Canon LTM For Canonet QL17 GIII users! DOF scale!

Canon M39 M39 screw mount bodies/lenses

Spyderman

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Hi,

I just finished making a DOF scale for my Canonet. I would put it on my webpage, but don't have any at the moment time. So I'm placing it here.

Just save the attached image file, print on a sticker at exactly 600dpi (!), cover with transparent tape, cut and place on the lens barell - on the thin part between focusing ring and aperture ring. And you've got a DOF scale :cool:

Enjoy :D
 

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This is something extremely useful for a rangefinder. I'm sure some of you would appreciate it. I'm sure this would get an extreme amount of traffic. :D

Thanks Spyder
 
I'll be doing this later! Could you confirm the print size should be:
width 1.6 cm
height 0.7 cm

Also how did you calculate the depth of fields?
 
ben lloyd said:
I'll be doing this later! Could you confirm the print size should be:
width 1.6 cm
height 0.7 cm

Also how did you calculate the depth of fields?


There is some convienent website online that contabulates all the info from your lens (focal length, max. aperature, focus markings) and somehow wizards it all together to make a DOF table. I've forgotten where it is, however.
 
erikhaugsby said:
There is some convienent website online that contabulates all the info from your lens (focal length, max. aperature, focus markings) and somehow wizards it all together to make a DOF table. I've forgotten where it is, however.


The site is "DOFmaster" or something very close to it.
The guy made a lot of work to bring other people something that´s really wonderfull. It also includes a Windows aplication that works perfect.

Anyway, Thank you Spyderman.... this is really good!! (My Canonet will be happy!!)


Ernesto
 
There are no stupid questions. DOF stands for depth of field and means the extent of area being projected sharp (enough) on the film. At f1,7 that area is minimal and at f16 that area is much bigger.
Markings like these are put on many lenses to aid in scale focusing. The moving scale distance markings opposite both '16' lines of this scale show the minimum and maximum distance considered sharp.
Check any SLR lens, at least the older ones, have markings like these. Many RF lenses have them as well.
 
Amazing! This week end when walking around with my Canonet I thought "what a great little camera this is, if it only had a DOF scale it would be close to perfect"!
Thank You Spyderman!
 
Well, how I did that?
I put an empty sticker on the lens, marked positions for hyperfocal distance at f16(3.5m) f11(5m) f8(7m) f5.6(10m). Then took the sticker off and measured. Drew everything in PS.

Printed, cut, placed, works :D

BTW: some more in-depth info:
mark at f16 is 5mm from the centre, f11 is 3.5mm (5mm / 1.4), f8 is 2.5mm (3.5mm / 1.4), f5.6 is 1.7mm (2.5mm / 1.4).
funny, but it works. originally I measured it, but found the rule empirically :) I knew that the distance between the marks for f16 and f8 should be in ratio 2:1, the same for f11 and f5.6, f8 and f4 etc.

before I had the same thing but hand made... now that I did this digital version I thought it might be helpful also for the others at RFF.

before that I made a dof scale for my SLR lens Tokina 19-35. and before that I made a distance scale for Canon EF 50/1.8 :rolleyes:

PS: I also have a sticker with focal lengths on the retractable (read collapsible ;) ) lens of my Canon PowerShot G3. Just to be able to set particular focal length like 50, 85 or 100 :cool:

Could you confirm the print size should be:
width 1.6 cm
height 0.7 cm
Yes, right.
 
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I put mine in on the inner barrel of the lens - the portion that extends/retracts when you focus. There is a thin gap where you can tape the DOF scale to.

You align the centre of the DOF scale to the focus mark on the body.
 
I'm having a hard time figuring out how to print this thing out at the proper size. I'm using one of those old (4 years old) white Macbooks and only have the basic iPhoto that came with the computer and Preview. Will either of these allow me to adjust the image?

I know the last reply to this thread was two years ago, but hopefully somebody is around and can help me out with this. I feel like I'm just going to be wasting film in my Ql17 until I get this DOF chart on there.

Thanks so much!
 
This is a great addition to the Canonet QL17III, thanks for sharing!

I have attached a picture to show the placement of the DOF scale on my Canonet. I printed it on an avery label using photoshop at 600dpi as the author stated, cut it out and it matches the iDOF app hyperfocal distances very closely. It was relatively easy to apply to the groove in the lens barrel using a pair of tweezers, aligning the center with the focus mark on the camera body.
 

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