fredmiranda.com
Login

Moderated by: Fred Miranda
  New fredmiranda.com Mobile Site
  New Feature: SMS Notification alert
  New Feature: Buy & Sell Watchlist
  

FM Forums | Leica & Alternative Gear | Join Upload & Sell

  

Archive 2008 · Can we use linear polas with digital?

  
 
Cableaddict
Offline
• • • •
Upload & Sell: Off
p.1 #1 · Can we use linear polas with digital?


I'm looking to invest heavily in some top polas.

I've read a bit about them, and I understand that circular polas were developed for modern cameras that use a semi-silvered mirror to pass light to the metering and AF systems. I don't really understand that technically, but OK, with a linear pola, my 5D will not have accurate metering or AF.

My question is: So? For alt glass users, is this a significant thing?

In other words, if I always chimp my exposures (stop-down metering isn't 100% accurate, anyway) and if I never use AF (I almost never do) can I save a pile of loot & buy a linear pola?



Oct 16, 2008 at 12:23 PM
mpmendenhall
Offline
• • • •
Upload & Sell: Off
p.1 #2 · Can we use linear polas with digital?


Yes. If you aren't relying on the camera to either autofocus or meter accurately, then linear polarizers will be fine.


Oct 16, 2008 at 01:16 PM
Alex
Offline
• •
Upload & Sell: Off
p.1 #3 · Can we use linear polas with digital?


I may be wrong, but I don't think that metering is affected. AF will not work properly with linear polirizers.

Alex



Oct 16, 2008 at 01:36 PM
Cableaddict
Offline
• • • •
Upload & Sell: Off
p.1 #4 · Can we use linear polas with digital?


Alex,

Every article I've read on the subject says that linear polas affect the metering in modern cameras.



Oct 16, 2008 at 02:20 PM
Mike Ganz
Offline
• • • •
Upload & Sell: Off
p.1 #5 · Can we use linear polas with digital?


Cableaddict wrote:
I'm looking to invest heavily in some top polas.

I've read a bit about them, and I understand that circular polas were developed for modern cameras that use a semi-silvered mirror to pass light to the metering and AF systems. I don't really understand that technically, but OK, with a linear pola, my 5D will not have accurate metering or AF.

My question is: So? For alt glass users, is this a significant thing?

In other words, if I always chimp my exposures (stop-down metering isn't 100% accurate, anyway) and if I never use AF (I almost never do) can I save
...Show more

If you're looking to use a square linear polarizer in a filter holder, I doubt very much that you'd save a lot of money. Instead of spending it on multiple circular polarizers, you'd be spending it on multiple adapter rings to fit the various lens diameters. You might be able to save a few dollars more by using a single adapter ring with various step-up rings instead of having several adapter rings themselves...but then you get into vignetting issues when placing all that extra crap in front of the lens. I'd just recommend biting the bullet and getting one or two high-quality CPLs, such as a B+W or Heliopan, for the lenses that would get the most anticipated use. No reason to overcomplicate the matter (no offense intended).

This is another reason why I like my little Oly's and Leica Elmarit-R 35...the same 49mm filter size across all the lenses...one CPL and a single Lee adapter ring when using GND's for them does the trick.



Oct 16, 2008 at 04:38 PM
Cableaddict
Offline
• • • •
Upload & Sell: Off
p.1 #6 · Can we use linear polas with digital?


Yeah, Mike, I've been looking at the Lee system, but it seems like a bit of a hassle.
(still the only way to put a cpl on the Nikon 14-24)

I like the idea of being able to use my hoods.

The reason for my question is that linear polas are significantly cheaper. IIRC, with a 67mm I can save around $30 on a Kaesemann. I'm not talking about drop-in square GND's, just regular old linear polas.
-----------------------------

BTW- What is this Lee adapter ring you mention? I am in fact getting filters for my 49mm Zuikos, and might want to stack filters.




Oct 16, 2008 at 05:48 PM
Mike Ganz
Offline
• • • •
Upload & Sell: Off
p.1 #7 · Can we use linear polas with digital?


Cableaddict wrote:
BTW- What is this Lee adapter ring you mention? I am in fact getting filters for my 49mm Zuikos, and might want to stack filters.



The adapter ring is used to attach the filter holder to the lens. It simply threads onto the lens' filter threads, and then the holder is simply clipped to the adapter ring. Take for example the Lee holder...this has two fixed tabs and a spring-loaded clip. The tabs fit into a slot that has been machined along the perimeter of the ring; the spring clip also fits into the same slot and secures the holder to the ring. The slot allows the user to rotate the filter holder to any desired angle that suits the composition. Ostensibly, you would need an adapter ring for each lens diameter that you intend to use the holder with. Luckily, most of my Canon L lenses are a common 77mm filter size, and like I mentioned above, my Zuikos and Leica are each 49mm...I have both a 77mm adapter ring and a 49mm adapter ring which lets me use my Lee holder with many different lenses.

Then, there's another rub. There are two types of adapter rings..."normal" and "wide angle". The Lee WA adapter ring is designed such that it sits 3-4 mm further back on the lens barrel...this helps to avoid vignetting when shooting wide. In all actuality, you can probably get by with just a WA adapter ring. If I'm shooting with my 24-105L or 28-70L on a 5D, I don't have any problems with the WA adapter. If I shoot longer than the 105 end, I'd probably use the "normal" adapter ring since, in the case of GND's, it gets very difficult to see the gradient line due to DOF blur. Using a WA adapter ring with a longer lens moves the gradient that much closer to the lens, adding to the DOF blur effect at longer focal lengths. Since my Zuikos and Leica primes are all wide angle, I simply use the 49mm WA adapter ring.

No one ever said that this was a cheap hobby.

BTW, came across this blurb on on of the Nikon 14-24 review sites...not sure if you were aware of this:

"The front scalloped shade also does not accept any filtration. You can't use a 4x6 split grad either. The shape of the shade which you can see below does not permit the filter to lay flat against the front element."



Oct 16, 2008 at 06:14 PM
Cableaddict
Offline
• • • •
Upload & Sell: Off
p.1 #8 · Can we use linear polas with digital?


Mike Ganz wrote:

No one ever said that this was a cheap hobby.


Man, you said it. -but cross-out "hobby" and put "obsession" or "compulsion!"

Thanks for that explanation, I see what you're talking about now. That a great little gizmo.
(Lee's website needs a serious overhaul)



Oct 16, 2008 at 06:30 PM
Cableaddict
Offline
• • • •
Upload & Sell: Off
p.1 #9 · Can we use linear polas with digital?


Mike Ganz wrote:

BTW, came across this blurb on on of the Nikon 14-24 review sites...not sure if you were aware of this:

"The front scalloped shade also does not accept any filtration. You can't use a 4x6 split grad either. The shape of the shade which you can see below does not permit the filter to lay flat against the front element."


Check out Anton Moss's info in this thread, somewhere in the middle:

https://www.fredmiranda.com/forum/topic/660637/2

Supposedly, the Lee system works, albeit with just a touch of vignetting at 14mm, wide open.



Oct 16, 2008 at 06:32 PM





FM Forums | Leica & Alternative Gear | Join Upload & Sell

    
 

Welcome back
Log in to your account