May 29, 2015, 02:31:17 AM

Recent Posts

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41
Technical Support / Re: Dottune distance: from lens or sensor?
« Last post by Zen on May 28, 2015, 08:33:12 PM »
I know there are those who denigrate the dot tune method, and I know it's not "scientific", but it CAN be effective. Either I'm lucky or easily satisfied, but whatever the reason, I've had few problems with any of my dozen or so lenses. I've dot tuned all of them and have only found two that needed adjustments, neither of which were more than +3. So, I'd suggest to anyone that they try the method before spending the money for Focal. If it doesn't work, you've lost nothing, right?

BTW, the recommended distance is x20 to x50 the focal length, and it matters little whether you measure from the front element or the focal plane. In my experience,  x50 the focal length is more effective that the shorter distance.

zen :)
42
Lenses / Re: Review: Sigma 150-600mm f/5-6.3 DG OS Sport
« Last post by TWI by Dustin Abbott on May 28, 2015, 08:30:03 PM »
Why is Dustin Abbott always described as a "friend of the site"? Is a Facebook friend or does he buy the mods a beer when he sees them, or what?

 they are all pretty chummy up there in the great white north.
Yep, it's a very small country, you know.  ;D
43
Software & Accessories / Re: How to fit securely head on a Gitzo?
« Last post by Valvebounce on May 28, 2015, 08:26:59 PM »
Hi Alan.
I would either use some Loctite 242 as recommended by Neuro, or I would drill and tap a thread for a grub screw if it is within your abilities. The Loctite will come undone without undue force when you want it to, in fact it may come undone when you don't want it to if you forget to loosen the pan lock, however the rubber disc will likely be less effective than Loctite.

Warning, do not use the green Loctite (stud and bearing fit), I forget the number, this product will not accidentally undo as once set you have to heat it above 80deg C to break the bond, unless of course the marriage of head and legs is to be permanent, then why not!

Cheers, Graham.
44
Technical Support / Re: Is there something wrong with this lens?
« Last post by Zen on May 28, 2015, 08:22:15 PM »
For the dot tune method, distance to target should be 20 to 50 times focal length. At 70mm, the x20 distance would be about 5 feet, but that is the extreme short edge of focus. Better to go out to about 11', which represents about x50 focal length. Also, as someone else has said, it's more likely you will shoot at distances far more than 5'.

On the ship image, the letters look consistent with the other edges in the image. A very slight softness, but that can be attributed to camera motion, not necessarily the lens. My 70-200 f4 is tack sharp.

Good luck.

zen :)
45
EOS Bodies / Re: EOS 5D Mark IV Testing Has Begun [CR2]
« Last post by Tugela on May 28, 2015, 08:17:24 PM »
...Clearly, there are things they felt were more deserving of R&D expenditures.

Or much more likely, they just aren't capable with their 20year old semiconductor technology...

That would be a remarkably naive assessment.

They probably look at it that they can make the money they are with the tech they are selling, ergo how much more revenue would they generate if they spend hundreds of millions of dollars on a new sensor fabrication line? Probably a wiser investment to diversify (cinema, security, etc) and bring a unique twist to their DSLR system like lens selection and flashes. Probably closer to the truth.......

Regardless of their fab, there could be patent issues preventing them from doing it. I could have formulated myself better, but making statements that assume they are able to is just speculation and should be formulated as such not as facts.

Considering the tech they have showcased, the number of patents they register every year, and their R&D size when compared to their competitors I feel fairly confident is stating my opinion that Canon have not spent the money on a sensor fab so far because they haven't seen the return opportunity, nit because they don't have the tech.

Having lots of patents doesn't mean they have (or have access to) the critical patents.

Most of the time when companies like this don't do something that would seem obvious to do, it is because they don't have IP rights to do it, or they are blocked from using it in specific product areas through cross licensing deals.

I suspect that is the main reason why Canon's mirrorless options are so sad, for example. It isn't because they don't know how to do it, or don't want to do it, they have obstacles blocking them from doing it that are business related.
46
EOS Bodies / Re: 5DS and 5DS R Sensor Scores at DXO
« Last post by tron on May 28, 2015, 08:15:31 PM »
What can i say..my cat..she knows bigger is better  :P
Bigger pixel or bigger raw file?  ;D ;D ;D
47
EOS Bodies - For Stills / Re: 5ds/r not for me after reading this.
« Last post by tron on May 28, 2015, 08:14:23 PM »
I will wait for Ken Rockwell's review to decide.
Only if you help him support his growing family  ;D
48
Lenses / Re: Will the Wondapanner 145mm filters work on the new ef 11-24L?
« Last post by Bombo on May 28, 2015, 08:12:26 PM »
I don't think 145mm filters can work on very large diameter Canon 11-24mm (108mm) with 126.5o angle, you may look the Bombo165C1124 Holder for Canon 11-24mm f4 use 165mm filter system can work fine
49
Technical Support / Re: Dottune distance: from lens or sensor?
« Last post by Valvebounce on May 28, 2015, 08:08:51 PM »
Hi Folks.
I think there are situations where it will make a significant difference, when I had problems it was during the calibration of a Sigma Contemporary lens, Sigma's dock software gives the opportunity to set AFMA for four different focal distances at four different zoom points, at mfd the difference between the front of the lens zoomed in to zoomed out was a significant proportion of the distance, however the distance to the focal plane did not change. Given that the software is expecting a set distance and I was moving the camera to get the distance to the front of the lens correct it is no surprise that I had flakey results.

Cheers, Graham.
50
EOS Bodies / Re: Full Frame Astrophotography DSLR Coming [CR1]
« Last post by meywd on May 28, 2015, 08:00:39 PM »
I only asked to clear a point, if we don't need a modded camera for landscape astro, then the modded camera will be used for deep space objects, and so a 5Ds/5Dsr will be better than a 5DIII/6D
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