digital camera question?

You have observed the effects of scale.

Digital cameras have shorter focal lengths, and smaller actual apertures. This means that the diameter of the aperture for f8 is much smaller on the small lens of the digital than on the large lens of the SLR. The f-stop relation to depth of field doesn't scale down exactly. Below about 1/64th" aperture, f-stop actually doesn't mean much: you effectively have a pinhole lens. (Cheap point-n-shoot "fixed focus" film cameras take advantage of this, too.)

NB that the actual sharpness of the image is a function of the grain in the image sensor, whether that is a film or a CCD. CCDs have larger grain than film. Detail smaller than the grain will be not be recorded, no matter how finely the lens resolves the image. The effect of this is that fuzziness at a smaller scale than the grain is not recorded, so that the image appears sharper, hence has greater apparent depth of field. IOW, sharpness, and hence apparent depth of field, is as much an effect of how we see an image as of the image itself.

It may be of interest that the best SLR lenses have greater resolving power than most films, and much greater than current CCDs.

BTW, this effect of grain size can fool you when you check the image on the LCD screen. Fuzzy images will seem much sharper on it than when viewed on the computer monitor. Make sure your camera has a play-back zoom function, so that you can check the focus of different areas of the image.

HTH

Reply to
Wolf Kirchmeir
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35mm film, like Kodak ASA 64, has about 13 megapixels equivalent from what I've read (but that is sort of apples to oranges: see below). You can get 13MP cameras now from Canon (the new F5, for example, has 13MP and a CCD imager the same size as 35mm film, so no lens conversion is necessary; but it costs about $3k).

Pixels and film grain are different, so direct comparisons are not completely accurate. Pixels are square or rectangular beasties, and very regular. Film grain is random and changes with each piece of film. So, techniques like stacking "identical" negative actually work better with film then digital if registration is perfect. But none of that matters much to model railroad photos unless you are going to do stacking to increase contrast, color, etc. like what is done in astrophotography.

Ed

in article CfXmf.379$ snipped-for-privacy@news20.bellglobal.com, Wolf Kirchmeir at snipped-for-privacy@sympatico.ca wrote on 12/11/05 7:07 AM:

Reply to
Edward A. Oates

Try this. I haven't, but it sounds good.

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Reply to
leguit

I have gotten excellent results with F11 on a Olympus 4MPixal camera that is now out of date. Here is an example showing the outer edges of the depth of field (Subject N Scale).

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You can see slight blurring of the forground (the Aspen tree) and a little blurring of the rock face to the left rear.

The problem is that the F stop is a ratio and it depends on the size of imaging device. 35mm film is a 35mm imaging device. If I remember correctly the imaging device in my camera is 1/4". The smaller the imaging device the better. 110 film had good depth of field just no resolution. I think some of the newer larger mega pixal cameras have sacrificed depth of field for higher speed. As the number of pixals on a chip goes up the light sensitivity goes down. This happens because the area of the pixal decreases and so therefore so does the light. This is probably not the whole story but it seems to be happening.

When I purchased my last digital I did not purchase the higher megapixal one because the F stop offered was not as good and the chip size was the same. I had previously had a 3.2 Mega Pixal and was also happy at F11.

BTW the above image appeared in N Scale magazine in July 2003. The image on the web is at much lower resolution then the one submitted.

Ken Harstine

[This followup was posted to rec.models.railroad and a c> When ever I go into a camera store and ask the geek squad about "depth of
Reply to
Ken Harstine

How about a plain old 35mm camera and a film scanner?

Any thoughts or experience on film scanners out there?

Reply to
<wkaiser

a) Film cameras have the same problems w/ depth of field as digitals, only more so. That's because the lenses are physically larger, so that the smaller f-stops (higher numbers) are physically larger, so you won't get the pin-hole effect that increases the d.o.f on digitals.

b) That being said, a good 35MM SLR plus good lighting will produce excellent effects - but you'll have to learn how to do it. :-) OTOH, the same techniques work to produce long d.o.f on digital cameras.

c) The film-scanning attachments for ordinary flatbed scanners are dismal: I gave up on using mine. The scanner does an automatic digital zoom with pixel interpolation, which produces a fuzzy image. For good slide/film scanning you need a scanner capable of 4800 _physical_ dots per inch, or better. That means a separate machine, but if you have the desk space, and a $400 or so, go for it. Film/slide scanners are more expensive because the market for them is small, and the scanning module requires much higher mechanical precision. I have one, but I haven't attached it to my computer yet. Desk space....

HTH

Reply to
Wolf Kirchmeir

I use the PrimeFilm 1800 slide scanner. It works vastly better then the flatbed scanners for slides and negatives. It may not be as good as the other scanners but it is much cheaper. I have been using it for several years now with no problems.

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Cost is about $150.

I used it for all the slides on my web site

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The site includes scans of old faded prints as well as some not so great slides including from 110 slides. So don't judge the quality by the worst that you see.

Ken Harst> Ariz> > When ever I go into a camera store and ask the geek squad about "depth of

Reply to
Ken Harstine

Ken Harstine spake thus:

Not bad; 1800 (true) DPI, yielding about 4 MP, which should rival medium-end digital. Too bad it doesn't do 4x5.

Reply to
David Nebenzahl

I do have a Nikon Coolscan 4000 (about $550), and it is very good. The color rendition is accurate, but if you scan at max resolution (4000dpi or so), the images are HUGE (raw or tiff). But unless you already have a decent 35mm SLR (or a room full of old slides like I have), you would be better served in this day and age to spend the money (scanner plus 35mm SLR) on a digital SLR, like the Canon Rebel XT, or better yet, the Canon 20D, then learn how to use that digital camera with its interchangeable lenses (used the regular Canon lenses, plus some new ones designed just for those cameras with their smaller than 35mm imagers).

But the original poster wanted to spend $400. Try eBay for something like the Sony F717 (they have a newer camera out now) which has a decent lens (attached), automatic macro focusing, full manual control, jpeg and TIFF image formats, and 5MP resolution.

Ed

in article CRBnf.1524$ snipped-for-privacy@news20.bellglobal.com, Wolf Kirchmeir at snipped-for-privacy@sympatico.ca wrote on 12/13/05 7:36 AM:

Reply to
Edward A. Oates

Knowing nothing about photography myself, I'm curious, then, what the group opinion is on this camera for just general use, railfan and model pix.

Thank you all.

"Paul - The CB&Q Guy" (Modeling 1969 In HO.)

Reply to
The CB&Q Guy

The resolution of most flatbed scanners is inadequate for acceptable film scanning. Few exceed 1200 dpi (REAL, NOT including 'interpolating'), and this is nowhere near great enough (by about 25 times) to do a decent job of scanning slides or negatives. It may be 'OK' if all you want is a low quality picture for a webpage or such, but you won't get a ghost of the information actually in the film.

That's why slide/film scanners exist.

Dan Mitchell ============

Reply to
Daniel A. Mitchell

A good camera. Going by the reviews, it will give very good results once you learn how to exploit all its features.

Would I buy it? No, because at $500 this camera is getting up to the price range of an SLR camera. I'd rather spend $800 on an SLR than $500 on a range finder camera. In fact, I'm accumulating pennies towards that goal. :-)

OTOH, if you just want very good quality photos with a minimum of fuss, plus the opportunity to expand your photographic skills when the mood strikes, the E900 is as good a choice as any other in its class. Wally's price seems to be average street price. Look at Best Buy etc, too, and it doesn't hurt to check a real camera shop - they will often match or come close to a big-box price, but they give you service that the big boxes don't give.

OTOH (lessee, that's three hands, now :-)), if you don't expect to ever want more than just pretty good pictures with minimum learning curve, a

4-6MP camera in the $200-300 price range would give you a better price/quality ratio.

HTH

Reply to
Wolf Kirchmeir

Yep. Its 'still' a good camera.

fl@liner

ps: Just go with the memory cards that you already have...

Reply to
fieromike1945

Ken , thanks for the information on the slide / film scanner. I have a bunch of slides that I was going to take to a lab and have them scanned. I have a good flat bed scanner with a slide scan attachment, but the slide scanning is a joke on this one. Rather than dropping a lot bucks just to get these slides scanned , think I'll look into a scaner like yours. I enjoyed the freight car pics on your site. Very good quality , IMO.

Ken Day

Reply to
Ken Day

Having been an amateur photographer for a good many years (VERY amateur) I might add , Not knowing exactly what you want to do it's really hard to say , but I would recommend spending a little more and go with a SLR. I still use my 35 mm for many shots but also have a Sony DSC S70 , which produces some quality shots and also does video in 15 second pops. I think this one is my 4th digital and the best so far but I'm still not happy with it. It is NOT a SLR . If it were I'm sure I would be happy, You're limited in many ways without a SLR.

I would recommend doing a Google search, something like " SLR vs non SLR"...or something like that. I'm sure you would get the info you need or get links to information that will help you determine which is for you.

Hope this helps. Without

Reply to
Ken Day

Looks to be a pretty decent machine. Good close focusing for the wee trains, decent WA to short tele for the larger ones. One thing if you are making "large" blowups with this type of hi-megapixel camera, you get a bit more digital noise than those with larger sensors, especially at higher ISOs. OTOH, if you are semi-amateur as advertised, you won't go much beyond

8x10 (if that) and the camera should be exceptional for that. Bill
Reply to
William Vickrey

Slight correction - the F5 is a Nikon FILM camera with a 1005 pixel metering system - it's not a digital. The Canon new body is a 5D with the specs you cite. I don't know why they went this way with the numbering system - it would lead one to think that it's a lower end camera than the old 10D that I use, when it's a far more capable body. Nikon still doesn't have a digital camera with a full 35mm frame sensor. The D2x has a 12.4 mp sensor but with a focal length multiplier of 1.5x versus 35mm. This is from Nikon's website.

Reply to
Jack

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