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-   -   Stopping down light on aspherical ultra wide lenses on the 5D2? (https://www.dvinfo.net/forum/canon-eos-full-frame-hd/489268-stopping-down-light-aspherical-ultra-wide-lenses-5d2.html)

Kris Koster December 23rd, 2010 06:00 AM

Stopping down light on aspherical ultra wide lenses on the 5D2?
 
I had been after a copy of the Canon Super Wide Angle EF 14mm f/2.8L II USM lens for a long time, but couldn't afford it's £2,000 price tag. As luck would have it, I managed to source a perfect, used copy of the lens for a mere £600.

This lens has an aspherical front element, so you cannot screw filters on the end like you can on my 17-40 EF L copy. It does have a gelatin slot on the rear which can be used to slot in gel filters. So here's my question:

What gel filters (particularly ND) should I get and where can I get them from? I know using a polarising filter is a no-no with ultra-wides, but if I want to shoot, say, timelapses and drag my shutter, I will need to stop down in light quite a bit. Also, for filmwork to achieve shallow DOFs where I need to open the aperature up wide, I will certainly need ND gel filters.

I can't really use my mattebox to slot in filters either as the box would be in shot for such an ultra wide lens on a FF sensor camera. Anyone have any experience with this lens for filmwork on the 5D2?

I'm very excited at the prospect of experimenting with this lens on the 5D2, but there appears to be very little information on these rear-end filter slots anywhere and I would be very grateful for some advice.

David W. Jones December 23rd, 2010 08:31 AM

It sounds like your choices are, either purchase a wide matt box that will not obstruct your lens, or have an optics house fashion a set of ND filters to fit the filter slot on the lens.

Good Luck!

Kris Koster December 23rd, 2010 01:08 PM

I don't think my request is so unusual as to need optics houses fashion ND filters especially for me. This lens, and lenses like it have been around for years. Surely there is a more practical solution for this that exists already?

I do know of a special filter holder made by Lee to fit super-wide angle lenses like the Lee Filters SW150 Filter Holder that is not out until March 2011. But it looks like they're making it for the Nikon 14-24mm lens with the possibility of introducing adaptors to it later. However, at £250 + VAT for just the holder, it appears a bit pricey to me for a bit of plastic that snaps onto the petal part of the lens.

How do others that have this lens deal with this issue I wonder. I guess manually holding an ND filter close to the lens is an option, but again, not very practical when filming live action (Ok for still photography though). I hope and pray that I don't need to cut a cheap piece of wiggly gel for it. I have a hard time believing that such an expensive lens has no professional grade filters made just for it

David W. Jones December 23rd, 2010 01:39 PM

My mistake, most of the lenses I have with rear mounted filter slots require special sized glass filters.
The 14mm as you said just takes gels. Here in the U.S.A. places like B&H have a great selection of ND filters which can be cut to size. ND Gels

I'm not sure where to get them where you are located.

Good Luck!

Luc De Wandel December 23rd, 2010 04:21 PM

If you lower the ISO to, say, 100, can't you work without filters then?

Opening the aperture completely will not get you a more shallow DOF with this lens: it's DOF stretches from 10 cm to infinity. Moreover, I would advise to close the aperture to at least 5,6 or 8, as most Canon wide-angles tend to lose a lot of sharpness in the corners at wide open aperture. Plus there's a considerable amount of vignetting too.

Kris Koster December 23rd, 2010 04:58 PM

Hi Luc,

Thanks for the suggestion. I think even 100 ISO isn't going to cut it. I have the 17-40mm f/4 EF L lens too, which is excellent glass for the price by the way, but my fader ND is almost permanently attached to it during daylight hours, I just dial in my light with ISO set to 160.

I live in southern Spain, which is nearly always sunny and very bright. There's just no way I'm going to be able to stop light flooding through by keep the shutter within the crucial 50-160 fps so not to break the 180 degree rule and get proper film motion.

I don't have any experience with the 14mm f2.8 EF L lens yet, I'm still waiting for it, but after reading many reviews, they report it does have a wonderful bokeh wide open (or a couple of stops down). I don't know how true this is until I get my hands on it. But from what you say about the DOF, this is normally true in ultra wides... I'll just have to wait and see. I'm also aware of the light falloff in the corners wide open, but completely gone by f8. This doesn't bother me as much though, a little light falloff can look artistic in filmwork and draw attention to centre stage (just a personal opinion).

With the image below using my 17-40, I can't use the Colkin filter in the normal way in in its holder. I have to just physically hold it in front. Can't get wider than 23mm either or I get viginetting from the filter. If I get these kinds of problems with my 17-40, imagine how much worse with my 14mm

Honestly, I can see myself buying cheap ND gels and getting my scissors out, or else forgoing any DOF and closing her right up.

http://farm6.static.flickr.com/5090/...486f452f00.jpg
Canon 5D2 - f6.3 - EF L 17-40@23mm - 1/250s - ISO 160 - Colkin Blue & Yellow

Chris Soucy December 23rd, 2010 06:34 PM

Hi, Kris............
 
Just Google "ND Gels" in Spanish and limit your search to Spain (shed loads of hits in the UK but there must be a Spanish supplier).

Can't be too hard to track down a supplier close to home.


CS

Nigel Barker December 23rd, 2010 11:56 PM

Quote:

Originally Posted by David W. Jones (Post 1601381)
My mistake, most of the lenses I have with rear mounted filter slots require special sized glass filters.
The 14mm as you said just takes gels. Here in the U.S.A. places like B&H have a great selection of ND filters which can be cut to size. ND Gels

I'm not sure where to get them where you are located.

Good Luck!

B&H ship worldwide.

Luc De Wandel December 24th, 2010 12:50 AM

Quote:

Originally Posted by Kris Koster (Post 1601435)

I live in southern Spain, which is nearly always sunny and very bright.

That explains everything, I was thinking in terms of our grey, dark weather over here. Lucky you! I'll take the filter problem any time to get rid of the white wet misery here!

Kris Koster December 28th, 2010 06:49 PM

...One of the reasons I moved Luc! My available production days have increased 3-fold by living here! Also the area has a softer, longer golden hour. Only downside is smaller client base who want everything for nothing!

But back to my ND problem - I don't like the idea of cutting small strips of wiggly gels to make up my ND filters. It feels tacky and unprofessional, not to even mention the potential loss of image quality by using low-grade material with high-grade equipment. Has anyone else found a better DIY solution to this problem?

I'm completely flabbergasted that there doesn't exist, a set of professional grade ND glass filters that can be slid into this rear slot on the aspherical ultra-wides.

Niche in the market?

Martin Catt December 31st, 2010 08:15 PM

Kris:
Check out the ISO Expansion custom function setting. Setting it to "ON" gives you access to the "L" ISO setting, which is an ISO of 50 (you can ignore the H1 and H2 settings, which are ISO's of 12800 and 25600, respectively). I find myself shooting a lot at the "L" setting, particularly with a 300mm f/2.8 Nikon lens when I want a paper-thin DOF.

Martin

Nigel Barker January 1st, 2011 02:35 AM

Quote:

Originally Posted by Martin Catt (Post 1603435)
Kris:
Check out the ISO Expansion custom function setting. Setting it to "ON" gives you access to the "L" ISO setting, which is an ISO of 50 (you can ignore the H1 and H2 settings, which are ISO's of 12800 and 25600, respectively). I find myself shooting a lot at the "L" setting, particularly with a 300mm f/2.8 Nikon lens when I want a paper-thin DOF.

Martin

I may be mistaken but I thought that you could only access the ISO 50 setting when taking still photographs & not video. I shall have to check it out in case I have been missing something as while the daylight intensity here in the South of France probably doesn't reach Spanish levels overexposure is a frequent danger.

Kris Koster January 1st, 2011 01:05 PM

Martin -

Thanks a great deal for that gold nugget, I didn't know about ISO expansion. It will certainly help matters when shooting timelapse photography. Unfortunately, as Nigel's suspicions appear to be correct, I cannot access the 'L' ISO setting when in Live View mode, so sadly not available for video.

Tried this out myself just now. When I set 'L' in viewfinder mode, it turns into 'Auto' in Live View mode.

The second most wanted upgrade I would like to see in the mark III (after aliasing and moire reduction improvements) is integrated ND filtering that are there as standard in most prosumer camcorders.

Martin Catt January 1st, 2011 07:11 PM

Ah ha! Another (minor) mystery solved. I've used the L setting while taking stills. The (probably) one time I went video with the camera previously set on L, I noticed that it kept saying ISO was Auto, but that was right after I did my last firmware update, we were shooting indoors with natural light, and I bumped the ISO to 200 manually. Haven't thought much about it afterwards, but suddenly it all makes sense. I have to admit it's a rare situation where the camera blinks at me at 1/8000 sec because it has too much light, but it's done that at high noon on a cloudless day at f/2.8.

I confess I long for the days when cameras were stupid and the photographer did the thinking. Even when set on Manual, the 5DMk2 will find ways to jack with you. What I --REALLY-- want is a digital equivalent of my old Pentax MX's: fully manual ONLY, with the five-LED metering on the left side of the viewfinder. No autofocus, very little to go wrong.

Martin

Chris Soucy January 1st, 2011 11:39 PM

Ah, Martin............
 
If only!

What I want is a digital version of my old Canon A1's (yes, I still use them).

Smart enough to work out exposure if asked but too damn stupid to screw your shot because they thought "it wasn't right", and then spent the next half hour arguing over it!

My Nikon D80 drives me to absolute distraction taking stills (no, thank God, it doesn't shoot video - I'd bin it).

More programmable features than my PC (99 percent of which are utterly useless and totally uninteligable) and an attitude that makes King Kong look like a wimp.

I've loathed it since I first bought it 4 years ago, and we're not developing a better friendship as the years pass, in fact I thnk it's getting worse.

Geez, why can't you just take the damn picture, machine?

I don't want to know about the bloody histogram being off, or the black level or the fact that some esoteric setting deep in the bowels of your programming has been set to not take dark pictures on a Tuesday!

Just take the bloody picture and do it right - too much to ask?

Even when I've told you how to take it, you wanna argue?

Please, Canon, re - do the A1's, they were a true classic act and a digital version (skip the sodding video) would be a Godsend.


CS


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