Focus Issue

Tom Potter

Hey Guys,

Doing some food photography and having a focusing issue. I shoot with a Nikon D810, and have been taking food shots with both the Nikon 50mm 1/4G and the Nikon 105mm 2.8G (1:1 Macro). I am shooting on a tripod. The 50mm does not have VR, but the 105mm does. So, I turn off VR for the 105mm while it is on the tripod. I have shot in both Auto and Manual focus. I shot with both Aperture f/8 and f/11. A few of the shots come out very sharp. However, the vast majority seem out of focus and have a considerable amount of noise. I have had my ISO set between 64 and 200. I feel I have tried everything, but am at a total loss as to why my food shots are not coming out incredibly sharp. Appreciate your feedback. Tom

pathfinder

You have used both Auto and Manual focus, you say, and both lead to out of focus images, sometimes.

Have you used Live View with a magnified view?

Are you shooting with a cable release on your tripod, too?

Do these lenses AF correctly on other camera bodies?

Is the food you're shooting on a stable non- mobile platform too?

Tom Potter

I have been viewing subject via both view finder and Live View. Although, I have not thought to magnify view while in Live View. Yes, I use a remote shutter release (as opposed to a cable release, actually). Since I do not own another camera body, I do not know if they will AF or, manually focus correctly, for that matter, on another camera body.

pathfinder

I think I would try Manual Focus with magnified Live View and see how that works. If those images are out of focus I would wonder about lens issues. Magnified Live View SHOULD be quite precise as a focus technique.

Tripod with remote release, sounds like you're doing your part. What shutter speeds are you using? Any thought about mirror lock up if you're using shutter speeds near 1/8 or 1/15th ?

Tom Potter

pathfinder wrote: »

I think I would try Manual Focus with magnified Live View and see how that works. If those images are out of focus I would wonder about lens issues. Magnified Live View SHOULD be quite precise as a focus technique.

Tripod with remote release, sounds like you're doing your part. What shutter speeds are you using? Any thought about mirror lock up if you're using shutter speeds near 1/8 or 1/15th ?

I will definitely try magnified Live View. Both lenses have been fantastic otherwise - issues just now when trying to use for this close-up stuff. The shutter speeds are dictated by the Aperture I set. As I stated previously (or not) I am using Aperture f/ 8 and f/11.....WAY sufficient, as far as I understand it, for this type, and even most types of photography....I really appreciate you trying to help me out with this :O)

Tom Potter

Follow-up......as I am thinking about this.....and, as a reminder, it is not just that the focus is off, but, I am also getting considerable noise - and, again, I've had my ISO bewtween 64 and 200. So, I am just truly baffled at this point.

kdog

Depending on how close you're shooting the food, you may well have a simple depth of field problem. If for example your food is only one-foot away from your camera, your depth of field at those apertures is paper thin, about 1/10th of an inch. So most of your photo will be blurry anyway. Try backing up a bit which will increase your DOF and then cropping in post. See if that increases your keeper rate.

Tom Potter

kdog wrote: »

Depending on how close you're shooting the food, you may well have a simple depth of field problem. If for example your food is only one-foot away from your camera, your depth of field at those apertures is paper thin, about 1/10th of an inch. So most of your photo will be blurry anyway. Try backing up a bit which will increase your DOF and then cropping in post. See if that increases your keeper rate.

Hey Kdog.....Understood....I have tried to shoot further than each lenses "Minimum Focusing Distance" spec......That is, of course, what u r referring to, correct....Regardless, I will implement your suggestion too....move my tripod (lens) a bit further back, and check those results. I will let you guys (gals??) know the results....really appreciate your help with this! :O)

kdog

Tom Potter wrote: »

Hey Kdog.....Understood....I have tried to shoot further than each lenses "Minimum Focusing Distance" spec......That is, of course, what u r referring to, correct..

That too! If you're under that then everything will be out of focus. But even if you're within the MFD, you still have a paper thin DOF to deal with at close distances. Food photography can be really tricky for that reason. Try the same set up shooting a dollar bill taped to the wall. I bet that works perfectly every time.

ziggy53

Food photography is one of the most challenging facets of a type of photography, Product Photography.

I suggest that you hone your skills first on still life product photography. Choose simple subject matter, matte finishes (not polished chrome or any reflective finish) and diffused lighting. (Glints and spectral highlights can throw off your exposure.) A gray/grey card in the scene helps to find proper exposure. Include a photographic white and photographic black in the scene to help with exposure.

(In a pinch, you can make a photographic white target using strips of white teflon tape, also known as PTFE tape or white plumber's tape. Just tape the strips onto a white card stock until the strips cover the card. Around 3 layers of strips are necessary to provide proper reflectivity and to prevent bleed-through of the underlying card stock.)

Use only manual exposure, but do check the histograms to make sure that you aren't blowing out the scene. When you said, "I am also getting considerable noise - and, again, I've had my ISO between 64 and 200" that leads me to believe that you are under exposed and increasing/pushing the exposure in post-processing.

Also bracket your manual exposure, and process immediately so you get a feel for what exposures work with your lighting. Again, you should not need to do any exposure lifting in post if you have the correct exposure for the lighting conditions. If anything, and if the scene lacks dynamic range, it's OK to "Shoot to the Right" of the histogram, as long as highlights are not clipped.

For the Nikon D810 I strongly recommend using Mirror Lock Up (MLU) and a 5 second settle time before exposure. The D810 also has Electronic Front-Curtain Shutter and Nikon suggests using that to further reduce shutter vibrations. (The large mirror and large shutter assembly of the D810, as well as most other FF/FX bodies, typically creates considerable vibration that needs a bit of time to dissipate.)

http://nps.nikonimaging.com/technical_solutions/d810_tips/the_electronic_front/

Room temperatures need to be somewhat cool, as the Nikon D810 does not have a massive heat sink and protracted use of live view can lead to some additional internal heat, which can show up as noise in the final processed image.

In post processing avoid any actions or sharpening that uses LAB color space, as that can increase apparent noise. Also, don't use any additional contrast over factory default and don't use Clarity as that can also increase apparent noise in the middle tones.

What I'm suggesting is that you gain control over lighting and exposure first, and then gain control in post-processing. Then test for camera vibrations. When these things are in control then we can deal with DOF and focus issues.

---

To recap, ...

1) Diffused lighting and a scene with no spectral reflections or shiny surfaces.

2) Set your camera to full manual exposure and lower ISOs, specifically ISO 64 or 100. Bracket the exposure and use a gray/grey card, and photographic white and black, in the scene to help gauge proper exposure. Shoot to RAW/NEF files.

3) Process the exposure bracket set immediately to help determine proper exposure. Use software defaults on everything to determine proper exposure. (Letting the software choose AWB is OK.) Avoid exposures which either clip (whites too far to the right, according to the software histogram) or crush (dark tones and blacks too far to the left of the software histogram). Choose the exposure which does not clip the whites, but which has the whites to the right of the software histogram.

3a) At this point check for noise levels and let us know if you still see a problem.

4) Now that you have proper exposure, proceed to test for vibrations which can lead to camera shake. Take shots (at your chosen exposure) both with and without MLU and Electronic Front-Curtain Shutter. Yes, I recommend always leaving lens VR off when the camera is on a tripod.

4a) Please do let us know if you see any difference between the vibration test images.

Tom Potter

ziggy53 wrote: »

Food photography is one of the most challenging facets of a type of photography, Product Photography.

I suggest that you hone your skills first on still life product photography. Choose simple subject matter, matte finishes (not polished chrome or any reflective finish) and diffused lighting. (Glints and spectral highlights can throw off your exposure.) A gray/grey card in the scene helps to find proper exposure. Include a photographic white and photographic black in the scene to help with exposure.

(In a pinch, you can make a photographic white target using strips of white teflon tape, also known as PTFE tape or white plumber's tape. Just tape the strips onto a white card stock until the strips cover the card. Around 3 layers of strips are necessary to provide proper reflectivity and to prevent bleed-through of the underlying card stock.)

Use only manual exposure, but do check the histograms to make sure that you aren't blowing out the scene. When you said, "I am also getting considerable noise - and, again, I've had my ISO between 64 and 200" that leads me to believe that you are under exposed and increasing/pushing the exposure in post-processing.

Also bracket your manual exposure, and process immediately so you get a feel for what exposures work with your lighting. Again, you should not need to do any exposure lifting in post if you have the correct exposure for the lighting conditions. If anything, and if the scene lacks dynamic range, it's OK to "Shoot to the Right" of the histogram, as long as highlights are not clipped.

For the Nikon D810 I strongly recommend using Mirror Lock Up (MLU) and a 5 second settle time before exposure. The D810 also has Electronic Front-Curtain Shutter and Nikon suggests using that to further reduce shutter vibrations. (The large mirror and large shutter assembly of the D810, as well as most other FF/FX bodies, typically creates considerable vibration that needs a bit of time to dissipate.)

http://nps.nikonimaging.com/technical_solutions/d810_tips/the_electronic_front/

Room temperatures need to be somewhat cool, as the Nikon D810 does not have a massive heat sink and protracted use of live view can lead to some additional internal heat, which can show up as noise in the final processed image.

In post processing avoid any actions or sharpening that uses LAB color space, as that can increase apparent noise. Also, don't use any additional contrast over factory default and don't use Clarity as that can also increase apparent noise in the middle tones.

What I'm suggesting is that you gain control over lighting and exposure first, and then gain control in post-processing. Then test for camera vibrations. When these things are in control then we can deal with DOF and focus issues.

---

To recap, ...

1) Diffused lighting and a scene with no spectral reflections or shiny surfaces.

2) Set your camera to full manual exposure and lower ISOs, specifically ISO 64 or 100. Bracket the exposure and use a gray/grey card, and photographic white and black, in the scene to help gauge proper exposure. Shoot to RAW/NEF files.

3) Process the exposure bracket set immediately to help determine proper exposure. Use software defaults on everything to determine proper exposure. (Letting the software choose AWB is OK.) Avoid exposures which either clip (whites too far to the right, according to the software histogram) or crush (dark tones and blacks too far to the left of the software histogram). Choose the exposure which does not clip the whites, but which has the whites to the right of the software histogram.

3a) At this point check for noise levels and let us know if you still see a problem.

4) Now that you have proper exposure, proceed to test for vibrations which can lead to camera shake. Take shots (at your chosen exposure) both with and without MLU and Electronic Front-Curtain Shutter. Yes, I recommend always leaving lens VR off when the camera is on a tripod.

4a) Please do let us know if you see any difference between the vibration test images.

Ziggy,

Thanks SO much for all the great info and going into such great detail! I will try out all your suggestions.......Tom

Tom Potter

Tom Potter wrote: »

Ziggy,

Thanks SO much for all the great info and going into such great detail! I will try out all your suggestions.......Tom

Ziggy.....follow-up....

"A gray/grey card in the scene helps to find proper exposure. Include a photographic white and photographic black in the scene to help with exposure." I get the gray card part, but, I do not know what you mean by " Include a photographic white and photographic black in the scene to help with exposure."

Use only manual exposure, but do check the histograms to make sure that you aren't blowing out the scene. When you said, "I am also getting considerable noise - and, again, I've had my ISO between 64 and 200" that leads me to believe that you are under exposed and increasing/pushing the exposure in post-processing. Do I understand you correctly that you are recommending I bump up the ISO, to something like 400-800, for instance?(In your "Recap", you state I should use 64 - 100)

For the Nikon D810 I strongly recommend using Mirror Lock Up (MLU) and a 5 second settle time before exposure. The D810 also has Electronic Front-Curtain Shutter and Nikon suggests using that to further reduce shutter vibrations. (The large mirror and large shutter assembly of the D810, as well as most other FF/FX bodies, typically creates considerable vibration that needs a bit of time to dissipate.) I did have Electronic Front-Curtain Shutter set up. However, I totally forgot about Mirror Lock-up - duh!!

Thanks,

Tom

ziggy53

Tom Potter wrote: »

Ziggy.....follow-up....

"A gray/grey card in the scene helps to find proper exposure. Include a photographic white and photographic black in the scene to help with exposure." I get the gray card part, but, I do not know what you mean by " Include a photographic white and photographic black in the scene to help with exposure." ...

A photographic white means a pure neutral white without brighteners and flat/matte finish. A "GretagMacbeth (X-Rite) ColorChecker" includes both a photographic white and photographic black. As I said previously, a white card stock (index card) wrapped with three layers of white plumber's tape will suffice (pretty darned good). In a true pinch, if you're looking for dirt cheap and easy, 2 white styrofoam cups stacked together also works reasonably well.

I like to use either a color chip chart, i.e. the ColorChecker type chart, or other chart designed for photography. A Kodak Gray Scale card works pretty well.

Ideally, lamp black is awesome for camera black, just awfully messy. (Not recommended) Some black foam has neutral black qualities for some photographic work. (Radio Shack used to sell an anti-static foam for record players, way back when, and it was very nice for a camera black. It happened to have a high level of carbon black as part of its composition, and that lent to the purity of black.) I gather some of the prefilters for HEPA air cleaners might work, but haven't seen them myself.

We need the white, gray and black components to help determine optimal exposure and processing for your lighting conditions.

Tom Potter wrote: »

... Use only manual exposure, but do check the histograms to make sure that you aren't blowing out the scene. When you said, "I am also getting considerable noise - and, again, I've had my ISO between 64 and 200" that leads me to believe that you are under exposed and increasing/pushing the exposure in post-processing. Do I understand you correctly that you are recommending I bump up the ISO, to something like 400-800, for instance?(In your "Recap", you state I should use 64 - 100) ...

Yes, use ISO 64 or 100. Use shutter speed alone to control exposure at your desired f-stop (within reason), and bracket the exposure to determine the ideal exposure in post-production.

Tom Potter wrote: »

... For the Nikon D810 I strongly recommend using Mirror Lock Up (MLU) and a 5 second settle time before exposure. The D810 also has Electronic Front-Curtain Shutter and Nikon suggests using that to further reduce shutter vibrations. (The large mirror and large shutter assembly of the D810, as well as most other FF/FX bodies, typically creates considerable vibration that needs a bit of time to dissipate.) I did have Electronic Front-Curtain Shutter set up. However, I totally forgot about Mirror Lock-up - duh!!

Thanks,

Tom

Camera shake caused by mirror slap and shutter slap/shock can seem similar to the blur caused by out-of-focus and diffraction. We are trying to eliminate variables to determine the root cause of that you are seeing and trying to correct.

Tom Potter

Ziggy,

Thanks again! )

tOM