Messages

1

Lenses / Re: Lens sharpness and distance from subject

« on: April 28, 2013, 01:36:05 AM »

On the other hand, my 100mm macro is better suited at close work.

If one goes through the detailed lens descriptions the term "floating elements" crops up. Thats a way to deal with the different needs of extreme close focus and infinity - move some elements around as if it where a zoom lens, but instead of changing the focal length its the aberration control that gets adapted. (Well, IF/RF adds another layer of complexity and there may be partial overlap, but the idea stays). Most of the time you find that in macros.

2

EOS Bodies / Re: Why not higher resolution video?

« on: April 27, 2013, 12:20:16 PM »

We don't need higher resolution, we just need something other than the Youtube codec. 

The 4K-spec tell something about that. Which means that we can get 4K-sized video, but finding a camera that also can meet the 4:4:4 requirement is...troublesome. If you stick w. bayer-pattern sensors you'd need 39.3MP (Wouldn't that be a nice resolution for a 1Dxs? )

3

EOS Bodies / Re: Why not higher resolution video?

« on: April 26, 2013, 02:07:51 AM »

Why don't all the current body's feature 4k or higher video resolution?

4k@30fps are ~250MP/s, or about the same rate as 18MP at 14fps. Coincidently the max. framerate as the still frame counterpart to the 1Dc manages. Which in turn is the fastest still cam you can buy.

4

Lighting / Re: OC-E3 ettl-cord original vs 3rd party quality?

« on: April 25, 2013, 09:57:14 AM »

The Yongnu otherwise is fine, but the metal screws into plastic is just cheap and cannot take any strain at all (at least my copy).

My 3rd-Party cord had a similar problem, a bit of 2k-glue proved to be a much sturdier connection then those fine threads in plastic. (I don't think it would ever come apart even if I wanted it to do )

5

Lenses / Re: Why aren't zoom lenses faster than 2.8?

« on: April 20, 2013, 10:07:11 AM »

But if the formula is as simple as focal length / f stop, why does my 135/2 vignette much more at f2 than my 200/2.8 does at 2.8 ?

Basically: The lenses have the same diameter, but at longer focal lengths they need less curvature.  The latter is the cause of most flaws in a lens. More a problem with wide angle lenses would be the cos^4-law, i.e. the kind of vignetting that comes from rays hitting the aperture from far off the optical axis. Think of a disc, if you look at it from lets say 45° it looks like a cats eye, less area to get light through then the full circle (or just look at bokeh-discs, round in the center, recompose and they get squashed)

6

EOS Bodies - For Stills / Re: 1D X NOT compatible with Pocket Wizard!

« on: April 12, 2013, 04:09:10 PM »

I feel ok since the current beta firmware supports normal manual control with the 1D X, including AC3 and blended TT5/monolight control.

I actually prefer the 1Dx-version over the TTL-capable default - power tracking for manually controlled speedlights is more helpful then the TTL-inherent randomness if one works with changing apertures. Makes me wonder if that will transfer to the other cameras...

7

Lighting / Re: How much light(watts) do you need to shoot f8 to f11 in studio

« on: April 07, 2013, 12:03:22 PM »

Lumens, not watts! 

To get an exposure you need lms/m2, lumen-seconds/square meter. Good thing: flashtubes have about 40lm/w and a flash duration shorter then the sync time, so all strobes set to say 100Ws produce the same 4000lms, about the same as four 30W CFLs in one second (or a 650W halogen during a 1/5s exposure)

8

Lighting / Re: Does the flash pulse when <x-sync & hss on?

« on: April 06, 2013, 01:55:30 PM »

Indeed, my 60d also doesn't to a proper exposure reduction to x-sync but just overexposes -

My old 30D had safety shift, that stopped down until sync speed was ok if required. Did the rip that out?
(That way you lose only the stops from the exessive light value, but don't have to pay the HSS-price, about 40% more flash range)

9

Lighting / Re: How much light(watts) do you need to shoot f8 to f11 in studio

« on: April 06, 2013, 01:39:08 PM »

You guys know the min light(watts) I should be looking for? or any good suggestions?

At 2m with a rect. softbox in the 2'x3' to 4'x6' range I need about 150Ws to get f/11; a bit more with very narrow boxes or grids. With a white BD you're in the same ballpark. If you're in a confined space without black light absorbers the walls will act as fill cards, giving you more, although uncontrolled, illumination.
Keep in mind that you might want to dial light down, either to fill in shadows or to shoot wider open or with inherently more efficient tools. Thats where to much power and a narrow range is a problem.
(From a european perspective the elinchrome RX one or renewed D-lite2 are an interesting entry level offering. Enough power for indoor use, a clean accessory/upgrade path and they can be remote controlled via iPhone or PC - at a price point compareable to chinese imports.)

10

EOS Bodies / Re: Big Megapixel Development Announcement in the Fall? [CR2]

« on: March 26, 2013, 01:59:39 PM »

Once you reach the resolution limit of the lens, the sensor will represent the image the best it can.  If the data is not there it will be soft. 

Thats not how lens resolution works - instead higher frequency detail gets dampened, like in a low pass filter. More resolution just means slightly lower contrast for microdetail. Thats unless lens aberrations convolute detail in a nonrecoverable way, but the new canon lenses show little tendency to do so.
(But even with perfect lenses we're sooner or later have to choose between lack of DOF and diffraction...)

11

EOS Bodies / Re: Big Megapixel Development Announcement in the Fall? [CR2]

« on: March 26, 2013, 10:28:45 AM »

Canon always differentiate their product line, so I feel if it was a new line in a 5d style body they would separate it from the 5d line by lowering fps and autofocus.

They could differentiate upwards. 1DX AF and metering, all the other bells and whistles(how much would freedom from the shackles of x-sync be worth?), and charge an adequate premium. Keep in mind that the 5D3 will be at the half of its product cycle by then...

12

Speedlites, Printers, Accessories / Re: Flash life of speedlites?

« on: March 19, 2013, 03:24:44 PM »

i read that article when he posted it.. and honestly think the number is too low.
he gave no creditable source for his information.

Looking at the actual data sheets of various flash tubes: something in the 1-10k pops range is quite common, if those discharges are at 30% of their explosive energy. Drop the energy to 10% and we're at about 50k flashes. Given the size auf the average flashguns tube and the energy in the caps the latter number seems to be closer to reality, w. reduced output on the flashgun following the progression I'd expect other parts to give first...cavet emptor, rough estimate.
Bad thermal management or shock are a bad idea otoh.

13

Canon General / Re: your scariest photography moment?

« on: March 11, 2013, 01:29:20 AM »

what silly thing have you done?

Maybe the most uncalculateable dangerous, individual reactions varied:
Some environmental fashion shots in the aftermath of the Tel Aviv fashion week.
A perfectly reasonable idea, even got free assistants in uniform.
Until someone decided that rockets coming our way would spice things up.

More leaning to the silly side: having an assistent set up some HMIs for cont. light shooting and not double checking everything. The guy must have missed the memo about the need for heavy UV filtering(and never overriding the safty switches detecting those filters) & about everything started to look like painted w. daylight flourescent paint at the moment htat light came on. Lesson learned: never assume someone has taken care of it, make sure it has been done properly...

14

Lenses / Re: 70-400/ f4.0-5.6 Zoom ... Canon, where are you?

« on: March 05, 2013, 09:05:08 AM »

It is therefore NO alternative to a newly designed, excellent 100-400 II

It doesn't need to, it just closes the proverbial box.
With more attractive alternatives up- and downward plus sides that make a lateral breakthrough difficult we're looking at a limited audience with lots of options.
About the same dilema the 24-70/4 faces, but from more angles.

15

Lenses / Re: 70-400/ f4.0-5.6 Zoom ... Canon, where are you?

« on: March 05, 2013, 04:15:58 AM »

Not able to stick a new 4-stop IS into the current 100-400

In a way they did just that, plus an 0.7TC in the lens design to obscure it. Lets assume the 200-400 eventually becomes available to paying customers the actual utility of a new 100-400 would be reduced again, as in either 300mm is enough or I'd prefer closer to 5-600mm. With the high MP numbers common cropping is much easier then dealing wit a to narrow FOV.