The end of 35mm adapers and hv20s....

Sorry, I'm moving part of a dpreview thread over here =)

kevm14 wrote:
>
> ericBlair wrote:
> > this is what i don't get. you are exposing for shadows @ >f5.6 so
> > presumably the AE picks a slow shutter but what stops it jacking the
> > gain up too?
>
> Hitting AE-L fast enough stops it.
>

Can someone explain this? So the theory is that the camera has enough time to register a slow shutter speed, but not enough time to crank up the ISO?

Also, how can you see what shutter speed and ISO the camera picked for a video clip? I don't see this metadata anywhere.

Lastly, I assume you need a non-CPU lens in order to manually open aperture until desired exposure is achieved? I tried moving the aperture ring on my 50mm 1.8 but it had no effect on the exposure (this was in manual mode while the AE-Lock was enabled, btw)
 
cacophony said:
Also, how can you see what shutter speed and ISO the camera picked for a video clip? I don't see this metadata anywhere.

Lastly, I assume you need a non-CPU lens in order to manually open aperture until desired exposure is achieved? I tried moving the aperture ring on my 50mm 1.8 but it had no effect on the exposure (this was in manual mode while the AE-Lock was enabled, btw)
Click to expand...

There is no shutter speed or ISO data anywhere to my knowledge. You can measure the shutter speed with a variety of methods. You can also take the shutter speed measurement, combined with the known aperture, and guess the ISO based on the image appearance and knowledge of the scene's lighting. But that's a lot of work.

I think you need a lens without the aperture lever thingy. If you take the 50mm off the camera and manually set the aperture at F22, then mount it on the camera, you'll notice that as you twist the lens to mount it, the aperture actually opens up. That's how the aperture control works. So you'd have to modify that lever to not contact the body. I think I am explaining this right. The higher end bodies allow you to use the lens to set the aperture but not the D90.
 
Kholi said:
How I spend my money is none of your business, but I'll humor you anyway:

No, it doesn't matter to me if I spend 1400.00 on a d90 or 2999.99 on a 5D if the 5D shoots better video. Yes, even with the RED ONE sitting right next to me on the floor.

If you can't fathom why I would want a DSLR that shoots decent 720p, even after you take the time to imagine what a DSLR Body looks like sitting beside a RED ONE built up for minimal production, you need to stop posting about Logic and shoot more.
Click to expand...

Whoah, you own dual REds?? small size really is king.
 
cacophony said:
Sorry, I'm moving part of a dpreview thread over here =)

kevm14 wrote:
>
> ericBlair wrote:
> > this is what i don't get. you are exposing for shadows @ >f5.6 so
> > presumably the AE picks a slow shutter but what stops it jacking the
> > gain up too?
>
> Hitting AE-L fast enough stops it.
>

Can someone explain this? So the theory is that the camera has enough time to register a slow shutter speed, but not enough time to crank up the ISO?

Also, how can you see what shutter speed and ISO the camera picked for a video clip? I don't see this metadata anywhere.

Lastly, I assume you need a non-CPU lens in order to manually open aperture until desired exposure is achieved? I tried moving the aperture ring on my 50mm 1.8 but it had no effect on the exposure (this was in manual mode while the AE-Lock was enabled, btw)
Click to expand...

1) If my "theory" (as ghetto as it is) is correct, using the exposure setting adjusts your shutter speed manually. If you set it at a positive value then it overrides, I think, the camera's auto shutter value setting. Same thing as negative value being a high speed shutter. When it goes in and out of LV (Live View) mode the camera employs a quick ISO adjustment or, what we're used to calling it around here, a gain adjustment: it seeks out what it thinks is the right amount of light to see everything in the image as opposed to actually caring whether the image looks great or not.

2) You can't. There's no ISO read out or Shutter readout in metadata as far as what I've seen. Not even in the camera display. I think that we, as video shooters, just have come to see what a high and low shutter "looks" like in video. So it's all guesstimating. I can't see doing anything that requires knowing exactly how this scene or that moment was shot so it's not a big deal to have approximations on ISO, Shutter, etc etc. As long as it "looks" fine then cool.

3) To see the effects of a manual lens and exposure you should be able to look through the viewfinder directly. It does, however, work plenty fine in Live View mode. I suggest, if you're going to shoot video with this thing and want optimal results, to use the full manual lenses that you have in your arsenal or at the lenses that have auto/manual iris switches.
 
Matthew Bennett said:
Whoah, you own dual REds?? small size really is king.
Click to expand...

No~o. Once again, I don't own the REDs. LoL. I just keep them. If that makes sense. I rent them out, I use them, and maintenance them etc. etc. and they live with me but I only own in a sense that I'm the one that works them. Guess it's a pseudo co-ownership situation where both parties benefit.

Just as well, there are a volley of uses for something like the d90. I can't imagine walking into a grocery store without a permit with even the lightest RED setup in my hands to steal a shot.

I can, however, imagine spending a good half hour in a grocery store with the d90 getting that shot and many others because of the small footprint.

RED is not the end all of video acquisition. I still use my HVX-Ultimate for a LOT of work and even have the tendency to have a hard time choosing which one to shoot on projects that I have a choice. It's not all that easy.
 
Well, I got mine. Just as I thought, first thing you have to do after charging the battery and putting it in is you have to PUT THE CAMERA ON A TRIPOD! This camera's image in DMovie wobbles so much it will make you seasick after a few seconds looking at the LCD. I don't even think anything but a tripod would work, I tried a monopod for a test but did not spend too much time with it. I guess a dolly or tracks would be a solution for moving it. The problem is that any single jerky movement would affect the image.
On the tripod the panning looked excellent. Up and down no problem. In the next few days I will be testing it as much as possible and see how much it can be tweaked and work on sample footage. BTW, the stills look fantastic, which as a professional photographer makes me very very happy.
I am keeping this baby just for the photography alone, lets see how the movie side turns out.
 
Erik Olson said:
I haven't read through all the pages, but this is a cool new tool. Can anyone tell me why I'm seeing what I think is a rolling shutter issue in the trains clip? Again, sorry if this was covered on page 186 or something, but I simply can't find it. I guess I'm wondering how a locked-off shot seems to be wavering.

e
Click to expand...

Hi Eric- It looks like that is due to camera vibration from the trains (and possible a wimpy tripod). The rolling shutter on the d90 is very slow, so fast movement (or vibrations) can give you that effect.
 
Kholi said:
I suggest, if you're going to shoot video with this thing and want optimal results, to use the full manual lenses that you have in your arsenal or at the lenses that have auto/manual iris switches.
Click to expand...
Here's one thing I don't understand (apart from the question why on earth they wouldn't allow full manual control to begin with):
I thought the aperture was the one thing the D90 doesn't auto-change once you go into video mode? So why do you need iris control on the lens?
 
Because, once you leave LV mode and re-enter it the Camera goes, for a split second, into "AUTO" willy-nilly land and totally destroys your 'ghetto' rigging of the ISO value.

I.E. You've worked to get a clean image but you need to open the iris more now. Oops, as soon as you exit LV (Live View) and re-enter the camera took away all of your hard work.

You defeat this by using a manual aperture, that way you don't have to switch out of LV mode.
 
Kholi,

I forgot if you (or someone else) answered this but is it true that the smallest aperture the camera allows (in auto aperture control obviously) is f/8?
 
DESHAKER virtualDub filter first-try on d90 footage

DESHAKER virtualDub filter first-try on d90 footage

i downloaded the deshaker filter referenced earlier in the thread, ran some of kholi's wobblier footage through it, converted it to xvid and uploaded to youtube, here's the before and after.

BEFORE deshaker

http://www.youtube.com/watch?v=y484jV_2IfA&fmt=6

AFTER deshaker

http://www.youtube.com/watch?v=ye3Ag8wTzvg&fmt=6

you won't be able to tell from this if the filter degrades the quality and i see some tearing of the video that isn't there in what i uploaded, so google (or my browser/ video card) must be adding it but ... it seems to be supressing the jelly-roll quite nicely. also there are dozens of config options in the filter and i almost certainly haven't done it optimally. seems quite promising tho.

here's the link to deshaker if anybody else wants a go.
http://www.guthspot.se/video/deshaker.htm#rolling shutter setting

Cheers
theabsurdman AKA dpreview's ericBlair (name already taken @ dvxuser)
 
Last edited:
Car3o said:
straight up, so far, is it better than the dvx?
Click to expand...

I can't say that it's better. =\ Which doesn't help anyone. LOL. It's fun! For now, but the DVX100B is a fully manual, fully dedicate apparatus; the d90's D-Movie mode is just an afterthought.

I like what you can do with it, the implementation lacks sorely, though. Wouldn't sell my DVX100 + 35mm Adapter combo for it. But would have it on stand-by as a second unit option in conjunction with.
 
kevm14 said:
Kholi,

I forgot if you (or someone else) answered this but is it true that the smallest aperture the camera allows (in auto aperture control obviously) is f/8?
Click to expand...

I don't believe that's right. I've gotten it down to F22~32 by putting the Auto 18-105 lens at it's telephoto end. The problem is that even if you lock it there, once you switch out of LV to 'jimmy' the ISO it goes away.

Tsk.
 
I really wish Nikon is somewhere listening and hopefully able to manage to add manual control via firmware upgrade. I doubt they can do anything about the rolling shutter at this point, but maybe compression and datarate?

It also kinda makes sense that this movie mode isnt more advanced. D90 is first and foremost a DSLR and thus using most of it's processing power for still image related stuff. The video implementation probably didnt cost much in R&D and since Nikon dont have a dedicated video line, they have everything to gain but nothing to lose.

However, if Nikon made a more specific video camera with the same sensor with an F mount where all the cpu power goes towards video, it might be something really spectacular.

Then again, i'm a still image dude and dont know too much about video except editing small cips from my 4 year old Sony P&S using Windows Movie Maker! :)
 
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