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Messages - K-amps

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1411
Lenses / Re: New L Series Lenses coming out with the 5D Mk3?
« on: September 23, 2011, 12:50:36 PM »
It's not likely that anyone will produce a 24 - 105mm f/2.8 IS L.
That is likely what people were saying in late 80's when the 35-70mm f2.8 was being made, and again in the mid 90's with the 28-70mm f2.8, and now with the 24-70mm f2.8.  Look at the progression, what makes you think it will stop?

UWA
20-35mm f2.8 (1989) -> 17-35mm f2.8 (1996) -> 16-35 f2.8 (2001)
Normal
28-80mm f2.8-4 (1989) -> 28-70mm f2.8 (1993) -> 24-70mm f2.8 (2002)
Tele
80-200mm f2.8 (1989) -> 70-200mm f2.8 (1995)

On top of that we could add the Nikon 14-24mm f2.8 to UWA list, and the 35-70mm f2.8 to the Normal list.  Also, we could look further back in history with the FD mount: (24-35mm f3.5 [1979] -> 20-35mm f3.5 [1982]).  Constant aperture zooms have grown from less than 2x (24-35 is 1.46x, for example) to 5x (Nikkor 24-120mm f4).

You will notice that the short zooms coordinate with the long zooms on your list. If they were to produce a 24-105 f2.8, it would likely mean there would be a move to a 105-300 f 2.8.

The 24-70 2.8 and the 70-200 2.8 are the perfect tag team. The 24- 105 2.8 is just too much overlap IMO, unless they were to add the 105-300 2.8... which would be a sweet lens!

Lets say we were to frame at 70mm, would we choose the 24-70mm or the 70-200mm ? And why?


1412
Canon EF Prime Lenses / Re: Canon EF 180mm f/3.5 L Macro USM
« on: September 23, 2011, 12:33:02 PM »
Neuro... I don't mean to pry.. but you have awesome gear... are you a pro, or just are lucky enough to have spare cash?

Photography is just a hobby, but I happen to have a decent budget for gear, mostly from consulting work that I do outside of my day job (I don't spend a lot of time at it, but $300/hr adds up  :D ).

Nice!  I am glad that someone who knows what he is doing and has a passion, is not constrained by other things. 

Have you compared the 180mm to the 100mm L? What do you think are the pros/ cons of each? (IQ wise) I know the 180 weights a bit....

1413
Many of the microsoft wallpaper images, including some on Windows 7 were taken by a Microsoft Employee, Mike Swanson with a lowly Canon Digital Rebel XT.

http://blogs.msdn.com/b/mswanson/archive/2005/11/10/wallpaper.aspx


What a nice read !! Thanks for the link.

1414
EOS Bodies / Re: Canon EOS 3D?
« on: September 23, 2011, 10:14:11 AM »
12 yrs of my great internet rep wiped out in one screengrab  ???  :)

Rep is overrated. One who can admit to his mistakes, deserves tons of respect.

1415
Canon EF Prime Lenses / Re: Canon EF 180mm f/3.5 L Macro USM
« on: September 22, 2011, 08:59:18 AM »
Were you the guy that shared a pic of the pink flower / trident stamen with the MPE-65? It was gorgeous. What do you use for illumination?


This one?  (small size since this is not the MP-E 65mm thread)



If so, yes, that's me...and thanks!  Lighting was with the MT-24EX Twin Lite (with StoFens on the flashheads).


Yep  :)  thats the one!  I had it as my desktop background for a few days as I watched the dazzle of nature... of course the dazzle of the photographer as well :)

Neuro... I don't mean to pry.. but you have awesome gear... are you a pro, or just are lucky enough to have spare cash?

1416
EOS Bodies / Re: Ball pitching speed / Shutter speed accuracy experiment
« on: September 22, 2011, 08:54:48 AM »
The question that I would have is "Does the difference in the crop factor make any difference?".  The 1d2 has a 1.3 crop factor whereas the 5d is FF

This wouldn't be a problem as the ball is a constant size so if the OP has measured the distance using the diameter of the ball then this would be the same for each picture as the ball is a standard size.

Correct, the ball is 6.7cms and I am going off the ratios of width of the ball vs. length of the blur.

I did take 3-4 shots each, and these are the longest "blurs" for each bowler. The bowler's had relatively consistent blurs in the 3 shots I took.

There is some movement in shot #1 but it is more vertical (look at the blur of the ball, there a slight hump); without that movement, the ball would have been even faster, so that's not what is causing my 15% difference.

Goes back to the accuracy of the shutter speed. I was googling "shutter speed accuracy" and came about some experiments people did at 1/100th of a sec and found after 75 shots, the shutter was languishing at 1/140 -1/160th of a second... sadly I forget what camera it was.

So does anyone know if Canon shutter speeds are accurate or does +/- 15% fall under an "acceptable tolerance" ?

1417
EOS Bodies / Re: Ball pitching speed / Shutter speed accuracy experiment
« on: September 21, 2011, 05:06:38 PM »
Hi, K,

I am trying to estimate the velocity of a pitcher (the radar gun I have does not seem to be not accurate) using a framed capture at 1/60th of a second.

Does the "scan" aspect of the FP shutter introduce any complication into your process? Perhaps with a shutter speed of 1/60 s it would not be a factor.

Is the travel of the ball parallel to the focal plane (or at a consistent angle to it)?

Interesting project.

Best regards,

Doug

Doug: thanks for reading through my "blog" there.

I am afraid I have to plead ignorance to the ""scan" aspect of the FP shutter" question. This was a series of stills, the capture should have lasted 1/60th of a second in my mind.

The angles and other aspects of the ball line were far from perfect, for Pitcher 1, the 1d2 was handheld and there is vertical blurring, but it has little impact (little) on the horizontal trajectory. A +/- 5% margin of error is very much a given;  the way i did the experiment, but I am getting an over 10% difference from expected result.

See the attached pictures and see what I mean. The blur of the ball is clearly different lengths. Pitcher #2 should be faster or equal to Pitcher #1.

1418
Canon EF Prime Lenses / Re: Canon EF 180mm f/3.5 L Macro USM
« on: September 21, 2011, 04:08:18 PM »
100mm is a bit short for insect shots... either I scare them or they scare me at 2 feet.

now if I can get a nice cheap, and sharp used 180mm :)

Depends on the insect.  I've gotten some nice insect shots with the MP-E 65mm f/2.8 1-5x, and the working distance on that lens is between 1.6-4 inches, depending on magnification (and since you can't go below 1x due to the lack of infinity focus, 4" is the longest working distance possible!).

I have seen a 180mm f/3.5L Macro pop up on my local Craigslist in the $950-1000 range a few times, as recently as a month ago.

Were you the guy that shared a pic of the pink flower / trident stamen with the MPE-65? It was gorgeous. What do you use for illumination?

1419
PowerShot Cameras / Re: Sensor Pixel Density
« on: September 21, 2011, 02:43:15 PM »
Q1: I would think no, because native pixels are sharper (more clarity) than interpolated pixels. This is assuming your Camera uses the whole sensor and not a crop at 10mp. I am saying this because if you set your monitor to a smaller resolution than it’s native resolution, it is interpolating pixels and it gets quite blurry. At magnification levels that are square roots or similar proportional numbers, the perceived sharpness is better e.g. 50% magnification looks better than 66% magnification on screen. So there is a relationship between the nativity vs. interpolation of the pixels. So I think the answer to this question might be a “No”

Q2) Might better to use a good software to reduce it. For example bicubic scaling is better for reductions as it naturally sharpens, and Bilinear is better for enlargements as it smoothens jaggies. Fractals are even better at enlarging. My guess is specialized software for resizing should out-do the in camera resizing.

Here's some info on the reduction/expansion algorithms: http://www.codinghorror.com/blog/2007/07/better-image-resizing.html

1420
EOS Bodies / Ball pitching speed / Shutter speed accuracy experiment
« on: September 21, 2011, 02:27:53 PM »
I am trying to estimate the velocity of a pitcher (the radar gun I have does not seem to be not accurate) using a framed capture at 1/60th of a second.

I set a 1d2 at 1/60th sec capture then measured the trail of the ball and (how much it moved in 1/60th of a second); did some on screen measurements; ran some calculations; to get at an expected speed of 90.12mph.

I think this is very close to what I thought his speed would be, so I was confident in the modelling.

This was a cricket pitch, but lets use baseball analogy if it helps.

We have another pitcher that we think might be a bit faster or at least the same than Pitcher #1.

This time I set a 5Dclassic (that I had on me at the time) with the similar (though not same) framing and 1/60th frame capture. I figured as long as I can get a ratio of the ball trail vs the diameter of the ball, I’d end up with a constant that could be uses to compare the two captures and calculate the speeds. We also have a third pitcher who we feel is a bit slower than #1 and #2 that I framed the second time as well.

To summarize:

Pitcher #1 = 1d2 1/60 sec
Pitcher #2 = 5D 1/60 sec
Pitcher #3 = 5D 1/60 sec

For that batters (batsmen) who have faced these 3 guys feel Pitcher 1 & 2 and neck and neck at around 90mph, while pitcher 3, is about 7-8%  slower.

Results:

Pitcher 1 = 90mph (1d2)
Pitcher 2 = 77mph (5d)
Pitcher 3 = 67mph (5d)

While the speed differential between pitcher 2 & 3 is absolute since the test and the conditions are identical (even the trail in the photo bears out a 14% difference between them) what I cannot believe is that Pitcher 2, is only 77mph (though he seems very close or faster than pitcher 1).

I may not be able to assemble these guys together for a retake with the same equipment so here is my question:

When the 1d2 takes a picture at 1/60th of a second, how accurate is that? Same for the 5D.

Based on this, it seems to me that there is a 15% difference between the 2 bodies. Should I trust one or the other? Are shutter speeds that accurate?

1421
Canon EF Zoom Lenses / Re: Canon EF 70-300 f/4-5.6L IS
« on: September 21, 2011, 01:32:26 PM »
Hi K-amps,
I use CS5, and I still have a LOT to learn. Generally I select what I do not want to blur, refine the edge and then invert the selection to apply the blur. I use the quick selection tool and then use the lasso for fine-tuning.


Same here. Did you use gaussian or lens blur?

1422
Canon EF Prime Lenses / Re: Canon EF 180mm f/3.5 L Macro USM
« on: September 21, 2011, 01:16:25 PM »
@K-amps

I don't know what your definition of nice or cheap is, but there is a 180L on B&H right now for $1250.

Thats not too bad, what I was thinking is Near MINT used for $950  (good copy... if it matters)

1423
EOS Bodies / Re: Nikon unveils V1 and J1 Mirrorless Cameras
« on: September 21, 2011, 11:30:26 AM »
.......   but f/2.8 on their CX sensor is equivalent to f/7.6 on FF...not very impressive....


I never knew there was a correlation as direct as that. So if I have a 24-105 f4, is that like f6.4 on a APS-C sensor; or do we need to consider other factors too.

Just learning here... cause then my f4 lens on a 5D is not too bad compared to his 70-200 f2.8 II on his 7D (f4.48 equivalent) or should I consider other factors too.

Basically, yes.  But to be clear, the crop factor applies to aperture in terms of depth of field for equivalent subject framing...so, f/2.8 on APS-C gives you the same depth of field that you'd get at f/4.5 on FF, for the same subject framing.  The reason is distance - the crop factor means a narrower angle of view, so to match the framing you need to be further away with APS-C, and that extra distance means a deeper DoF. 

Many people don't realize this.  A great example is people who state they won't upgrade to FF until the 24-70mm has IS, because they want a FF equivalent of the very nice EF-S 17-55mm f/2.8 IS.  What they don't realize is that such an equivalent exists...and is actually better spec'd - the actual FF equivalent of the 17-55mm is a 27-88mm f/4.5, so the 24-105mm is wider, longer, faster, and still has IS plus on the 5DII it will out resolve any APS-C sensor.

The effect of crop factor on aperture does not apply to exposure, though with the better ISO performance of a FF sensor, you can bump up the ISO to compensate for the loss of a 1.3-stops of shutter speed.

 I was thinking the exposure, but this clears it, thanks neuro and Liberace

1424
Canon EF Prime Lenses / Re: Canon EF 180mm f/3.5 L Macro USM
« on: September 21, 2011, 11:08:28 AM »
I also owned 100L, then got myself a 180L, and sold the 100L right away.

IS is surely nice to have, and i'm sure they will release the 180L IS version eventually, but at this point I consider 180 so much more my type of lens due to a special bokeh (looks somewhat old-school to me), reach that you need for macro work (insects tend to escape when approached with shorter focal lengths), and it can also serve as a long portrait lens, more so than 100L due to the fact that there are many other alternatives in that range (85L, 100/2, 135L etc).

I am glad I am not the only one that has thought of ditching the 100L for the non-IS 180mm... Fully agree, 100mm is a bit short for insect shots... either I scare them or they scare me at 2 feet.

now if I can get a nice cheap, and sharp used 180mm :)

1425
EOS Bodies / Re: Nikon unveils V1 and J1 Mirrorless Cameras
« on: September 21, 2011, 10:30:21 AM »
.......   but f/2.8 on their CX sensor is equivalent to f/7.6 on FF...not very impressive....


I never knew there was a correlation as direct as that. So if I have a 24-105 f4, is that like f6.4 on a APS-C sensor; or do we need to consider other factors too.

Just learning here... cause then my f4 lens on a 5D is not too bad compared to his 70-200 f2.8 II on his 7D (f4.48 equivalent ?) or should other factors dwarf this correlation?

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