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Author Topic: Best buy camera and lens?  (Read 9546 times)

bmc130

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Best buy camera and lens?
« on: August 12, 2014, 01:44:06 PM »
This question has probably been up here way to many times. Did some search but didnt find exactly what I was looking for. Also I dont have best knowledge of cameras and lenses so I need some help:)

At my company we are using Canon 5D Mark III cameras with these lenses:

Canon EF 24-70mm f/2.8L II USM Lens
Canon EF 70-200mm f/4L IS USM Lens
Canon EF 50mm

Now we are planing to buy a camera for an outsourced guy and the company don't have the money or wanna spend to much money on camera and lens.

We are looking into buying a Canon D70 together with a cheaper zoom lens.

Any one here using this camera for photoscanning?

How important is the lens quality for using it for photoscanning, really? is it worth spending lots of money on what it really gives you?

Other ideas of setup? most for the money?

Lambo

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Re: Best buy camera and lens?
« Reply #1 on: August 13, 2014, 12:04:12 AM »
I can not answer all the question right now but from the choices you put up there of lenses you have, the Canon EF 50mm is the best.
They recommend not using zoom lenses and 50mm seems to be the best focal length.
The quality of the lenses of course matters, but it is also important to know what are you using it for. If you are like me, doing the scanning for 3d printing figurines, then you don't need the high quality lenses (even though it would be great to have them) since the bundle lenses capture enough detail for what I am doing.
Now if you are doing stuff like some of the other guys like ten24 or Lee in Infinite Realities where you need the highest quality possible and the most detail out of your scans, then the lens is very important.
Leo

meshmixup

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Re: Best buy camera and lens?
« Reply #2 on: August 13, 2014, 10:49:58 AM »
Hi Lambo,

Have you tried 40mm pancake lens? I read previous posts but didn't get any conclusion. How is it comparing with the kit lens and ef 50mm prime lens? in terms of cost and quality.  ;D

Jim

Lambo

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Re: Best buy camera and lens?
« Reply #3 on: August 13, 2014, 09:51:04 PM »
Unfortunately I have not tried it.
For what I have read (and someone correct me if I am wrong), the pancake 40mm is better than the bundle ones for sure but not completely up there with the 50mm on cropped  frame cameras (seems to be much better suited on full frame cameras)
Also the pancake 40mm is more expensive than the 50mm. So I would still stick to the 50mm.
Leo

meshmixup

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Re: Best buy camera and lens?
« Reply #4 on: August 15, 2014, 06:22:43 AM »
I personally would prefer 35mm prime w/ APSC considering the trade off between the shooting area and number of cameras. I have not tried the 40mm at the moment, I hope it is a cheaper options  (cheaper than 35mm  ;D) and same performance in PS
« Last Edit: August 15, 2014, 06:30:42 AM by meshmixup »

David Cockey

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Re: Best buy camera and lens?
« Reply #5 on: August 15, 2014, 07:08:17 PM »
I have used the Canon 40mm extensively on a Canon T1i/500D (APSC sensor size) with excellent results in PhotoScan but I have not done any rigorous A-B testing comparing it to other lenses.

bmc130, the original poster, mentioned possibly using a Canon D70. I assume he means a Canon 70D which has an APCS size sensor. The 5D MarkIII he has been using has a "full" size sensor.

nadar

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Re: Best buy camera and lens?
« Reply #6 on: August 17, 2014, 08:03:02 PM »
The lens is the most important part of the equation. Especially if you want to use very high resolution camera. The most important feature to look for is image sharpness and its homogenity (some lens are very sharp in the center, but blurred in the corners).

A rule of thumb I used for many years: put 50% of your budget in the camera body and 50% in the lens.
Nowadays, in the digital area, I would even spend more on the lens, because these don't depreciate as fast as the bodies.

Never buy a lens without a try. Don't base your choice on somebody's experience or on a published test. Lens quality is very inconstant, and one sample of one model may be very good while a second sample will be very poor.
I always try before buying by taking a few photos of a newspaper page fixed on a wall and some photos of a brick wall (or any regulary textured object). Zoom 200 % and compare the sharpness of the center and the sharpness in each corner. If you find important differences, don't buy it.
« Last Edit: August 17, 2014, 09:18:31 PM by nadar »

Magnus

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Re: Best buy camera and lens?
« Reply #7 on: August 17, 2014, 10:31:48 PM »
Hello!

I think what should also be taken into consideration is what workflow you will be using and what objects/subjects you will be photographing.
For example if you are intending to process at Ultra High, if you choose JPEG or raw workflow, what F stops you will be working at.
For generating the mesh I do not think the lens should matter that much unless you process at Ultra High (if I recall correctly High is processing the images at 50% scale).

We have had great results with just the standard 18-55mm kit lenses (head scans, over f11, raw, processing at High, textures 4-8k+) I think it is a good idea to try them first and they come basically for free.

We have actually used the 1100Ds a lot and even with them you can get great results though my favorite is the 100D.

Also, if you are in the US there are places like lensrental where you can rent gear to try out.

For general photography I cannot agree more with nadar though, the glass is IMO the most important thing (we have lots of L glass and they are lovely, hehe)

Best, Magnus.


David Cockey

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Re: Best buy camera and lens?
« Reply #8 on: August 19, 2014, 07:04:01 PM »
Keep in mind that unless the subject is relatively flat the lens aperture will usually be set to f5.6 or small (larger number) to increase depth of field. Differences in image quality between lenses are usually much less at smaller apertures. Also lenses with smaller maximum aperture generally cost significantly less then lenses with large maximum apertures, and the smaller maximum aperture lens may be sharper.

nadar

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Re: Best buy camera and lens?
« Reply #9 on: August 19, 2014, 11:28:08 PM »
each lens has a optimal aperture value. Maximum sharpness is obtained for this value. Larger aperture (=smaller f values) are softer, and smaller aperture (higher f values) are affected by diffraction problems.
Photozone has a comprehensive set of tests of image sharpness at various aperture value
http://www.photozone.de/Reviews
just go to the MTF results diagram and read the aperture corresponding to the maximum number of line widths/picture heigth. This cvalue is the optimal aperture setting.
You will realize that the optimal aperture of a bright lens (= one with a wide max aperture) corresponds to a wider aperture than a lens with a narrower max aperture. In other words, the optimal aperture of a bright lens will be lower  than the optimal aperture of a darker lens .

exemple:  lens A: max aperture f=1.8, optimal aperture = f:5.6
                 lens B: max aperure f:4.5, optimal aperture = f:8

Between f:8 and f:5.6, the amount of light is 3 times lower. This means with the darker lens, you will have to lower the speed by a factor 3, or triple the ISO setting, and these parameters contriburte to lower the image quality.

So yes, large max aperture lens are more expensive, but in actual situations, the benefit on image quality is usually worth the price....



David Cockey

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Re: Best buy camera and lens?
« Reply #10 on: August 20, 2014, 06:29:39 AM »
Perhaps the considerations for aperture selection are different for aerial photography than for the close range photography of three dimension objects which I have experience with.

Selecting the aperture based on maximum sharpness as determined by a lens tests ignores depth of field. Lens tests only report the lens sharpness for a flat subject with the cameral perpendicular to the subject.

Depth of field can be ignored ff the subject is almost flat and all photos will be taken perpendicular to the subject or if the photos are taken at a sufficiently large distance. Otherwise depth of field matters, such as for close range photos of three dimensional objects.

Optimizing sharpness over a three dimensional object at close range may require using an aperture smaller than the optimal aperture from a lens test in order to increase depth of field and improve sharpness away from the focal plane.

Shutter speed may or may not affect sharpness depending on the light conditions, if the camera is moving or static, and camera support or stabilization used. If a sturdy tripod is used then shutter speed is generally not an issue if the subject is static. If the photographs are taken outside during the day then typically the shutter speed will be sufficiently fast for hand held photographs of static objects, assuming the person holding the camera is on solid ground.

The amount of light on sensor at f:8 is one-half the amount of light at f:5.6 (not "3 times lower") which would result in a shutter speed twice as long, or an ISO setting two times larger.

Large maximum aperture lenses are more expensive. Whether they will result in higher image quality for photos taken for PhotoScan will depend on the circumstances.

 

nadar

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Re: Best buy camera and lens?
« Reply #11 on: August 21, 2014, 12:28:43 AM »
Fully agree. I'm always shooting at infinite distance (the focus ring is locked with tape on all my lenses...), and depth of field is never an issue.
I can imagine you have other constraints shooting close range...