Camera Labs

I used ISO 100, 1/100, F1.8.

When I looked through the viewfinder on the 500D, the photograph was in focus, yet when I took it, I noticed afterwards that it was blurred.

What is going on here? Did I not sufficiently stablise the camera, is the viewfinder giving a false interpreutation, or what?

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Canon EOS 500D
Lenses: EFS 18-55mm IS, EF 50mm F/1.8 II

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You might find the article Live view versus the cheating DSLR viewfinder relevant.

Bob.

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OM-D E-M5 + ED 12-50mm, H-PS14042E, H-F007014E, L-RS014150E, M.ZUIKO DIGITAL 45mm 1:1.8.
Gitzo GT1541T, Arca-Swiss Z1 DP ball-head.
Astrophotography: TEC 140 'scope, FLI ML16803 camera, ASA DDM60 Pro mount.

I am beginning to wonder whether there is actually any purpose in the viewfinder being there.

Do Sony use a different system in their DSLRs?

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Canon EOS 500D
Lenses: EFS 18-55mm IS, EF 50mm F/1.8 II

50mm at f1.8 gives a very shallow depth of field if you're shooting anything reasonably close. Even slightly recomposing or the subject moving ever so slightly could be the culprit. Live view can help for critical focussing but I only ever use that with a tripod myself.

I usually frame in live view and expose with the viewfinder.

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Canon EOS 500D
Lenses: EFS 18-55mm IS, EF 50mm F/1.8 II

using the 50 at 1.8 makes it often very tricky to get everything in focus as the dof is so shallow.
Also, at least with my 50 it focuses in front of the subject when the subject is close, typically under a 1meter or so, after that its pretty good.
Also you may have moved slightly forwards or backwards, it will only take 1cm and you could be out.
The size of dof can be calculated if you google dof calculator.

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Canon Powershot S95, Canon 7D, 15-85, Canon 85 1.8 USM, Sigma 30 1.4, 50mm 1.8, Canon 100 2.8L IS Macro, Canon 70-300L IS USM+Kenko 1.4 Pro 300DGX, Canon 430EX II and RS 4 Classic

good Link Bob thanks, I enjoyed that read, cleared up a couple of things.

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Canon Powershot S95, Canon 7D, 15-85, Canon 85 1.8 USM, Sigma 30 1.4, 50mm 1.8, Canon 100 2.8L IS Macro, Canon 70-300L IS USM+Kenko 1.4 Pro 300DGX, Canon 430EX II and RS 4 Classic

1.8 is such a wide aperture, that it's pretty hard to tell what's in and out of focus using your DSLR's viewfinder. Modern DSLR viewfinders aren't really designed to focus anything larger than f/2, they're generally too small and dim. About a week ago when I was shooting at a banquet with my 50mm f/2 (Manual Focus Only) in very dim light, and I found it pretty much impossible to focus through the viewfinder. I needed the larger, brighter, easier to see screen where I could magnify the image to get a precise focus, and even that was difficult.

I personally use my display for Live View only where manual focusing is critical, otherwise I prefer the viewfinder. On occasions, I use live view for macro shots, especially when I'm at an awkward angle but overall I don't use it very often. The contrast based AF system is just too slow and I can't (of course) see the screen for my live in bright daylight.

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-Evan

Gear: 7 Nikon Nikkor AI-S and AF-S lenses, SB-700 flash, Nikon D7000, Nikon FM, variety of accessories

"There are no rules for good photographs, there are only good photographs."
- Ansel Adams

Regardless of the F setting, the viewfinder shows a false representation, and it only offers a 95% view anyway. Part of me is considering going back to point and shoots, at times.

Are full frame cameras all that better at focussing with the viewfinder and providing a decent representation?

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Canon EOS 500D
Lenses: EFS 18-55mm IS, EF 50mm F/1.8 II

Ah, this reminds me of all the cons of using old fashioned manual focus lenses, and getting bashed for using them!

Do you have a focus confirm dot in the viewfinder as with Nikon? Tried manually focussing? Is the issue when hand holding the camera or also when locked down on a tripod?

I'm unsure that the 95% viewfinder is an issue. There'll be something wildly wrong with your composition if it is

Hi Canon 500D,

I think you have to remember that the focussing screen on your camera is more about a brighter view than accurate manual focussing. If manual focussing is a priority the consider one of Canon's pro or semi-pro models which, with the exception of the 7D, have the option of interchangeable focussing screens.

For example, if I were looking for the best manual focussing option for my 5D2 whilst using fast lenses I'd buy a "Focusing Screen Eg-S Manual Precision Matte" which, from the Warehouse Express write-up, "is designed for manual focusing with high-speed lenses (f/2.8 or faster). The Eg-S screen has finer microlenses than the Ee-A or Eg-D along with a steeper parabola of focus to make the image pop in and out of focus more vividly in the viewfinder. However, the Eg-S focusing screen is not recommended for slower lenses because it's not very bright."

Interchangeable screens are cheap enough but that can't be said of the cameras that take them, I'm afraid.

Bob.

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OM-D E-M5 + ED 12-50mm, H-PS14042E, H-F007014E, L-RS014150E, M.ZUIKO DIGITAL 45mm 1:1.8.
Gitzo GT1541T, Arca-Swiss Z1 DP ball-head.
Astrophotography: TEC 140 'scope, FLI ML16803 camera, ASA DDM60 Pro mount.

You asked above if Sony uses a different system for their DSLRs. If you mean for the viewfinder itself...no - Sony's DSLRs use either a mirror or pentaprism, the same as other DSLRs. Sony do have models known as the SLTs - those use an electronic viewfinder feeding off the main sensor just like live view on your camera - but without any delay or having to switch back or flip mirrors, so these do operate quite differently.

If you are referring to live view systems, then yes - Sony uses a very different system than any other brand. Sony's live view on their DSLRs has multiple modes, one of which is 'quick AF' mode - in this mode, the camera switches to live view using a second sensor mounted up by the viewfinder and a slight deviation in the mirror angle to obtain a live view feed while maintaining the same normal phase-detect focus and shooting performance. In this mode, you can focus and shoot identically fast whether in live view or optical viewfinder, even up to 7 frames per second burst mode. They have a second live view mode working off the main sensor that works like the other brands, feeding off the main sensor and using contrast-detect focus (slower) and long pauses or delays for the shutter trigger waiting for mirrors to move or focus to confirm.

It is at least one way in which the Sony live view system is really the only one meant to be used for every-day casual shooting, or handheld shots, rather than tripod-mounted, fine-tuning type still subject shots. Be it in their SLT systems with electronic finders, or their DSLRs with second-sensor phase-detect AF modes, switchng between live view and viewfinder mode is a simple slide switch on top of the camera, with no performance degredation.

Using strictly the viewfinder, you should be able to obtain very accurate focus, as long as you don't move a hair from the time you achieve focus and trip the shutter. If you are using live view, there could be long delays which result in some minor movement, or discrepancies between the slow contrast-AF system if switching back to optical view before shooting...and depth of field cannot be accounted for unless you use DOF preview to confirm before shooting.

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Justin Miller
Sony DSLR-A580 / Sony 18-250mm / Minolta 50mm F1.7 / Sigma 30mm F1.4 / Tamron 10-24mm / Tamron 200-500mm / Tamron 90mm F2.8 macro / Minolta 300mm F4 APO
Sony NEX5N / 18-55mm F3.5-5.6 / 55-210mm F4-6.3 / Pentax K adapter / Konica K/AR adapter / bunches o' Konica & Pentax lenses!

Galleries:
http://www.pbase.com/zackiedawg

I am not talking about AF systems here, I am speaking specifically of the clearity of the viewfinders, and whether they offer a true representation of what the lens is seeing or not.

I am aware that the higher up the camera is, the better quality viewfinder you have with it. (eg 5D II over 500D) Does a prism viewfinder still have the mirror?

The Sony system sounds good.

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Canon EOS 500D
Lenses: EFS 18-55mm IS, EF 50mm F/1.8 II

OK - for pure viewfinders, no...Sony's system at least on DSLRs is identical to most. Mirrors are most common for entry and mid level bodies, and pentaprisms for higher end and full frame cameras. Pentaprisms do not have the mirror, have much larger viewfinders, are usually much brighter and optically clearer, and usually show 100% framing or close to it.

Sony's SLTs which use the electronic viewfinders tend to have larger viewable field than most APS-C DSLRs - quite similar to full-frame pentaprisms in optical size - however are an electronic view as opposed to pure optical view, so you are looking through the sensor just as with live view, only through the viewfinder instead of on the LCD screen. This has some advantges and some disadvantages - which you'd want to consider before getting one. The types of shooting you do may play a part as to whether you want or need an optical finder or an electronic finder.

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Justin Miller
Sony DSLR-A580 / Sony 18-250mm / Minolta 50mm F1.7 / Sigma 30mm F1.4 / Tamron 10-24mm / Tamron 200-500mm / Tamron 90mm F2.8 macro / Minolta 300mm F4 APO
Sony NEX5N / 18-55mm F3.5-5.6 / 55-210mm F4-6.3 / Pentax K adapter / Konica K/AR adapter / bunches o' Konica & Pentax lenses!

Galleries:
http://www.pbase.com/zackiedawg