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Blurry photo again


jiwooseok

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The type of lighting is relevant too. The original was taken with (assumed) a mains powered light "a regular light for a test on a tripod"

 

And I think we've established that the very shallow DoF (about 4mm) and the high ISO combine in a result which the OP is terming "blurry", plus, it is likely that the OP did not nail focus on exactly the part of the eye intended. Also micro focus lens adjustments might be necessary

 

As rodeo joe points out, when using mains powered lights the flicker rate needs to be considered.

 

If the OP wants to make Portraits like the example, then using Flash as the main lighting source would be a good option; using a smaller aperture than F1/4 would be a useful approach; and a lower ISO would reduce the noise. Flash lighting also would arguably eliminate Subject Motion Blur, and, with a quick reaction time on the shutter, assist in nailing the shot "as focused".

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WW

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On a technical point of Shutter Speed only, disregarding all other considerations.

 

For mostly all of my Portraiture for the last 20 years, I have used only Available Light. For tight shots, for example Half Shot to a Tight Head Shot, I would always be pulling 1/125s or faster, preferably 1/250s, for an healthy and composed adult, standing. Any slower shutter speed was/is too dangerous in respect of capturing Subject Motion Blur in the face region.

 

WW

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If the OP wants to make Portraits like the example, then using Flash as the main lighting source would be a good option

Do we really need to complicate things (at this stage) by introducing speedlights and avoiding the awful lighting got from on-camera flash?

 

1/125th @ f/4 and 100 ~ 200 ISO should be easily doable with the sitter next to a window in reasonable daylight. And side window light can be very beautiful and flattering.

 

It's overcast and dull today here, and I'm still getting 1/125th @ f/2 for 100 ISO at 1 metre from a south-facing window.

Edited by rodeo_joe|1
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On aperture, I tend to aim for a depth of field of at least 20-30cm when shooting portraits, that will give an aperture of f4 or f5.6 with most common portrait lenses.

 

Obviously, if light levels are low, I'll open up and accept a softer result (I do like my fast lenses), but if you want nose to ears to be sharp and still defocus the background, f4 is a good starting point.

 

The 'classic' rangefinder portrait lens was a 105/3.5 or a 135/4, SLRs started to get faster as a brighter image made for easier focussing, monster lenses like your Sigma are a relatively recent thing. I find the depth of field on my 135/2.8 Pentacon to be thin enough that the slightest movement changes my point of focus.

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Whilst of some interest agreed; the spend is not the main point.

 

Agreed, and I apologize if my post seemed gratuitously critical. My point was that many newbies are misled into thinking that it's gear, rather than study and practice, that makes for a good photo, and they waste a lot of money and are very disappointed when the find out that this isn't true.

 

I urge newbies not to spend a great deal because they won't know for a while which purchases might really help them and which will be simply a waste of money. For example, I realized at some point that the Canon f/4 70-200 would be BETTER for me than the f/2.8 that everyone raved about. I lug stuff on my old back, and I needed the lower weight (half) more than the extra stop. Saved me literally half the purchase price as well as the unneeded extra weight.

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Do we really need to complicate things (at this stage) by introducing speedlights and avoiding the awful lighting got from on-camera flash? 1/125th @ f/4 and 100 ~ 200 ISO should be easily doable with the sitter next to a window in reasonable daylight. And side window light can be very beautiful and flattering. It's overcast and dull today here, and I'm still getting 1/125th @ f/2 for 100 ISO at 1 metre from a south-facing window.

 

I think that the example/suggestion was not complicating anything at all.

 

The OP clearly states the example shot was "a test" for him/her being able to get non blurry photos. Clearly it has been explained to the OP that the image was not "blurry" in the sense that it was explained a sharp focus was, indeed, attained.

 

Additionally, the commentaries have touched on and explained various matters, including but not limited to: Aperture relationship to DoF; Shutter Speed related to Subject Movement Blur; Mains Power Cycle Rates/Shutter Speeds related to Exposure (and Colour) differences; Micro Lens Adjustments; Live View Focusing. . . mentioning the use of Flash is no more complex nor simple than these points already mentioned

 

Moreover the OP has the option to ask further questions should s/he not understand fully any general suggestion made in these commentaries.

 

Au contraire to the position of limiting discussion of aspects which have a relevance to the Opening Post, (in this case arresting Subject Movement Blur in Portraiture), I think it is good to open the conversation, by introducing general aspects whereupon the OP can then choose to question and investigate, should they want to pursue any particular line of development and learning. In fact it could be seen as judgemental to assume that any OP is incapable of so doing.

 

WW

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by introducing general aspects whereupon the OP can then choose to question and investigate, should they want to pursue any particular line of development and learning. In fact it could be seen as judgemental to assume that any OP is incapable of so doing.

Those are high ideals William, but unfortunately we're not running a 3 year, hands-on photo course. Just responding to questions.

 

I don't think anyone's making patronising assumptions about the OP's abilities. However, lighting is an entire subject in itself and do we really need to go off in that direction at this stage?

 

The D850 doesn't have a built-in popup flash that could be used for a quick test. So the OP would need to buy a speedlight, and possibly get sidetracked from mastering basic camera-craft into the field of portrait lighting.

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Those are high ideals William, but unfortunately we're not running a 3 year, hands-on photo course. Just responding to questions.

I don't think anyone's making patronising assumptions about the OP's abilities. However, lighting is an entire subject in itself and do we really need to go off in that direction at this stage?

The D850 doesn't have a built-in popup flash that could be used for a quick test. So the OP would need to buy a speedlight, and possibly get sidetracked from mastering basic camera-craft into the field of portrait lighting.

 

Yes, high ideals, agreed.

 

I think that no one was being patronising.

 

To be precise, I didn't think you were. I thought long and hard about that sentence before I published it and in so doing I considered your reaction to it: it was not meant directed to you.

 

I answered you question as it was asked asked: I think that bringing the subject of Flash into the conversation is not an issue and probably beneficial. I further think that it is not a good idea to limit the conversation.

 

You disagree with that view, and that's appropriate: your rationale has been clearly explained and certainly understood by myself.

 

I apologize if you considered the tag of my last comment to be a personal barb, it was not, it was a general comment: your contributions are IMO, considered, valuable and based on much experience.

 

WW

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Do we really need to complicate things (at this stage) by introducing speedlights and avoiding the awful lighting got from on-camera flash?

 

1/125th @ f/4 and 100 ~ 200 ISO should be easily doable with the sitter next to a window in reasonable daylight. And side window light can be very beautiful and flattering.

 

It's overcast and dull today here, and I'm still getting 1/125th @ f/2 for 100 ISO at 1 metre from a south-facing window.

I think Joe's window light is rather better than mine was yesterday! Raining here in France though...

 

Here is an example shot taken yesterday afternoon. Window light, 1/60th, F2.8, ISO 2000 on my Fuji XT2 with a 33mm f1.4 lens, which gives around the 30cm depth of field I mentioned in my post above. My house is too small to use a lens like your Sigma for a casual portrait, my 33mm is equivalent to a 50mm 'normal' lens on your Nikon.

 

This is a 100% crop from a 'typical' portrait, head, shoulders and upper chest. Autofocus point was manually selected to be the eye, I can't really tell if it actually focussed on the eye, the glasses or the eyelashes, but it doesn't really matter as the depth of field takes care of it (I suspect it was the glasses rim, AF likes sharp edges).

 

If I was trying to reproduce your shot from the first post, I would switch the camera to manual focus (and live view, on your camera) in order to position the point of focus exactly where I wanted it, but for the purpose of the shot I took, AF was fine.

 

At f2.8, the background is still nicely defocussed, not completely obliterated, but pleasantly softened. I should have moved the electric cable!

 

Detail is lost from shooting at a high ISO, as with your image, though not nearly to the extent seen in your shot. You might also want to look at the noise reduction settings on your camera, turn them down a couple of notches as noise reduction tends to obliterate fine detail.

 

Example 100% crop, from RAW, no post processing other than darktable's 'standard' base curve, 33mm @ f2.8, ISO 2000, noise reduction set to -3 (very weak).DSCF7446.jpg.f5ccad5d008d32eecd72ce8f2c28eae0.jpg

 

Original shot, with my wife's permission, straight camera jpeg, no post processing.DSCF7446_01.thumb.jpg.eed619d72dc842805311959f2df0bf9e.jpg

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On aperture, I tend to aim for a depth of field of at least 20-30cm when shooting portraits. . .

 

I concur.

 

Sometimes shallower DoF can be useful, but, 200mm to 300mm DoF is where I generally aim for, too. 200~300mm is about the 'thickness' of a person, and for a tight shot, such as the Tight Half Shot of your Wife, it works well.

 

WW

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I can see the clarity and details in the viewfinder but when I take the shot, 10 out of 10 come out blurry.

First, the viewfinder doesn't show the true depth of field for really wide apertures like f/1.4, and what you see in the viewfinder is less magnified than what you see on your monitor or even a modest sized print.

 

I would suggest getting yourself a Speedlight, aiming it at the ceiling to bounce the flash (which makes the lighting more natural and reduces harsh shadows), setting your ISO below 1000, and stopping your lens down to f/4 or more (to get more of your subject within the focus plane); and skip using a tripod in this scenario.

Edited by tonybeach_1961
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  • 2 weeks later...
As previously explained: Mains powered artificial light flickers at twice the mains AC frequency. Therefore any shutter speed shorter than that flicker frequency will give a variable exposure, due to only part of the cycle being captured.

 

 

(snip)

 

Tungsten lamps can barely cool that fast, so have only a small flicker.

 

Fluorescent lamps can change that fast.

Traditional magnetic ballasts are mostly a big inductor and the lamp runs at line frequency.

Newer electronic ballasts run at 20kHz or so, and limit current with a series capacitor.

I am not sure if the lamp can follow that or not, but it should be fast enough for most photography.

As noted, the flicker is double operating frequency, as they light on both half cycles.

 

LEDs require a current regulated power supply. That may or may not pass line frequency

(double as noted) through to the lamp. Some run the lamps half wave rectified, so at line

frequency and off half the time.

-- glen

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