Looking for a DSLR with razor sharp pic for an indoor close range use

[Eildosa]

Hi,

The main purpose of this camera would be to do photogrammetry (building 3d models from multiple pictures), mainly from human heads.

Lighting condition will be under control, cameras will be on tripods with a remote trigger and around 30-40Cm away from the subject.

What I need is a camera that can do sharp pictures with these restrictions:
Low ISO (noise = errors during reconstruction)
small aperture opening (thing out of focus cannot be reconstructed)
1/250 shutter speed (Fast enought for not getting movement bluryness from subjects during "emotion shots")
12Mpix minimum
subject head must fill a maximum area in the picture

I read everywhere that the canon 600D is delivering razor sharp images with beautifull colors.
But I also read similar things about the 1100D which is significantly cheaper.
I'm planning on using a stock 18-55mm Lens.

So would one of you have tried both of them and tell me which one would deliver sharper images?
Or could you think of a better one?

Thanks.

PS :
I read a review of the 1100D here
I find the examples pictures a little bit soft (maybe because I lost my glasses) : http://www.ephotozine.com/articles/c...s/IMG_0999.JPG

[Max von MeiselMaus]

I'm not a technical whizz, so wait for others to add more sophisticated suggestions, but to get the ball rolling, it is not the camera body that will make a difference in these shots, but the lens. Either of those bodies, with a good lens, should produce comparable shots. The only thing that might make a difference is how each responds to ISO noise, as this can vary between EOSs. However, if you are shooting at ISO100-200, that doesn't really factor.

You might need a macro lens, for working distances like that. I would suggest something from the Sigma EX range, as these are beautiful things and well-priced.

Sounds like an interesting project. I will now step back and let those who know more about it pitch in.

[Polar01]

I think you need to think about this in another way, the camera (s) is last thing you have to worry about. You need to find a lens that will focus down to between 12 and 15 inches with no distortion. Now do I assume that you know the difference between a full frame camera and a cropped sensor, if you do not than, short story down and dirty, field of view that you see with a full frame camera with a 50mm lens is basically the same as you would see with a 35mm lens on a cropped camera.
As for ISO noise no worry as you state that you are controlling the lighting. Choice of f/stop not that small as that will cause distortion if too great an besides you only need about 6 inches of DOF. Manual focus should be used, not auto as you want to control where the focus is.
With the right lens razor sharp images should not be a problem, if there is a problem it is you. Number one cause of out of focus images is not the equipment, but the operator.


Cheers: Allan

[Eildosa]

I think you need to think about this in another way, the camera (s) is last thing you have to worry about. You need to find a lens that will focus down to between 12 and 15 inches with no distortion. Now do I assume that you know the difference between a full frame camera and a cropped sensor, if you do not than, short story down and dirty, field of view that you see with a full frame camera with a 50mm lens is basically the same as you would see with a 35mm lens on a cropped camera.
As for ISO noise no worry as you state that you are controlling the lighting. Choice of f/stop not that small as that will cause distortion if too great an besides you only need about 6 inches of DOF. Manual focus should be used, not auto as you want to control where the focus is.
With the right lens razor sharp images should not be a problem, if there is a problem it is you. Number one cause of out of focus images is not the equipment, but the operator.


Cheers: Allan

Allright then, perspective distortion is not a problem, I did various test, it has no impact on the reconstruction process.
Lens distortion can be measured and taken in account during the reconstruction process, never did it but I'm guessing that it means that lens distortion has no impact too.

Unfortunatly Manual focus is impossible, there will be 21 cameras minimum and if each shot needs refocus.

I'm going for the Canon 1100D then, easy to find at 180€ on second hand's websites, never used a DSLR before tho.
For the moment I plan to buy one and make comparaison with my compact cameras.

Could someone get me some advice on a lens that would fit my needs?

[Donald]

Again, it all comes down to budget. How much do you have to spend? If you want the ultimate in clarity and have a big pocket, then pre-orders are being taken for the Canon 5DS R. But you referred to the 600D and 1100D in your post, so is that the range for which you have a budget at the moment?

[Eildosa]

Well, I'm going for 200€ max for the lens, however I'm only buying second hand product so I guess it's retail price could be around 400€.

Plus maybe I don't need razor sharp images, maybe sharp images produce the same reconstruction that razor sharp images.
I'd like to try several lens in order to make comparaison before making the whole thing (14-21 cameras 3d scanner)

If you could provide me with a list of lens that could fit my need, there is a photography group in my old school, maybe they have some of the lens and would be kind enouth to let me try them.

For now I only have a 4000€ budget for the whole setup.

I found >this< apparently cheap lenses can be as good as very expensive lenses

[ionian]

I have the 1100D - it's dated with regards to several features (LCD screen quality, ISO performance, mpx count) but is a fun camera to use. With regards to the body, the only thing you should know is that it doesn't have spot metering - is this an issue for you? You didn't mention exposure accuracy in your OP.

With regards to lens, just be aware that the kit lens with the 1100D is the 18-55mm II (the one with no image stabilisation). Whilst the IS is unlikely to be an issue as you will be using tripods, it is a jack of all trades and suffers from chromatic aberration. You definitely want to upgrade this for tack sharp images. If you can work with prime lenses, the 50mm f1.8 has great optics for the price, and of course works well at f-stops well above its wide open capabilities.

[Eildosa]

I didn't knew what spot metering was, if I understood correctly it allow the camera to choose a better exposure setting.
I won't use this because I need all camera to have the exact same iso speed, obturation speed and aperture opening.

I was just looking at prime lense, one question, I saw a 50mm and it said that 45Cm was the minimum focus distance, don't you get a very low depth of field at the minimum focus distance?

[Manfred M]

It seems to me that we've had this chat sometime in the past, but at that time you were looking at doing this type of work with an array of point & shoot cameras. Your lack of in-depth photographic knowledge is going to be a bit of a challange.

1. I believe your choice of doing to a low end DSLR makes sense. Canon or Nikon; no difference in image quality at all. Crop frame is doing to be about a stop more forgiving than a full-frame model for depth of field.

2. Sharpness is all about your lens choice, not so much the camera body. Going with the kit 18-55mm lens does not make sense. Setting an identical focal length for each lens is going to be impossible; and you will need that to ensure good registration from image to image. I would suggest going with a standard f/1.8 50mm lens (although this means you will have to further away than 30 - 40 cm). Getting too close with a wider angle lens introduces facial distortion and about 80mm full-frame equivalent (which is what a 50mm lens will give you on a Canon crop frame body) is as short a focal length as is generally recommended to get a relatively distortion free image for a headshot. Longer is even better, but that means a more expensive lens and more room required for the camera and as well as more cameras (I push closer to 200mm for head shots on full-frame). The 50mm lens is going to be the least expensive option; in the used market, it might even be less money than the kit lens. Both Canon and Nikon have put out a significant number of 50mm models, I would go for the same lens model on each of the cameras. I can't comment on the Canon lenses, but have read that the latest release is not as good as the earlier models, so that would be worth checking in to. Nikon is a bit trickier ans only the newest model has autofocus that will work on the lower end models like the D3100.

If your are planning to shoot jpeg, the camera will apply distortion correction algorithms; if you shoot RAW, the conversion software will do the same. You should be able to get very high quality images this way.

3. Aperture - anything smaller than around f/11 (or perhaps f/13) will bring diffraction softening issues into play. For the work you are planning to do f/11 should be the "sweet spot" for the lens / camera combination.

4. Prefocus - absolutely 100% requirement is that you manually focus each of the camera lenses to the right spot before the shoot. Once you have set everything up the first time, as long as you don't move the camera or the model, the shots will all be 100% bang on. With auto focus, you never know and issues like focus breathing could throw things out of alignment.

5. Shutter speed of 1/250 should be quite safe; but you will have to throw a lot of soft, even light at the subject give the small aperture you will be shooting at

6. ISO - low (base) ISO will give you the best colour depth and the lowest amount of noise. That being said, so long as the exposure is correct, noise is generally not an issue, even at higher ISO levels.

7. I'm wondering as to how you plan to light your subject. You will want soft, even and diffuse lighting all around. What are you planning to do here? This is going to be critical in getting your shots to work out for you.

[Inkanyezi]

I think you will have to give a bit more information about your project. My guess so far is that you mount a "globe" of cameras around the location where the subject's head should be. Then I wouldn't suggest any DSLR, as I don't know many DSLR cameras that are up to the task, and moreover, there are other cameras that are more suitable than DSLR. You wouldn't have much use, if any, for the main feature of the DSLR, the one that makes up the moniker.

A good contender for this task might be for example Samsung NX300, and I would suggest using fully manual lenses. Just about any fully manual lens can be fitted with an adapter, so it's only to make a choice and get a set of similar lenses for all the cameras, set them to correct focus and aperture and shoot away. The tricky part may be getting those lenses all the same, but you could use any brand, Pentax Takumar, Yashinon, Fujinon, Canon you name it. It's just a matter of getting adapters for the kind you find in sufficient numbers. You could even try finding old Edixa lenses, as the Xenar 50 mm which is one of the best lenses there are.

The main advantage of a mirrorless as the NX300 is that you can easily sync them to take the image at the same time, and you can do all settings from a tablet, even see the viewfinder image. Also other makes have such features, but I don't think you'll find it cheaper.

[rpcrowe]

I previously wrote a long and involved post and deleted it because I realized that am not sure what your needs are or even what your plans are. So I deleted that post.

Being metrically challenged, I at first did not realize how close to the subject 30 to 40 cm would be.

If you are intending to shoot with twenty one cameras at one time at any subject 30 to 40 cm away from the individual cameras, it seems that you would have difficulty finding room and a means to place these cameras as well as a means to secure the cameras. Additionally, after placing 21 cameras around a human head, it would be extremely difficult to light the head. Also I am wondering how you might trip these cameras at one time.

IMO - one of the greatest stumbling blocks for your project is the 30 - 40 cm distance at which you have elected to shoot.

I tried shooting a head at approximately a 30-40 cm distance using a 17 mm focal length on a crop frame camera using a 17-55mm f/2.8 IS lens and this is what I got. I could not imagine shooting with twenty one cameras from that short distance.



This was done using ISO 1600 which gave me an exposure of 1/30 at f/11. I went high in my ISO because I wanted to use f/11 and still wanted to hand hold my camera. Light was from a window on an overcast day. I thought that this might give you an indication of the DOF you might achieve at 17mm using f/11...

Here is f/5.6 using 24mm just to show the difference. You can see that her hair begins to fall out of focus...



Is there a reason that you need your camera so close to the subject? Allowing more distance would be easier to set up and would (IMO) provide better results.

The camera you choose will not make a great difference except for the difference between crop and full frame formats. Shooting virtually any DSLR camera at the minimum ISO would give pretty noise free results (if the head is lit correctly)

The lens you choose will make a great difference and while the kit lenses are fairly decent, I don't think that they might be the best choice for your work.

If I were shooting this, I would prefer to use a 90-100 mm macro lens on a full frame camera and would adjust my shooting distances for that focal length and image size.

I might suggest that you team up with someone versed in photography to assist you in this project...

[Eildosa]

=================GrumpyDiver==================

seems to me that we've had this chat sometime in the past, but at that time you were looking at doing this type of work with an array of point & shoot cameras.

Yes, and I did
Since then I discovered a lot of things, my main problem at the time was that
I didn't knew that low end point and shoot camera would not let you set ISO, TV speed and aperture.
Because of that I have 21 pictures with different settings and a crappy 3d model.
Well, it's still is a good one, but I want better.

I did some other stuff in betwen and now I'd like to make version 2.0

going with the kit 18-55mm lens does not make sense. Setting an identical focal length for each lens is going to be impossible

Indeed, I was planning to either use a 18mm focale or a 55mm focale and no other If I were to use this lens.

Getting too close with a wider angle lens introduces facial distortion

Facial distortion does not matter, it's ugly but has no impact on the reconstruction process.
All I need is to calculate the distance of various point on the face, this is possible when the same point appear on 2 pictures.
Facial distortion does not affect the result at all.

I'm wondering as to how you plan to light your subject. You will want soft, even and diffuse lighting all around. What are you planning to do here? This is going to be critical in getting your shots to work out for you.

Yes this will be a challenge, I plan to build my own lighting rig.
As of now I plan to use led strip to illuminate during focus then trigger a lot of 100W high power LED during the shot,
I have no idea if this will be sufficient or not, I'll experiment until I find the right way.
I know about high CRI led but those are just too expensive for me

=================Inkanyezi==================

as I don't know many DSLR cameras that are up to the task

Why are they not up to the task?

=================rpcrowe==================

Very nice, thanks for the pics, it's giving me an idea of what I'll get with each focale.

The 30-40 cm distance would make a a sphere smaller than a soccer ball. I don't think that I could find space for the 21 cameras around a soccer ball...

You probably made a error during the convertion, because what you get is a 1-1.3m sphere, you can fit plenty of soccer ball into that.
I can't represent distance with inches, did not expect anyone to use those units, from now on I'll post in metric and imperial system.
40Cm = 15.74 inches

[quote]
it seems that you would have difficulty finding room and a means to place these cameras as well as a means to secure the cameras. Additionally, after placing 21 cameras around a human head, it would be extremely difficult to light the head
[quote]
I build everything, the frame, the lighting, the triggering system.
For the frame I uses hard wood.
For the lighting I'll experiment (see my awnser to GrumpyDiver)

Also I am wondering how you might trip these cameras at one time.

For triggering the cameras I believe DSLR have a convenient jack plug that allow you to do that,
At 1/250 I don't think that I'll have to worry about delay.
With my point and shoot I had to solder on the board.


for those wondering this was the point of shoot version (well it evolved since then, some
angles changed, at the time it was a half scan, and it had no 100W high power led)


So all that being said, I think I'm going with a 1100D and a fixed 50mm to do some tests.
Review :

CANON 50MM F/1.8 II - 125$
Every photographer should own a 50mm f/1.8 lens as your first upgrade from the kit lens that came with your camera. This lens is significantly sharper than the kit lens, has an extremely fast aperture for blurry backgrounds and shooting in low light, and the price is unbelievably good.
This little guy will just simply astound you at the great quality and stunning images you will get. At the low price, it’s nearly a no-brainer to add this lens to your lineup. This lens maintains great quality all the way to the edge at lower f/stop values. This is a prime lens, so you will have to physically move to zoom in and out and potentially get in your client’s face.
I used the “nifty fifty” (as photographers often call this lens) for several years before investing in uber-expensive pro lenses. Looking back, this lens is only a tiny bit less sharp than pro lenses, but for me the real benefit of the more expensive lenses is the zoom. Many photographers love shooting prime lenses such as this, but most of the time I prefer a zoom.

[rpcrowe]

Now, I understand what you are aiming at... Sorry that I was confused...

I was thinking about a sphere with a diameter of 30-40 cm. I should have been considering a portion of a sphere with a radius of 30-40 cm. BIG difference in area

How much is your budget for the 21 cameras? Canon is selling reconditioned SX50 HS Bridge Cameras for $178.

http://shop.usa.canon.com/shop/en/ca...hs-refurbished

I don't know about shipping or tax where ever you are located.

The SX50 HS has manual exposure capability as well as manual focusing.

Looking at your image, I am wondering if you could not dispense with the fluorescent bulbs and use the built-in flash on each of the cameras.

The SX50-has remote shutter release capability.

[Inkanyezi]

Why are they not up to the task?

As DSLR cameras are not usually conceived to be remotely operated in all their respects, while many non-DSLR cameras have convenient access to most, if not all, features also from remote, including viewfinder. DSLR cameras also tend to be a bit bulky for packing into such a configuration.

[shreds]

Why not get something like a Structure Sensor?

http://structure.io/?gclid=CMCHpf7q4sUCFcXLtAodvgUAKg

[Manfred M]

Canon is selling reconditioned SX50 HS Bridge Cameras for $178.

The optical quality of the lens is going to have similar issues to the ones he has in the P&S cameras. Barrel distortion on the wide end is pretty typical. I strongly suspect that this is going to be a key issue; the 50mm fixed lens is likely to totally outperform the superzoom.

the built-in flash on each of the cameras.

Small light source = harsh shadows. While I'm not convinced that his LED setup is going to work, but the built-in flash is going to provide terribly, harsh light. I would be surprised if this will work for the precision mapping he is trying to do. The mapping software is likely to work best with soft, diffuse light.

[Eildosa]

I was thinking about a sphere with a diameter of 30-40 cm. I should have been considering a portion of a sphere with a radius of 30-40 cm. BIG difference in area

ahah I understand now too^^
By the way, radius is 40+10cm because the cameras are away of the head by 40cm and a head is usually 20cm in radius

How much is your budget for the 21 cameras? Canon is selling reconditioned SX50 HS Bridge Cameras for $178.

Sensor is much smaller than the 1100D and the lens probably won't be of the same quality, I'm really aiming toward very high res scan this time.

Looking at your image, I am wondering if you could not dispense with the fluorescent bulbs and use the built-in flash on each of the cameras.

I tried that with my point and shoot camera, they won't trigger all at the same time when using the flash
If they did that would have been wonderfull

Why not get something like a Structure Sensor?

http://structure.io/?gclid=CMCHpf7q4sUCFcXLtAodvgUAKg

Acquire time is much too slow (for scanning emotions), scan resolution is too low

As DSLR cameras are not usually conceived to be remotely operated in all their respects, while many non-DSLR cameras have convenient access to most, if not all, features also from remote, including viewfinder. DSLR cameras also tend to be a bit bulky for packing into such a configuration.

All I need is to be able to trigger the shutter.

Small light source = harsh shadows. While I'm not convinced that his LED setup is going to work, but the built-in flash is going to provide terribly, harsh light. I would be surprised if this will work for the precision mapping he is trying to do. The mapping software is likely to work best with soft, diffuse light.

Even if the DSLR were evenly distributed on the rig the flash would be too hard?
What I need is an even lighting with no shadow

[Manfred M]

Even if the DSLR were evenly distributed on the rig the flash would be too hard?
What I need is an even lighting with no shadow

Lighting 101 - Small light source = harsh light; large light source = soft light.

Go outside at noon on a sunny day and take a picture of someone's face; harsh shadows, raccoon eyes, etc. Even though the sun is huge, it is so far away that it acts like a relatively small light source. Do the same thing on an overcast day, where the clouds diffuse the light, and the lighting will be extremely flat and the face will be quite easy to photograph as it is so evenly lit.

Same thing happens in a studio; the small lightsource (small flash; even when there are lots of them) cast a very harsh light. Watch a professional photographer; he / she will have a large softbox positioned close to the subject. Nice soft light.

[Eildosa]

Lighting 101 - Small light source = harsh light; large light source = soft light.

Go outside at noon on a sunny day and take a picture of someone's face; harsh shadows, raccoon eyes, etc. Even though the sun is huge, it is so far away that it acts like a relatively small light source. Do the same thing on an overcast day, where the clouds diffuse the light, and the lighting will be extremely flat and the face will be quite easy to photograph as it is so evenly lit.

Same thing happens in a studio; the small lightsource (small flash; even when there are lots of them) cast a very harsh light. Watch a professional photographer; he / she will have a large softbox positioned close to the subject. Nice soft light.

This is gonna be tricky, it's true that with a 1m diameter and DSLR I won't have a lot of place for lighting.
My roomates probably won't let me build a 3m 3d scanner.
Well, I'll see what it does

[xpatUSA]

Indeed, I was planning to either use a 18mm focale or a 55mm focale and no other If I were to use this lens.

Why is that word being used? According to WikiPedia:

"The focale (plural focalia), also known as a sudarium ("sweat cloth"), was a woolen or linen scarf worn by ancient Roman military personnel. It protected the neck from chafing by the armor."

Just my pedantic tuppence-worth