Olympus-OM
[Top] [All Lists]

[OM] Re: OM mount

Subject: [OM] Re: OM mount
From: Tim Randles <tim.randles@xxxxxxxxx>
Date: Sun, 3 Sep 2006 22:48:00 -0700 (PDT)
Moose, Chuck, and everyone here..

As always, I am astounded at the simplicity and elegance that everyone here put 
into your answers. I am so thankful for having shots to compare to, for 
everyone here having taken the time to gently explain to this "bull in a china 
shop" but enthusiastic novice something that I could have gone and read 35 
books and spent 200 hours online reading about, and impovershed my good wife by 
5000.00 quid on equipment just to learn that my ideas and understanding was 
merely a fart in a windstorm. I am so grateful for this.

I really wished I had an SLR when I was younger, there is so much to learn.. 
and so much fun doing it here.

Needless to say, I wasnt about to drop a couple shekels on that lens until I 
heard "his masters voice" on things, and frankly, I'm totally pumped about the 
ZD50-200mm F/2.8, that I'm holding off getting anything at all until I have 
that in my greedy little hands..

Cheers.. Tim

Moose <olymoose@xxxxxxxxx> wrote: Tim Randles wrote:
> Would this mount on  my E-500?
>
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ih=006&item=160025632616&rd=1&sspagename=STRK%3AMEWA%3AIT&rd=1
As others have pointed out, attaching camera and lens only requires a 
simple adapter.

But that's when the trouble starts. This is a big long series of tubes 
that move relative to each other, with decent lenses mounted in them. 
Guess how rigid everything is for $260? I seem to recall a post about 
how this lens sags a bit. Maybe it was jmac who built a sort of brace to 
hold it straight, someone here, anyway, I seem to recall he did get some 
good shots with it, but it took a great deal of special 
effort/technique. I believe he used it on a large bag of sand/shot/?? 
placed on something really sturdy and with another bag on top; something 
like that.

Getting sharp images from really long lenses is quite difficult. When 
Gary tested the long Zuikos, 400, 600 and 1000 mm in his test series, he 
went to extremes like freezing the legs of his tripod into the ice of a 
skating rink. Still, the lenses don't look very good in his tests 
..

He later said that his tests were not representative of the sharpness of 
the lenses, but of inadequate vibration control in his tests. He later 
used them in the field with other techniques and found that they could 
be very sharp, but it was really hard to get those kind of results.

So far, we've talked about results on 35mm film bodies. Because of the 
sensor size of 4/3, any given image has to be magnified twice as much 
for the same viewing size as for 35mm. And that magnifies the motion 
blur twice as much. A 35mm eq. of 1300-2600 mm lens will require 
extraordinary measures to be sharp. The little tripod set-up they show 
on the ad is a joke for this lens. Even mounted on a concrete post set 
deep in the ground, this thing will have sympathetic vibrations from 
even mild breezes, the camera shutter/mirror mechanism and even those 
that come up through the ground. People walking, traffic, machinery...

The E-500 is also not the ideal body for such a use, as it's noise goes 
up pretty rapidly past iso 400. I'll bet this lens isn't sharp at all 
wide open, so you would be shooting at f11 or f16. Sunny-16 says the 
exposure for f16 in bright sun at iso 400 is 1/400. That just isn't 
going to cut it at these focal lengths, so you would need to experiment 
with higher isos to determine where the trade off is of motion blur vs. 
sensor noise. This is one of the places where cameras with lower noise 
at high isos have an advantage. High shutter speeds cure many long lens 
ills.

I'm with Jeff in suggesting more modest long lens(s) to begin with. 300 
mm on 4/3 is like 600 mm on 35mm and gives a lot of reach. Here are a 
couple of 260-300 mm shots on the 300D, which is only a 1.6 factor so 
the area covered would be significantly less on 4/3 
. That's 
quite a lot of reach.

If you still want something longer and with zoom for framing, you might 
consider the Tokina AT-X SD 150-500/5.6 or the Tamron SP 200-500/5.6. 
These will be much more rigid, solidly built lenses with better glass 
and are fast enough to be much easier to focus than the lens you are 
looking at. And at the 35mm equivalent of 1,000 mm on 4/3, they have 
real reach. Like the 650-1300, of course, they will require manual focus 
and aperture operation. These are all big, heavy lenses and require a 
serious tripod. The various 5-600 mm mirror lenses are much lighter, but 
also slower and with other quirks.

Here's a shot with the Tokina at 500 mm with sample portions that 
represent what would be captured on a 4/3 sensor 
. Lens, 
tripod, head and camera for this shot weighed over 21 lbs.

Moose



==============================================
List usage info:     http://www.zuikoholic.com
List nannies:        olympusadmin@xxxxxxxxxx
==============================================


                
---------------------------------
 All-new Yahoo! Mail - Fire up a more powerful email and get things done faster.

==============================================
List usage info:     http://www.zuikoholic.com
List nannies:        olympusadmin@xxxxxxxxxx
==============================================

<Prev in Thread] Current Thread [Next in Thread>
Sponsored by Tako
Impressum | Datenschutz