Rifle scope magnification vs telephoto lens size

[tony_craig]

I would like to photograph deer and other woodland animals such as

fox squirrels, turkeys, coyotes, racoons and bobcats. It's been

years since I sold my manual slr camera, the lenses and filters. Got

a wild hair and bought a used camera just like my first one and now

I'm trying to build a set of lenses for general and wildlife

photography. I'd like to know if anyone could tell me what mm lens

would equate to the 9x magnification on a rifle scope.

[mag_miksch]

in terms of 35mm SLR a 450mm lense should bring about 9X magnification

[tony_craig]

Thanks. Should I assume that the magnification power equates to about 50mm for each 1x increment, ie, 4x = 200mm? Is there a table or a scale which represents this? I have a Minolta SRT201 with 50mm and 100mm lenses. Want to add one or more lenses that I can do nature shots for my own use. Looking at ebay/classifieds/budget/used fixed or zooms and thinking I should go up to at least 500mm for deer sized animals from a distance. What are the 500-1000 opteka lenses worth on ebay - priced about $250 new?

[larry h.]

Tony, look on keh.com for used gear. Right now they have a Minolta 500mm/8 mirror lens for $189 and up. They also have a Sigma 400mm/5.6 MD APO lens for $205.00. Either of these would be better than the Opteka (or whatever it was) 500mm or 1000mm lenses, which sound like they must be cheap mirror lenses. Mirror lenses from the brand-name manufacturer have disadvantages (doughnut shaped out of focus highlights). But mirror lenses from unknown 3rd party manufacturers are supposed to be generally awful quality in addition to having the same disadvantages.

[stephen hazelton]

Treat a 500mm lens as a simple lens or pinhole 500mm from the negative. A 35mm negative is 24mm high by 36mm long, and the same angle coming back to the negative would be the coverage in front. So, if you're looking at something 500' away, you ought to be seeing a swath 36' wide by 24' high. Or 50' away would be 3.6' wide by 2.4' high. That kind of reasoning should sort of help figure out what you need.

 

It's a bit misleading to compare it to a riflescope or binoculars because the field of view on those things can vary a lot, even at the same magnification.

 

With the smaller animals, it will be a challenge to get close enough to fill the frame with them.

 

Keep in mind that with the camera you can shoot in places like state or national parks where the deer are tamer. So you might be able to get a good bit closer than what you do when hunting.

[tony_craig]

Thanks again for the info. I've been monitoring keh.com and wonder about the condition of unpictured used equipment, especially the 'bargain' ones. keh has a good reputation, but I would like to see a lens I'm giving that much $ for. I'm thinking I want/need at least a 500mm lens to capture the deer, but wonder if more would be necessary. I will be 'in the wild' and not in state parks and can assume distances between 75 - 250 yds away from the subject deer. One final note - I am more interested in deer than smaller animals and am inclined to buy accordingly.

[larry h.]

Tony, if Stephen above is correct with his math, which I haven't bothered to check but it sounds right, you are going to need to be within 75' to get a frame-filling picture of a deer with a 500mm lens. If you are expecting to be no closer than 75 yds., the deer will fill about 1/9 of the frame. But as I describe later, longer lenses really are not a good option.

 

If you are handholding the lens, you will need a minimum speed of 1/500 sec to get anything usable. Your camera has a speed limit of 1/1000 sec. With even the Minolta 500mm mirror lens (3rd party mirror lenses are generally awful), you will have only a two stop exposure range with whatever film you choose, because it is fixed at f/8. So, with ISO 400 film, you will essentially need a subject in close to full daylight to get a decent exposure. I haven't seen too many deer stand in full mid-day daylight before.

 

If you choose a longer lens, you will *have* to put it on a tripod. There are really no longer options that have any kind of quality other than the Minolta 800+ mirror lenses, which cost a lot more than your budget (another, perhaps better option would be Tamron's 400mm/4 lens plus a good quality 2x converter, also expensive).

 

But realistically, the two options I gave you earlier are your best bets. I think you may need to set your sights a little lower. Perhaps you should start off getting a cheap Minolta 200mm/4 lens, improve your telephoto technique, then move up to the Sigma 400mm/5.6 lens. That is my recommendation.

[ron c sunshine coast,qld,a]

Larry gives some very good options there.

<P>If you do want a cheapo option,avoid the cheap ebay mirror lenses,they are woeful.There is however one decent inexpensive option-these lenses are quite good.

<BR>http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=4687&item=3874766733&rd=1

<P>Note that this one is of course for a canon mount but as they are T mount lenses,they are available to fit anything.Don't bother getting one with the 2x multiplier though,those things just stretch the optics too far to be usefull.Instead find someone selling the lens only .

 

 

<p> And here are some examples from an identical lens (different brand but the same design )<BR>

http://members.dodo.net.au/~l8r_ron/index_5.html