Why is that little mark still there? Just wondering, but in the digital photography age, why do camera makers still put the little film plane symbol on the top of digital cameras? I...

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Why is that little mark still there?

Feb 8, 2022 17:54:13 #

flyfisher

Just wondering, but in the digital photography age, why do camera makers still put the little film plane symbol on the top of digital cameras? I understood that it was necessary for exact macro measurement in the film era (or so I thought), but why would manufacturers still add it to the digital camera? (sorry the photo isn't clearer. handholding!)

Feb 8, 2022 17:56:52 #

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

Same reason. Distance from subject to sensor plane for macro.

Feb 8, 2022 17:58:53 #

flyfisher

Thought that might be it. Wonder if it's ever really used? Thanks for the reply!

Feb 9, 2022 06:02:25 #

Colosij

Never saw it before. Thank you for bringing it up.

Feb 9, 2022 06:20:49 #

JimmyTB

Some of the members here do high magnification images. Like Sippyjug104 who often has a stack of lenses attached to a bellows with a microscope objective at the end. With certain setups he says the end lens needs to be a specific distance from the sensor or film plane. Now I know how he measures that distance. Thanks for bringing up the topic.

Feb 9, 2022 06:52:30 #

billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont

flyfisher wrote:

That is where your sensor is located.

Feb 9, 2022 08:17:43 #

alberio Loc: Casa Grande AZ

Need to get precise distance to mount camera to telescope.

Feb 9, 2022 10:25:21 #

jackm1943 Loc: Omaha, Nebraska

flyfisher wrote:

Thought that might be it. Wonder if it's ever really used? Thanks for the reply!

I use it on mine almost daily to check that my macro objective is exactly 160mm from the sensor.

Feb 9, 2022 10:28:39 #

sippyjug104 Loc: Missouri

The majority of my sessions are Frankenstein configurations where I take a bit of this and a bit of that with no regard to specific brands.

I can measure the focal length of a lens or objective that I want to use so I will know how far it needs to be extended from the sensor plane of the camera.

I also measure the resulting magnification when they are extended by reading the number of millimeters that I see in the viewfinder of the camera.

For a lens or an objective that has a known or labeled focal length, I use the following formula to determine how far from the camera sensor plane it is to be extended on my bellows, extension tubes, or helicoid.

Amount of extension required measured in millimeters = Focal Lenght of the lens * (Magnification +1)

So....knowing where the sensor plane is located inside the camera is quite important to me and having its location marked makes it visually easier to identify for measurement.

Feb 9, 2022 11:06:13 #

amfoto1 Loc: San Jose, Calif. USA

Gene51 wrote:

Same reason. Distance from subject to sensor plane for macro.

Bingo!

It's still there because it's still relevant.

Yes, it's still used at times too. In fact the "minimum focus distance" of every lens is measured from this point. This may be most important with macro and close-up lenses, because the lens itself and part of the camera occupy some of that distance and leave considerably less distance between the front of the lens and the subject. That "working room" between lens and subject can be quite small... inches or centimeters or even mere millimeters in some cases... depending upon the lens focal length and the degree of magnification being used.

Feb 9, 2022 11:20:43 #

BebuLamar

Now that most people don't need to know the focal plane but the need to know it never changes.

Feb 9, 2022 11:36:43 #

flyfisher

Well, thank you all for your informative replies. I learn something every time I visit the site. So much knowledge that is always so freely shared. Beautiful!
JB (flyfisher)

Feb 9, 2022 15:23:31 #