Olympus-OM
[Top] [All Lists]

[OM] This is the first time I have posted questions...

Subject: [OM] This is the first time I have posted questions...
From: Chuck Norcutt <chucknorcutt@xxxxxxxxx>
Date: Tue, 29 Apr 2003 11:00:54 -0400
Hello, Richard. I'll chime in here with some answers of my own. If they're different from others you can weigh the preponderance of the evidence.

----------------
1.  When might one want to lock up the mirror on an OM1, OM2, and OM2n?
And how is this done?
----------------
You lock up the mirror to eliminate one of the three sources of vibration... mirror, shutter and diaphragm. In the OM line only the OM-1 and its variants (M-1 and OM-1n) have mirror lockup. The mirror is locked up by turning the small lever behind the lens mount located between the self-timer lever and rewind lever. If you don't have a user's manual you can download one here: <http://www.olympusamerica.com/innards/download_manuals.asp>

Using the mirror lock is only practical when the camera is on a tripod and the subject is stationary. The OM-2 incorporates a special damper to minimize mirror vibration but it is probably not as effective as locking the mirror. Some of the later cameras (OM-2s, OM-4 and its variants, OM-PC/40(???)) do something a bit better. When used in self-timer mode they pre-fire the mirror and aperture about 2 seconds before the shutter which give these vibrations a chance to settle down. The problem here is that the self-timer duration isn't variable and you always have to wait about 12 seconds for the shutter to go off.

Former list member and now just sometimes contributor Gary Reese in Las Vegas demonstrated quite conclusively that the diaphragm stop-down mechanism was a serious source of vibration. Gary performed extensive lens tests using an OM-1 with mirror lockup and then redid many of them after discovering that an OM-4 with both mirror and diaphragm prefire using the self-timer gave notably better performance. See his lens test site here: <http://members.aol.com/olympusom/lenstests/default.htm>

The effect of vibration is shutter speed dependent as someone else has already noted and worst in the middle range. A very fast exposure will tend to freeze the motion. A very slow exposure will experience vibration only during part of the exposure. For tripod use, Olympus has always recommended pressing down on the camera with your hand during exposure to absorb vibrations. The weight and flesh of your hand makes a good vibration damper. There are other tricks too such as hanging weights on your tripod.

-------------
2.  I see ads for lenses that claim absolutely no oil on the blades, or
the diaphragm is oil free. What is the nature and cause of this problem that many Ebay sellers (especially) say they don't have?
-------------
Aperture blades are driven by tiny springs and are supposed to be dry with a "snappy" action... no sluggishness allowed. Occasionally, (especially if exposed to high temperatures) oil/grease from the zoom mechanism or focusing helicoid will migrate onto the aperture blades. The spring does not have enough power to overcome the surface tension of oil. The automatic diaphragm mechanism doesn't work properly anymore and the lens is effectively useless. The oil can be cleaned off but requires at least partially disassembling the lens. An otherwise excellent 50mm f/1.8 Zuiko that might fetch $20-30 is essentially worthless if facing a $50 cleaning bill. Some of the later, better performing 50mm f/1.8's are particularly prone to oil on the diaphragm. To add insult to injury, some have been assembled with glue on the threads and it's impossible to open them up and clean them.

-----------
3.  I know it depends, but should I buy a T32 or a T20?
-----------
Depends. If it's for the OM-1 which does not do TTL flash (where camera controls exposure) I'd get a Vivitar or Sunpak or other third party auto flash (where flash controls exposure) with built-in tilt and swivel. If you want to use that flash with the OM-2 as well then you can also get one that has dedicated OM TTL function as well as auto mode.

Assuming it has to be Olympus for TTL, by all means a T-32 and preferably a BG-2 to go along with it. The BG-2 will get the flash off the camera and provide swivel motion to go with the T-32's built-in tilt. However, the BG-2's swivel motion won't be usable in flash controlled auto mode with the non-TTL OM-1. When the T-32 flash is used in its auto mode the body of the flash (containing the sensor) must be pointing at the subject.

A third party flash with built-in tilt and swivel will allow you to keep the flash on the OM-1 with the sensor pointing at the subject while the flash head points to a convenient wall/ceiling for bounce. The Sunpak 422-D is one relatively inexpensive solution which is available dedicated for Olympus OM TTL and has tilt and swivel along with variable power control in manual mode. There are others. John Lind of this list is particularly knowledgeable on third party flashes for OM.

-------------
4. Ever hear of reversing a 50mm lens on my OM1 and using it for close up shots? Why in the world should this work?
-------------
The optical design of a normal lens is such that it performs best when the subject to lens distance is greater than the lens to film distance. In extreme close ups this relationship gets turned upside down so the lens can be reversed to better maintain the relationship of subject and film plane distances. It's not something you should obsess over. It probably doesn't matter very much and there are better ways to take closeups. Using the lens reversed also raises issues of loss of auto diaphragm control and exposing the protruding rear element to accidental collisions with the subject.

--------------
5. I am drawn to stark, contrasty, sharp black and white photos. What film should I use, Tri-X or Tmax? Or maybe something else?
--------------
I'll let somebody else address this. It's been 35 years since I used much black and white. No doubt you'll get recommendations on Ilford and Scala.

--------------
6. The Photoworks lab does OK with color, but doesn't develop and scan black and white film. Is there someone around who does this well and for a reasonable price?
--------------
Somebody on the list does.  I wish I could remember who.

--------------
7.  Do you think there is a quality difference between the Om1 and Om2n,
or are they all the same high quality?
--------------
The single digit OM bodies are all professional quality cameras. The double digit and letter bodies (OM-10, 20, 30, 40, G, F, PC, etc) are consumer grade. Good cameras but not designed to stand up to heavy usage in tough environments. For the OM-1 and OM-2 the "n" designation nominally gives you a flash ready indication in the viewfinder but also means that this is a later built camera. It *may* have less wear than an earlier camera but also benefits from various engineering improvements that Olympus incorporated over the years.

--------------
8.  Does Olympus still sell anything for the OM cameras?
--------------
The OM line was officially discontinued on March 31, 2003. All manufacturing ceased a long time ago. Various distributors have, I believe, bought all of Olympus's remaining stocks.

--------------
9.  What is the best way to clean a lens without damaging it?
--------------
Blow or lightly brush off any dust or abrasive particles. Use a lens cleaning fluid on a non-abrasive, relatively lint-free absorbent cloth or paper. Apply the cleaning liquid to the cloth first so that liquid cleaner does not run across the lens and run under the retaining ring.

I personally use a method similar to one recommended by Thomas Tomosy in his camera repair books. After blowing away surface dust I take a small piece of facial tissue and roll it into a cylinder about 35mm long and 10mm in diameter. I wet the end of the cylinder with Windex window cleaner and swirl it in a circular pattern around the surface of the lens working from the center to the edge. I may do this several times if necessary and also use the other end of the cylinder. I finish with a light polishing using a dry end of the cylinder and blow away any remaining dust with compressed gas.

Some people are horrified at the thought of using Windex on lens coatings since it contains ammonia. However, I have done this for years and my lens coatings are in perfectly fine shape. It will take much more than ammonia to ruin them and ammonia is a fine glass cleaner. Facial tissue also seems to be free of abrasive particles.

-------------
10.  Why is a 135mm/2.8 a telephoto lens, whereas a 135mm 4.5 is a macro
lens?
-------------
Everything to do with the optical design of the lens and nothing to do with its aperture. The macro lens is designed to perform well at close distances. It is also designed for flatness of field. A flat field is important if you are copying flat objects like the cover of a book. In a more normal lens the plane of best focus would actually be slightly curved. In the macro lens the plane of best focus is flat to accommodate a flat object. The 135mm macro is preferred by some people over other Olympus macro lenses because the longer focal length allows greater working distance from skittish (or even dangerous) critters.

--------------
11. If Ebay is any measure, are prices for Olympus OM cameras, lenses, and accessories skyrocketing? Is this something we can expect to continue?
--------------
Things that are relatively rare and/or are in new or like new condition will probably see their prices rise as they continue to be taken up by collectors. I personally think that the price of very common items will slowly fall as more of us move on to digital over the next several years.

Chuck Norcutt
Woburn, Massachusetts, USA


< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >


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