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Messages - TrumpetPower!

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Lenses / Re: Focal Distance: furthest possible maintaining blurred BG
« on: November 25, 2012, 10:17:00 AM »
My guess would be the EF-800mm F/5.6
My too.
I use/d 85/1.4, 135/2, 200/2, 300/2.8 and the most blurred background I've got with longer FL.
FL does affect the isolation of the subject more than open [wide] aperture.
(Using the same framing of a human body / face.)

If the two of you are guessing based on the maximum physical size of the aperture, then the winner is actually the 600 f/4. The 400 f/2.8 and the 800 f/5.6 are tied for second.

800 / 5.6 = 142.857
600 / 4 = 150
400 / 2.8 = 142.857

If you're going off focal length, then the 600 with a 1.4x teleconverter would beat the 800 without one.

At the same time, there's really not any significant difference in actual aperture size between them, just a small fraction of a stop: stop the 600 down to f/4.5 (a third of a stop, one click of the wheel) and it's now got a 133mm physical aperture.

If you were trying to decide between the three, your decision should be made primarily on focal length needs and you shouldn't give any consideration to the physical aperture. Indeed, they might all actually be the same, what with rounding and all: 600 / 142.857 = 4.2, which is closer to f/4 than f/4.5.



EOS Bodies - For Video / Re: Best movie settings?
« on: November 24, 2012, 10:23:40 PM »
1- Take a bit of A4 paper. Hold it unfolded / unwrinkled under the exact same light as your subject.  Take a still image of it.  Go into custom WB menu, choose that image as the reference.  Select manual WB in the WB menu.

Actually, paper makes a miserable white balance target. The substrate itself is almost always decidedly yellowish, and then they add fluorescent dyes that glow slightly blue to trick your eyes into seeing something that's brighter than white. There are a few high-quality inkjet papers out there that would make good targets, but it's frankly not worth it.

My best recommendation would be polystyrene. It's spectrally flat and just the right lightness. Get a disposable beer cooler and use the lid, or see if you've got any packing material left over from something. For event photography, shoot a styrofoam cup; you can then eyedropper sample the light from any direction. Or, fit the cup over the lens, take a shot, and use that for your custom white balance. (It'll average all the light in the scene, which is often an excellent choice for white balance.)

Tyvek is another possibility. Your local office supply store probably sells Tyvek envelopes. Watch for glare, though...I'd really only recommend it for copy stand work, in which case it's excellent.

The gold standard would be Spectralon, but that's just a wee bit outside of your price range, I'm sure....



EOS Bodies - For Video / Re: Best movie settings?
« on: November 23, 2012, 02:59:10 PM »
A few things come to mind.

First, I don't think anybody can offer any advice about picture style without knowing your post-processing workflow.

If you're just going to be using consumer-level tools such as iMovie, then you want to get everything exactly the way you want it to look in the camera. If you like the way it looks on the back of the camera, that's the proper setting. If you don't like what you see, fiddle around until you're happy and then use that.

If you're going to be doing the post-processing yourself using more advanced tools, the same advice applies. You don't have enough experience and knowledge to properly make use of more advanced camera settings.

If somebody else is going to be doing the post-processing, ask that person to set up the camera for you.

Next...cinematography is a hugely complicated skill. If this is the first movie you've ever shot, accept right now that you're going to screw things up, and don't beat yourself up over the fact that you will. And make sure that nobody is relying on you to get everything right the first time.

Here's enough to keep yourself from hurting yourself too badly:

1. Shoot manual exposure. Either use 24 FPS and 1/50 second if you want a film-like presentation, or 30 FPS and 1/60 second if you want more of a TV-like presentation. Set the aperture for your desired depth of field. Then, get the proper exposure ideally by adjusting the lighting of the scene, by using neutral density filters (a variable filter is especially handy) if that's not practical, and lastly by adjusting your ISO. Whatever exposure you go with, you'll very much want to stick with it through the entire scene. The pros use expensive meters to get the light right, and their insanely-expensive lenses are calibrated in T-stops to let them do so. You're better off just putting the camera's built-in meter in evaluative mode and trusting what it says. Point the camera everywhere you will when you're shooting, and pick the least-worst compromise for your manual exposure.

2. Use a custom (manual) white balance. See the camera's manual if you don't know how to do this. If you don't, unless you've got superb lighting, your movie will have a distracting color cast to it.

3. Use a tripod. The cheapest video tripod you can get at your big-box electronics store will be horribly inadequate and a thousand times better than hand-holding.

3a. If you must hand-hold and you don't have a Steadycam rig (and somebody who knows what to do with it), use a lens with image stabilization. The results won't quite look like the Blair Witch Project that way.

4. You're going to have to use manual focus, no matter what. "Pulling" focus for video is a special talent all unto itself, and ideally performed by somebody other than the person operating (aiming) the camera, generally by watching an external monitor and by knowing exactly where to physically turn the ring to based on where the subject is on the stage. "Good luck with that," as they say. If there's any doubt, go with the smallest aperture you can live with to get the most depth of field, and then see #1 above again. If there's nothing distracting on the set that you need to mask with out-of-focus blur and if you've got enough light, pick a hyperfocal-style combination of aperture and focus distance that will cover the entire stage, and then tape down the focus ring.

5. Record audio externally. If you were planning on using the camera's built-in microphone, get a Zoom H-series recorder and use it instead. Just put it on a mic stand next to the camera, and be sure the stand doesn't get bumped. You can use the recorder's auto-levels feature to figure out what the "good enough" audio level is, but then turn the feature off and manually set the audio level for the actual shoot. Changing audio levels during a shoot is as bad as changing exposure. Just let the audio run during the entire shoot. You can sync the audio afterwards very easily if you use a clapboard, and almost as easily if you just have a person on camera clap hands.

6. Practice, practice, practice. Do the above and you're probably not going to embarrass yourself too badly, maybe, but you're obviously not going to win any Academy Awards. The more you practice, the less your chances for embarrassment. Practice enough and you'll get past the danger of embarrassment and towards the possibility of actually doing something with merit.

Good luck!



EOS Bodies - For Stills / Re: Dumb question?
« on: November 23, 2012, 10:43:31 AM »
Photoshop and (similar applications) can be a great tool at doing this kind of math.

First, start with a full-resolution picture from each camera (you can find samples all over teh Innertubes). With the Resize Image dialog and without scaling / re-sizing / interpolating set the image size to the same physical dimensions as the camera's sensor (24mm x 36mm in the case of the 5DIII). Note: this needs to be the dimensions of the camera that took the picture, and the pixel dimensions of the picture need to remain unadulterated from when it came out of the camera.

Now, you can use the Canvas Size dialog to either crop or expand the canvas to match the physical size (not pixel dimensions) of the other camera's sensor.

What you'll see is either the amount of crop that you get plus the actual file size and resolution, or the amount of extra real estate and the file size you'd have with a larger sensor with the same pixel density.

And, at that point, you can start playing around with printing / resizing / further cropping / whatever and get a fair understanding of what that means in the real world.



Lenses / Re: Portrait: 85mm 1.8 or 100mm 2.0
« on: November 21, 2012, 11:29:45 AM »
The two lenses are really quite comparable, though not exactly interchangeable.

If you're planning on using it for portraiture, the only real difference is that you're going to need a bit more working distance with the 100 to get the same composition, and you'll as a result have a bit more compression of the perspective and get a bit more background blur. Not a huge amount, but you'll be able to tell the difference in side-by-side comparisons.

There're a few favorite variations on the "holy trinity of primes" theme for event (especially including wedding) photography. The classic one is 35 / 50 / 85. Also popular is 24 / 50 / 100. Some who're especially fond of the 135 mm focal length might go for something like 35 / 100 / 135. With the new Shorty McForty and the new 24mm f/2.8 IS combined with the insane low-light performance of the 5DIII, some serious consideration should be given to 24 / 40 / 85. However, if you're not sure, you're far better off doing your event photography with a standard zoom until you <i>are</i> sure.



No video means no live view. Nothing, and I mean nothing, beats live view focussing for still life work. That includes landscapes. Not sure what the optimal aperture is for the depth of field you want? No worries; just press the DoF preview button while in live view and your eyes will tell you.

A DSLR without video is crippled, and it would take serious effort to do the crippling.

Thanks, but no thanks.

And, yes. I write this as somebody who has virtually no interest in videography whatsoever.


Technical Support / Re: Best Methods For Long Term File Storage ??
« on: November 14, 2012, 06:39:03 PM »
Lots of questionable advice, here.

First, do not rely on Teh Cloud, in any form. If you don't have physical control over your data, you don't own it, and whoever does own it can do anything they want to it and you've got very little recourse. That could include deleting it, peeking inside it, or even sharing it with the world.

If you're not overly worried about your cloud provider accidentally or intentionally sharing your data with the world, it can make a nice additional supplement to your data archiving strategy, but only as a "if everything else I'm actually relying upon goes tits-up, I'd hopefully still be able to get to it in the cloud" sort of last gasp hope.

With that out of the way, the only reliable method is to continually keep all your data readily available and online and part of your regular backup routine. As others have pointed out, old media die in lots of different ways. If you copy all your old media to whatever you're using today, you don't care if the old stuff dies for whatever reason, and you're also confident that you've got a valid copy. There's no worry that your several-year-old DVDs might be starting to delaminate, or that your Zip drives will have the click-o-death, or whatever.

Yes, that means you need bigger hard drives today, but the good news is that hard drives are dirt cheap compared to whatever you spent on your old media. A single DVD doesn't even store as much as a typical CF card. A hundred bucks gets you a hard drive that holds the equivalent of a few hundred DVDs. When that drive fills up, get another.

The simplest and most reliable backup method these days is to get three times as much disk space as you need. Disk(s) 1 are where you keep everything. Put a copy of everything on disk(s) 2. Every week (or month or whatever), take disk(s) 2 offsite to your bank deposit vault or your parent's place or somewhere you trust and exchange it for disk(s) 3, which you bring back with you and start treating as you used to do with disk(s) 2. The next week, do the swap again.

Also worth investigating, depending on your performance needs and your desire for tidyness, are RAID arrays. Be careful; many commonly-used RAID modes actually put you more at risk for data loss than a single hard drive, meaning you need that much more redundancy in your backups to compensate. Safer RAID modes eat up more disk space. Duh! But you only want to think about RAID if a single disk isn't big and / or fast enough to hold all your stuff, and you should then think of the RAID array as a single disk that happens to have some extra moving parts.

IOSafe also makes near-indestructible hard drives: fireproof, waterproof, crushproof. They're more expensive than a regular hard drive, but very reasonably priced. If you're on a Mac, just get one (or three or however many you need) and point TimeMachine to it (them), and the only reason you'd need an offsite backup is if you're worried about theft.



It is a nice picture. But why, when you are spending all that money, would you rent that lens. It does not even have IS, so in a helicopter your shot has to be lucky that you get it at the right moment. True that applies to a lot of photography. But surely he could have taken something else!

I very much doubt that IS can dampen the high-frequency vibrations you get from a helicopter in flight. It's designed to deal with the low-frequency motion of human muscles. Aside from some stupid-expensive gyro-stabilized rig, about your only realistic choice is going to be what I call, "poor man's IS:" shoot a burst of images as steadily as you can, and if your boost is long enough, you'll catch a shot as the vibration takes you to the extreme of one swing before it starts the next sway -- that is, just as the pendulum is frozen at the end of its swing.

A 1Dx that can do 12 FPS with a really deep buffer is ideal for such bursts. And its extra mass doesn't hurt, either.


Lenses / Re: EF-M 55mm f/1.3 Coming in 2013? [CR1]
« on: November 02, 2012, 07:56:18 PM »
One of the primary thing that determines the noise level is the pixel size.

Actually, pixel size in and of itself has no bearing whatsoever on noise. Once again, it's entirely a question of (absolute) enlargement.

The only reason pixel size appears to relate to noise is that people like to compare noise at a 100% pixel view. But, right there, you're now comparing different enlargements. A 36 megapickle full-frame camera has twice the linear resolution as a 9 megapickle full-frame camera. To compare the noise, you'd need to either show the one at a 50% view (turning the noisy small pixels into unnoticeable fine-grained smoothness) or the other at 200% view (thus making the noise in those big pixels much nastier and blotchier). Or, much better, by actually making prints and comparing the prints. But, then again, your 24" x 36" print (or whatever) is going to be done at 300 ppi by the one camera and only 150 ppi by the other.

The short version is that there will be the exact same S/N ratio (all else being equal) between the two; you just get to pick between more fine-grained noise or less large-grained noise. If it helps, imagine scanning film at different resolutions; the grain is still there no matter what, and all you get to do is decide how faithfully you want to render the grain.

And, of course, the usual engineering caveats apply. Newer cameras are made with more megapickles and thus smaller pixels, yes, but also with newer and better and more efficient electronics that's therefore less prone to noise. And there may well be engineering matters that make it easier to design bigger circuitry and so forth.



Lenses / Re: EF-M 55mm f/1.3 Coming in 2013? [CR1]
« on: November 01, 2012, 03:15:01 PM »
I think stating the same thing in ISO would only serve to confuse less informed people attempting to understand the fundamentals of photography and the differences in formats.

Quite the contrary.

Image quality and noise / grain is very closely tied to the degree of absolute enlargement, which is itself very closely tied to the format.

ISO is determined in no small part by the noise / grain threshold...but that very threshold in the practical real world is dependent upon image quality, thus enlargement, thus format.

In a very real sense, one that you see hold up as a rule when comparing cameras from the same generation of technology, each larger format has roughly a one-stop ISO advantage. If you need to shoot at least at ISO 200 on a 135 format camera to get noise to levels you find acceptable, then you need to shoot at at least ISO 100 on APS-C, but you can get away with ISO 400 on medium format.

(And, yes, it doesn't scale linearly -- despite their size advantage, many medium format cameras have lousy extreme-high-ISO performance. This is partly due to there not being much demand for low-light utility in the medium format world, and the manufacturers putting their efforts into improving low-ISO performance instead. The fact that it's a much smaller market also plays a role.)

Understanding why this is so is a very basic part of photography, and essential to understanding why the different formats exist in the first place and one of the reasons why you would choose the one over the other.


Lenses / Re: EF-M 55mm f/1.3 Coming in 2013? [CR1]
« on: October 31, 2012, 08:20:03 PM »
So the noise from a EOS D30 (2001) is one stop behind the 1D X?

No, of course not. Don't be silly.

Forget digital for the moment and think of film.

Your favorite film has an effective one-stop ISO advantage with each increase in format size.

If you're happy with the grain you get from an 8" x 10" print from APS-C with ISO 50 Velveeta, you'll be equally happy with an 8" x 10" print from 135 format with ISO 100 Velveeta and with an 8" x 10" print from 645 format with ISO 200 Velveeta. Couple all those film and camera choices with a 50mm @ f/1.4, an 85mm @ f/2, and a 135mm @ f/2.8 respectively, adjusting shutter speed (but not composition / distance / framing / etc.) as needed, and you'll wind up with very closely comparable images from all three, with the only variable remaining being resolution.

Obviously, you can shoot your medium format camera with a 135mm f/1.4 lens and ISO 50 Velveeta and get an image that's comparable to what you'd get with an APS-C camera with a 50mm f/0.5 lens and ISO 12 Velveeta...which would be quite the trick!

Comparing a D30 with a 1DX is as silly as comparing Velveeta with Cojack; make the comparison instead between an EOS-M and a 6D.



Lenses / Re: EF-M 55mm f/1.3 Coming in 2013? [CR1]
« on: October 31, 2012, 05:28:20 PM »
"For arguments sake, that would give an approximate field of view of 90mm f/1.3. A nice portrait lens for the new system."

Just to clarify, it would be the approximate equivalent of a 90mm f/2.0 FF lens. You have to take the crop factor into account when comparing apertures as well as focal lengths.

You are right if yuo think about Dept of field, but in term of shutter speed the aperture it is still faster (must admit that with crop you have to use faster speed to avoid shake).

Actually, when you take noise into effect, you also have to decrease the effective aperture to get a valid comparison with a larger format. I can't do the math, but it's also roughly a stop.

That is, f/1.3 @ ISO 100 on APS-C really is comparable to f/2.0 @ ISO 200 on full frame. And f/1.3 @ ISO 100 on full frame would be comparable to f/1.0 @ ISO 50 on APS-C. (Roughly, with rounding, etc., etc., etc.)


EOS Bodies / Re: Is 22Mpx Really Enough?!!!
« on: October 25, 2012, 01:18:32 PM »
Have a look at some actual Adams prints.

First, of course, they're marvelous -- absolutely fantastic works of art.

But, can get at least comparable and often better sharpness and image quality with today's high-end DSLRs.

Heresy, I know -- to suggest that puny 135 format might be better than Ansel Adams's legendary 8x10 view camera. But today's lenses are far superior to the ones he had access to, and digital sensors are far superior to his film emulsions.

So, yeah. When I can make prints with my 22 megapickle 5DIII that are technically (though not, to be certain, artistically) superior to what Adams did, I've got plenty of resolution.

More would be absolutely loverly, of course -- especially since I do some fine art giclée reproduction work. Hell, I'd drool over an 8x10 camera with the pixel density of a digicam, the dynamic range of a Nikon, and the rendering quality of a Canon.

But that doesn't mean that what I have isn't already enough.



Animal Kingdom / Re: GODZILLA!
« on: October 23, 2012, 10:05:42 PM »
I'm with anand on the highlights: not a problem.

I'd have liked just a wee bit more in focus on the first one, but you nailed it to the wall on the second -- perfect control of depth of field.




Seriously? April?



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