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02-12-2015, 12:51 PM   #46
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Pro: Potentially large, bright viewfinder for manual focus

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02-12-2015, 01:29 PM   #47
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QuoteOriginally posted by bdery Quote
There is no link between sensor size and DOF.
Again, leaving out enough information to be misleading.

Larger sensors usually allow more control over DOF because the physical aperture used for the same F-stop and same FOV is larger with the typical lenses used. I've been involved in pages and pages of discussion on this myself, I'm hoping we don't have to go there again


QuoteQuote:
. There is a lot of misconception, however.


FF does offer IQ advantages (noise, DR and DOF control) for the same FOV and exposure. We assume we're not talking about 2005 FF vs. 2015 aps-c sensor tech of course.

.
02-12-2015, 01:49 PM   #48
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Pros: Image Quality, Better Bokeh, Improved high iso performance.

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02-12-2015, 02:07 PM   #49
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QuoteOriginally posted by blende8 Quote
No.
So far we have lower resolution.
Even the A7r with 36 MP has a lower resolution than the K3.
no, 36mp has higher resolution than 24mp, period.

you can see that easily on any dxomark comparison.

i can't believe some of the misinformation in this thread.

02-12-2015, 02:25 PM   #50
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QuoteOriginally posted by jsherman999 Quote
Again, leaving out enough information to be misleading.
I certainly hope not!

QuoteOriginally posted by jsherman999 Quote
Larger sensors usually allow more control over DOF because the physical aperture used for the same F-stop and same FOV is larger with the typical lenses used. I've been involved in pages and pages of discussion on this myself, I'm hoping we don't have to go there again
QuoteOriginally posted by jsherman999 Quote
FF does offer IQ advantages (noise, DR and DOF control) for the same FOV and exposure. We assume we're not talking about 2005 FF vs. 2015 aps-c sensor tech of course.
you are saying exactly the same thing as me.

You very well can think in terms of field of view when discussing composition. However, when discussing optical performances, discussing field of view is the most convoluted road you can take. It creates approximations, inaccuracies, misunderstandings, in short it's a mess.

A given lens will perform exactly the same on every camera you mount it too (except for the eventual crop of course).

A fixed field of view requires a different lens. And that requires evaluation of its aperture, optical performances, resolving power. A lens with more resolving power will create a smaller circle of confusion, thus narrowing the field of view (as long as the sensor has enough resolution). Contrast will also play a role. The shape of the aperture too.

It's a mess.

You can't simply compare different lens designs and assume it's directly applicable to DOF when the sensor size changes. Heck, even lens testers will state the camera body they used (if they are rigorous) for a given sensor size!

Thinking in terms of field of view gets everyone confused and is not accurate.

I have been talking as accurately as I can, now and forever, without intending to be misleading. I am 100% confident about the information I provide because it's my job and training. If you don't understand an element that I wrote about, I'll try to be clearer. I have written nothing that was misleading and I'll thank you not to imply anything of the sort...
02-12-2015, 02:44 PM - 1 Like   #51
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QuoteOriginally posted by jsherman999 Quote
This ^ leaves out just enough information to be misleading, IMO.

50mm on FF and 50mm on aps-c also delivers a completely different image, because the aps-c shot is 1.5x tighter. It's kinda moot to worry about DOF differences when the framing is radically different.

50mm f/2.8 on FF vs. 35mm f/2.8 on aps-c from the same position - there we have the same FOV, and the FF shot would have a bit over a stop less DOF (equiv to 35mm f/1.8 on aps-c.)

50mm f/2.8 FF == 35mm f/1.8 aps-c in terms of FOV and DOF.

(50mm f/2.8 FF on left, 35mm f/2.8 aps-c on right)


.

---------- Post added 02-12-15 at 01:48 PM ----------



I get why you'd want to do that, but using f/4 zooms on D800 doesn't give you any or much IQ advantage over say a sigma or Pentax 50-150 f/2.8 on D7000/K5. You'll get more overall pixels, more lp/ph in the image, but you give up the noise advantage and additional DOF control.

I guess it's attractive if you want to just have one camera and want a lower-weight option for it, and if that f4 zoom is awesome... but buying FF and then only shooting f4 zooms with it is not taking full advantage of what you bought, IMO.
Thank you. :thumbsup: A voice of reason.
02-12-2015, 02:49 PM - 1 Like   #52
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Cons of Pentax FF
1. this forum will split and members will argue between themself much more....
2. you will feel compelled to buy a FF camera, then realise you miss the more compact, and adequate, APSC system
3 People will look at you more
4. Your kids teeth will stay crooked (ie you are broke)
5. You will develop back problems (mostly lens related)
6. You will wish you chose a higher F stop more often

Cons of APSC
1. Like most of us, it's adequate, but not a celebrity. Everybody wants to hang with the cool guys....right?

Last edited by noelpolar; 02-12-2015 at 03:00 PM.
02-12-2015, 02:56 PM - 1 Like   #53
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Put simply, I very much hope this thread does not degrade into semantic stand-off.

02-12-2015, 02:56 PM - 4 Likes   #54
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QuoteOriginally posted by bdery Quote
I certainly hope not!
If someone asks you if changing sensor size will have any practical effect on their ability to control DOF, and your answer is "there is no link between sensor size and DOF, FULL STOP," then I'm sorry to say that you're misleading them by leaving information out. You really are. I fully believe it's not your intention.

It's akin to the question "Is a 50mm lens still a 50mm lens on FF vs. aps-c?" being answered with "a 50mm lens is a 50mm lens. The lens doesn't change. FULL STOP."

That's an extremely unhelpful answer, to the point that it implies something factually wrong - that the photographer will see no difference using a 50mm lens on any format. It's an answer that's not really answering what's being asked. And anyone who isn't suffering from Aspergers should know what's really being asked 95% of the time that question comes up - does the FOV change, and if so, how?

That question should always be answered with a variation of: "The physical properties of the lens can't change, it's still 50mm, however a 50mm lens of a larger format will give you a wider FOV." (and then you can go into effects on DOF if you have the fortitude...)


QuoteQuote:

you are saying exactly the same thing as me.

You very well can think in terms of field of view when discussing composition. However, when discussing optical performances, discussing field of view is the most convoluted road you can take. It creates approximations, inaccuracies, misunderstandings, in short it's a mess.
The reason FOV needs to be tied to it is because it determines what FL is used which determines what the physical aperture will be for that exposure. The physical aperture (not f-stop) is what determines the total light hitting the sensor which is the only reason larger sensors of the same generation realize any advantage in the first place - they are getting more light.

The FOV is one of the grounding parameters the photographer cares about - maybe even the most important parameter, even more than exposure. You start with FOV, with framing.

Perhaps unfortunately, to establish a standard so we know what FOV we're talking about, we use 135mm equivalents.

Otherwise, if you walk into a camera store intending to buy this:



... and you ask the clerk if that 5mm lens will be wide-enough - say if it will look like at least 24mm on your aps-c camera which is your personal requirement for the purchase - the clerk will answer: "5mm is 5mm is 5mm. It's a 5mm lens. FULL STOP."




.

Last edited by jsherman999; 02-12-2015 at 03:10 PM.
02-12-2015, 04:58 PM   #55
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QuoteOriginally posted by bdery Quote
As I wrote earlier (good to see we all read each other's replies thoroughly ) this is wrong. There is no link between sensor size and DOF.
Please can we not have an equivalency discussion? That horse has been dead for years.

QuoteOriginally posted by jsherman999 Quote
50mm on FF and 50mm on aps-c also delivers a completely different image, because the aps-c shot is 1.5x tighter. It's kinda moot to worry about DOF differences when the framing is radically different.
This is the point. Anyone who does not understand this point, should take the time to learn how theory and practice differ. Measured front to back at a given aperture, depth of field is the same regardless of format, but in practice that's not how we use a camera. Thanks J.
02-12-2015, 05:36 PM   #56
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Well guys, this forum is indeed historically full of such discussions and new people will come on board to challenge the common knowledge about FL equivalents. Perhaps directing them to authoritative articles on the topic will help so we can avoid the frustration of repeated correction.

e.g. dSLR Crop Factor Explained and Focal Length Equivalents
02-12-2015, 05:36 PM - 1 Like   #57
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I think basically the issue when comparing APS-C and full frame is that there are faster equivalent lenses available for full frame. And faster equivalent lenses are capable of more narrow depth of field.

I don't know why folks are arguing about this fact. It is just true. A 50mm f1.4 lens on full frame needs something like a 30mm f1 lens. Now, I would argue that that isn't a big deal, because I shoot stopped down most of the time.

Just to bring it full circle, I think folks need to ask themselves why they are dissatisfied with their current gear. If they say "there is too much depth of field," or "I want to print bigger," or "I don't like my current viewfinder," then those are all reasons to move to a larger sensor. On the other hand, if you say "my pictures are all lousy," then you need to figure out why you don't like them.

Phil said that the photos on the full frame thread are a mixed bag and they definitely are. Folks who shot great photos with APS-C continue to do so on full frame, others not so much.
02-12-2015, 10:13 PM   #58
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QuoteOriginally posted by jsherman999 Quote

FF does offer IQ advantages (noise, DR and DOF control) for the same FOV and exposure. We assume we're not talking about 2005 FF vs. 2015 aps-c sensor tech of course.

.
if both sensors have the same pixel density than their is NO advantage of the 35mm sensor.
02-12-2015, 10:45 PM   #59
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The advantage is extra photo size. If the FF image is cropped down to APS-c size, the resolution would be the same as the APS-c image, but the FF image overall has the advantage of all that extra peripheral photo information.
In practical terms, if a FF camera were used with the same lens as with an APS-c camera, and a portrait were being taken a FF camera would need a closer camera-to-subject distance to get a similar FoV as the APS-c camera - this means shallower DoF, but of course this also alters the perspective.

There is a difference if say a FF + FA 77 at f/4 portrait were compared to the same portrait taken by a K-5 + DA 50 at f/2.8 (approximately!). There would be better resolution with the FF shot, as long as the lens is up to it (and I'm sure the FA 77 is up to such a task).
02-12-2015, 10:50 PM   #60
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QuoteOriginally posted by Volker76 Quote
if both sensors have the same pixel density than their is NO advantage of the 35mm sensor.
If the FF is 36 Mp as rumoured, it will have a lower pixel density than the K-3, so should offer better high-ISO performance, while delivering higher resolution.

Am I missing something?
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