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-   Panasonic LUMIX S / G / GF / GH / GX Series (https://www.dvinfo.net/forum/panasonic-lumix-s-g-gf-gh-gx-series/)
-   -   Sigma 30mm F/1.4 depth of field (https://www.dvinfo.net/forum/panasonic-lumix-s-g-gf-gh-gx-series/495140-sigma-30mm-f-1-4-depth-field.html)

Jeff Harper April 27th, 2011 03:39 AM

Sigma 30mm F/1.4 depth of field
 
I went to the park last night to see the effect of changing aperture value on depth of field. This of course is nothing new, except for me. I have read of how aperture values effect the DOF, but wanted to see it for myself, as I have played with the GH2 a minimal amout of time and I have much to learn about basic photographic principles.

I learned a couple of things yesterday. By following the "recommendations" of the on-camera meter, images were overexposed, at least in the outdoor scenario last night.

I also learned the 30mm lens is easier to focus with on the fly than the 20mm Panasonic lens. This is for two reasons. The 30mm's narrower quality causes objects to be larger, where the width of the 20mm has objects appearing smaller, thereby making it harder to see details with which to focus upon.

In addition, even though it was relatively mild lighting at the time of the test, I suspect that for the shots of the branches (at the end of the video) would have looked nicer had I been using a polarizer.

All focusing was done without focus assist, which was deliberate, as I have to learn to focus on the fly without the taking time to set up shots when shooting wedding parties outdoors.

Lastly, I've learned the 30mm is not "better" than the 20mm lens, but for run and gun style shooting it is much easier to work with. The focus ring is extremely smooth and pleasure to work with, whereas the 20mm is a pain unless using auto focus or focus assist.


Jeff Harper April 27th, 2011 03:49 AM

Re: Sigma 30mm F/1.4 depth of field
 
Oh, also learned that XDCAM ex is the best render setting I have found in Vegas for rendering files for Vimeo, wow what a difference. I have jewelrey store footage rendered to Sony AVC codec and the pans just turn out jittery, even though there is no jitter visible in the original footage.

Gerald Webb April 27th, 2011 06:53 AM

Re: Sigma 30mm F/1.4 depth of field
 
Hey Jeff,
Fancy finding you here, what a small world.
I've been scouring the net all night trying to find the best option for a wider prime to go on my GH1, I have an FD 50mm f1.4, but need to get closer to the subject.
That Sigma looks pretty nice in your video, I think I'll start looking for one.
Are you pleased with it?

I did my second wedding last weekend, and jumped in the deep end, so to speak.
I shot almost all of it on the GH1 with the 50mm FD prime.
I gotta say, I really enjoyed it. I made heaps of mistakes, but learned a lot as well.
A 30mm, or 20mm may even be better, and the 50mm would make a nice pair I think for the next one.
Here is my Bride prep....

Jeff Harper April 27th, 2011 08:06 AM

Re: Sigma 30mm F/1.4 depth of field
 
Gerald, masterful work, considering your lack of experience. Unbelievably steady. I cannot believe you were using a Canon 50mm and keeping it as steady as you were. Were you handheld or were you using a mount of some sort?

The Sigma has many advantages over the 50mm when using it on the GH2. I only learned recently that AFS mode doesn't work with the GH1 and the Sigmas which really stinks.

You next lens? Hmmm, I don't know. I really find the 30mm to be my favorite single lens, period. But the 20mm is invaluable as my wide lens from the rear, and it produces VERY nice images.

For getting ready stuff like you shot, I would really prefer how much steadier the 30mm would be if it were me. I suspect you would really like it, and it can be had for around $375 used.

The 20mm gives you many more options and features, and does not require an adapter like the Sigmas do.

Gerald Webb April 27th, 2011 03:07 PM

Re: Sigma 30mm F/1.4 depth of field
 
Thanks Jeff,
I'll admit, i've watched your demo vids a few times, it helps to aim high when you do knew things.

The prep is all done with the 50mm apart from the last cpl of shots which were with the 20mm pancake.

I hold a tripod with my left hand on the upper tube, have the control arm extended to the right which rests on my right upper forearm while my right hand pulls focus. I have to say it works really well for balance and control.

Auto focus doesn't worry me, I cant seem to trust it anyway, especially in low light, hence the 20mm pancake lens spends most of the time in the bag.

Which mount did you get for your 30mm ?

I'm weighing up getting a 5dmk2, and relegating the GH1 to the continuous shot at the rear, I may rethink and just go GH2 though. Save some dollars for sure, lol.

Jeff Harper April 27th, 2011 03:22 PM

Re: Sigma 30mm F/1.4 depth of field
 
Gerald, the Canon is fine camera, would love to have one for a day to play with. I have the Panasonic mount, it's very nice, highly recommend it.

GH2 has so many great features, but it is a consumer gadget, like the GH1, and the menu and form factor really prove it. It's so small it is a pain.

Some have defended it's size, which is fine, but I recently came across three reviews in a row that each slammed it for being difficult to handle, so I don't feel quite so unjustified in my feelings about that. It is what it is, but I do not like this aspect of it.

The GH2 really is superior to the GH1, but a great F/1.4 lens really nullifies the differences. Except for when I need gain, I will work with either camera, they are essentially the same. I admit though some of the touch-screen features are very nice, and I do miss them when I work with the GH1.

Patrick Janka April 27th, 2011 03:47 PM

Re: Sigma 30mm F/1.4 depth of field
 
Gerald, don't take this personally, but as someone said in the Canon XH series forum,

"By the way, the video community is starting to suffer from rack-focus-itis. Too many people are overusing the DOF manipulation and its like some law was passed that every shot has to have a rack focus. Rack focus is like garlic, a little goes a long way and the effect is good when used in moderation. Same with DOF; sometimes its nice to see what's happening in the background! Focus should reinforce the action/story/dialogue. It shouldn't be just a random trick!"

It pervaded your video throughout making it pretty jarring.

Gerald Webb April 27th, 2011 04:55 PM

Re: Sigma 30mm F/1.4 depth of field
 
No probs Patrick, I'm watching now a couple of days after editing thinking,
Yep, too much there.... And there..... And there, lol.
It's very much the, kid with new toy syndrome.
But, the next one I do will be 100% better than this one, just like this one was 100% better than the first one I did.
The people are thrilled, so all is good.

I can't see me going back to a camcorder after using DSLR though,
For weddings you need low light ability which to get in a camcorder just isn't in my budget.

Cheers people.

Jeff Harper April 27th, 2011 05:03 PM

Re: Sigma 30mm F/1.4 depth of field
 
Yes there was a lot of rack focusing, but knowing it was your first real attempt, it was clear you were enjoying the lens and it showed. It is normal to go a bit overboard, but in time you will pick and choose when and where you use each technique. You yourself have already seen the bits you might scale back on.

While at it, I would cut back on the flash transition as well as the rack focusing.

I just re-watched it and yes, it is a bit much, but hey, you'll clean it up and it will be fine. Still can't get over how steady you were with that lens, I must try your technique.

Gerald Webb April 27th, 2011 06:13 PM

Re: Sigma 30mm F/1.4 depth of field
 
Oh no, To many dissolves? ok, back to the star wipes. Lol
Buying the 30mm sigma tonIght.
Thanks Jeff

Patrick Janka April 27th, 2011 06:37 PM

Re: Sigma 30mm F/1.4 depth of field
 
Yeah, definitely too many dip to white transitions, it's cool, every shoot is a learning experience, and I don't think anyone ever reaches perfection. There's always something that could have been done differently or better. Keep at it!

Jim Snow April 27th, 2011 09:34 PM

Re: Sigma 30mm F/1.4 depth of field
 
Quote:

Originally Posted by Patrick Janka (Post 1643618)
Gerald, don't take this personally, but as someone said in the Canon XH series forum,

"By the way, the video community is starting to suffer from rack-focus-itis. Too many people are overusing the DOF manipulation and its like some law was passed that every shot has to have a rack focus. Rack focus is like garlic, a little goes a long way and the effect is good when used in moderation. Same with DOF; sometimes its nice to see what's happening in the background! Focus should reinforce the action/story/dialogue. It shouldn't be just a random trick!"

It pervaded your video throughout making it pretty jarring.

Patrick, I can't tell you how much I agree with you. I think there will be a lot of growing up over the next couple of years with some self-proclaimed 'cinematographers'. Some of them don't realize that their 'work' looks more like a kid playing with a new toy than a professional production. I have had two brides express concern that I "don't do too much of that stuff". They had seen demos of a few of these 'masterpieces' and didn't like them. Star wipes, wowey zowey zooms, were the 'rage of the age' with earlier amateurs. Today's crop of amateurs' 'thing' is non stop rack focusing and extremely shallow depth of field on every shot to add to the nauseous impact of their 'creations'. But this too will pass.

Want to see artful shooting? Look at Hollywood. Like to sling around the word 'cinematographer'? Hollywood = CINEMAtography. You won't see them doing relentless and pointless rack focusing or totally wiped out backgrounds with extremely shallow depth of field on every blasted shot. Like salt and pepper on your eggs in the morning? Good, huh? Well, why not just dump the whole box on them; that ought to really make them 'good'. Capice?


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