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Messages - Drizzt321

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946
EOS Bodies - For Stills / Re: DxOMark "Perceptual Megapixel"
« on: December 17, 2012, 07:21:22 PM »
Quote from: DxOMark
Can you define MTF? Do you know if an MTF20% of 50lp/mm is better or worse than an MTF 50% of 30 lp/mm? And when reviewing an MTF chart, can you distinguish which curve is best? The short answer is probably no.

Yes, yes, and yes.   :P


Yea, but can the rest of us? I keep re-reading the same couple of articles now and then on MTF, and I sorta, kinda can describe the general purpose, but have a hard time actually getting meaningful information out of MTF charts still :(

947
Lenses / Re: Long lens recommendation for surveillance.
« on: December 17, 2012, 06:37:17 PM »
Since he's not interested in photography, why not just pick up the Canon PowerShot SX50 HS: http://www.bhphotovideo.com/c/product/889965-REG/Canon_PowerShot_SX50HS_Digital_Camera.html

50X optical zoom, 24-1200mm, 12.1MP, Full HD 1080p Video, Optical Image Stabilizer and High-Speed Burst HQ for 13fps Shooting.
That looks amazing.  And a small camera like that is very discrete.  I just wonder whether it would be any good at night?

That's the big question. Also a question of Auto-Focus. Contrast detect is very accurate, but tends to be slower and you may not be able to easily tell it what part you want in focus. I haven't read any reviews, so I don't know if that applies to this camera or not.

948
EOS Bodies - For Stills / Re: DxOMark "Perceptual Megapixel"
« on: December 17, 2012, 05:16:32 PM »
Paging Neuro. Doctor Neuroanatomist, please post to this thread.

Overall, it looks like there is something to the 'perceived' resolution, and that the problem they are stating, that MTF charts are not what the vast majority of photographers read, seems fine. But I think they need to publish (if it wasn't in the article, I may have missed something) how they came up with the numbers. Give us the methodology, and then we (meaning not me, someone like neuro probably, or Roger at LensRentals.com) can run their own numbers and thoughts and see if DxOMark's number makes sense.


I was fairly certain that Roger at LR had concluded the D800 out resolved quite a good deal of Nikon lenses.
Roger's Article on the D800 and Lens Choice

Quote
The D800′s ultra-high resolution sensor can provide amazing detail. Not every lens (in fact, not most lenses) are going to be able to give you the maximum resolution the camera is capable of.  This list isn’t about great lenses, it’s about what lenses can wring the most resolution out of a D800 when you need every ounce of resolution. Maybe you have a two page magazine spread to shoot, or more likely you just want to post your pics on a Canon forum to rile everyone up.

Ah, I think that was before I started reading his blog regularly. Thanks!

949
Lenses / Re: Long lens recommendation for surveillance.
« on: December 17, 2012, 04:58:33 PM »
Anyone notice what camera kit Virgil uses in Homeland? He always gets the perfect shot of his target's face, and it looks like a light setup.

It's magic movie fairy dust. Can't you see the sparklies in the air whenever he uses it?

950
EOS Bodies - For Stills / Re: DxOMark "Perceptual Megapixel"
« on: December 17, 2012, 04:37:54 PM »
Paging Neuro. Doctor Neuroanatomist, please post to this thread.

Overall, it looks like there is something to the 'perceived' resolution, and that the problem they are stating, that MTF charts are not what the vast majority of photographers read, seems fine. But I think they need to publish (if it wasn't in the article, I may have missed something) how they came up with the numbers. Give us the methodology, and then we (meaning not me, someone like neuro probably, or Roger at LensRentals.com) can run their own numbers and thoughts and see if DxOMark's number makes sense.

951
Lenses / Re: Long lens recommendation for surveillance.
« on: December 17, 2012, 02:19:00 PM »
What does this mean: "Oh, and doesn't Canon have some kind of strong signing of an image that it comes from a person/camera? Maybe he should look into that, since it probably would help with chain of custody kind of thing for any evidence." Strong signing?
Canon offers a Data Security Kit for some cameras, although a quick google suggests it's been cracked.

Yea, that's what I was referring to. Too bad to hear it's been completely cracked.

Oh, and maybe he should also get the GPS logger for the 1DX/5d3 if that's what he gets? That will help place the location of where he's shooting, and I believe even a digital compass to say which direction he's shooting in.


How far away does he need to do surveillance?
This is the question.  Because it determines the focal length of the lens.  The ultimate low light telephoto is probably the 200 f/2 ($$$), but whether that is the appropriate focal length depends on the subject distance.

Pro-level tripods are big and easy to spot.  Leaning the camera on something sturdy, perhaps with a bean bag, may be more practical.  Or perhaps a monopod or a very short tripod/stand, like what some sports photographers use for their remote cameras. 

The essentials are going to be:
- high res, high ISO camera = Canon 5D3, 1DX, 6D, (or Nikon D4, D800, D600?)
- wide aperture (f/2.8 or faster) prime or zoom with image stabilization, probably a discrete non-white lens (Nikon, Sigma) or white lens with an appropriate dark cover.
- practice focusing; practice steadying the camera.

Depending on the distance, a camera with quiet shutter mode may be of use (5D3, 6D).  Also, it will be important to learn how to turn off / tape over anything that lights up on the camera.

The 200 f/2.0 would probably be overkill, although I'd love to own one :)  The 70-200 2.8 IS would probably do just as well, and be much cheaper as well. Add on the 2X TC, and you get the 140-400, even though it does go to f/5.6 it probably could still be usable at high ISOs like on the 5d3/1DX.

Great point about the big tripod. A beanbag on a car/wall or good quality monopod would be less obvious and easier to move around with. I'd also make sure to be using the lens-hood, even though it'll make it bigger and bulkier, it might help prevent reflections off of the front element of the lens. Most photographic lenses aren't made with the non-reflective coating like military/surveillance binoculars/scopes generally have on them.

952
Lenses / Re: 2.8 vs F4
« on: December 17, 2012, 12:39:40 PM »
Is it like freeway numbers? Take the 55 to the 5 to the 10 the 15 to the 395 or take CA55 to I5 to I10 to I15 to US395. :-X

You left out the 405 to the 101 to the 170 to the 118 to the 210 :P

953
Lenses / Re: Long lens recommendation for surveillance.
« on: December 17, 2012, 12:37:06 PM »
How far away does he need to do surveillance? As Neuro said, the 600 f/4 with 2X TC on the 1DX or 1Dm4 for the 1.3x FOV crop. Don't forget to get one of those lens wraps to hide the great BWL if that's a concern. If he's at closer distances. you can go for the other, shorter primes, or go for the 100-400 for more versatility between closer and further reach. Oh, and don't forget he should get a really good tripod or other support devices if he's going to be shooting at night with the BWL glass. Hmmm...the other thing might be a good laptop which he tethers to the camera to view the images on a larger screen.

Oh, and doesn't Canon have some kind of strong signing of an image that it comes from a person/camera? Maybe he should look into that, since it probably would help with chain of custody kind of thing for any evidence.

954
Nice work :)

I've started doing a similar thing with my 5D mk3. The last attempt of mine, taking 325 images over 4 hours ended up with heavy dew after image 24  :'(

What lens did you use?

I was worried about fogging up, but I got lucky. I think the combination of a cold camera (matching the temp outside), and the wind bowing around the lens kept it clean. I was shooting on the 24mm 1.4 II, which is one of my favorite lenses

Oh, I love that lens. I'm hoping to get one sometime, but I've got a 24-70 (looking at the Tamron, I'm pretty impressed so far), 70-200 2.8 IS v2 to acquire first. Then I can start going after the lovely, lovely primes :)

955
Canon General / Re: DxO Mark explained
« on: December 17, 2012, 03:03:21 AM »
the d800 is equal to 5dmk3  up to 12800iso, i have them , i have tested them and compared them step by step and Im talking raw files.

this is 5dmk3 together with 70-200/4 and Nikon d800 with the new zoom 70-200/4  6400iso, my purpose was to se if Nikons new zoom is good as Canons.
Nikon file size down sampled to Canons 5dmk3 and  latest Camera Raw
canon to the left

Not saying your method isn't valid for you, but remember as you sample downward, you remove more and more of the noise that appears. So if you regularly use the D800 files at the 5d3 size resolution, you may see similar or better performance for some of the higher ISOs, while if you often use the full resolution, you'll be more likely to see the noise in the D800. Try down sampling both to 18, or 12, or some other size and see what happens to the noise in both. For example, when I export for the web (1200px long edge), often much of the noise disappears, unless it was truly horrible to begin with.

I think this is the real power of the newer generation(s) of high megapixel-high ISO sensors. The ability to get pretty good files straight out of the camera at full resolution, and be able to down-sample to a smaller resolution and get stunning results in lighting that would previously be considered next to impossible to shoot in.

956
Very awesome :) Thanks for sharing. What'd you do for power? Was that on just the 2 batteries in the grip? They lasted the whole 6 hours of continuous shooting in that cold? Wow!
The 1DX only takes a single battery, and it is different from the batteries in the 5D's (maybe someone here can explain what makes them different as I'm not entirely sure). I was worried that the cold might zap it a little quicker, but it held up just fine. At the third hour I swapped out for a fresh one, but there was still a bar left.

1D-series use 3 cells in series (~11V), compared to 2 (7.2V) for others. In terms of mAh, the higher voltage gives 50% more capacity in theory, but if you calculate energy density, it comes to same number. So it's all about volume, and 1D batteries are roughly same size than 2 "standard" batteries, thus giving roughly twice the capacity compared to one normal.

Cold hurts batteries, at ~-15C (~0F) you typically get only 50% of the nominal capacity.

I knew is twas higher voltage, didn't realize that the 1D only took 1 battery, I thought with it's built-in grip would take 2 like the other battery grips.

957
Reviews / Re: Review - Tamron SP 24-70mm f/2.8 Di VC USD with Pictures
« on: December 16, 2012, 10:55:33 PM »
The focusing is a bit slower than the L lenses I've used (24-105, 135, 17-40, rented 14L, 24-70L v1, 70-200 2.8 IS v2). Not bad really, but not snappy like I'm used to. I shot most of the night in AI-Servo, since they were dancing and moving all around. As I said the lighting was quite challenging, but even when the AF points I was using was over the subject in decent lighting, I always felt like I had to wait a second or two for the camera to lock focus and start tracking. Quite annoying actually, and nothing something I'm used to. Part of it may have been, as stated above, my fingers rested right on the focusing ring so I may have confused it.

Leaving aside the IQ, if I can't figure out the AF in this kind of lower light, I might have to not get this lens, which would make me sad as this is exactly the environment I'd use this in. I'll try using my 24-105 briefly in the same lighting conditions to see if it shows similar hesitation, and if so it's the camera/lighting, and not the lens and I'll have to test out in other dim lighting conditions.

FYI, the low light AF Lock issue probably isn't the lens, it's the 5D3.  That's why TWI didn't have AF problems.  If you look around on this forum, the canon forums, etc you'll find a LOT of low light AF complaints with the 5D3 using any lens.  Your comments sound a lot like the same thing.  Some bodies seem to be affected more than others.  I myself had to return my first copy of the 5D3 it was so bad.  So it very well may have nothing to do with the lens.

Yea, that's kinda what I was feeling by the end of the 2nd night. I expect normally there would even be somewhat more light. It was just exceptionally bad lighting.

958
Very awesome :) Thanks for sharing. What'd you do for power? Was that on just the 2 batteries in the grip? They lasted the whole 6 hours of continuous shooting in that cold? Wow!

959
Reviews / Re: Review - Tamron SP 24-70mm f/2.8 Di VC USD with Pictures
« on: December 15, 2012, 05:13:29 PM »
Yea, lighting conditions were cray. but I got some good shots! Anyway, I think I will be getting it, as I said.

Whenever you do get the 5d3, I would recommend holding onto the 5d2. Backup camera is always a good thing, and you can always 2-gun it, put one lens on one, and another on the other so you don't have to wait to switch lenses before continuing to shoot. Put a wide/super-wide on the 5d2, and your normal or telephoto on the 5d3. The great part is you can share both CF cards, AND batteries!

That is what I am leaning towards.  I do something similar with my 60D, but it works less well now that I have reoriented my lens collections towards all FF glass.  Fortunately my 60D does share batteries with the 5D already, but not memory cards.

One thing I'm sorely missing from the 1DX that I'd love is the spot-linked metering. Obviously not so useful when shooting full manual, but if I can even leave ISO on auto with spot-linked metering, I can worry less about the subject that I'm AF on to have blown out highlights in changing lighting conditions. Ah well, when I hit the lotto I'll buy me one  ::)

You know, if you've got a spare 60D laying around, maybe you can throw MagicLantern on it and maybe play with doing some video. If you can even have just a bit of video of the ceremony, some clips of the reception party, a bit of crying when people are giving toasts, that's probably worth something good. Just need a pretty good tripod, and a lot of practice.

960
Reviews / Re: Review - Tamron SP 24-70mm f/2.8 Di VC USD with Pictures
« on: December 15, 2012, 04:34:35 PM »
Yea, lighting conditions were cray. but I got some good shots! Anyway, I think I will be getting it, as I said.

Whenever you do get the 5d3, I would recommend holding onto the 5d2. Backup camera is always a good thing, and you can always 2-gun it, put one lens on one, and another on the other so you don't have to wait to switch lenses before continuing to shoot. Put a wide/super-wide on the 5d2, and your normal or telephoto on the 5d3. The great part is you can share both CF cards, AND batteries!

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