Rick - Ditto - Big Time!

Grazie

I just wanted to provide this link again to a depth of field chart. Maybe if you see it in print, Brad, your keen engineering mind will accept what your filmmaker's heart wants to ignore:
http://www.panavision.co.nz/kbase/op...alcFOVform.asp

Great chart, Wayne! Thanks.

(Whenever I have actually tried to calculate DOF I always end up falling into the circle of confusion myself.)

The whole DOF came by accident during an interview shoot on a local university campus. The sun was going down, and I was forced to open the iris all the way. It wasn't until I went to edit the footage sometime later that DOF first sparked and obsessive reaction. I liked it then, and I like it now. However, I do agree with Rick about the possibilities of overdoing it. The "Images" from Michael Pappas on the GL2 Watchdog website are still some of my favorites, and I really like the DOF of some of these images.

Thank you all again for you input. This site has become my favorite forum because of folks like you.

Brad

. . . thanks Brad . . .
 

"Here's Lookin' at you kid!"

One technique that can be used to produce "narrow" or "shallow" DOF is to film your subject with a telephoto lens or in the case of the GL2 increase your distance to your subject and zoom in. The result will be a very shallow DOF. Another benefit will be that filming/photographing people in telephoto mode produces a very flattering image of the human face as a result of the lens ability to compress or flatten the field of view. By contrast wide angle filming exagerates facial features (read nose look bigger).

Hi Val and Welcome to DV Info. Thanks for posting your thoughts on DOF and the compression abilities of telephoto lenses. However, you may want to take a look at the Ultimate DOF thread for a more complete look at all of the factors and how they interact.

Jeff,
Thanks, for the welcome and the link to the ultimate DOF thread(still digesting the info). Fascinating to see people fiercely disagree about a subject but still maintain a cordial attitude.

Back to DOF. I am planning to do a side by side comparison of DOF with my GL2 and my Nikon F3 with a 300 mm telephoto lens. One difficulty will to accurately simmulate the equivalent zoom with the GL2...any thoughts?.

I've got several posts on that in the archives. Use the search function and search >chip size< and my name. It should turn up what your looking for. The factor is basically 9.x for the small chip. Multiply the focal length of the GL2 by 9.X to determine the approximate 35mm equivalent.

Ahh, the search for the "Holy Grail" for shallow depth of field with small chip cameras continues.

Val, if you will familiarize yourself with the Depth of Field guide from Panavision, you will get a lot of the answers to your questions.
http://www.panavision.co.nz/kbase/op...alcFOVform.asp
For example, using your 35mm still camera with a 300mm lens at twenty feet at f/2.8, we calculate an effective depth of field of just over two inches. Very nice shallow depth of field.

Convert the 300mm lens to the one-quarter inch chip GL2 camera, by dividing 300 by 9.2, we end up with a 32mm lens on your GL2. Calculatin that on the guide, at twenty feet at f/2.8, we have a depth of field of almost five and one half feet! And remember; the focus gradually softens, rather than the more abrupt fall off you will get with the 35mm still camera format.

What you are saying is basically correct, Val; long lens equals shallow depth of field, but the narrow depth of field is nowhere near as dramatic on small chip cameras as on 35mm formats. It simply is not possible for the aspiring filmmaker to get the same shallow depth of field shots that we see in motion pictures. And with a wide angle lens that the original poster asked about, it is absolutely out of the question. The only "trick" that could be used is with a camera that has macro lens capability, but that is a different issue.

Jeff, Wayne,
Thanks for the links and comments. The information is overhelmingly convincing that shallow DOF is a near impossibility with a 1/4 chip. It is a real disappointment because I've widely used shallow DOF in my photography and wanted to widely(or narrowly) use it in filming with my GL2.

But all is not lost, as I've read numerous comments on this board, the use of aperture and ND's and even polarizing filters combined with other techniques may yield an acceptable level of shallow DOF.

The trick for shallow DOF is to always shot at the widest aperture (smallest numerical F number, F1.6, F2.0, or F2.8). This doesn't guarantee the results will be what you hope for. But rather, the shallowest given your choice of medium and equipment. Longer focal length lenses (telephoto) will have shallower DOF than shorter focal length lenses (wide angle). The further you are from your subject the larger the DOF, closer to subject the shallower the DOF.

Don't get caught in the trick of moving further away and zooming in. The DOF will stay the same.

Given the limits of our medium (small format video) the following will give you the shallowest or least amount of DOF.

1. Use the longest (largest) focal length lens.

2. Use largest lens opening (smallest numerical F number).

3. Get as close to your subject as possible.

Food for additional thought, see my post here.

Rob writes:

"But all is not lost, as I've read numerous comments on this board, the use of aperture and ND's and even polarizing filters combined with other techniques may yield an acceptable level of shallow DOF."

Of course I don't know what you consider "acceptable," but have you seen any pictures? Your camera will shoot at f/1.6 (I believe) at the wide end. As you increase the focal length, that f/stop will change to eventually f/2.9. You can add all the ND's and pola filters you want, you still can only shoot at the available maximum stop for the focal length. The only way that you can gobble up more light and narrow the depth of field, is to shoot at a higher shutter speed, and accept the motion effects this high rate will cause, which are unacceptable to almost everyone for normal shooting situations.

I am not trying to pick on you, Rob, but you are making it sound like there is some magic workaround for this limitation, and there really is not.

Wayne,
I didn't mean to imply there was a magic workaround. I was merely indicating that by using max aperture, ND filters and other techniques like Jeff and others suggested, one could achieve certain reduction of DOF and at this point ANY reduction of DOF would be acceptable given the limitations of the medium.

Hi Guys
We had a terrable time trying to get a narrow depth of field on our canon g2(still camera)and our xm2. We were useing it for stopmotion animation purposes. As the g2 has a very lame 3x zoom lens everything was wide angle looking and all in sickening focus.
So we did lots of experimenting to try amd combat this. One way was to stick a magnifying glass in front of the lens making a macro lens which creates epic depth of field but only when you are 1 ft away from your subject. usable for some animation purposes but not something viable for live action shooting. It works with our xm2 aswell. But the best results we got were useing a homemade mini35 adaptor(same principles as the ps technik adaptor for the xl1-pd150) This consited of a 35mm stills lens mounted on a box which has a spinning ground glass about an inch from the back of the lens. This creates an epicly shallow depth of field on the surface of the ground glass with the 35mm lens cranked openf1.7. The only problem now is that the image created was upside down. But because we were useing out little g2 for the shooting of this image we just flipped the camera on the back of the box upsideown. Next problem was the g2 couldent focus on the ground glass as the rear projected image is only 35mm in size so we glued a 50mm stills lens on to a 58mm step down/ step up/stepdown ring. so now it screws onto the front of the g2. (thus creating an extream macro) Now we can shoot a 35mm image onto film resolution digital still. This technique works fine on the our xm2 aswell. As the 58mm thread fits the front of the xm2/gl2and our g2. The only reason we havent built a version for our xm2 is that we don't want our xm2 to be costantly upsidedown. Might hurt the camera(seeing it cost a sh*tload more than or g2)!! So the solution will be a parallex mirror setup to correct the upside down image (a fair bit of messing around) and we will have a xm2/gl2 that shoots with a 35mm dof. If anyone is interested in seeing some photos you can email me Mulesfilmworks@optusnet.com.au
Sorry if you found these technical detail boring!

Hi Miles,
Very interesting stuff. let us know when you have the xm2/gl2 working.

We're Wandering A Bit...
 

Brad's original question related to DOF using the WD58H adapter on his GL2. If anyone has anything to add specifically to this subject, please do so.

Otherwise, please start a new thread if you really have something new to add to the general, and enormous, body of depth-of-field information we already have on the boards.

Thanks again to you all, especially Jeff for summarizing the necessary steps to get the most DOF from the GL2. With no photography background, as many of you obviously have, the DOF that I have seen from the GL2 is impressive. Perhaps writers set the bar a little lower, or maybe ignorance truly is bliss.

Thanks again,

Brad

Brad,

it's apparent you are happy with the DOF you are achieving. Besides implementing Jeff's suggestions, are you using ND filters or polarizer?

Val,

I just received two ND filters, and our polarizer has been great. The DOF appears to be good when we take the time to work for it. My only major complaint is that I like the image stabilizer when used with the WD-58H, and I am a little disappointed that shallow DOF is achieved better without the adaptor attached.

I look forward to using the ND filters in the days ahead.

Brad

My WD-58H vs. Century .65x Tests -- Updated
 

For those of you looking to save a few bucks, but still get good quality, I'm sure this is one of the points where we all ask ourselves -- "Is it really worth that much more?!"

In a nutshell, the answer is no. I shot identical video last week using my GL2 with both the Century Optics' $400 .65x bayonet W/A adapter and Canon's $170 0.7x screw-mount W/A adapter. The only difference was that the Century was imperceptibly wider and had a hair more barrel distortion all the way out (both have noticeable distortion, there's no getting around it).

The Canon was just as sharp all the way through to max zoom. There is a slight, but noticeable, drop-off in sharpness when zoomed all the way in while using the adapters as well. I reviewed the video on my new Sony HDTV monitor and the video was of the same subject using the same settings.

Best of all -- the Canon will used the same Century accessories! I am using the Century matte box fastened to the Canon WD-58 and it fits PERFECTLY! I will post a link to a photo later. Also, if you won't be using filters the Canon comes with a very nice, very usable HOOD that is an absolute necessity as both W/A adapters are HIGHLY flare-prone without adequate shading.

Just a quick FYI for those interested. Naturally, if you need a teleconverter/extender, a 16:9 adapter, or fisheye Canon has no options and you'll need either the Century or Optex, but in this case feel absolutely safe and free to save $200 and get the Canon over the Century. I went in thinking I was going to buy the Century and almost didn't even bother to test the WD-58, but I'm glad I did as it is a really impressive adapter -- regardless of price.

PS. I can post screen shots of each zoomed all the way in if any wish them. It'll take me a few days as I'm still reviewing the video we shot at the Rain Forest in Olympic Nat'l Park, Ruby and Second Beaches, Eagle Creek, Punch Bowl, and Cape Flattery.

==========
REVISED
==========

I thought I would add a couple of important notes. The first would be regarding the use of the optical image stabilizer and any W/A adapter. The use of any W/A adapter on either the GL2 or the VX2000 seriously degrades the stabilizer's performance in either of these cameras. I have the Sony 0.7x W/A adapter on the VX2000 and both the Canon WD-58H and Century 0.65x with the GL2. Using the adapters renders the IS on both cameras virtually ineffective, so be aware and take this into account if you're shooting handheld.

The second point is to emphasize the optical abberations that all of these adapters introduce. No matter how good the optics of the adapter are you're still putting a lot more glass in front of the stock lens. Not only is the barrel distortion pronounced and readily visible when zoomed all the way out (widest), but when shooting either horizontal or vertical lines they really advertise the distortion to even the untrained eye. It's not fisheye, by any mean, but as the old saying goes "you need to give a little to get a little." Also, all of these adapters visibly reduce sharpness at the long end (max zoom) -- there's just no avoiding it. If you don't have anything to directly compare it to, then it looks pretty sharp, but if you compare identical, full-zoom shots with and without an adapter you can see some image softening. It's not dramatic, but if you're a stickler for ultimate sharpness you need to know that there is degradation.

Thanks for the info. I was looking at that choice for the next month or so. I'll save my money.

WD-58H Wide Angle Lens
 

I have this wide angle lens, but when I got it there was not the small hood that I was told that comes with it now. Has anybody picked this lens up with the hood, and where did you get it. I would like to see if I can get just the hood.

Mark

Just did that myself, through B&H in NYC (I bought on-line). It was about $39USD and I had to phone to get a part # to search with as I couldn't find the item offered anywhere on the site.
I'm probably the only poor sap who would do this but I'll mention that while it fits in any position there's only one right way to mount it. Viewing my footage after first using it I discovered I had caught edges both left and right in full wide, because I had it at 90 degrees to the correct position. The tightening screw should be at 3 o'clock, like the hood that comes with the camera - I should have seen that as a clue.

David Hurdon

Mark,

if you bought it as "WD-58H" the hood should definititely be in the package. Otherwise you bought the "older" version, the WD-58 and you'll have to order the hood seperately.

Chris

Thanks Chris
 

I bought the lens about a year ago and it did not have the "H"on it, so unless I hear back from someone else with a better place to get the hood, I'll just contact Canon.

Kind regards,

Mark

A year ago the hood wasn't available. It wasn't introduced until the GL2 came out last July. The hood is always available as a separate item from any authorized Canon dealer. I urge you to consider purchasing from any of our DV Info Net Community Sponsors, as you'll be supporting this message board when you buy from them. Hope this helps,

Chris, what happened to Lyle Pendy's post with the B&H URL for buying the WD-58 lens hood? I no sooner read it than it disappeared, when yours arrived with the comment about forum sponsors.

David Hurdon

David, it's my policy to point readers to our sponsors. I removed the B&H link because it's detrimental to the folks who are paying for these boards... our site sponsors, who are dealers every bit as good as the "Big & Huge." I promote small businesses because I myself am a small business. Many of our members are small business people. B&H is not going to suffer in the interim. Meanwhile, our site sponsors have the same item in stock at the same price. I've stated before many times, and will state once again now, that as the owner of the boards, I reserve the right of having the final say on all where-to-buy questions. Hope this helps,

Raynox .3 wide angle clip on lens. Good or bad?
 

Recently, I purchased a .3 Raynox wide angle clip on lens for my Gl2 for $100. I could of gotten a more expensive one but recently, all I have been shooting is shots for my upcoming rollerblading video and I really don't need the "best". Anyway, people have been saying that the clip on is a bad lens but I really don't see a problem with it. I just found out they made a screw on .3. I had heard about it a while ago but I just found it a few days after I got my clip on. What is better about the screw on then the clip on. Since I will be getting closer shots, I think its good to have the clip on incase someone hits my camera, that way only the lens would come off. Reply back, thank you. :)

Is that a 0.3x? Seems like it would get very fish eyed looking video if you have that wide of a lense on a GL2. Bottom line is if you are getting video that you like, it works for you.

Yes, it is a .3x wide angle clip on lens by raynox. It seems to be getting good clips so I'm happy with it. Its just people were saying on this other skate related messageboard that the lens is horrible. Oh well, later on.

I also use the .3 raynox on my GL1 and I get great quality. Its not quite full fish-eye...maybe about say 150 degrees but it does the job for me. As you probably allready know its not a zoom through lens....after you zoom about 4x the focus drops. The clip on is nice becuase I have had several skateboards take it out and it just merely fell off. One hint that I would definitely do...there is a small hole on the lens...that is made to tie the lens to your camera. TRUST me this will save your fish-eye more than once. One more thing....there is some crazy lense flare when you are filming in the sun...be careful or you will get some whacky shots. Otherwise the clip on works just as good as the screw on. I have both and tend to use the clip on because its so easy to go long lense in a hurry. hope this helps

I was suspicious of the clip-on facility until I tried it. It may look ungainly but it shure holds on tight and the very best thing is the ease and *speed* of fitting and detaching the lens. This is an important aspect with any non zoom-through, and I think Raynox have a goodie here.

All the Raynox clip-ons have lots of barrel distortion though, and that's why I passed on owning one. Their 6600 PRO lens is so distortion free that I wonder why theu don't do a distortion-free single element aspheric in their line up. I'd certainly have one of those.

tom.

man oh man we seem to have similar products. I have the Raynox 6600 pro 52mm lens for my Nikon digital and it is great. And yes there is no noticeable barrel distortion.

The thing with the .3 raynox...its a semi-fisheye so barrel distortion is what we're looking for...........nearly every "line" done filming skateboarding, rollerblading, etc is done with a fish-eye. Granted most films use a 700 dollar century optics "death" lens. So the 100 dollar Raynox is an amazing fish-eye for the guy who just spent 1800-2500 on a GL1 or GL2.

HEHE, that would be me. I just got 2 more clips tonight, they looked amazing.... what is barrel distortion? I'm still new to the lens department, thanks, later.

Barrel distortion is the fisheye effect you see, the "bending" of the straight lines.

<<<-- Originally posted by David Woodland : ...what is barrel distortion? I'm still new to the lens department, thanks, later. -->>>

Image curvature typically most noticeable in vertical lines near the left and right edges of the frame.

the easiest way to see barrel distortion is film a normal size doorway with the door open. get close enough so it fills the frame horizontally and you will see the sides of the doorway bow out quite a bit. Its what tends to make that 4 foot gap you are jumping with your rollerblades look to be about 8 feet. Proper filming also gives you that effect. Besides the fact that it makes a skate "line" look more stable...less camera shake, allows you to get closer, and allows you to not have be looking into LCD all the time, the fish-eye makes it much eaiser to make skating look good. Long lense is damn hard to perfect, but if you want to see an awesome video using a lot of long lense buy or download
Es' Menikmati....its great.

Is that a skateboarding video? I can't stand to watch skateboarding videos for some reason. Mainly because I'm a rollerblader and I gap 25 stair sets like nothing since ive been fruitbooting for almost 7 years. I know the tricks are hard on a board but I'd rather watch people put their life at risk while doing a sport. later.