Dazed767
Topic Author
Posts: 4967
Joined: Tue May 18, 1999 11:55 am

Should I Get A More Powerful Lens?

Thu Oct 12, 2000 5:31 am

Right now I have a Tamron 28-300mm lens. It's great and all, but I wish I had a little more range on it. I went today looking at lenses and found a Sigma 100-500mm lens for $769 (he told me it was the best price in FL). But if I bought that lens and sold my other one, I'd need to buy another 30-70mm or so lens. Is the extra 200mm a BIG difference? I was looking through it, and I could see some of the difference, but not as much as I thought it would have. Would it just be smart to keep what I have now? Is there anything I could buy to give it more range?
 
ake0404ar
Posts: 2379
Joined: Wed May 24, 2000 10:55 am

RE: Should I Get A More Powerful Lens?

Thu Oct 12, 2000 6:05 am

100-500 mm lense??? Sigma????
As far as I know Sigma has only 2 500mm lense in the production line.
50-500mm and 170-500mm. I personally have the second one and I am pretty happy with it although you can not use any teleconverter on that. In addition to that I have a 24-70mm and 70-300mm.
I am still thinking about buying a fixed 400 or 500 mm but the money is missing.

Regards
Vasco

Btw....if you go to

http://www.cameraworld.com

you may find it cheaper there......good luck.
 
Dazed767
Topic Author
Posts: 4967
Joined: Tue May 18, 1999 11:55 am

Sorry...

Thu Oct 12, 2000 6:23 am

It was a 170-500 lens. Teleconverter was what I was trying to think of in my first post. Maybe I can find one for $150 or less hopefully.
 
mirage
Posts: 3612
Joined: Mon May 31, 1999 4:44 am

RE: Sorry...

Thu Oct 12, 2000 8:17 am

I bought a 2x teleconverter about 1 month ago for US$130, the results are not very good, I only use it with good light conditions or the photos will be of poor definition. The lens (Sigma 100-300) itself is not very luminous and the teleconverter "eats" a lot of light, I must overexposure always and my camera (Minolta 500Si) can't focus with it so it's manual focus. It's the price for having cheap material.

These photos were taken with the Sigma 100-300 and the 2x teleconverter (600mm)

Click for large version
Click here for full size photo!

Photo © Luis Rosa



Click for large version
Click here for full size photo!

Photo © Luis Rosa

 
ake0404ar
Posts: 2379
Joined: Wed May 24, 2000 10:55 am

RE: Should I Get A More Powerful Lens?

Thu Oct 12, 2000 8:33 am

with the teleconverter you normally use one F-stop as far as I know => good light conditions are mandatory.
Wouldn't it be nice to have access to really good equipment like Mark G. has?
But for now I guess we have to save some money wait and shoot with what we have.  

Regards
Vasco
 
nscaler
Posts: 236
Joined: Wed Aug 18, 1999 2:00 pm

RE: Should I Get A More Powerful Lens?

Thu Oct 12, 2000 10:02 am

Vasco,

Love your latest shots. What body do you shoot with?

Saul
PS (remember who pays for Mark's equipment!  
 
ckw
Posts: 4586
Joined: Fri Aug 27, 2010 12:26 am

RE: Should I Get A More Powerful Lens?

Thu Oct 12, 2000 4:58 pm

Do you really need another zoom? I'd look to a fixed focal length for those occasions when you need the extra length ... after all, if you are buying a lens for max reach, why pay for all the complexity of a zoom to get shorter focal lengths as well? Teleconverters are OK IF you pay the money and get top of the range models - but they are v. expensive - plus a 2x converter will eat not one, but TWO f-stops!

The cheap way to long focal lengths is mirror lenses - 500mm or 600mm are often available 2nd hand at good prices. They can be tricky to use, but can produce good results.

Cheers.

Colin
Colin K. Work, Pixstel
 
ake0404ar
Posts: 2379
Joined: Wed May 24, 2000 10:55 am

RE: Should I Get A More Powerful Lens?

Thu Oct 12, 2000 8:34 pm

Saul,

Nikon N60 => takes great pictures      
 
mirage
Posts: 3612
Joined: Mon May 31, 1999 4:44 am

RE: F-stop

Fri Oct 13, 2000 4:48 am

I'm not sure what's the meaning of F-stop, in my Minolta there is a function to reduce or increase the amount of light received and when I'm using the 2x teleconverter I put this function at -2.0. Is this the F-stop?

thanks
 
ckw
Posts: 4586
Joined: Fri Aug 27, 2010 12:26 am

RE: F-stop

Fri Oct 13, 2000 6:11 pm

This is the problem with the new all singing/dancing wonder cameras - no one needs to learn much about photography to take good pictures ... most of the time .. but then when you want to do something a little unusual ...

F-stops refer to a setting on the lens which determines the aperture of the lens iris which lets the light in. Each "stop" reduces the incoming light by half. So if f2.8 is wide open (most light coming in) f4 reduces this by half, f5.6 by half again and so on. The aperture also determines the depth of field (ie. the amount of background and foreground in focus) the smaller the aperture (perhaps confusingly, the bigger the fstop number) the greater the depth of field. So at f16 you don't get much light, but great depth of field.

Of course the correct exposure is a combination of shutter speed and aperture setting. There is a reciprocal relationship between the two - so f5.6 at 1/250 gives the same exposure as f4 at 1/500. In this case, the photographer would be trading some depth of field in order to freeze fast movement.

Auto-exposure cameras set the appropriate fstop, shutter speed (or both) for you so you don't need to think about it - most of the time. But there are situations where the autoexposure can be fooled (eg. strong backlighting) or you wish to exercise some "creative" control. To allow for this, most cameras are fitted with an exposure compensation control, typically in the range of -2 to +2 - basically what this does is allow you to tell the camera to determine the exposure and then add or subtract by a factor of 1 or 2 to that setting. So if the camera works out that the exposure is f4 at 1/250 and you have requested a compensation of +1, the camera will take the picture at either F2.8 at 1/250 or f4 at 1/125 (depending on the program mode).

The important thing to note is that the exposure is determined correctly by the camera regardless of what lens/convertor you are using. You do not need to dial in any compensation because you added a converter. However, because you are adding a lump of glass between the lens and the camera, the light reaching the film is reduced by a factor of two - this turns your f2.8 lens into a "virtual" f5.6 lens - ie. you lose two stops. But the camera knows about this - you do not need to manually compensate.

That is (believe it or not) the simple explanation - it gets more complex because modern cameras can operate in fractions of fstops and shutter speeds, or even in a "stepless" fashion, but the same principles apply.

Cheers,

Colin
Colin K. Work, Pixstel
 
User avatar
hias
Posts: 337
Joined: Thu Sep 07, 2000 4:17 pm

The Most Powerful Lens

Fri Oct 13, 2000 6:26 pm

Hi Vasco and all the others,

I have different lenses. A Sigma 2,8-4/28-105mm, a Nikon 4,5,-5,6/75-300, a Nikon 2,8/80-200 and a Sigma 5,0-6,3/170-500mm.

The Nikon 80-200 is by far my best lens, as range is not always the most important thing. I have so many different lenses as a "multi-zoom" like Vascos 28-300 lens, brings not the best results compared to other lenses as vignetting is the problem and the sharpness in the edges.

The Sigma 170-500 is a good lens, but with 500mm you need at least 1/500 sec to make a sharp shot and don't forget with that lens haze is becoming a problem for you, as you will shoot while with your smaller lens you won't.

I am doing slides and there you see every unsharpness on the slide. I don't know how it is, when you make color prints.

Best regards

Mathias
http://www.spotter.de.vu
mathias.henig@gmx.de
 
User avatar
hias
Posts: 337
Joined: Thu Sep 07, 2000 4:17 pm

RE: The Most Powerful Lens

Fri Oct 13, 2000 6:34 pm

Sorry Vasco,

I mixed up the facts...  

Dazed uses the 28-300mm lens and not you.

Here are two examples from my last trip to Corfu and both are shot with my Sigma 170-500mm lens:


Click for large version
Click here for full size photo!

Photo © Mathias Henig




Click for large version
Click here for full size photo!

Photo © Mathias Henig



I hope this gives you an example what you can do with such a lens.

Regards

Mathias
 
Dazed767
Topic Author
Posts: 4967
Joined: Tue May 18, 1999 11:55 am

RE: The Most Powerful Lens

Fri Oct 13, 2000 9:31 pm

Ok...I have an N70, the instruction booklet doesn't HELP at all. It was becoming dusk, and I went to shoot a KLM 747-300 that came here to MCO for about a month, of course it was too dark, and my shutter speed was slower, which caused the pic to become blurry. How do I fix that? I thought if I tried to change the aperture, it would help, but if I do, it won't let me take a picture (basicly i have a camera smarter than me). How do I change the F-stop then (if that's the problem?)
 
nscaler
Posts: 236
Joined: Wed Aug 18, 1999 2:00 pm

RE: Should I Get A More Powerful Lens?

Sat Oct 14, 2000 1:34 am

Justin, I have the N80 and am able to change the settings to fit what I want (rather than what the camera thinks I want) easily. I'm not that familiar with the N70 but it should be basically the same. Regardless, you would need to use a short shutter speed and a large aperature at dusk/night. Try panning with the subject. You would need a tripod of course. I have seen some great shots using this technique, but have failed to produce anything with it so far. It takes a lot of practice.

Saul
 
mirage
Posts: 3612
Joined: Mon May 31, 1999 4:44 am

RE: Ckw

Sat Oct 14, 2000 4:12 am

Thanks a lot Colin for your reply. I'm aware of shutter speed and exposure but this function in my camera has made a lot of confusion in my head.

thanks
 
Braga
Posts: 5
Joined: Fri Jul 04, 2008 5:51 pm

RE: Should I Get A More Powerful Lens?

Fri Oct 20, 2000 7:41 am

most common problem with the lenses is the "volume" of light which can go throuh the glass. and this is indicated by the f: nr, should be as small as posible. for tele lenses f:2 is excelent by this way you can usee lower speed films and get bigger prints what will do the same as more powerfull tele. 300 is enough
best wishes
zpik
ps pls exuse spelling
 
Braga
Posts: 5
Joined: Fri Jul 04, 2008 5:51 pm

RE: Should I Get A More Powerful Lens?

Fri Oct 20, 2000 7:52 am

by the way using teleconverters you will increase also by the factor /2X/ the f: number. in some cases when the f: will be bigger then 8 you won't be able to use autofocus
zpik

Who is online

Users browsing this forum: No registered users and 9 guests