+- Opticallimits (https://forum.opticallimits.com)
+-- Forum: Forums (https://forum.opticallimits.com/forumdisplay.php?fid=4)
+--- Forum: Just Talk (https://forum.opticallimits.com/forumdisplay.php?fid=17)
+--- Thread: Tamron 18-400mm f/3.5-6.3 VC coming ... (/showthread.php?tid=256)
Tamron 18-400mm f/3.5-6.3 VC coming ... - JJ_SO - 06-19-2017
He's applying for a position in da test-lab ^_^
Tamron 18-400mm f/3.5-6.3 VC coming ... - toni-a - 06-19-2017
Interesting ? Maybe not much more than their already existing line of superzooms, however a 15-200 would have made much more sense, I found my 15-85 range more handy than that of 18-200 I used for a while.
Tamron 18-400mm f/3.5-6.3 VC coming ... - JJ_SO - 06-20-2017
Given that you are thinking about buying a 17-55 again, your comment is a little bit nitpicking. Never thought about there's a reason that superzooms - none of them AFAIK - start at 18mm? With two lenses like 8-16 or 10-24 and this 18-400 I could cover a set for lightweight travel.
Or in other words: It's not Tamron's fault that Canon uses smaller sensors than other APS-C candidates and therefore would benefit from shorter FL for wide-angle - and on the other side it gives you a "longer" tele equivalence. It's not Tamron's fault and Canon themselves might see reasons to not go for a 22× zoom for DSLRs. It has yet to be proven these 400 mm can be used with satisfying results.
Btw., a 1.5× instead of 1.6× sensor would give 18 × 1.5 = 27 ÷ 1.6 = 16.875
Tamron 18-400mm f/3.5-6.3 VC coming ... - Brightcolours - 06-20-2017
Quote:Given that you are thinking about buying a 17-55 again, your comment is a little bit nitpicking. Never thought about there's a reason that superzooms - none of them AFAIK - start at 18mm? With two lenses like 8-16 or 10-24 and this 18-400 I could cover a set for lightweight travel.And a 1.53x crop sensor?
Or in other words: It's not Tamron's fault that Canon uses smaller sensors than other APS-C candidates and therefore would benefit from shorter FL for wide-angle - and on the other side it gives you a "longer" tele equivalence. It's not Tamron's fault and Canon themselves might see reasons to not go for a 22× zoom for DSLRs. It has yet to be proven these 400 mm can be used with satisfying results.
Btw., a 1.5× instead of 1.6× sensor would give 18 × 1.5 = 27 ÷ 1.6 = 16.875
Tamron 18-400mm f/3.5-6.3 VC coming ... - JJ_SO - 06-20-2017
Higher math (more than 1 digit on the right side) I leave to people who dedicated their life to the religion of eqivalencism :lol:
Tamron 18-400mm f/3.5-6.3 VC coming ... - Brightcolours - 06-20-2017
That puts into question your 16.875 result :lol: :ph34r:
Tamron 18-400mm f/3.5-6.3 VC coming ... - JJ_SO - 06-20-2017
Result and input are two things. One I have to type, the other to read. Or paste...
Tamron 18-400mm f/3.5-6.3 VC coming ... - Brightcolours - 06-20-2017
So in other words, you don't want to use exact figures in a calculation, but you have no issue reading a too exact result?
18 x 1.53 = 27.54 / 1.61= 17.1
Just for optics 17mm looks better than 16mm :lol:
Tamron 18-400mm f/3.5-6.3 VC coming ... - JJ_SO - 06-20-2017
Don't you get it?
I was making fun out of toni's ridiculous 15-200 idea. And I do agree very much with Rover's "da wide", "da tele" and "da whatever" categories as these are precise enough.
Meaning, your equivalence calculatuions with 4 digits behind the comma are the best indicator to "not care about THAT post". I really don't give a sh_t about calculations which imply to show a truth which is simply depending on much other factors without lots of high resolved numbers.
Tamron 18-400mm f/3.5-6.3 VC coming ... - davidmanze - 06-20-2017
As we are talking precision focal equivalents, (probably the most tedious process known to man), just for kicks and giggles I decided to resurrect my brain and verify the crop factor figures.....using the Pythagoras's theory (for the diagonal dimension).
The crop factor for the D500 (23.5 X 15.7mm) as 1.53067 so 1.53 is near enough.
For the 80D (22.3 X 14.9mm)* I have it at 1.6156 so 1.615 will do!
*Dimensions from Canon's official site for the 80D. ...
http://www.canon.co.uk/for_home/product_finder/cameras/digital_slr/eos-80d/specification.aspx
So, 18 X 1.53067= 27.55206/ 1.6156 = 17.05376 mm!