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Comment by K10D posted on Full Frame Pentax!!!!!!! at 25/01/2010 - 21:02
Daniel Bridge wrote:
an interseting site.link
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Quoted from that link:K10D wrote:
Dan
Can't go into the science but a lot of point & shoot apertures never go lower than f8 as there DOF is equal or greater than a DSLR at f16.Daniel Bridge wrote:
[quote:3496ace15f="K10D"]A 300mm on my K7 provides exactly the same target object size as a 300mm on my D700. The D700 has less DOF and a larger FOV.
Surely if you've got a 300mm on each, the DoF is the same. Granted, if you were to use a 200mm on the K-7 to get the same FoV, then the DoF would be greater.[quote:3496ace15f="K10D"]A 300mm on my K7 provides exactly the same target object size as a 300mm on my D700. The D700 has less DOF and a larger FOV.
Dan
an interseting site.link
Regards
Quote:
As sensor size increases, the depth of field will decrease for a given aperture (when filling the frame with a subject of the same size and distance). This is because larger sensors require one to get closer to their subject, or to use a longer focal length in order to fill the frame with that subject.
So if you use the same lens, and stay in the same place, the DoF will be the same. Imagine your FF sensor. You take a shot, then crop that image down to APS size. Why would the DoF change?As sensor size increases, the depth of field will decrease for a given aperture (when filling the frame with a subject of the same size and distance). This is because larger sensors require one to get closer to their subject, or to use a longer focal length in order to fill the frame with that subject.
The DoF with a compact camera is more because the focal length can be a lot shorter to get the same FoV as a DSLR.
Dan[/quote]Sorry Dan, your correct. With the same lens /subject distance as above.
I was probably remembering something about the group f/64 club where they had to use f/64 to get acceptable DOF on large plate cameras.
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Comment by K10D posted on Full Frame Pentax!!!!!!! at 25/01/2010 - 19:52
iceblinker wrote:
K10D, Do you agree that you generally get better image quality when using a longer lens than when cropping? If so, FOV is highly important.
You don't want excessive FOV if you could have done better by having a smaller FOV.
All I'm claiming here at the moment is that you need longer lenses on a larger format to get the full advantage of that format - and I'm sure I'm right on that as it's so simple.
The grey area is about whether you can get just as good results with cropped FF as uncropped APS-C with the same lens. I don't understand the maths well enough to argue about that, so I'm leaving it to others.
Hmmmm.K10D, Do you agree that you generally get better image quality when using a longer lens than when cropping? If so, FOV is highly important.
You don't want excessive FOV if you could have done better by having a smaller FOV.
All I'm claiming here at the moment is that you need longer lenses on a larger format to get the full advantage of that format - and I'm sure I'm right on that as it's so simple.
The grey area is about whether you can get just as good results with cropped FF as uncropped APS-C with the same lens. I don't understand the maths well enough to argue about that, so I'm leaving it to others.
What about if I set my D700 to APS C and shoot with a 200mm lens, then I take the same shot on FF. Assuming the "sunflower" didn't move, what would be the difference when both shots are printed to an A4 print?
The cropped shot would have a larger "sunflower" as the printing has a factor of 1.5 where as the FF shot would be with a larger FOV of course.
Now I agree that to get the FF shot to match the cropped shot I would need a 300mm lens to get the same FOV, but the "sunflower" is also larger as the magnification of the lenses is different. Effectively 4x closer for the 200mm but 6x closer for the 300mm lens.
Hence I dont sort of consider FOV when composing, yes I need "in frame" images of what I want but generally use longer glass than wider.
Your right about FOV and longer glass but it is not relevant if we can afford or not, nature shooters still require longer glass, more for the magnification than FOV.
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Comment by K10D posted on Full Frame Pentax!!!!!!! at 25/01/2010 - 19:32
Daniel Bridge wrote:
Dan
Can't go into the science but a lot of point & shoot apertures never go lower than f8 as there DOF is equal or greater than a DSLR at f16.K10D wrote:
A 300mm on my K7 provides exactly the same target object size as a 300mm on my D700. The D700 has less DOF and a larger FOV.
Surely if you've got a 300mm on each, the DoF is the same. Granted, if you were to use a 200mm on the K-7 to get the same FoV, then the DoF would be greater.A 300mm on my K7 provides exactly the same target object size as a 300mm on my D700. The D700 has less DOF and a larger FOV.
Dan
an interseting site.link
Regards
Comment by K10D posted on Full Frame Pentax!!!!!!! at 25/01/2010 - 19:29
iceblinker wrote:
If you agree about the crop then you agree about longer lenses. You even said earlier than you use longer lenses yourself rather than cropping.
I would bother with something larger than APS-C if it was practical and affordable enough for me. Once I had it, I would want to use appropriate lenses with it to get the full advantage from it. That means using a 450mm lens instead of a 300mm, for example.
That's my only point. I'm not anti FF.
Pete,If you agree about the crop then you agree about longer lenses. You even said earlier than you use longer lenses yourself rather than cropping.
I would bother with something larger than APS-C if it was practical and affordable enough for me. Once I had it, I would want to use appropriate lenses with it to get the full advantage from it. That means using a 450mm lens instead of a 300mm, for example.
That's my only point. I'm not anti FF.
Yes I agree that to get the same FOV from a 300 on a FF as the same lens/conditions as an APS C you wouls crop the larger FOV down.
My point is that I don't shoot FOV. If I do a golf comp, my positioning is generally fixed at most holes etc. I use a tele lens. Whatever FOV I get is what the shot is taken at. I then crop to suit the shot/image content.
The distance is the main issue here, not FOV. As I said before, the magnification is the main issue for me. A 300mm on my K7 provides exactly the same target object size as a 300mm on my D700. The D700 has less DOF and a larger FOV. So isolation, cropability or increased surround image are options I have.
I think better disussed over a pint, with both systems and lenses present.
Regards
Comment by K10D posted on Full Frame Pentax!!!!!!! at 25/01/2010 - 19:12
iceblinker wrote:
You have to crop a FF image to make it the same as an APS-C image unless you use a longer lens.
What is the advantage of FF if you're going to crop it?
I agree with you about the crop, I dont always crop my FF images or APS C images.You have to crop a FF image to make it the same as an APS-C image unless you use a longer lens.
What is the advantage of FF if you're going to crop it?
By your question of whats the point, indeed, why bother with anything larger than APS-C?
What is so special about APS C and why is it your only acceptable format? You are only comparing FOV here.
Would you advocate cropping medium format images to APS C? If not, why not?
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Comment by K10D posted on Full Frame Pentax!!!!!!! at 25/01/2010 - 18:42
Mongoose wrote:
Area goes like the linear dimension squared.
On the plus side, lower pixel pitch means better noise characteristics, but you are going to need to project a larger image if you want to get the same result as we currently enjoy on APS-C. Larger image = longer focal length.
I'm much too lazy (not to mention poor) to lug a 450mm F2.8 lens around with me, so I'll stick with my APS-C DSLR thanks.
32MP is a wee bit high, the 12MP FF seems to work fine, even as JPEG.Mike-P wrote:
I'm just thinking that as the sensor is larger to start with, if you have a 18PM FF camera then with the extra megapixels you can crop it to give the same effective length as a 1.5 crop 12MP APS-C at its largest.
I hate to be the one to urinate on the meat grilling aparatus, but acording to my calculations a FF sensor with the same pixel pitch as the K7 would have to be ~32MP.I'm just thinking that as the sensor is larger to start with, if you have a 18PM FF camera then with the extra megapixels you can crop it to give the same effective length as a 1.5 crop 12MP APS-C at its largest.
Area goes like the linear dimension squared.
On the plus side, lower pixel pitch means better noise characteristics, but you are going to need to project a larger image if you want to get the same result as we currently enjoy on APS-C. Larger image = longer focal length.
I'm much too lazy (not to mention poor) to lug a 450mm F2.8 lens around with me, so I'll stick with my APS-C DSLR thanks.
link
You can view in full size, I think?
The focused target size would be no different whether FF or APS-C. A 300mm lens is 300mm regardless of what is behind it.
Do you only refer to FOV in respect of 450 on a FF?
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Comment by K10D posted on Full Frame Pentax!!!!!!! at 25/01/2010 - 17:57
Look slightly HDR so they look fine to me.
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Comment by K10D posted on Rocks on the beach .. yes or no? at 25/01/2010 - 15:34
So does anyone have any "candid shots"?
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Comment by K10D posted on Candid or expected? at 25/01/2010 - 10:52
I don't mind a bit of conspiracy theory now and again. Not to do with cameras though.........???
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Comment by K10D posted on K-7 now £799!! at 25/01/2010 - 10:51
K10D, I don't know what APS-C mode on the D700 does because I don't do Nikon. Please instead let's get straight to the point:
Do you agree or disagree that, compared to what you would use on APS-C for the same images, longer lenses are needed on FF to have the full advantage of FF?
I gree that longer glass is needed on FF for the same FOV for the same shot (camera / subject distance). So having put a longer lens on to match the FOV, how do I sort out the larger subject size as I now need to reduce it to match the smaller APS C subjest size (not image size or FOV)
As for full advantage? Well my 14-24 lens on FF is effectively distortion free without bending verticals, what lens do you use to give you those qualities? It should be around a 9.3mm for the 14mm end. Now my 10-17mm will not do that.
Why are other manufacturers selling lots of FF if there is no advantage, indeed why even make them?
Did you use 35mm film at all? Why would Pentax bother with FF (35mm) when the 110 format was much better (according to your point of view).
Hang on, the Olympus system must be better than our APS C, its smaller sensor needs even shorter glass for the same FOV.
and it continues...
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