Importance of Sensor's size

[aaron_w.]

I've been a film buff for a great many years, but now I've decided

to get a quality 'point & shoot' digcam (it seems to make a lot more

sense when traveling).

 

Checking out the specs of various models I noted differences in the

size of their sensors and I was wondering about that. Is sensor-

size analogous to film-size?

 

I'd appreciate some insight as to how much 'weight' I should give to

sensor-size in determining which model to get.

[steven_clark]

Larger size sensors tend to have lower noise and thereby higher useable ISO's.

[donald_choi]

Sensor size is also a consideration when dealing with depth-of-field.

[marcin harla]

<i>(...)how much 'weight' I should give to sensor-size in determining which model to get</i>

 

<p>

Sensor size is probably more important than resolution. As Steve mentioned noise is also a big issue. Digicams are practically useless above ISO200.

And if you want to obtain shallow DOF you gonna need bigger sensor.

[jbq]

Yes and no.

 

Sensor size has a similar effect as film size when it comes to the noise/sensitivity curve: larger sensor/film results in less noise/grain on prints of the same size. The larger sensors also offers more control over depth-of-field. However this doesn't mean that the camera with the tiniest sensors have the fastest lenses (cameras with the fastest lenses seem to often used 1/1.8" and 2/3" sensors).

 

However, in digital (especially in the small-sensor world) resolution isn't limited nearly as much by the sensor (real-world resolutions are limited to about 80 lp/mm with the finest films, whereas with small-pixel sensors values of 170 lp/mm are currently within reach). Whether P&S digicam lenses are really able to resolve such fine details, over the entire zoom range, through the entire frame and with aberrations under control remains to be seen.

 

In a nutshell, with a smaller sensor you'll have more noise (just like you'd have more grain with a smaller piece of film), but not necessarily much less print resolution.

[conrad_hoffman]

Digital has just as many tradeoffs as film. You have to decide what tool best fits the job. Film cameras smaller than 4x5, or using films faster than ISO 64 are completely useless for quality work, but some situations can only be handled by fast film in a 35mm. Ya gotta choose. Digicams at ISO400 will give images that look like fast grainy film. Usable for some things, useless for others. Remember that grain from a film camera is a romantic and artistic part of the image. Visible noise from a digicam assigns it to the scrap heap. Not a clue why. Digicams with active image stabilization will often allow you to shoot at lower ISO settings, offsetting some of the noise problem. Small sensors allow extreme zoom ranges that wouldn't be practical with larger sensors. Image stabilization again makes the large zoom range useful without a tripod. In terms of raw image quality, get the largest sensor you can afford, IMO even if the megapixels are less. In terms of real world picture taking, get the feature set that will cover the kind of shots you want to take, and live with the sensor size that dictates.

[aaron_w.]

Thanks for the education (this is interesting stuff). Conrad's reply was downright psychic in that he seems to be describing my digicam of choice (so far)... Panasonic's Lumix FZ20!

[larrybc]

<p>Aaron W. wrote:<br><i>

I've been a film buff for a great many years, but now I've decided to get a quality 'point & shoot' digcam (it seems to make a lot more sense when traveling).

</i></p>

<p>I'm curious about why you think it makes more sense to have digital when travelling? Memory card prices have dropped a lot over the last few months but it still requires a bit of careful consideration if I decide to go on a 3 week trip. I have 1.5GB of storage which is about 210 shots (RAW format) using my 5MP camera. I typically shoot 10-12 rolls of 24 per week, so that's almost enough for one week. I'd need another 3 GB for 2 more weeks, so that would be close to USD$300. Or I could buy a hard-drive storage unit. And then there's the need to charge the camera and the storage unit. I can get around 350-400 shots on a single charge. So one spare batt. and a charger should be enough, it's just a matter of finding a place to plug in every 600-800 shots. With film, the only consideration is film buying/processing costs and luggage space for the film (x-rays have never been a problem for me).<br>

I just wanted to point that out in case you haven't considered all the costs/requirements. Also bear in mind that the ability to instantly review and delete bad shots means that a memory card with room for 100 photos actually has more capacity than enough film for 100 photos. Oh, and if you shoot colour film under artifical light (eg: fluorescent or incandescent bulbs), you need bring film balanced for that colour (or use filters) whereas digital provides automatic white balancing. Same thing applies to different film speeds, although most P&S digicams are practically limited to ISO 100 or lower unless something like 5x7 is the largest size print you'll want.</p>

 

<p>Conrad Hoffman wrote:<br>

<i>

Digicams at ISO400 will give images that look like fast grainy film. Usable for some things, useless for others. Remember that grain from a film camera is a romantic and artistic part of the image. Visible noise from a digicam assigns it to the scrap heap. Not a clue why. </i></p>

<p>I used to think that way, too. But after some experimenting with my digicam, I found that shooting in RAW and then using Adobe PS's RAW converter provided much more grain-like noise. The resulting noise wasn't as random in that it didn't create as much multi-coloured noise. So now I use ISO400 with my 2/3 sensor digicam but only in RAW mode.</p>

 

<p><i>In terms of raw image quality, get the largest sensor you can afford, IMO even if the megapixels are less. </i></p>

<p>And I would also recommend a camera that support RAW file mode, although in that price range, I doubt that any of them do.

</p>

<p>Happy shopping,</p>

<p>Larry</p>

[jimstrutz]

The FZ20 has a very small sensor, even for a digicam. Panasonic has done a remarkably good job of keeping noise down, but at 200 ISO it's still very easy to see it. At 400 ISO the images are just plain bad. A good noise filter also does wonders to improve this, but at some bit of quality/detail loss.

 

What makes the FZ20 a great camera is the very good 12x f/2.8 lens with excellent image stabilization. the combination of fast optics with IS allows you to keep your ISO down when most other digicams would be shooting at ISO 400. Also, color fringing is very well controlled, adding to it's sharpness.

 

All digicams are filled with the compromises dictated by the choices their designers make, but in my opinion, the FZ series comes down on the right side of a whole lot of those choices. A digital SLR is capable of better images in a lot of situations, but for the price and convenience, this is a good camera.

[aaron_w.]

Larry~ To satisfy your curiosity, the reason a digicam makes lots of sense for traveling is that it circumvents the risks of x-ray damage to film. Security at airports (and cruise lines) is at the point where most now refuse to visually inspect cameras/film, insisting that it be passed through x-ray. As a result, I wound up with lots of fogged 35mm film after my last trip, even though it was ASA 100/200.

 

Jim~ Thanks for the validation on the Lumix FZ20. I was concerned about its small sensor, but overall it appears that it has a well thought-out synergistic design. I'm also giving serious thought to the Canon G6. While its optical range is only 4x, it gets very good reviews and I really could make good use of its articulating LCD.

[phule]

<< As a result, I wound up with lots of fogged 35mm film after my last trip, even though it was ASA 100/200. >>

 

Given the number of threads here on photo.net about this, I would say there was something wrong with the film before you traveled. Either that or you left it in your checked baggage and it went through the more powerful x-ray machines.

 

The x-ray machines used for carry-on objects do not harm slow speed film. There is a tremendous amount of evidence for this on this very site.

[aaron_w.]

Rob~ Based on my post 9/11 travel experiences, the 'evidence' to which you refer is wrong. Most of my trips involve multiple airline connections and therefore my film receives several doses of x-rays. Although my last trip resulted in the worst fogging I ever experienced, I've noticed the problem after other trips as well (albeit to a lesser extent). ~Aaron

[stefan_pop_lazic]

I agree about the sensor size, but, about the abillity of digicams to use high iso's, I believe that all of you who say that above iso 200 they are unusable, have forgotten film grain.

[aaron_w.]

PS to Rob~ None of my film was ever placed in my 'checked' luggage; it is always carried onboard (with my camera) in a cushioned flight bag.

[phule]

<< Rob~ Based on my post 9/11 travel experiences, the 'evidence' to which you refer is wrong. Most of my trips involve multiple airline connections and therefore my film receives several doses of x-rays. Although my last trip resulted in the worst fogging I ever experienced, I've noticed the problem after other trips as well (albeit to a lesser extent). >>

 

Aaron,

 

There are plenty of "post 9/11" threads about x-rays and film on photo.net and there are plenty of people that also do a lot of traveling. I myself have traveled quite a bit, sometimes taking the same un-shot rolls of film with me between trips.

 

Not a single instance of fogging. You can believe what you want, but the evidence based on the threads here is overwhelming. Your film was not ruined by x-ray machines that scan carry-on luggage.

[phil_v.]

Aaron:

 

I for one don't think you are crazy and let me guess that the film you are/were using is Fugi Superia. I never had any such problem with Reala, but I felt I needed an ISO 200 film for my last vacation, so I opted for Superia 200. My film was always passed through the passenger conveyer xray inspection machines (a total of 6x during the roundtrip), and I too have noticed some fogging. :(

 

Btw, this past summer I decided to join the 21st century, so I bought a Canon G6 and I absolutely love it. As you envision, its variable positioning LCD is a very valuable feature. It works simply great for low and overhead shooting (I don't know anything about the Panasonic FZ20, but I would give a big thumbs-up for the Canon G6)!

 

Phil

[larrybc]

<p>Stefan Pop-Lazic , dec 08, 2004; 02:49 p.m. wrote:<br><i>

I agree about the sensor size, but, about the abillity of digicams to use high iso's, I believe that all of you who say that above iso 200 they are unusable, have forgotten film grain.</i></p>

<p>

Not at all. Others have already mentioned that film grain is generally more pleasing that digital image noise. You <i>can</i> get better looking noise if you do the right post processing, though (again, it it something that has already been mentioned in this thread).

</p>

 

<p>And Aaron, thanks for the answer about "why digital?" It appears to have created some controversy. ;-) Personally, I've never experienced film fogging. I had some rolls of ISO800 (Fuji Superia) that went to Hawaii and back (post 9/11) before being exposed and had no fogging problems. Same with my ISO400 film (again, Superia). I carry my film in a lead lined back but I don't know if it makes a difference. OTOH, I've never taken my film through eight x-rays.

</p>

<p>Aside from the lack of a manually MECHANICALLY controlled zoom ring, I like the Canon G series of cameras. The tilting LCD is very useful and I have gotten some great candids using the one on my Minolta A1. When picking a small sensor camera, I would encourage you consider one with some kind of image stabilization so that the slow ISO speeds become more useful under a wider variety of conditions. ISO100 is slow but when you can shoot interiors at 1/4s hand-held, it becomes surprisingly flexible. I've even gotten good candid shots of people on a subway while shooting at 1/10s.</p>

 

<p>Larry</p>

[phil_v.]

Larry: I'm convinced that film-fogging can result when film is exposed to radiation multiple times (4x or more) as radiation is cumulative. I too never experienced this until my Superia 200 went through inspection 6x on my last vacation.

 

Aaron: While (as I said) I love the Canon G6, if you prefer a greater optical zoom range with image-stabilization plus a variable LCD, you may want to check-out the new Minolta A200 (if your budget extends to the $700 neighborhood). ;)

[conrad_hoffman]

I wasn't very specific in my post, but I'm not bothered much by digital noise. It looks enough like film grain that it isn't some visual shock. My post took the tone it did because it seems like the standards people apply to digicams are quite different to film, and IMO everybody seems to have forgotten all the grain, exposure problems, and indifferent printing associated with film. The FZ20 offers a great combination of features. Technically, the images don't compare to what I can get out of 4x5 (nor does 35mm Leica stuff), but it can take shots where the monorail could never go. 8x10 prints are no problem, and I find some images will hold up far larger than that. It also fills a completely different niche than a dSLR in terms of size and the lenses you'd have to carry to equal it, not to mention cost.

[phule]

<p>

<a href="http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=001mBX">http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=001mBX</a>

 

<em> "Under the most demanding conditions the discriminating examiners found it virtually impossible to detect the effects of 16 inspections upon 200 speed color negative films. Even at 100 times the effect was very difficult to see in areas having no photographic image and even more difficult in the scenes. Enlargments (8x10) were made of the 200 speed films. Virtually no effect was observed up to 16 inspections. Those inspected 100 times exhibited a very slight increase in grain and a very minor color balance shift. These effects would probably also go undetected except in the most demanding professional applications. High speed color negative films were similarly affected up to 16 times. However, at 100 times the 1600 speed films diverged somewhat exhibiting effects that would sometimes be detectable in prints of demanding scenes viewed by discriminating examiners."</em>

<p>

There was also a thread here where a photo.net user sent his film through the carry-on scanner 16 times with no problems what so ever.

<p>

It's also been pointed out that the amount of radiation film receives while in flight FAR exceeds any received on the ground with a security check scanner.

<a href="http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=0026a3">http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=0026a3</a>

<p>

I don't doubt that eventually film can be fogged by traveling via airplane and that the x-ray machines certainly cannot help the situation. However, I find it completely erroneous to assume that a few passes through an x-ray machine will ruin your film every single time. There is far more going on.

[scott_eaton]

<I>Checking out the specs of various models I noted differences in the size of their sensors and I was wondering about that. </i><P>The bigger the sensor, the lower the amount of noise, and the less critical the camera is in regards to optics because there's less degree of image circle magnification. It's also irrelevant since in terms of the point -n- shoots, they all basically suck in terms of sensor size, and it's a battle of what camera sucks the least and produces the least amount of purple fringing. The new 5mp+ Panasonic and Fuji point -n- shoots produce fairly clean images at their lowest ISO's, but they still stink under any other circumstance and will require post processing to clean the images when shot at higher ISO's. The fact you are concerned about sensor size and considering a 'push here dummy' toy digital camera is also an oxymoron. If you have a comprehension of sensor size and quality, which it sounds like you do, and are concerned about it, get a decent dSLR (D70 or DReb) and leave the toy cameras in the display rack at Target and Walmart for teenage girls to buy. If I need a flip out LCD and movie mode, I'll buy a digital camcorder. End of rant.<P><I>Others have already mentioned that film grain is generally more pleasing that digital image noise</i><P>Basically an army of one since I don't know of any dSLR owners that would agree with you along with your, er, numerous uploads. I'll also challenge your grocery store Superia 400 to a test against my 10D at ASA 400 anyday of the week.