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Old Mar 21, 2010, 9:47 AM   #21
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It depends on the size of the wall I guess if the tokina would be a good option. I know when I visit castles around Europe, The 18 is a bit tight sometimes on a crop body. So if it is a huge wall a wider angle lens would help. But if it is the general size wall the kit lens at 18mm stop to f9 would do nicely.
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Old Mar 21, 2010, 9:52 AM   #22
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I'm not sure the difference in LCD positioning ability (tilt only versus fully articulating) is going to make much difference for doing something like shooting paintings on a wall, as long as you can see what you're framing in the LCD. Ditto for AF speed (as you wouldn't care about AF speed if shooting a stationary subject using a tripod).

Now, perspective distortion may be an issue shooting paintings, even if you are using a lens that has relatively little barrel or pincushion distortion, depending on how you can position a camera. IOW, you'd need to make sure the camera is centered with the painting and "square" to it (versus pointing left, right, up or down) in order to avoid any perspective distortion.

You could get around that using a Nikon or Canon model with a Tilt/Shift (i.e, perspective correction) type lens. But, they're relatively expensive and that would probably put the OP *way* over budget. For example, a Canon 45mm TS-E f/2.8 EF mount lens is selling for a bit over $1200 right now at popular online vendors; and a Nikkor 45mm PC-E f/2.8 lens is selling for a bit over $1800 right now. You'd want shorter focal lengths if you don't have room to back up. For example, Nikon makes a 24mm and Canon makes a 17mm. But, they're even more expensive than their 45mm tilt/shift lenses.. Note that these are manual focus lenses. But, if you used a magnified view with Live View, that could help out with focusing.

If you can't keep a camera centered and square to a painting on a wall, then you can expect perspective distortion unless you are carefully using a tilt/shift (a.k.a., Perspective Correction) type lens.

So, you may end up having to do some amount of optics correction in Post Processing anyway, depending on your vantage point to a painting, even if you're using a lens that has little or no barrel and pincushion distortion (just to correct for perspective problems).
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Old Mar 21, 2010, 10:09 AM   #23
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peripatetic,

Beside the speed of the focus, I can tell you when testing the canon and the nikon. Both had allot of inaccurate focus in live view needing me to wait for the lens to go back to infinity and refocus, while the sony live view focus was dead on pretty much all the time. Having to wait for the camera to refocus can be annoying. And neither the canon or nikon does it fast.
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Old Mar 21, 2010, 10:30 AM   #24
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Thanks Jim for the correction. Do you have a link to their live view system...
I don't know what you mean by a link to their live view system. My explanation should explain it (or if not, I can try to clarify).

Basically, Autofocus works exactly the same way as it does with any other dSLR model that's using an Optical Viewfinder when you're in Live View mode with a Sony model, with a dedicated Autofocus Sensor Assembly located at the bottom of the mirror box.

Autofocus SLR (and dSLR cameras) have a mirror that's slightly translucent in the center, allowing the image to been seen by a dedicated AF Sensor assembly in the bottom of the mirror box (9 points in the case of the current Sony models with Live View) using fast Phase Detect Autofocus.

http://en.wikipedia.org/wiki/Digital...tion_autofocus

The Sony models work exactly the same way as any other Autofocus dSLR or SLR cameras in that respect when using their Optical Viewfinder, only the Sony models can also work that way when in Live View mode, because they have a separate sensor in the Viewfinder Housing that sees the same image that's normally projected to the Optical Viewfinder when you switch to Live View (which just tilts a mirror in the Viewfinder Housing so that the image goes to the Live View Sensor versus the Pentamirror).

With non Sony dSLR models in Live View mode, one of two things has to happen -- either they need to use slower Contrast Detect Autofocus with their main imaging sensor (since the mirror is flipped up and the main AF Sensor in the bottom of the mirror box isn't seeing the image anymore), or they need to interrupt the Live View from their Main imaging sensor by flipping the mirror back down to use their primary AF sensor with faster Phase Detect Autofocus. That mirror flipping down to focus interrupts the Live View feed from the main sensor, making it difficult to use for a moving subject. So, neither method is very desirable from an AF speed perspective.

Sony's method allows Autofocus to work exactly the same way (fast Phase Detect Autofocus with a dedicated AF sensor assembly in the bottom of the mirror box), using either Live View or the Optical Viewfinder. So, you don't have an Autofocus Performance penalty when using Live View with a Sony dSLR.

Now, Sony did start adding some interesting features with the Sony A500 and A550 models. They can actually do things like face recognition using the separate Live View sensor, while still making use of the dedicated AF Sensor with Phase Detect Autofocus (basically, determining the AF point that's closest to where a face is being detected for focus purposes). IOW, the separate Live View sensor and the dedicated AF sensor can work in conjunction with each other to provide additional focus features when using Live View if you set it to use those features.
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Old Mar 21, 2010, 10:33 AM   #25
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I see the photo you posted, and wanted to get more in-depth about it. That is all, the techy side of me like to get more info sometimes but not to often.
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Old Mar 21, 2010, 10:39 AM   #26
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Olympus actually used a similar system with their [discontinued] E-330 model. But, that's the only other dSLR model I'm aware of that used a similar system (with no AF performance penalty using Live View, depending on how you set the focus mode with one).
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Old Mar 21, 2010, 11:07 AM   #27
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But, again, for something like shooting paintings, you're not going to care about AF speed anyway. :-)

For non-stationary subjects, the Sony Live View system can be very desirable, allowing you to more easily shoot a non-stationary subject with no performance penalty.

But, for stationary subjects like a painting using a tripod, a bit slower AF speed with other Live View systems shouldn't be an issue, as long as they're able to focus in the light you're shooting in (and that can be an issue with some systems like the D5000 that only offer Contrast Detect AF with their main imaging sensor when in Live View mode, as sometimes the main imaging sensor won't work well for AF when light gets lower, even if you don't mind how slow it is).

Some models with Live View offer more than one focus mode, so you can switch them to use Phase Detect AF instead. For example, your T1i has a "Quick Mode" setting when using Live View so the camera can make use of it's main AF Sensor Assembly for Phase Detect focusing, versus trying to do Contrast Detect AF with it's main imaging sensor. But, because the mirror needs to be flipped down to focus in that mode, you're impacting performance by needing to flip the mirror down, temporarily interrupting your Live View feed while the camera is focusing, then flipping the mirror back up to restore the Live View feed. So, neither method is ideal when shooting moving subjects (but, for stationary subjects like a painting, AF speed shouldn't matter much).
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Old Mar 21, 2010, 12:17 PM   #28
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...So, neither method is ideal when shooting moving subjects (but, for stationary subjects like a painting, AF speed shouldn't matter much).
Jim!

I am not questioning neither your authority as an expert nor your vast knowledge of digital cameras, of which you clearly have an aweful lot of.

In my hopeless ( because the ideal camera does not exist...) search for an ideal replacement for my G1, I have now studied the Sony a550 quite thoroughly and repetedly as a contender, and this camera provides - I think as the only one in existence - actually a continuose shooting speed of 4 fps in Live View AND with continuouse AF switched on (7 fps with AE and AF locked)! Something quite unusual, as I understand.

If you look at camerlabs.com's brief video tour of the a550 - http://www.cameralabs.com/reviews/So...o_review.shtml - this is shown and demonstrated quite convincingly in the video @ 4minutes and 30 seconds and onwards. Interesting viewing!

But now I am straying from the OP's request and ask for forgiveness of diverging....

Best regards,
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Old Mar 21, 2010, 12:46 PM   #29
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Yep... AFAIK, the Sony A500 and A550 models are the only current dSLR models without any AF performance penalty when using Live View, since they can still use fast Phase Detect Autofocus via their dedicated 9 point AF sensor assembly, without the clumsy mirror flip routines needed like the "Quick Focus" mode some models have available with Live View, or the slower Contrast Detect AF other dSLR models use when trying to use the main imaging sensor for Autofocus.

How useful Sony's faster AF with Live View would depend on how much you use Live View, and the types of subjects you're shooting. It's not a feature that I think I'd use a lot unless shooting at unusual angles or with a tripod. I'm very accustomed to using an optical viewfinder instead.

But, if I were using one for an extended period, perhaps I'd try to use that feature more. I've had both a Nikon Coolpix 950 and 990 with a tilting body (and I still have the 950), and I used to like having the ability to shoot from waist level for candids at parties, etc., since as soon as someone sees you holding up a camera and pointing at them, they'll often pose (ruining the candid part of the shots). Being able to keep a camera at waist level or in your lap while sitting is not as noticeable if you're trying to get more candids. It can also come in handy for lower shooting angles to keep from needing to stoop down. So, I can see where it could be a desirable feature. I'm just very used to an optical viewfinder anymore. lol

Yes, there is no perfect camera. There are pros and cons to any of them. ;-)
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Old Mar 21, 2010, 12:54 PM   #30
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IOW, I wouldn't be in a hurry to replace my Sony A700 with a model that has Live View, since I'm so accustomed to using it's Optical Viewfinder (and the A700 has a larger optical viewfinder compared to the A500 or A550). But, if I ever did buy a dSLR model with Live View like an A550, perhaps I'd change my shooting style some after using it more.
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