Hrow wrote:
For natural light bug shooters I suspect the 40D is a better option. For flower shooters, I think the 5D would win hands down better bokeh and better IQ. Both models have serious flaws in the placement and limit of their AF points but the 5D is much easier to MF due to its brighter and bigger viewfinder.
When you say the 5D is much easier to MF are you comparing it to the 40D - and I know your comment is about the viewfinder but I am just wondering if you have considered the 40D Live View when commenting on MF? I guess I am asking that even with the live view and excellent lcd, do you think the 5D is easier to MF than the 40D? I have not used a 5D so I don't know much about it - Thanks!
live view @ 5x or 10x for manual focus on static subjects is an entirely different animal. live view IMO is a formidable tool. i have tested manual focus view finder vs. live view with the 40D and live view wins hands down. if i could use an f stop analogy 'live view has a 1.5 - 2.0 stop advantage in focusing over the view finder'.
rachp wrote:
When you say the 5D is much easier to MF are you comparing it to the 40D - and I know your comment is about the viewfinder but I am just wondering if you have considered the 40D Live View when commenting on MF? I guess I am asking that even with the live view and excellent lcd, do you think the 5D is easier to MF than the 40D? I have not used a 5D so I don't know much about it - Thanks!
I have Live View on my 1DMkIII and I wouldn't think of using it as a focusing tool in the field accept in rare conditions. It is a very easy and useful MLU and it is easier to detect things like wind movement but as my main focusing method? No way.
#1 - trying to see the LCD in bright light is always tough. It is little better with the latest generation of cameras.
#2 10X on a grainy LCD is no great fun to focus with.
#3 bouncing from back and forth between 10X and full view for focus / composition is a royal pain.
#4 In a studio, Live View has some real potential. I don't do much studio work.
Dalantech wrote:
You've kinda mixed apples and oranges my friend
A full frame sensor will give you more depth of field than a 1.6x crop factor camera at the same Fstop (about a 33% difference) because the pixels on the FF camera are larger. The pixel size changes the area of confusion, and that's why DoF calculators ask you for the camera that you are using.
A P&S camera has a tiny sensor, and therefore tiny pixels. So you might be wondering why the DoF is so much better than cameras with bigger sensors (and pixels). It's because the P&S camera has an ultra wide angle lens -sometimes as little as 5 to 7mm of focal length at the wide end. With a lens that wide you're going to get a lot of depth no matter how small the sensor is... ...Show more →
In real terms I am not sure I agree with you on this one but then again, it depends how one is defining the problem. You are right. If you put a 100mm lens on both a FF and a 1.6x camera the 1.6x will have less depth of field. However, if you are trying to replicate the equivalent angle of view then the equation changes. For example, you would need a 160mm on the FF to achieve the same angle of view and the 160 mm lens is going to have significantly less DOF than does the 100mm.
Let's look at an example - all at 10 feet and all at F16. DOF =
Hrow wrote:
In real terms I am not sure I agree with you on this one but then again, it depends how one is defining the problem. You are right. If you put a 100mm lens on both a FF and a 1.6x camera the 1.6x will have less depth of field. However, if you are trying to replicate the equivalent angle of view then the equation changes. For example, you would need a 160mm on the FF to achieve the same angle of view and the 160 mm lens is going to have significantly less DOF than does the 100mm.
Let's look at an example - all at 10 feet and all at F16. DOF =
Agreed -you'd need more reach to get the same apparent size in a print or on the screen. But, and I know I'm the wrong person to say this, you could always crop the FF image and get more depth
As for distance: Irrelevant when you're talking about macro photography. Life size with the EF-S 60mm and the 180mm L will give you the same depth of field at the same aperture on the same camera, even though the 180mm L will give you a little over twice as much working distance (~4" for the EF-S 60mm and ~9 inches for the 180mm L). So there are only a few factors that come into play when looking at depth of field from a macro perspective: Sensor size (due to the circle of confusion), Fstop, and magnification.
No one shoots life size at 10 feet -although there are times when I wish I could...
Think you argue this around in circles but I'm pretty certain that at the standard print size (10*8) that DOF is normally measured against then If the shots are taken with the same FOV (ie the 1.6 crop camera will be less than 1:1 if the FF is at 1:1), then the DOF will be higher in the crop camera pic.
Not so certain about the next bit but suspect if you take the pics both at 1:1 and crop the FF pic to the same size as the 1.6 crop camera then the DOF will be exactly the same as you are effectively reducing the sensor size used in the pic.
BTW pretty certain that pixel density does not come into this - it's only sensor size that matters.
R.H. Johnson wrote:
live view @ 5x or 10x for manual focus on static subjects is an entirely different animal. live view IMO is a formidable tool. i have tested manual focus view finder vs. live view with the 40D and live view wins hands down. if i could use an f stop analogy 'live view has a 1.5 - 2.0 stop advantage in focusing over the view finder'.
I am loving the 40D live view. I have not used a 5D so I have no idea how good the bright viewfinder is but I think I would choose the live view for myself
Hrow wrote:
I have Live View on my 1DMkIII and I wouldn't think of using it as a focusing tool in the field accept in rare conditions. It is a very easy and useful MLU and it is easier to detect things like wind movement but as my main focusing method? No way.
#1 - trying to see the LCD in bright light is always tough. It is little better with the latest generation of cameras.
#2 10X on a grainy LCD is no great fun to focus with.
#3 bouncing from back and forth between 10X and full view for focus / composition is a royal pain.
#4 In a studio, Live View has some real potential. I don't do much studio work. ...Show more →
I have had good luck with the live view outdoors but like I said, I have never used the 5D so I don't know what the viewfinder is like. I was curious about just how good that 5D is - I know the price sure is making it very tempting I usually don't bother with macro outdoors if there is a good wind blowing. I do like the live view for shooting flowers and such (some bugs, too!) outside - in the right conditions.
LordV wrote:
Think you argue this around in circles but I'm pretty certain that at the standard print size (10*8) that DOF is normally measured against then If the shots are taken with the same FOV (ie the 1.6 crop camera will be less than 1:1 if the FF is at 1:1), then the DOF will be higher in the crop camera pic.
The depth of field increased for the 1.6x camera because the magnification changed -not because of the size of the sensor...
LordV wrote:
Not so certain about the next bit but suspect if you take the pics both at 1:1 and crop the FF pic to the same size as the 1.6 crop camera then the DOF will be exactly the same as you are effectively reducing the sensor size used in the pic.
How can physically cropping an image change the area in the image that's in focus Brian? I can't see it, unless you're cropping out the area that's in focus and keeping the parts that are not sharp...
LordV wrote:
BTW pretty certain that pixel density does not come into this - it's only sensor size that matters.
Brian V.
The size of the sensor, and the pixel count, effect the density of the pixels on the sensor and their size -and the size of the pixels changes the circle of confusion which is one of the things that factors in to determining depth of field. Sorry my friend, but what you said reads like "It's not because it's black, it's because it's so dark". So who is arguing in a circle?
Hi John,
Just on one point - I used a couple of the on -line DOF calculators and using a set up similar to macro with a 100mm lens the DOF did change with sensor size but did not change if I tried cameras with the same sensor size but different Pixel densities now this may be errors in the way they calculate the DOF. The only link I found with pixel size (density) was with diffraction softening.
The reason I said it was a circular argument is that it's difficult to agree on the starting conditions - I think with FF vs 1.6crop images you should compare images with the same FOV which can only be done using different magnifications.
Physically cropping an image does change the apparent DOF if the images are blown up to the same size- thats why I commented that DOF is normally measured against a standard 10*8 print looked at I think from about 18" away- It's why thumbnails of images have more DOF than a larger version of the image.
LordV wrote:
Hi John,
Just on one point - I used a couple of the on -line DOF calculators and using a set up similar to macro with a 100mm lens the DOF did change with sensor size but did not change if I tried cameras with the same sensor size but different Pixel densities now this may be errors in the way they calculate the DOF. The only link I found with pixel size (density) was with diffraction softening.
The Xti and 20D comparisons are like that, even though the Xti has more pixels. I suspect it might have something to do with the micro lenses that cover each pixel.
LordV wrote:
The reason I said it was a circular argument is that it's difficult to agree on the starting conditions - I think with FF vs 1.6crop images you should compare images with the same FOV which can only be done using different magnifications.
I'd like to see a comparison between a 1.6 crop 1:1 shot and a FF image taken at ~ 1.6x (not sure if the math works out). In effect have two images with the same apparent FOV and Fstop and then see which one has more DoF. Granted it's still an apples and oranges comparison since the magnification isn't the same.
LordV wrote:
Physically cropping an image does change the apparent DOF if the images are blown up to the same size- thats why I commented that DOF is normally measured against a standard 10*8 print looked at I think from about 18" away- It's why thumbnails of images have more DOF than a larger version of the image.
Brian V.
A thumbnail is an image that's been reduced in size from the original, but it's not the same as cropping. You can take a poorly focused image and if you reduce the size of it enough it will start to look sharp. But if you take a crop of that same image it will look even more out of focus. So cropping an image will not increase the apparent depth of field, but resizing the image will (and the two are not the same)...
milmoejoe wrote:
I am at a point of wanting to simplify my rig- I find that I do much better with a standard simple rig, making the best of what I have and not thinking about the greener grass on the other side.
The how did you get to this point? Seriously - no reason to deprive yourself.
Anyway - I have very little problems with dust on the sensor and I change my lenses all the time in some nasty places. I just cleaned it for the first time in *months* last weekend. Now I do have dust and cruft in the viewfinder - but I don't let it bother me. No pun intended but I just don't focus on it - my attention is on what I'm trying to accomplish. If you are stressing over a bit of fluff in the viewfinder that you *know* will have no effect on your shot then I think maybe you need to take a breather. Seriously - I don't intend that in a a mean way. I've just noticed with myself that if I'm stressed I'm more likely to find reasons why I can't do what I supposedly want to do. Truth is I probably didn't really feel like it but rather felt obligated or I "should" for some dumb reason or another. Everyone needs some down time and perhaps you're pushing yourself to the point where it isn't as fun and rewarding as it should be. Take a breather try drawing instead. Better than burning out.
regards,
Jon
LordV wrote:
It's why thumbnails of images have more DOF than a larger version of the image.
Brian V.
Well they don't actually - they *appear* to have better sharpness. When resizing you obviously have fewer pixels as a result. Edges are preserved in resizing and as we all know, the edge contrast is what is perceived as "sharpness" and in this context DOF.
regards,
Jon
I'd say that pixel density, while not irrelevant, is not really a factor. What is important is the arbitrary determination of the evaluation criterion - the circle of confusion (CoC). Then all images produced by various sensors have to be compared on equal terms - i.e. same size print - and same CoC size relative to the size of a 35mm frame --> hence divide the CoC by the crop factor. (circle of confusion... I'm killing myself... it's so confusing...!)
The last para of the linked article basically sums up what you need to remember, though.
I'd say that pixel density, while not irrelevant, is not really a factor. What is important is the arbitrary determination of the evaluation criterion - the circle of confusion (CoC). Then all images produced by various sensors have to be compared on equal terms - i.e. same size print - and same CoC size relative to the size of a 35mm frame --> hence divide the CoC by the crop factor. (circle of confusion... I'm killing myself... it's so confusing...!)
The last para of the linked article basically sums up what you need to remember, though.
Brad
Thanks for that brad- think that's what I was trying to say - interesting that the DOF is supposed to be higher for the 1.6 crop with same FOV by using a wider lens (or less magnification).
The only thing that worries me about this is whether going into macro mode ie shooting at 1:1 changes any of the rules. For example I'm aware of the statement that in macro the DOF will be exactly the same at the same aperture and magnification no matter how it is achieved. Yet this seems to conflict slightly with the observation of better bokeh (lower dof ?) with longer focal length macro lenses or is this a case of the apparent DOF being different. eg the region beyond the DOF limit is more out of focus in a longer macro lens than in a short one ?
BubbaJon wrote:
Well they don't actually - they *appear* to have better sharpness. When resizing you obviously have fewer pixels as a result. Edges are preserved in resizing and as we all know, the edge contrast is what is perceived as "sharpness" and in this context DOF.
regards,
Jon
Jon I know they don't in reality if viewed at the same print size- I was just trying to get over the point that DOF calculations do refer to a standard print size (normally 10*8).
Remarkable that this thread started with the confusion between DOF and FOV.
I am glad that Dalantech finally recognizes that there could be some value in cropping occasionally!
DOF and COC are optical concepts. Although sensor pixel size and resolution will reveal a poor COC lens (ie a non sharp lens), the sensor is not effecting the optics of the lens.
FOV is also an optical concept, but cropped sensors do effect FOV -- they reduce it. This isn't because the sensor effects the lens in any way, the cropped sensor just records less of the available image circle.
The marketing of cropped sensors has unfortunately introduced a lot confusion. There are a lot of photographers out there who seem to believe that a 1.6 sensor increases your lenses focal length. It does not, rather it decreases your lenses' FOV as if the lenses had focal lengths longer by a factor of 1.6. It would be much better if we all just thought of 1.6 sensors as 62.5% sensors because that's what they are -- sensors that are 62.5% the size of 35mm and capture 62.5% of the FOV that is available on our 35mm designed lenses. I believe that we call them 1.6 crops is because that sounds a lot better than 62.5% -- a C minus! Finally -- to finish my rant -- the only advantage of cropped sensor is that it is cheaper. Some people talk about "tighter framing" but this is silly, FF shooters can easily crop their images.
Duncan Gibson wrote:
Remarkable that this thread started with the confusion between DOF and FOV.
I am glad that Dalantech finally recognizes that there could be some value in cropping occasionally!
DOF and COC are optical concepts. Although sensor pixel size and resolution will reveal a poor COC lens (ie a non sharp lens), the sensor is not effecting the optics of the lens.
FOV is also an optical concept, but cropped sensors do effect FOV -- they reduce it. This isn't because the sensor effects the lens in any way, the cropped sensor just records less of the available image circle.
The marketing of cropped sensors has unfortunately introduced a lot confusion. There are a lot of photographers out there who seem to believe that a 1.6 sensor increases your lenses focal length. It does not, rather it decreases your lenses' FOV as if the lenses had focal lengths longer by a factor of 1.6. It would be much better if we all just thought of 1.6 sensors as 62.5% sensors because that's what they are -- sensors that are 62.5% the size of 35mm and capture 62.5% of the FOV that is available on our 35mm designed lenses. I believe that we call them 1.6 crops is because that sounds a lot better than 62.5% -- a C minus! Finally -- to finish my rant -- the only advantage of cropped sensor is that it is cheaper. Some people talk about "tighter framing" but this is silly, FF shooters can easily crop their images. ...Show more →
Whilst a 1.6 crop camera seems to make DSLRs affordable for many, I don't look on them as the poor cousins of FF cameras. For macro and telephoto work there are positive advantages of 1.6 crop cameras over FF. Unless you are using one of the very expensive 20mpx FF cameras you will always lose resolution cropping the image of a FF camera to that of a 1.6 crop camera. The only advantage of a larger sensor for macro work is the lower noise available at highish ISO which is rather nice for natural light shots.
This has been the most civil discussion of this complex subject that I have ever seen. Normally I am concerned that war will break out or a death match will occur. Brian really nailed the problem earlier when he pointed out that much of the debate occurs because it is difficult to agree on the starting conditions.
I have totally failed as a macro photographer to date so I can't tell you if there real world differences in DOF at macro distances but I can assure you from experience that there are differences at what would be considered close-up distances. My 1.3x sensor has less DOF than my 1.6x. I can see it in my images and have had to make adjustments in my settings to compensate.
