Alley in Pisa, Italy

by Lars Kotthoff

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0
votes
1answer
70 views

Does manual focus carry over to a different aperture, lens or focal length?

This is in the manual focus mode. If I focus my lens so that a certain object is clear and crisp, and then do one of the following, will I have to focus again? Change the aperture Switch to a ...
1
vote
3answers
305 views

Why image at 400mm is LARGER THAN DOUBLE of image at 200mm? (according to lens formula)

Like most of us, I thought it was yes. Until I really look into the Lens Equation: (1/subject distance) + (1/image distance) = (1/focal length) ...
2
votes
3answers
213 views

Why do two zoom lenses set to 200mm on the same camera produce different fields of view?

I've been testing out a Nikon 18-200mm F3.5-5.6 against a Nikon 55-300mm F4.5-5.6 I took two pictures of a door knob from an equal distance of about 3 meters away with the same Nikon d7100 DX camera ...
0
votes
1answer
122 views

What's the practical difference in an image taken at focal length of 200mm vs 300mm? [duplicate]

I'm confused about the 200mm and the 300mm zoom ranges. I am looking for some examples of the same subject, in order to visualize the difference between 200mm and 300mm focal lengths. I want to ...
1
vote
3answers
245 views

How can I take a picture at 50mm with a Finepix s8200?

I have this camera. How do I take a picture at 50mm with zoom lens? Does this camera support zoom lens at 50mm?
8
votes
4answers
777 views

Is it the same if you take a picture by setting 50mm in a 18-55mm lens and by using a 50mm prime lens?

Is it the same if you take a picture setting 50mm with a 18-55mm lens and a 50mm f/1.8 prime lens? Assuming that ISO, aperture, and shutter speed are the same, will both the lens give same results? I ...
1
vote
3answers
351 views

How to get focal length from a camera specification which gives a value like “4.5-22.5”?

I am using a Sony W520 camera. The specifications mention Focal Length (f= mm) 4.5-22.5. What number should I take? The lower value or the higher? And if not both of them, then how to calculate actual ...
4
votes
2answers
654 views

Why does calculated distance of an object in an image vary when zooming?

I would like to calculate the distance of an object from my camera, so i used the formula given in this question and I got a very good answer, but I've found that when I zoom and take the picture and ...
3
votes
2answers
2k views

What is the conversion between focal length and times zoom? [duplicate]

Possible Duplicate: How do I convert lens mm to optical zoom times? What is the conversion between focal length in mm (e.g. 50mm) and x zoom (e.g. 20x) commonly used in compact cameras? Is ...
5
votes
1answer
1k views

Should my flash zoom match my lens focal length or its 35mm equivalent?

I have a camera with an APS-C sized sensor. Should my flash zoom match my lens's actual focal length or its 35mm equivalent? I am hoping that someone can shed some scientific light to this matter.
5
votes
1answer
4k views

Why does my aperture setting change as I zoom on my DSLR kit lens?

I am new to the photography field, there are few things which I am not able to understand. I am playing around with my Nikon D90 along with its kit lens (18-105mm). While reading about Depth of ...
4
votes
2answers
1k views

Is it normal for focal length to change while focusing?

When I change the focus distance on my Pentax 55-300mm lens, the focal length appears to change. More specifically, the lens appears to zoom in as I focus towards the minimum focusing distance. This ...
8
votes
1answer
1k views

Why does the maximum aperture change with focal length? [duplicate]

Possible Duplicate: Why do zoom lenses and compact cameras have varied maximum aperture across the zoom range? It is rather common with zooms that the maximum aperture changes (in fact, ...
29
votes
5answers
72k views

How do I convert lens focal length (mm) to x-times optical zoom?

What is the rule to convert the 'mm' notation to the 'optical zoom' notation? I searched a bit and found this one: optical zoom = maximum focal length / minimum focal length For example a 18-55mm ...
6
votes
7answers
4k views

How can I visualize or simulate the effect of different focal lengths?

I have seen many camera review sites illustrate the effect of using different focal lengths on the same photograph using frames. There are also similar illustrations to compare different sensors (full ...
12
votes
2answers
4k views

What differences between point and shoot zoom versus DSLR zoom cause the price disparity?

I'm just getting into the world of photography, stepping up from a point-and-shoot. I've just purchased a Nikon D3100 and it should be here in a couple of days. I've done lots of research, but ...
13
votes
5answers
1k views

Why do we talk about focal-length when frame sizes are different?

I keep seeing people talking about focal-length of lenses without saying how large the frame is. Is there a more sensible way to talk about how much a lens “zooms”? (I have seen so many adverts ...
12
votes
4answers
4k views

How can a lens like a 18-55mm have more than one focal length?

How can a lens have a range of focal lengths? Shouldn't it be a single number? Isn't focal length supposed to be fixed for a lens of a particular shape and geometry? What am I missing? How many ...
20
votes
4answers
3k views

What is focal length and how does it affect my photos?

What is focal-length? Are focal-length and zoom synonymous? How does the focal length of a photo affect it?
13
votes
4answers
4k views

How does changing focal length affect depth of field?

I'm curious about how my "area of acceptable focus" changes when the focal length of the lens I'm using changes as I zoom (or switch lenses). In particular, I'd like to know how the front & back ...