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Messages - Jens_T

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1
Lenses / Re: Checking Real Focal Length - 70-300l
« on: September 04, 2013, 01:10:52 AM »
You can calculate it using the simple lens formulae to a good approximation using a tape measure.  Measure the height of an object, h, at a distance v away from your lens, where v is much greater than the focal length, f, say 15 metres for a 300mm lens. Calculate the height of the image, i, from the number of pixels it spans and the size of the pixels (which you can calculate yourself or read in websites). Then, f = vi/h. For an extra couple of % of accuracy you should use u = vi/h, where 1/v + 1/u = 1/f.

Thanks Alan, I might try that if focus breathing isn't the answer.
What variable is u?
f = distance * image height / object height

BR
Jens

2
Lenses / Re: Checking Real Focal Length - 70-300l
« on: September 04, 2013, 01:06:05 AM »
Two issues at play here, rounding and breathing.

Breathing is the change in apparent focal length with focusing distance (distance to subject).  The actual (and specified) focal length(s) are with the lens focused at infinity. As you focus closer, the 'apparent' FL gets shorter. 
Did you try comparing the lenses in question with both of them focused at infinity?

Thank you Neuroanatomist - now I remember reading about breathing and suspect this is the answer. I was playing around with the lenses in my flat to check how well AF performs in bad light and noticed the focal length difference. Will compare the lenses outside at infinity.

BR
Jens

3
Lenses / Checking Real Focal Length - 70-300l
« on: September 03, 2013, 04:01:44 PM »
Hello,

today I bought the EF70-300L lense to replace my old Tamron 70-300VC. When playing around I noticed that the 300mm on the Canon seem to be a good bit wider than on my Tamron.

Is there a website that actually checks the "nominal" focal length? I remember Lensrentals sometimes comments on the the real focal length but they don't list the details.

Or is there a simple way to calculate it without too much hassle?

Thanks in advance
jens

4

Answer= Cartel.

The Japanese (or South Koreans/Chinese) do not abide by the same competition rules as the West whether it is cameras or shipbuilding!


Apologies taking this off-topic but I have to disagree to the way this statement is made, Plainsman.

Yes - there are governments protecting / supporting certain industries. Yes, competition is often not perfect. But that applies to most countries - the dispute between the US and EU about subsidizing / protecting Boeing / Airbus is just one example.

The whole FX impact topic has nothing to do with cartels. Such behaviour is normal business and can be found in any corporation, regardless of HQ location. Please consider this before accusing other countries of foul play.
But please let's not get into monetary politics :)

BR
Jens

5
Lenses / Re: Telezoom lens (70-300L vs 70-200 vs 100-400)- Advice
« on: May 19, 2013, 09:59:27 AM »
Thank you all

6
don't know where to start here....honestly Canon make products that cost them X, then they sell them for X+Profit = Y, they publish Y in a Product Price List to Retailers....

later...that Retailer in say New York sees that Y is now a lot cheaper because their currency (the Dollar) has risen against Canon's currency (the Yen)....but here's the bit that everyone is MISSING: 'Price Y' for Canon is THE SAME....it is no different

....the only real benefit is that retailers will now be able to discount and still make a healthy profit and sell more units so they can now buy more off Canon


Andy, I am not sure if I get the tone you're setting right...

Without knowledge on how retail prices in the US are set - and how Canon Japan sets prices to Canon US everything is speculation. My experience tells me that it is unlikely that any corporation will pass on FX gains to it's customers unless it is forced to.
Canon's prices to retailers also will not be the same - the mom'n pop photo store will not get the same price as best buy - and both are unlikely to get Yen prices (or USD prices indexed to JPY).

But that really is just the background - prices are changed beyond what individual retailers do if Canon sees the need for it.

7
Lenses / Re: Telezoom lens (70-300L vs 70-200 vs 100-400)- Advice
« on: May 19, 2013, 06:09:57 AM »
Thank you to all your remarks to all that replied so far.

Besides that, what you need to do is to see the focal lengths you shoot at. That should tell you what you need. I got the 100-400L for birds and animals. Having said that, I shot with it at the Grand Canyon and I did use it at 400mm.

I did that and am in the 200-300mm (*1.6 for crop) range if I need details.
Price (in the range of the discussed lenses) is not so much an issue.
When the 70-300mm L came out I thought it was overpriced for the fact that it is a slow lense - which doesn't matter so much for landscape though.

Probably the best thing really is to rent the 70-300 and try it.

8
Lenses / Telezoom lens (70-300L vs 70-200 vs 100-400)- Advice
« on: May 19, 2013, 03:19:57 AM »
Hello,

I'd like to hear your opinion on what lens fits my needs best.
Recently I switched to FF and now it is time to upgrade my lenses as well.

What I do:
Mostly landscapes, tele for details and the occasional animal. While I am not hiking multiple days with my eqipment it should fit well into one backpack with other stuff and weight is an issue.
Sometimes people shots.

Current equipment
5D2, Canon 16-35, Tamron 24-70, 50/85mm primes and a Tamron 70-300VC

With the current cashback I was thinking about getting the new 70-200IS and a teleconverter for reach if I need it. On the other hand directly going for the 70-300 or 100-400 adds more reach at lower weight and cost.

The f2.8 of the 70-200 is nice to have but not an absolute must. A 70-200/f4 however would be too slow if I add a TC.
I understand that IQ from the 70-200/2.8 is best among these lenses and the -300 comes second.

Before I rent all these lenses for a weekend to test I'd be interested if you have advice or were in a similar situation.

Thank you
Jens

9
Simple answer - prices are only indirectly depending on FX impact.
First we're talking about consumer goods in a B2C market - no FX clause and very low value deals. No business wants to have permanently fluctuating prices as this would create extra work and makes planning even harder. Also Canon sells to retailers at completely different prices to what retailers charge the end customer. So first Canon would have to adjust prices to retailers and then this price change would have to be passed on to customers.

On a more fundamental basis - The price a company charges for its goods usually depends on its market strategy with the underlying given cost structure and the target to maximise return on investment (profit) in a specific time frame. If you have a multi-national set-up with income and cost in different currencies you incurr FX risk.
Canon Corp has a strategy for the US market and probably centrally sets revenue and income targets for the US entity. Based on this prices (to their resellers) are set to achieve the objectives.
How Canon internally operates, i.e. if Canon US gets USD objectives and which Canon entity bears the FX impact is a different story. If for example Canon US buys at a fixed FX rate from Canon Corp then the FX impact would only show up in Japan and Canon US would not have any incentive to change prices.

If FX rates change massively against a company, i.e. leading to losses, the company might still accept those losses in order not to loose market share. If FX moves the other way the company probably just sticks with the old price/strategy if everything was ok with it and enjoy the translation/transaction FX gains.

So I wouldn't expect any permanent price changes from FX.

The concept of prices as a function of cost is deeply ingrained in our minds, but it is not really true.

BR
Jens

10
Beautiful shots.

Please excuse my ignorance, but where is this city located?

(I am not the photographer, but might be able to answer that question)
Hello,

the last one is in Siena - the others are located in the Flickr Folder Tuscany / Cinque Terre - both are regions in northern / north-western Italy.

cf http://www.parconazionale5terre.it/?id_lingue=2

Br
Jens

11
Software & Accessories / Re: Induro C314 vs CT314
« on: April 20, 2013, 05:16:53 PM »
Would also be very interested in feedback on that topic.
Looking for a carbon tripod myself and Induro is one of the brands that are in my closer selection.

Thanks,
Jens

12
I do not shoot with my Rolleiflex anymore for lack of a darkroom.

13
I bought my first DSLR back in 2007 - after having shot with a Minolta X300 many years before.
The choice was between the Canon 40D and Nikon D200. The two decisive points were that the D200 was a tad to expensive for my budget and I liked the feel / grip of the 40D better.
My 40D is still in use and only recently I added a used 5D2. ( I guess I have would have been able to afford a D200 I would shoot a D800 now :) )

14
Very nice movie - it looks like you started at the Thingvellir / Gulfoss area and the moved via Vik to the Jökullsarlon and Myvatn area? It's a fantastic country. Where did you see the Orcas? Husavik?

While I overall enjoyed the movie I believe a little less obvious sharpening would better fit the nature of Iceland. The halos you see on some of the mountainranges or the orcas' fins looks "cheap" and plasticky - and that is sad because it does not do the rest justice.

Best regards,
Jens

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