Q: I am planning a 40-day trip to China, Hong Kong, Shanghai and Taiwan. I am quite anxious about taking too little or too much film and am considering 70 rolls. But second-guessing is always a problem and I may run out. Are there places in China that sell film? Also, are there ways to ease the film-inspection hassle? And what about having the film developed ?

I would like some suggestions on equipment. I'll be taking a Monolta ZD-11 with a 1.4 standard 50-mm lens as well as well as a 70-120 Sun Zoom. I have been advised that a 35-mm to 70-mm Rokkor Zoom would be a better bet than the standard 50-mm. What do you think ? A: The problems you may face on your trip are similar to those of most avid traveling photographers. The first is the amount of film to take. The best way to decide on your film needs is to estimate based on the number of rolls per day you have shot on previous trips. Be sure to exclude traveling days when you can't shoot, but add some extra rolls for the unexpected. Don't plan on buying film in China, but remember you can replenish at the airports and in Hong Kong.

Your estimate of 70 rolls sounds reasonable for a trip of 40 days, but if Hong Kong is on your schedule about midway, then carry only half the amount and pick up the remainder there.

You may run into some customs hassles with that amount of film. One way around this is to ask some others in your party to carry part of the film if they are carrying only the usual one camera and several rolls, or split up the film into different bags of luggage so it doesn't look like a large pile.

Developing can be a problem on extended trips. It's not a good idea to carry exposed film a week without developing it. You can get your film processed in Hong Kong, where there is a Kodak lab -- called Kodak (Far East) Limited at P.O. Box 48, General P.O., Hong Kong.

Or but prepared mailers and send the film back by mail as you shoot. (Kodak mailers are good for either Kodacrhome of Ektachrome, cost $5.85 for a 36-exposure 35-mm roll at this writing, and can be mailed back to your local Kodak lab from anywhere in the world.) Another advantage to mailing back your film is that your won't be resking all the pictures at once -- and you'll have room for more souvenirs.

I would side with the advice to take along a 35-mm to 70-mm zoom lens since these, and in between, are the focal lengths that you will need most. But the 1.4 lens has some advantages: It is essential for low-light candid shooting and also gives a bright image that is easy to focus on an SLR camera such as your Minolta. If you can handle the cost and slight inconvenience, take both the zoom and the 50-mm.

Additionally, you should consider a wide-angle lens of at least 28 mm. A light 200-mm lens or the 70-mm to 200-mm zoom that you mention can come in very handy for distant candids where you don't want to be obtrusive.

Actually, since you plan to visit Hong Kong, you might start out with the normal lens on your camera and buy additional lenses there (I understand that the lens prics are especially favorable). But a word of caution: Look over the available lenses before leaving to make sure what brand and focal length you may want to add.

(For other readers with trips planned elsewhere, it's better to buy lenses in this country before leaving.) Q: I am going to Glacier Bay, Alaska, during the middle of June. At this time the longest days of sunlight will occur. Some of my friends say that there will be an excess of blue color. Will a polarizing filter, which I like to use to cut glare, accent the bluish light? What other filters would you suggest? Maybe a type of film that attracts the reds might be the answer ?

I have a 35-mm SLR camera and like to shoot prints more than slides -- but if a transparency film is better, I could switch to slides and have prints made. What would you suggest ? A: The color oflight can vary greatly depending on time of day and "where in the world" you are shooting. This color change is caused by the "temperature" of the light, which is measured in Kelvin degrees. A sunrise or sunset scene can be rated at 3,000 degrees Kelvin while a clear blue sky can cool down to 10,000 degrees or 30,000 degrees K. (The lower the number, the hotter the light and redder the scene; the higher the digits, the bluer the mood.)

Professional photographers use a system of filter corrections for color temperature changes called "mired." (A mired is the color temperature of the light, expressed in K, divided into 1 million.) It's a very exact system of color correction, which needs accurate instrumentation to determine the K rating of the light and a full set of color-balancing filters to adjust the light to the film emulsion. You don't need to get involved in this kind of hocus-pocus for average photography.

Your primary problem in Alaska will be too much cold (bluish) light, because of the latitude and the clear sky. (The situation is very much like above-timberline mountain shooting -- and the correction is the same.)

To correct for the excessive blueness use a UV (ultraviolet absorption) filter. This filter is colorless to the eye and won't affect exposure. For an even warmer correction use a 1A Skylight filter, which also won't change the exposure but will cut even more of the blue. The amount of change these two filters will make will be just barely noticeable on slide film and hardly at all on negative color print film. This is because negative color films have greater latitude and more control in the printing process.

For best color you should use a polarizing filter sparingly. The glare that it eliminates may add interest to the picture. Look at a scene through the filter first and then compare the view without the polarizing effect -- then choose. Actually, a polarizing filter won't eliminate all glare and produces the most dramatic result when the sun shines on the scene from either the right or left of the camera position.

The best negative color film to use is Kodacolor 100 for prints, and the warmest slide film is Kodachrome or Fuji rather that Ektachrome, which really turns blue in the cold light.

Practically, you shouldn't have any trouble shooting up north -- just shoot the same way you would at home. Often pictures are lost on a trip because of experimentation -- trying something new that you're not too sure about