Full Frame Observations.

Dale.

Dale.

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Dale.
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Had my 5DMKiv now for around 2 months, I am chuffed to bits with it, especially after a woeful experience with my 7D. I'm not knocking the 7, in the right hands, it's a cracking camera but I just didn't get on with it.

Anyway, back to FF.

Detail retention is superb, I can make huge crops if I need to and the images will still pass as useable.

2 things though,

1, When I use my 100-400, I get dark vignetting in the corners, I'm presuming it's the hood. I have taken the hood off the lens now and out of my bag and I will try it without next time. Surely though, if it's the correct hood, it should be fine?

2, I seem to be getting slower shutter speeds on my Mkiv to what I've been getting off crop cameras with the same settings, a full frame quirk maybe, or just a setting I'm overlooking? I'm still learning the camera, so it may be operator error.

I love the Mkiv though, what a machine and I've only scratched the surface, 2 motnhs old and 250 clicks.
 
2 months and 250 clicks? Get practicing man, I took 490 on Sunday morning just because!

And vignetting is the lens, some are more than others, don’t worry about it.

Can’t comment on the other point, I’ve not had a cropped camera in almost a decade.
 
Dale. said:
2, I seem to be getting slower shutter speeds on my Mkiv to what I've been getting off crop cameras with the same settings, a full frame quirk maybe, or just a setting I'm overlooking? I'm still learning the camera, so it may be operator error.
Click to expand...

One thing which could explain slower shutter speeds with FF is if you're shooting at smaller apertures to get deeper depth of field. I know you said you're using the same settings but is the aperture the same? Could you be shooting with smaller apertures?

Other than that there should only be minor differences between APS-C / FF or different makes due to metering and / or how the manufacturer set the ISO etc.
 
Raymond Lin said:
2 months and 250 clicks? Get practicing man, I took 490 on Sunday morning just because!

And vignetting is the lens, some are more than others, don’t worry about it.

Can’t comment on the other point, I’ve not had a cropped camera in almost a decade.
Click to expand...
You have ,youve got a fuji crop lol.or did you mean dlsr?
 
Dale. said:
When I use my 100-400, I get dark vignetting in the corners, I'm presuming it's the hood. I have taken the hood off the lens now and out of my bag and I will try it without next time. Surely though, if it's the correct hood, it should be fine?
Click to expand...
It's not the hood. Is it physical vignetting or just a bit of shading towards the corners? All lenses do the latter, to some extent. Show us an example, with EXIF data.
Dale. said:
I seem to be getting slower shutter speeds on my Mkiv to what I've been getting off crop cameras with the same settings, a full frame quirk maybe, or just a setting I'm overlooking?
Click to expand...
There should be no difference. Show us some examples.
 
Thank for the comments everybody.

With the shutter speed differences I'm seeing, when I did the trial, all settings, (as far as I know) were the same, basically, iso and aperture, as well as metering and focus points, as near as they can be on different cameras, ie:- 5d and 7d.

Example of vignetting on an uncropped image. 100-400L with a 1.4TC, but I get the vignette without the TC too. I don't get a vignette with wider angle lenses. 1250/sec, iso1250, f8,560mm. I would've thought the shutter speed would've been a lot faster (not that it's slow) in this light at iso 1250.

IMGL0229 tp ex.jpg



I've not got any screen grabs as it were concerning the shutter speeds but when I tested it, it was a considerable difference. Settings were the same as near as could be, same iso, same aperture etc and I focused on a chimney on a house opposite and got 30th/sec with the 7D and 15th/sec with the Mkiv. I will double check this and also try to figure if there is a setting amiss as well as get 2 images up with exif, one off the 7D and one of the MKiv.
 
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Vignetting can be tricking the 5D into wanting more light and therefore slowing the shutter down by a stop
7D on the other hand uses the sweet spot of the lens without vignetting
 
Just to ask?

Have you got a filter on the lens and if so it a 'thin' profile one or 'standard' thickness?
 
Box Brownie said:
Just to ask?

Have you got a filter on the lens and if so it a 'thin' profile one or 'standard' thickness?
Click to expand...

Nope, no filter for these shots.

When I ran the test, I set both cameras with the same settings, then swapped the same lens between bodies. I'll try again later and post the results.
 
Dale. said:
Nope, no filter for these shots.

When I ran the test, I set both cameras with the same settings, then swapped the same lens between bodies. I'll try again later and post the results.
Click to expand...

If you swap the lens between bodies you'll get a different field of view and unless you step back when using the APS-C camera to get the same framing you'd get with FF the change in FoV could affect the scene, light and metering and so give you a different shutter speed.

Shooting side by side with my FF A7 and MFT with both fitted with lenses giving the same FoV I get pretty much the same camera settings and that's what I'd expect.
 
woof woof said:
If you swap the lens between bodies you'll get a different field of view and unless you step back when using the APS-C camera to get the same framing you'd get with FF the change in FoV could affect the scene, light and metering and so give you a different shutter speed.

Shooting side by side with my FF A7 and MFT with both fitted with lenses giving the same FoV I get pretty much the same camera settings and that's what I'd expect.
Click to expand...


You may have hit the nail on the head here.

So, if I'm at 100mm on the 5D, I should be at 60mm on the 7D to get the same exposure with the same aperture/iso settings?
 
You'll have to either change the focal length or your camera to subject distance to match the field of view and get the same framing. Assuming you can keep the same ISO and aperture when keeping the framing the same I'd expect the shutter speeds to be about the same but note that Canon might have changed something between the cameras and the settings may not therefore always be exactly the same.

PS.
I tend to apply the crop factor when using different cameras. For example if I'm at f8 with ff I'd be at f5.6 with aps-c and f4 with mft. This will give different settings but a more similar end result.
 
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woof woof said:
You'll have to either change the focal length or your camera to subject distance to match the field of view and get the same framing. Assuming you can keep the same ISO and aperture when keeping the framing the same I'd expect the shutter speeds to be about the same but note that Canon might have changed something between the cameras and the settings may not therefore always be exactly the same.

PS.
I tend to apply the crop factor when using different cameras. For example if I'm at f8 with ff I'd be at f5.6 with aps-c and f4 with mft. This will give different settings but a more similar end result.
Click to expand...


Nail hit very firmly on head I think. I have tried it and I get similar shutter speeds at same iso/aperture/metering settings if I pull the lens back on the 7D. My 100-400 happened to be on my Mkiv and I zoomed out to 200mm, got 500/sec (in manual mode so had to centre the meter) and then put the lens on my 7D and zoomed back in to 120mm (approx) and got 640/sec, bearing in mind that the light also may have changed slightly during the lens swap.

I think I can now dismiss that niggling doubt that there may be something wrong with my camera. It's such an obvious thing that I know can see having been crop all my camera life until recently. Going FF is in some ways like begining again. One thing I'm not used to is using higher iso settings as my 7D didn't do above 400 well at all, whereas 800 iso is my base setting on the MKiv. Cheers for that Alan. (y)
 
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Dale. said:
So, if I'm at 100mm on the 5D, I should be at 60mm on the 7D to get the same exposure with the same aperture/iso settings?
Click to expand...
Only if you're using centre-weighted or evaluative metering. They meter from the whole scene, so if the scenes are different then you shouldn't expect the same exposure settings. With respect, that's pretty fundamental, and nothing to do with the crop factor or full frame issue. If you change what's in the picture (either by zooming, or changing the lens, or hanging the camera), then the exposure can change.

If you're using spot metering then the exposures should usually be the same, because you would be metering off the central 1% of the frame and it's reasonable to expect them to be similar even if the overall compositions are quite different due to the crop factor. And if you're using partial metering, that looks at the central 5% (IIRC) of the scene, so you'd be more likely to get the same results than with centre-weighted or evaluative, but less likely than with spot.
 
Dale. said:
I think I can now dismiss that niggling doubt that there may be something wrong with my camera. It's such an obvious thing that I know can see having been crop all my camera life until recently. Going FF is in some ways like begining again. One thing I'm not used to is using higher iso settings as my 7D didn't do above 400 well at all, whereas 800 iso is my base setting on the MKiv. Cheers for that Alan. (y)
Click to expand...

I had film cameras but I adapted to APS-C DSLR's easily enough apart from wondering why 28mm wasn't very wide any more as I didn't know about the crop factor :D I actually struggled more when going back to FF with a 5D as I initially had trouble realising that I needed to use smaller apertures (and so had to watch the shutter speed and ISO) to match the depth of field I used to get with my 20D :D

Now I've got used to crop factors I swap between my FF Sony A7 and Panasonic MFT without a problem.

Anyway, I'm glad that you've put your mind at rest and can now get on with enjoying it all :D
 
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Thank guys.

Stewart, yes, it makes perfect sense now I've seen it.

Cheers again Alan, I'm still learning the camera and it's a giant leap from my 7D.

I'll share more observations soon. :LOL:
 
I think most things have been covered already. Assuming same framing etc the exposure settings should be the same, but as mentioned a lens on 7D will have a field of view of a focal length 1.6x longer than that of the 5D so the scene can be different and therefore exposure.

FF lenses on crop bodies will show less vignetting as you’re only using the centre portion of the image circle and ‘cropping’ off the vignette.
 
I would be surprised if a 100/400 showed signs of vignetting on a FF camera as that is what it was designed for. There might however be light fall-off in the corners, a lens profile should correct that in PP.
Bottom line though is it looks the same.
Matt
 
Just incase you missed it guys, an uncropped image with the 100-400.

IMGL0229 tp ex.jpg
 
Both the 100-400 MkI and II have around a stop of light fall off at 400mm wide open.
 
Mine is the Mk1, should've mentioned that.




Gaz J said:
Both the 100-400 MkI and II have around a stop of light fall off at 400mm wide open.
Click to expand...

I'd guess that's about what I'm seeing. Above shot would be @ 400mm with a 1.4 TC, so 560mm and f8. The TC, with hindsight, is probably contributing to the vignette/light fall off.
 
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john.margetts said:
Surely light fall-off in the corners IS vignetting?
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Maybe, depends on your definition, Vignetting is usually defined as being caused by a physical obstruction, be it aperture blades, internal element shadow or a hood etc. Light fall of is more to do with the distance the light has to travel before it gets to the film plane/sensor.
The physical diameter of a lens cause the light to travel further from the edge than the centre to reach correct focus on the sensor/film so they dont have the same intensity, least that's what I was told many a year ago.
 
Gaz J said:
Both the 100-400 MkI and II have around a stop of light fall off at 400mm wide open.
Click to expand...

Yes. Optical vignetting is a natural and unavoidable aberration suffered by all lenses, even the most expensive. It goes away at higher f/numbers. It is also substantially reduced on smaller formats, eg switching from a 7D to a 5D4, and it disappears with 'peripheral illumination' correction enabled in the menus.

There are other flavours of vignetting, eg mechanical vignetting caused by an incorrect lens hood, or by stacking filters etc. And some sensors can suffer from it too, particularly in mirrorless cameras with wide-angle lenses where the image towards the edges strikes the surface at a narrow angle. Sensor design and things like off-set microlenses reduce this.
 
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