I began my interest in photography with a Pentax Spotmatic 35mm SLR back in 1968 and if someone were to offer me a dollar each for all the 1.5x, 2x & 3x tele convertors that I have thrown away over the years I could take my GF out to dinner tonight..LOL. Over the years I have stayed with Pentax for two reasons. First off, I have shot over 250,000 frames with my original Spotmatic and it still performs well. In addition, while Pentax has always stayed on the cutting edge of technology, often being the first to introduce new technologies they have managed to design their cameras in such a way that we can use any Pentax lens ever made on the brand new DSLR's. In fact, both Nikon and Canon build adapters that will allow you to use the old Pentax screw mount lenses on their new cameras. Generally telephoto lenses are used for taking pictures of distant scenes or objects outdoors, well beyond the maximum limits of a flash unit so we are obligated to shoot under the available light conditions. If we are taking a picture of a stationary object we can easily mount the camera & lens on a tripod and compensate for low light conditions by extending the shutter speed but, if you are taking nature shots of birds and animals shutter speed is critical because the subject is not going to remain motionless long enough to permit long shutter speeds. You may have also noticed that as we extend focal length we loose effective aperture. By example, your normal lens may be f1.2- f2, but if you extend to 200mm the maximum aperture will be in the order of f3.5 and at 300mm it will be f4.5 - f5.6. Every time we close the lens one f-stop we must cut shutter speed in half to get the same exposure. By Example, if you have an exposure of 1/125 @ f2 then stop the lens down to f3.5 you must drop the shutter speed to 1/60 to get the same exposure. Let us assume for the moment that you are shooting a scenic shot in late afternoon with your normal lens and you get an exposure of f2 @ 1/125. That would be a very easy hand held shot but what if you changed to a 300mm lens that has a maximum aperture of f4.5 ? You are losing two f-stops of light so you must now change the shutter speed 2 f-stops so the exposure would now be 1/30 @ f4.5 which is well below the 1/250 minimum for a hand held shot with a 300mm lens. Years ago the big 3 camera manufacturers (Nikon, Canon & Pentax) did not even offer a tele converter but due to pressure from 3rd party aftermarket sources they do now offer them, although they keep them very low key in their advertising for good reason. The main problem with tele converters, and what none of the third party manufacturers openly state is the "light insertion loss". Typically a tele converter will introduce a minimum of 2 f-stops of light loss and some go as high as 4 stops. Now it can be argued that with most DSLR's we can compensate for the light loss by increasing the ISO index. (every time we double the ISO we gain one f-stop), which is true, but keep in mind that for every increasing in ISO there is a loss in image resolution and a significant increase in grain (called noise on digitals). Tele converters also introduce both Chromatic & spherical aberrations which is a color & edge distortion that becomes very problematic when printing enlargements. While on the subject of aftermarket products there is another option needs to be mentioned, that being mirror lenses. While the big 3 camera manufactures do make some very good mirror lenses, there is a long list of aftermarket manufactures that build inexpensive 500mm & 1000mm mirror lenses. Be very careful here because most of the inexpensive mirror lenses have a fixed aperture which is typically f-8. While they will perform marginally well for shooting scenics from a tripod, due to the fact that most birds and animals are most active in early morning or late afternoon those lenses are almost useless for nature photography.

I have also been a serious amateur / semi-pro photographer since the early 1960's and like you, when I retired I decided to take up Wildlife & Nature photography as my retirement hobby primarily to gie myself an excuse to get out of the house regularly, but even more specifically because I suffer from C.O.P.D. and I find taking long nature hikes carrying a 30lb backpack of photo equipment very theraputic, as an example, one year ago I couldn't walk to the mailbox without carrying a portable oxygen tank but today I think nothing of 5 or 10 mile hikes and I have not even had the O2 equipemtn for the last 6 months. According to my book, Birds of Ohio, there are 413 species of birds native to the state of Ohio. To date I have photo documented 119 species either in my yard or within walking distance of my house. Bird photography presents a number of unique challenges and with experience you will find that your technique is every bit as important as your equipment. Most birds fly between 20 and 30mph while some of the hawks and raptors are capable of speeds in excess of 70mph. This means that while in flight most birds are moving 30 to 45ft/sec which makes it nearly impossible to focus on birds while in flight, therefore if we have any aspriaton of getting flight action shots we have to anticipate where the bird will be, then set our equipment up in advance and await an opportunity to take the shot. Obviously shooting birds when they are still is much easier, but keep in mind that birds are very elusive so we must provide some means to attract the bird to our viewing area. IN winter this is very easy, we simply put up bird feeders, then sit back and wait for the birds to come to us, but what do we do in summer? Birds are opporunists and for basically the same reason that people frequent fast food restaraunts, birds can easily be attracted by bird feeders, bird baths, small decorative ponds in your landscaping and selected flowers and shrubs that attract birds. If your into capturing images of birds in their wild habitat you could do as I do, don full camoflage and stake out a spot where you have full view of wild fruits, berries, corn fields etc. Oh yes, I realize that this may seem gross to some, but don't overlook the photo opporunity of staking out a vantage point where you can watch some road kill. You will be amazed how many birds are scaavengers. Although much more difficult to get a good viewing angle, you can get some very unique photos ir you can find a nesting site, but be careful here. If you repeatedly get too close to a nesting site the parents may abandon the young. Under no circumstances should you ever touch a nest becuse that would leave your scent and the parents will nearly always leave. Now to answer your original question, what lenses do you need? Let me begin by clarifying a point for you. Rgardless of what kind of camera we use, a normal lens has a focal length equal to the diagonal measurement of the negative format or the electronidc sensor. By example, a 35mm film camera produces a negative that is 24x36mm therefore the diagonal measurement is 43.2mm. (due to the physical space reqquirements of the multiple elements, aperture and focusing linkages the industry has accepted 43 to 55mm as the normal lens). Any lens which has a focal length longer than the Normal lens is said to be a Telephoto lens. Generally lenses up to 3x the normal focal length are defined as telephotos while lenses longer than 3x the normal focal length are defined as super telephotos. Lenses with a focal length that is shorter than the normal focal length are called "Wide Angle" lenses. Lenses with a fixed focal length are defined as "Prime lenses" while lenses with a variable focal lenght are said to be a "Zoom Lens" meaning that is can be zoomed from its minimum to its maximum focal lenght, thus you could have a zoom wide angle or a zoom telephoto. On cameras that have a fixed lens they often define the focal ength by a number, by example, they may say the camera has a 10x zoom. In this case the numbrer is multiplying the focal length of the normal lens for that format, thus while the normal format for a 35mm film camera is 43mm, a 10x zoom would equal a 430mm lens. For 35mm film cameras or DSLR's a 300mm lens is considered the longest lens that can consistantly be hand held and they should only be used in hand held mode when the shutter speed is 1/125 or greater. Lenses longer than 300mm or in situations where the shutter speed will be less than 1/125 it will require a monopod, tripod or other suitable means of support. The actual diameter of the lens aperture can be mathematically computed by dividing the lens focal length by the index number, by example, if you have a 50mm lens set at f-2 the actual diameter of the aperture opening is 50/2= 25mm while a 300mm @ f-2 would have an aperture opening of 300/2= 150mm however due to the difference in angle of view both lenses would produce the same light level at the film plane. If we then examine the complete f-stop scale we would find that the the indexes are such that increasing the index one stop will reduce the cross sectional area of the aperture to 1/2 the cross sectional are of the previous aperture opening. If you then examine the shutter speed scale you will note that each increment is approximately double the time of the next higher shutter speed. Exposure is a combinastion of time and light intensity, thus if we change the f-stop one stop we either double or halve the amount of light striking the film or sensor, and if we change the shutter speed on index figure we also either double or halve the light to the film. In this manner we can change the overall exposure one f-stop by either changing the aperture setting or the shutter speed one index. You could use a 200mm lense with a doubler as was siggested before, but when we attach a doubler the actaul apertue size remains constant while we double focal length so we instantly loose one f-stop. In addition, we generally loose another f-stop to the light loss through the glass lens in the doubler. As a result the actual insertion loss of a doubler is typically 2 f-stops and some cheaper after market doublers have an insertion loss of 3 f-stops. When i first begani my interset in photography a built in light meter was still a new feature and in those days we had to learn how to eyeball an exposure. (When using my old manual focus pre-set lenses I still put my camera in manual mode and eyeball the exposure for practice) ISO is the actual shutter speed required to produce a proper exposure at f-16 in mean daylight at noon at the equator. As you move north of shuth of the equator the angle of incidence of sunlight changes and we must compensate the exposure, thue in the USA in bright sunlight at noon in mid summer the proper expose shutter speed would be equal to the ISO number with the lens set at f-16 and we loose one f-stop for each two hours before or after noon. Keep in mind that birds are most active in early morning or late afternoon. Using the aabove formula, if we are shooting a picture at 4pm on a bright summer day in mid summer our we could set the shutter speed to the ISO speed and set the lens to f 5.6. Keeping in mind that we want a shutter speed of at least 250 to stop action we must then use ISO 400 and if its a cloudy day or in shade the exposure would be f-4 but our lens will only open to f 5.6 so we must then increase the ISO to 800. If we were to attach a doubler we would need to push the ISO two more stops to 3200 and risk a lot of image loss to noise. In my humble opinion the best economical lens for what you want to do would be a 70-300mm f 4-5.6 I would also strongly encourage you to get a good heavy duty tripod and a remote shutter release. Your Canon Rebel uses the Canon EF mount and although I am not familiar with your camera it may also use the Canon EFs mount. Out of curiosity I did a quick scan on Ebay and found 11 Canon 70-300mm f4-5.6 EF lenses listed with a "Buy Now" price ranging from $119 to $189 ( avg was $139). I also found a couple Sigma 70-300mm f4-5.6 with canon EF mounts for $129 and if you are willing to go through the bidding procedures I saw a couple that went as cheap as $65+S&H. I am attaching some photos that i took with my Pentax ist DL (6.2mp) DSLR with a Sigma 70=300mm f 4-5.6 manual focus lens.

Got up at 5:30, darn race didn't start until 8, they said 7 on one of the news websites. Had to get there early enough so I didn't have to park too far away, people everywhere all over town. Hot already but not as bad as I thought. Here I am telling you what to do and my photos did not turn out too great. I shot sports mode, buildings & background were bright but runners too dark, many blurry or out of focus, many good and fixable. I am going to have to process each one that's worth keeping (shot 594) and brighten most of them up with shadow highlights. Good learning experience. I shot most in sports mode which kicks into burst, but I'm not happy with a lot of today's because I can't change any of the parameters in that, picks too large apertures and too slow shutter speeds and continuous auto focus I'm not used to at all. It is hard shooting a sea of people, never been in a situation quite like that before. I'm thinking about what to do next time, couldn't figure out how set burst so I could use tv mode standing out there with all those people, should have shot tv mode, 1/800, ISO 800, partial metering. Maybe. I'll have to get some help with that. Coming home, I was trapped in by lots of street closings, had to go way out of my way to find a way out of that maze, lucky I know my streets around here, only one way out from where I got myself. Filled two 1 gig flash cards in about 1/2 hour! Good timing though, a few stragglers were coming up the hill when both cards were full. I'll wait for your photos. Yours will be easy. I know people steal photos. I haven't caught anybody doing that to me yet, maybe mine aren't that good? Somebody in France liked my peacock java applet and wrote and asked, I said ok. What do I care? I just don't want people making money off my work. Will address some of the other issues later. Too bad you have to break up your lily garden, that would be very hard for me to do. You must be either a specialist or have special lilies and maybe getting older like I am? Granny out shooting a race. Hah! I wonder which lens would be best for that? Used 50mm with a different race, much smaller, this time went with the 28-135 so I could zoom. 70-200 not wide enough even if I had it which I don't. That is a conundrum for sure since I was so close to most of them standing on the sidewalk, brushed by a few, tried not to get in their way. Then some other photog gets in my way. There now you taught me something about bracketing. I've been doing it the hard way. Shoot, look at histogram, set exposure comp or some other adjustment. I'm going to try bracketing and quit on the bright end like you do. So thanks for that tip! I dared not shoot that race in AV (my favorite) because with the early morning bright light and shadows, it would have picked too slow a shutter speed. Frustrating. THIS is where I would like to have been positioned lol. She hadn't turned her camera toward the race yet, she had to swing it about 45 degrees to her right to be pointing at the runners coming up the long hill. I fixed this one a little. Later, Alice

Here's a fun study in contrasts. 1st pic is of our kitchen, just before finishing. Wide aisles, at 48". Incredible, kitchen "quadrangle" for cooks. Taken by either me or my contractor. 2nd pic is of the whole room, from the kitchen, by a pro- wide lens, again pre-fnish- built in floating media cabinet on the TV wall, shelves on niches not yet added. Look how cavernous the 2nd pic looks. Looks like 7' between the main sink to the left (not visible in the photo, and the island. Lol. Also makes the cabinets appear reddish, when they aren't. I'm not sure that's good marketing, as it gives a false impression of the home- could turn some people off, or could lead to unrealistic expectations, even when they "know" the total square footage.