PHOTOGRAPHIC THREADS: camera queries, any photo tech stuff!

[TC]

Try  Speed graphic for filters.  I am not sure of the type you mention but they have a B+W MRC UV Digital IR Blocking filter in their catalogue.  If this is not what you want, you could try phoning.  I have dealt with this firm for years and they always seem to come up with specialist equiment available no where else.

[gote]

They tend to be expensive since the good ones are not dye filters but block by interference. The one I used to use many years ago was from Balzers. It was square and a little awkward to use but worked all right. Try to look inside a second hand dia-projector. Some of them used to be used to keep the pictures cooler and they were sometimes of good optical quality. Otherwise I can only suggest Google.
The sensitivity for IR is very high in some sensors for digital cameras. so there usually is a good filter inside. I assume this is why Ramondas come out better in digital photography. If you remove that filter you get a camera that takes pictures in the infrared. Some people use them for snooping.   
Göte

[Ed Alverson]

There are so many more things that affect image quality than the number of pixels, but it is easy to lose track of this in the "pixel race" that seems to be happening.  Camera movement (use a tripod), accuracy of focus (autofocus can be problematic), and depth of field are particular issues that can't be overlooked.  In the days of photo enlargements, a lot of photos lost resolution in the process of making the enlargement, due to issues with the optics of the enlarger (or dust on the enlarger optics, etc. etc.).  One great thing about digital technology is that I can now get much higher quality enlargements from scanning my old 35mm slides than I could get from standard enlargements in the olden days.

In my own conversion from film to digital a few years ago, there were a few ramifications of the sensor size that I didn't quite expect.  One issue is that the size of the view in the camera viewfinder is much smaller with my digital SLR than it is with my old film SLR.  So I find that it is more difficult to obtain the correct focus, especially in lower light conditions.  This becomes more of a problem as my eyes get older.  I presume that this would not be an issue with the new larger sensor cameras, but I haven't checked that out myself.

The other factor, which I consider beneficial, is a ramification of the need to apply a conversion factor to the lens focal length to get the effective focal length comparable to a 35mm film camera.  Since I wanted to use a fixed focal length lens rather than a zoom, I purchased a 35mm lens.  With a film camera this would be a wide angle lens, but on a digital SLR it is equivalent to a "normal" 55mm lens on a film SLR.  The nice thing about it is that the 35mm lens is capable of focusing quite close to the subject, much more so than the typical 18" minimum distance with a 55mm film camera.  So while the 35mm lens on my digital camera is not a true macro, it focuses close enough to make good photos of even the smallest flowers, but is still small and compact, and much less expensive than a macro lens.  Plus, the optics are probably better than a multi-purpose zoom lens.

Ed

[Paddy Tobin]

Ed,

Your comment on the difficulty of manual focusing through the viewfinder of the digital SRL cameras echoes my own experience and especially so, as you mention, in poor light. My eyesight has become a bit blurry over the last few years - those floating bits in the eye - and focusing can be a slow process which can be frustrating at times.

I went the macro lens way for flower photography, a Nikon 100mm, and I am very happy with it. It's a good quality lens, far better than my general purpose lens which is a zoom.

Paddy

[gote]

The Panasonic Lumix that I use enlargs the picture in the viewfinder if I turn the focus ring in manual focus mode. That is very helpful.
I agree with Ed on all points except that I got good quality from my enlarger. (A pre-war Leitz)
I might add that I have to be careful when adapting the focus adjustment in the viewfinder to my glasses.
Göte

[mark smyth]

Can someone tell me what this means in plain English

The 70-300mm offers a lightweight and compact zoom lens with macro capability that can now be used with digital cameras. By flipping a macro switch in the focal length range of 180mm to 300mm, a maximum magnification ratio of  1:2 at a minimum focus distance as short as 95cm is obtained, enabling close-up shots of objects that normally require the use of a specially designed macro lens.

Does it mean from 95cm I could take a photo the same as my compact does from 1cm?

[Anthony Darby]

I think the short answer your last point is no Mark.

[maggiepie]

Mark, what is the lens you are referring to?
The idea of an add on lens that can be used with digital cameras is very interesting.

[gote]

The paradox is that closeup pictures are best taken with a telephoto lens. It is very awkward to need to have the lens a couple of centimeters from the flower or whatever. The problem with long lenses is, however, that they often do not focus close enough. The old bellows view camera was the perfect choice. It was possible to rig up the camera with a 21cm lens 42 cm away from the flower and get a 1:1 picture on the negative.
The answer to the problem is to use the longest available tele setting on your lens and go so close that you get the framing you want. You will then find that the lens does not focus to that distance. The answer to that is to get an auxiliary lens in front of the one on your camera. Such lenses can be bought in camera stores or from the guy who sold you your spectacles. The camera store lens may come with a mount that is a slip on or screw on to your existing lens. Your optician can cut the blank lens to a size that allows you to fix it to your lens with tape.
If you camera is like mine it will focus down to 2m as a tele lens. If I put a 0.5 dioptri lens in front it will focus from 2m down to 1m. If I put on a 1 dioptri lens it will focus from 1m down to 666mm.
A 2 dioptri lens will give you the range 500mm down to 400mm.
My latest 35mm non-electronic camera also had this problem. I bought a designated 2.5 dioptri lens which I use(-d) for close up. This meant that I did it the other way round. I knew that I had to keep a distance of 0.4m (1/2.5) in order to get focus and I then used the zoom function to frame the picture.
A 0.5 or 2 dioptri lens does little in the way of refraction; especially if it sits in front of a telephoto lens which only uses the central field of vision. Thus we can forget about the aberrations caused by astigmatism. coma etc. A simple lens from the optician works well as long as it is centred and the optician can fix that.
Photo shops usually do not sell lenses less strong than 2 dioptries so if you want to use the 0.5-1m range the optician is your choice. It might be a little awkward to have to fix your lens with tape but it is better than having to kneel on your most precious plant in order to get close enough to another one.
I am not sere that I have expressed myself with enough clarity but please ask if you need.
Göte

[TC]

Nikon D400

I came across this "rumour" when checking up on Nikon cameras.  There are several other Pro. photographic sites with much the same information.  It may be a controlled leak by Nikon to counter the latest Canon model.   

[Paddy Tobin]

Why, Tom, who would bother with a Canon?

Paddy

[Michael J Campbell]

I do and always have,wouldn't let a Nikon through the door.

[gote]

RE Nikon
Do they need a photographer or is it enough to humbly ask it to take a picture? 

The note about chromatic abberration is interesting. It means that they have found a way to correct for residual errors in a zoom lens by having a program that slightly changes the scale of the colours against each others. The question is does it work for more than one lens? I think no. It is important that it can be shut off for other lenses.
One day I will buy a digital camera that can use my old non-zoom lenses. They give superior pictures - especially in low light levels.
Göte

[Anthony Darby]

Nikon D400

I came across this "rumour" when checking up on Nikon cameras.  There are several other Pro. photographic sites with much the same information.  It may be a controlled leak by Nikon to counter the latest Canon model.  

How strange. This seems to be in addition to the two new full frame Nikons, the D700 and the 24mp D3x.

[JohnnyD]

Not Nikon, not Canon - just Fuji.
Finally decided to 'backgrade' rather than upgrade and purchased a refurbished Finepix s5700 from Fuji.
Brilliant small camera - super macro, 10X optical & 4.5x digital zoom and, with 2 year extended warranty just £75! (I reckon a lot of the refurbished Fuji cameras on ebay are bought this way.)
Had a s7000 for a long time but got fed up with the small screen. Good pics but just to small.
5700 has a 2.5" screen, is lightweight and feels really good.
First test is a week in the Algarve with the Bookeroos - will advise. (On the camera that is not the Bookeroos!)

JohnnyD