shot it at ISO 8,000, as I would be using a faster lens. In other words, a full-frame would need to have noise performance better than one stop in order to beat a crop body.

If you want your brain to explode, you can read more about so-called "equivalence" issues here.

[armand]

I recently acquired a full-frame body (Canon 6D and 24-105/4) and I was marveling about its ability to shoot reasonable portraits at ISO 16,000 in this post.

Then I realized that, had I shot the same scene with my other combo, 60D + 17-55/2.8, I would be having more or less the same DOF, but I could have shot it at ISO 8,000, as I would be using a faster lens. In other words, a full-frame would need to have noise performance better than one stop in order to beat a crop body.

If you want your brain to explode, you can read more about so-called "equivalence" issues here.

I've been trying to make a similar point here: http://www.luminous-landscape.com/forum/index.php?topic=95934.0

Granted, in the last month I mostly take out the D750, alone or with the Fuji along, but that's because I either shoot in better light, I photograph fast moving kids or I can afford to take and mostly use a tripod.
In controlled conditions I can use lenses close to their optimum and at that point the differences between lenses are not that big so the sensor can shine through, with its superior DR and color depth.

Plus when it's snowing the only weather sealed lens that I have is the Nikon 24-120 F/4 which is acceptable and doesn't really hold me back.

[Hulyss]

No, that's not what you said and I understood very well what you were trying to say.
You have something against APS-C (and Fuji in particular)

Not really but if you feel comfortable with you bias, enjoy. Slobodan will be more civilian than me to explain you things

You "combat" I do not (somehow). It is like comparing FF and MF, you can't. The bigger the sensor, the better the IQ, period. Maths and other calculations can't explain the final results (and this is a good thing). I combat ppl who always try to explain their environment with mathematics. So yea you're obliged when you are in engineering, rocket science, really "tangible" things who expressly need it. But in photography (so art) I see no place for such considerations.

Art is a place for "magic" ... at least the last bits of magic you can seek in this sick world.

The bigger your sensor, the bigger the IQ (and the tinnier is your wallet... but it's always been like that).

I combat the hype. I have been a fan boy and I came back tie between legs. I know what you are enduring 

In the other hand, It is easier to shoot with a DSLR (even with the weight) than any mirror less on the market. Was not sure because of the XT-1 EVF but at the end, I'm sure (and this is only my opinion).

Long story short : I have been an APS-C user for years. I started my enterprise with a DP2s ... I owned pentax gear for years, K10 K7 K5 + superb primes and zeiss, owned almost the whole SD1 system (primes mostly). One day I went to a photographer to learn more, just with my DP2s (http://www.francois-rommens-photographie.fr/ and http://www.sensual-photography.eu/index.php?lg=fr). This photographer allowed me to use MF, 4x5 and 5D2 with 90TS and said : Once you will taste bigger sensor, you'll never come back... proof in the picture. He was right. Now, especially in my workshops, I prove it "by the picture" to my patients and it always work (and will always work).

Have a close look at sensual photography and come here saying me that you can achieve the same rendering without PP with your XT-1

Now I have some clients to take care of. See you later.

[Hulyss]

Plus when it's snowing the only weather sealed lens that I have is the Nikon 24-120 F/4 which is acceptable and doesn't really hold me back.

This is paranoia. In the Nikon line at least, the material is pretty strong and protected. All the AFS-G line can endure even rain (even if not labelled as weather sealed). I would be picky with old AI-S lenses but the modern one are just tanks. I never exposed any fuji lenses to elements but my guess is they are quite resistant too.

The only lens who got a problem with me was the Nikkor 50f1.2. Focus ring is now a bit grainy and sandy but I was playing in the desert with it for weeks so ...

Two months ago, I was shooting a new model and while returning to the car I felt with the D700 and the 180/2.8. By felt I mean "crashed hard". I slipped on a rock, the camera did a parabola in the air while I was holding the neck strap and crashed on a rock with an awesome freaky sound and all went into the river. I was crying... but guess what ? All survived and work as nothing happened. Just little cosmetics scratch. Solid stuff me say.

[armand]

I combat the hype

That's what I'm trying to do also. I never disagreed that bigger sensor has the potential for better quality, but in less than ideal situations that potential is much smaller. You don't have to go to full frame for better quality or for bokeh you can only dream of on APS-C. I have zero experience with MF and considering the size and cost I think some travels will be more productive.
Keep in mind I bought the D750 long after the x system so psychologically I should be justifying the Nikon purchase by claiming the full frame is the only way to go; not really.


Ps. Btw, being condescending doesn't make your arguments any better

[armand]

This is paranoia. In the Nikon line at least, the material is pretty strong and protected. All the AFS-G line can endure even rain (even if not labelled as weather sealed). I would be picky with old AI-S lenses but the modern one are just tanks. I never exposed any fuji lenses to elements but my guess is they are quite resistant too.

The only lens who got a problem with me was the Nikkor 50f1.2. Focus ring is now a bit grainy and sandy but I was playing in the desert with it for weeks so ...

Two months ago, I was shooting a new model and while returning to the car I felt with the D700 and the 180/2.8. By felt I mean "crashed hard". I slipped on a rock, the camera did a parabola in the air while I was holding the neck strap and crashed on a rock with an awesome freaky sound and all went into the river. I was crying... but guess what ? All survived and work as nothing happened. Just little cosmetics scratch. Solid stuff me say.

You might be right that I'm paranoid but I don't want to push my luck (btw the X-T1 is weather sealed, I don't think that D750 has any official claims). I have a supposedly weather sealed that's good enough, why would I risk other lenses?


Regarding the dump in river, you are the first one that I hear who has a camera that survived after went down in the river/lake etc

[Petrus]

This is because of the difference in pixel density (or sensel size) and its impact on the circle of confusion. APS-C typically have smaller sensels (more pixels per square inch). "The depth of field can be based on when the circle of confusion becomes larger than the size of your digital camera's pixels" (source: Cambridge in Color).

So: smaller circle of confusion means that you are going to notice a drop in sharpness, used to determine DOF) sooner, making DOF shallower.

Clearer? Or we are still circling around confusion?

There is really no need to mix sensel sizes to this at all. Everything related to DOF and sensor/film size can be calculated with basic geometry and/or visualized by using a ruler and a pencil. There is nothing esoteric about it, nor even a camera, film or sensor are needed at all. Just use a DOF calculator if you skipped geometry in school. Also remember that bigger formats are even better than 135, do not limit your arguments to that only...

"Bokeh" is a different matter, and is not mathematically described. Certainly part of it is dependent on the lens design and various distortions it makes. Also, it seems, it is largely something people like to argue about, bit like audiophiles argue differences in cables or other matters of trivial importance. It is a fitting subject for that, as it can not be directly measured like sharpness etc. I rather stay out of it.

Especially when all sorts of "equivalency" formulas are happily thrown into the fray. In that case jump to the start of this post...

[barryfitzgerald]

I don't think we need to "measure" DOF the calculations are quite logical and easy to do we know what influences DOF. Despite the complaints it is possible to achieve satisfactory or shallow DOF on smaller formats (subject to faster apertures, distances) and not wishing to sound like a micro 4/3 user but it is not always desired to have wafer thin DOF either. It is certainly easier on a FF 35mm camera to do that, but many are quite happy anyway.

MF will NEVER be mainstream for 2 reasons cost and size whilst I don't necessarily subscribe to the ILC marketing that small is better (sometimes but not for some tasks) MF simply isn't going to be attractive to many buyers bar some pro level shooters who might make use of it.

Saying that high level results can be achieved even with crop bodies IQ has never been as good resolution is plenty high ISO performance is good enough for a lot of shooters
I played with MF in film days I remained a 35mm shooter I can't see that changing with digital much. MF is great for those who want it but it is not the panacea some suggest it is

As for Fuji some lenses like the 58mm F1.2 are designed to cater for those who want thin DOF and portraits