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A couple of weeks ago I photographed the dashboard of a customer's luxury car (Daimler DS 420), but I'm not really satisfied with the depth of field of the photo, especially where the array of switches and gauges left of the steering wheel is:

dashboard

Link to full-sized image: Daimler DS 420 dashboard

Parameters: f/8, 1/15", 28 mm, ISO 400. Canon EOS 70D + Canon EF 24–105 mm f/4 L IS

Illumination was quite good despite the fact that the car had a solid roof.

What's wrong here? Is there a method to make the field deeper without raising exposure time too much?

Neppomuk
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  • Not answering the question, but another option. I just applied the Topaz Sharpen AI filter to your linked image. Awesome filter, sharpened the guages on the left nicely. Doesn't create halos like some other sharpening filters. – Mattman944 Sep 13 '22 at 01:40

4 Answers4

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You don't necessarily need to make the field deeper, you just need to tilt the field with respect to the camera's film/sensor. That's what the "tilt" function of a tilt-shift (Canon nomenclature) or perspective control (Nikon's term) lens is used to do.

enter image description here

In the case of your example, you'd swing the tilt mechanism sideways to the right until the entire dash is equally in focus.

Tilt-shift lenses mimic some, but not all, of the available movements once possible with large format 'View Cameras'.

Michael C
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    @spikey_richie Olympus' Keystone Compensation is a software algorithm that mimics the geometric perspective correction of a shift movement of a lens by remapping the geometric shape of the image (including warping some areas of the frame out of the resulting image). It in no way can mimic a tilt movement that changes the relationship between the field of focus and the camera's sensor/film plane. – Michael C Sep 12 '22 at 04:26
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    A US$1900 tool buying opportunity. – Dennis Williamson Sep 12 '22 at 15:38
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    A quibble, but those movements are still possible with large format view cameras. – cjs Sep 13 '22 at 07:57
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    @DennisWilliamson or a bellows :-) – Russell McMahon Sep 13 '22 at 12:25
  • @cjs Sure, if you can find a functional one that is available for sale. No commercial manufacturer is making new ones these days. – Michael C Sep 14 '22 at 09:30
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    @DennisWilliamson I've previously rented them as I can't justify $1900 for a weekends experimentation. – Peter M Sep 14 '22 at 16:07
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Exposure time is moot if the subject is stationery and using a tripod. f/11 @ 1/8" or f/16 @ 1/4" or best f/22 @ 1/2" will accomplish your goal.

Depth of field -- from the point focused upon --- zone of acceptable sharpness is 1/3 back towards the camera -- 2/3 away from the camera. Likely the red button on the dash near the steering column.

Alan Marcus
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    The risk when stopping down is that, although you are gaining sharpness from the smaller aperture, you are losing sharpness from diffraction. For any given camera/lens/scene combination, there's an aperture setting that maximizes your sharpness. – Mark Sep 11 '22 at 17:58
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    @Mark you make a good point, but I think the problems of diffraction are often overblown. Sometimes it's better to lose a tiny bit of sharpness everywhere than to lose a lot in the areas outside the DOF. – Mark Ransom Sep 12 '22 at 03:24
  • Unfortunately, a tripod was not an option for me, as I didn't shoot the dash on a pre-arranged session. – Neppomuk Sep 12 '22 at 19:15
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There is hyperfocal distance/setting (HFD)... with an APS camera the hyperfocal distance in ft at f/16 is ~ the focal length as a percentage of itself. E.g. you were using a 28mm lens. For simplicity sake I'll round it to 30mm; and 30% of 30 (3x3) is 9ft (the actual distance for the 70D is 8.55ft).

If you set the focus to the HFD the depth of field extends from 1/2 the HFD to infinity (4.5ft to infinity)... so if you were at least 4.5 ft from the steering wheel everything would be acceptably sharp. And if you focus short of the HFD you gain a little DOF near and loose a lot at the far end, but you didn't need far.

The other issue is that you wasted about 50% of the DOF... at short subject distances the DOF extends ~ 50% in front of, and behind, the point of focus. So focusing on the steering wheel wasted the ~ 50% that was closer to you.

But for critical sharpness, what you probably need to do is focus stack multiple images.

Steven Kersting
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    The problem in this case seems to be that acceptably sharp (defined by standard viewing conditions) is not acceptable to the OP. – Michael C Sep 11 '22 at 06:58
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There is a technique called Focus Stacking, where you take several pictures at different focal lengths and then digitally combine them into one image by taking the best-focused parts of each image.

https://en.wikipedia.org/wiki/Focus_stacking

Eilon
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  • It was mentioned in another answer above. – n0rd Sep 12 '22 at 22:43
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    @n0rd Yes, it was barely mentioned in another answer, but, effectively, as an afterthought, even though that answer said focus stacking should be used for "critical sharpness". Given that there are 3 other answers which each primarily focus on one methodology, it's reasonable to have a fourth separate answer which is primarily about this fourth method. – Makyen Sep 12 '22 at 23:42
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    Unless you're in a hurry this will give you the same result as a tilt-shift lens without the high price tag. – JonathanReez Sep 13 '22 at 02:46
  • In particular, I didn't see the specific term "Focus Stacking" anywhere, hence my distinct answer. And it's possibly a free solution because it works with nearly any camera, and you just need to be good enough with Microsoft Paint! – Eilon Sep 13 '22 at 15:44
  • OK, thank you. But: Focus stacking would probably NOT have worked in my particular case as I'd still have to use a tripod. Sorry! :( – Neppomuk Sep 13 '22 at 20:19
  • @n0rd, don't assume the other answer is necessarily "above" for all viewers. It was lower down for me. – Toby Speight Sep 14 '22 at 06:51