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Messages - Hydrogen

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Third Party Manufacturers / Re: Gitzo GT2541 and GT1542T folded diameter
« on: December 03, 2013, 06:53:27 PM »
The 1542T has a max diameter of 3 1/4". I also have the 2541EX Explorer model which maxes out at 5 3/4" on the long side, but I assume you're referring to the 2541T Traveler. Hope this helps.

Brad thank you for the 1542T diameter - very helpful.  The 2541EX I believe would have a wider diameter than the standard Mountaineer 2541 (I am actually not referring to the traveler).

Anyone with 1541 (non traveler) and/or 2541 (non traveler) diameters?


Third Party Manufacturers / Gitzo GT2541 and GT1542T folded diameter
« on: December 02, 2013, 02:29:26 PM »
I am comparing these two tripods and need the widest diameter around the folded legs of both tripods to make an informed decision. If you even have one or the other and are willing to provide the measurement, maybe I stand a chance to obtain both.

GT2541 and GT1542T

Thank you!


Correct.  Looking for the Mitros+, which is the new one with the built-in wireless transmitter & receiver trigger.  Not the regular Mitros flash. 
 Cannot find it, though others seem to say they know where it is, and how much it is.  I am unable to find it using either Google or the Phottix website.  Am I just missing it?  Is it available in Asia, but not available in the US?

Looks like it's available now:

Lenses / Re: AFMA Accuracy vs. Precision
« on: May 12, 2013, 11:04:43 PM »
Thank you everyone for your responses.  Much appreciated.

I'm aware of Roger C.'s 3-part series on AF systems and lenses.  What a wonderful set of reads.  What I found most intriguing was the variance in AF consistency between lenses tested, irrespective of newer 'closed loop' sensors.  From the set he tested, the zoom with the lowest deviation shot-to-shot was the 70-300L.

See here:

FoCal's AF Consistency test's ability to evaluate 'x' number of shots using a range of 'y to z' AFMA values though would make one presume there is a difference in the precision (repeat-ability) of shot-to-shot AFMA values for a given body/lens combination.

I have seen it first-hand using that test.  Unless FoCal is lying, there does appear to be a correlation.  I can find some of my saved PDF test reports and post them.

Not disputing others' experiences.  I am but a 9-year intermediate user of these technologies so not an expert by any means, but there are clearly so many unknown and undocumented variables that folks like Roger and others end up having to deduce/prove, that one has to wonder if AFMA behaves differently with 'older gen' lenses than the 'next/newer gen' barrels.

Since in an older generation lens there is no 'confirmation' back to the camera that the lens did, in fact step-move only 'x' points forward or backward, one has to wonder.

I know my first-hand experience with my 70-200 2.8 non-IS (which I still own before I picked up the 70-200 2.8 IS II recently) was shot-to-shot variability and after Canon calibrated it, not only was it just about perfect at AFMA zero, shot-to-shot precision (repeat-ability) significantly improved, so much so, it's as good as my IS II is.

Lenses / AFMA Accuracy vs. Precision
« on: May 12, 2013, 03:37:11 PM »
Hello Everyone,

Just wanted to pose a question to those with sufficient experience AFMA testing and adjusting several lenses and bodies.  Specifically, I want to discuss Accuracy (how 'spot-on' focus is relative to a target) and Precision (the repeat-ability of focus).


I have found that more often than not, zero AFMA adjustment on a body for a given lens yields more precision (repeatable results) even if the depth of focus is "off" (front or back) rather than once you adjust the AFMA in either direction, even by +/- 1.  This is why I am starting to believe factory calibration of body to lens is better than AFMA tweaks.

Sometimes, but less frequently, higher precision (repeat-ability) is found on an AFMA setting other than zero, but it isn't always the "best" AFMA offset in terms of image accuracy/sharpness.

I believe this is why the FoCal AFMA testing application has a AF Consistency test, which allows you to test various AFMA values in a repeatable fashion, to seek-out the best AFMA setting with the most repeatable results.

Have any of you found the same to be true?  That sometimes you may want to trade accuracy for better precision (repeat-ability).


What were you hoping to fix with the new firmware? I sell enterprise software as my primary living and most customers do not want to be the early adopters of a new release.  I want to fix the focus performance with a speedlite AF-assist beam but do not want to get new problems.

I second Polarized's viewpoint.  I developed enterprise software for the past two decades and now oversee the architecture of such solutions.

In order to have a less error-prone upgrade or introducing odd behavior, I would recommend to anyone here that is upgrading their firmware to explicitly right-down (or take screenshots) of all settings and custom functions and then clear the entire camera back to factory defaults after you have upgraded the firmware.  Then, re-establish your settings.


EOS Bodies - For Stills / Re: 7D Rear Dial Cheap?
« on: May 04, 2013, 01:16:57 PM »
Thank you for your posts, especially those with 5D3 experience to compare.

I am starting to wonder if this isn't a characteristic of the 7D, but the SET button definitely feels cheaper in-the-hand than my 5D3, 20D after 8 years of use and 5D2s I've tried and another 7D.

Maybe I should exchange it, but then you trade one problem for another...

EOS Bodies - For Stills / 7D Rear Dial Cheap?
« on: May 03, 2013, 10:50:35 PM »
Just purchased a 7D and the rear main jog dial feels cheap. 

This is the third body I've used and one of the two previous ones were like this too.  Best way to describe it is a cheap, flimsy plastic feel.  It works just fine, but pushing the SET button makes a popping/clicking noise.  The dial itself turns just fine and has good tactile response but some play if you tap on it vs. turning it.

This is unlike any other EOS body with a rear dial I have tried.  Again, 2 out of 3 have been like this.

Is it just me?

EOS Bodies - For Stills / Re: Canon EOS 40D?
« on: April 27, 2013, 02:41:38 PM »
My thoughts after using several crop APS-C bodies would be to get the EF 28mm f/1.8 lens (I actually still have mine but since I have the EF 35 f/1.4L they are redundant to me).  Very well built and good image quality.  This will get you to around 45mm with the crop body and is a good focal length (close to actual 50mm on a full-frame/35mm) for general purpose photography.

The 50mm lenses are 'too long' as the sole lens in a kit on a crop body.

EOS Bodies - For Stills / Re: 1D III viewfinder visibility
« on: April 27, 2013, 02:37:57 PM »

Thanks for responding.  I appreciate it.  I tried it and yes it definitely helps, but its almost TOO bright, at least for indoor situations.

Would you mind confirming for me whether it does though, in fact, need to be looked upon almost straight on to keep it from looking like the AF points are faded?

Anyone else?


EOS Bodies - For Stills / 1D III viewfinder visibility
« on: April 25, 2013, 11:43:49 AM »
For any current or former 1D3 users...

I just picked up a used 1D3 body.  Note this is my first 1-series body. 

Is it me or do the AF points in the viewfinder fade a bit unless you are looking ON DEAD CENTER through the viewfinder?  Compared to other EOS cameras, it seems to need more 'directional' viewing.  I have used 20D, 40D, 5D II, 5DIII.

Also, seems that its harder to see the entire contents of the viewfinder like the exposure meter on the right side while wearing my glasses than with the other EOS cameras I have used.  If I take my glasses off and wear contact lenses, I can see it much better.  First time I must say that I can't see the entire perimeter of a viewfinder.


Lenses / Re: EF 17-40L inner barrel knocks @ 40
« on: April 23, 2013, 12:53:48 AM »
Thank you for checking.  Sounds about right.

Lenses / EF 17-40L inner barrel knocks @ 40
« on: April 21, 2013, 09:41:02 PM »
Anyone with a 17-40L that can check theirs real quick for me?

On the refurb. copy I recently received from Canon, the inner barrel 'knocks' (moves) when the lens is at a FL of 40mm.  You can hear it if you shake the camera around, but also induce it when applying some pressure with the index finger to the front lens element ring and moving it around.

I noticed this when I went to clean the front lens element with a microfiber cloth and solution as mine came with a smudge on the front element.

It only happens @ around 40mm (when the barrel re-extends at the longer end of the range.

Thank you

EOS Bodies - For Stills / Re: 7D vs 5D3 noise @ ISO400
« on: March 30, 2013, 10:49:12 PM »
ISO 400 on the 7D and 5D3 are completely different sensetivity levels and it's misleading to directly compare them.

Cameras are a function of geometry.

People have been misled with crop to full frame conversions  for years.

The 5D3 was my first FF camera body.  I previously used crops... 20D and 40D.  As stated, I am evaluating either a 7D or 5D2 as a backup to the 5D3.

I am not a physics major and thus, I am not going to dispute Radiating's calculations and references to physics.  I understand that it isn't a 1:1 comparison, but...

What I do know is that a photon of light is still the same size regardless of sensor and that a crop sensor 'extrapolates' the equivalent pixel dimensions due to the fact that pixel density is so great and thus pixel size is so small, that is is practically splitting a single photon of light.

I also know that at the end of the day, if any of us were to print either OOC image to their largest extent @ 300 dpi, that we would see the difference between the 7D and the 5D3 as seen clearly by these 100% crops and therefore, the reality is that a crop body's sensor is simply inferior.

Desiring to hold on to the 'reach' (cringe) benefits of APS-C, I wanted very much to keep the 7D as an all-around versatile camera and as a backup to the 5D3.  After the pictures I took today, and the grain I see in them even at 50% (heck, even looking at the entire image sized to fit on a 15" laptop display) there is clearly an improvement in IQ from a FF body.

After evaluating the 7D, it's clear an APS-C is inferior.  It's just the reality of physics.  We can't shrink light any further, but we are trying to over-resolve it.  Here come the arrows and darts...

EOS Bodies - For Stills / 7D vs 5D3 noise @ ISO400
« on: March 30, 2013, 10:11:55 PM »
This subject has been beaten into the ground, but I was surprised at how much noise I was seeing in even ISO 400 images in broad daylight with a 7D compared to my 5D3.  See comparison below.

The short story is I have two 5D2 refurb's and two 7D refurb's that I am evaluating as a backup body to my 5D3.

I believe I am going to stick with the 5D2.  Using Reikan's FoCal, both 5D2's OUTER AF points outperformed all 19 points from both 7D bodies in both Quality of Focus (QoF) and AF accuracy.  I will post a separate comparison of them in a new thread tomorrow.

Both are 100% crops of shots of the northern sky at ISO 400, RAW OOC, zero NR.  First is the 5D3; second is the better of two 7D copies I am evaluating.  You will need to download/save them to see the noise more clearly.

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