A Slew of Lens Questions I can't find on the intewebs

[klbasey]

I have a Canon HF S100 and I'm looking for SLR lenses to attach to it because:
1) I'd much rather use twist the zoom than to rely on the camera's own zoom control because I can manipulate depth of field more precisely
2) By combining the zoom lens with the cameras own zoom optical zoom I can film subjects further away than with the camera's own lenses
3) I'll have the lens to put on an actual DSLR camera in the future if I decide to go that route (I got such a great deal on the HFS100 that I couldn't justify spending extra money on a dslr to begin with faced with such a bargain)

My questions are:
1: Does anyone have a similar setup of using slr lenses on consumer/prosumer camcorders and are you happy or not?
2: If you do use slr lenses for camcorders what lenses are in your arsenal?
3: Do you find you use something in the 18-55mm range the most or something else?
4: I've had it in my head that adding glass that's a f/3 to my camera whose aperture is opened to an f/1.8 will make the aperture effectively f/4.8. Or Lens A f-stop + Lens B f-stop =overall f-stop. Is my thinking correct?
5: Any canon lenses with image stabilizing and auto focus features will be useless on the hfs100 because it's a camcorder and not an slr...Right? So I should spring for lower end lenses without all the cool motor upgrades and such (even from different brands)...Right? And will the camera's own image stabilization work to stabilize the image coming in from the other lens well?
6: Would using lenses of 77mm filter thread size vs. using lenses of say a 62 or 67mm thread produce noticeable differences in quality due to size differences of the glass?
7: In my research on step up rings going up isn't an issue. Do you know of any anomalies that would contradict that statement other than the obvious "I do know stepping down in lens size will cause vignetting". Up is what I'm looking for.
Thanks for any input you have and please take a stab at any you can help me with.

 

[gooberman]

You never mentioned using a DOF adapter. You have to have one of these if your going to attach a SLR lens to your video camera. Attaching the lens directly to the camera won't work.

 

[gooberman]

Most guys on here are going to tell you to skip the DOF adapter and ditch the HF S100 and get a T2i which is probably a good idea.

 

[Dreadylocks]

goob is right, you're going to need a 35mm adapter. Then you will actually lose your cameras zoom capabilites while you have the lens on since your camera is just focusing on the focusing screen.

You could still get a zoom lens, but most people stick with primes as the adapter is going to take away a stop or two (it'll be darker), and prime lenses are quite fast (low f-stop, takes in more light).

Those sound like negatives, and they are if you really need the zoom. Nevertheless I have an hf200 and 35mm adapter and I'm very happy with it.

 

[gooberman]

you can make your own DOF Adapter or you can buy one http://jag35.com/new/products/jag35st/

 

[klbasey]

Thanks for the heads up guys. Glad I came here before finding out the hard way. I might try my hand at making one. Again, thanks for the info.

 

[Cracker Funk]

You should stick around. That little bit of help they just dished out is barely the tip of the iceberg. Very active online community.

 

[David.rhsc]

1: Does anyone have a similar setup of using slr lenses on consumer/prosumer camcorders and are you happy or not?

Yes. I don't personally own the gear, but I work with similar setups frequently. You will need an adapter threaded for your camera and with a lens mount of your choice on the other end.

Search terms for here and Google: Red Rock Micro, Letus, Jag35, P+S Technik (might have the wrong spelling on that one.

2: If you do use slr lenses for camcorders what lenses are in your arsenal?
3: Do you find you use something in the 18-55mm range the most or something else?

The most common setup I have seen is a set of F mount Nikon primes, usually Nikkor and Sigma brands. It can also be done with FD mount Canon glass (currently collecting this for my AE-1 anyway), though those tend to be more expensive second hand.

There's no real reason to use EF or EF-S lenses on the setup you describe, unless you already have them.

Regarding lens choice, 18-55 zoom is okay on a budget, but a good one will probably cost you as much as several of those focal lengths in older SLR primes.

4: I've had it in my head that adding glass that's a f/3 to my camera whose aperture is opened to an f/1.8 will make the aperture effectively f/4.8. Or Lens A f-stop + Lens B f-stop =overall f-stop. Is my thinking correct?

Edit: My answer for this wasn't actually fully accurate or well explained. Removed for now, and might come up with a better answer when I'm not feeling sick.

5: Any canon lenses with image stabilizing and auto focus features will be useless on the hfs100 because it's a camcorder and not an slr...Right? So I should spring for lower end lenses without all the cool motor upgrades and such (even from different brands)...Right? And will the camera's own image stabilization work to stabilize the image coming in from the other lens well?

Well, it may be that Red Rock Micro has an adapter that uses these bells and whistles, but I prefer to work without them. Once you rig the camera on rods, with adapter, with lens, IS is not really needed on the lens. Never used IS in camera with an adapter so no idea on the results there.

6: Would using lenses of 77mm filter thread size vs. using lenses of say a 62 or 67mm thread produce noticeable differences in quality due to size differences of the glass?

Not really, those thread sizes are usually for mounting filters on the lens front, and can vary depending on the lens. It's more important that they are fast, high quality lenses designed for full frame 35mm still use.

7: In my research on step up rings going up isn't an issue. Do you know of any anomalies that would contradict that statement other than the obvious "I do know stepping down in lens size will cause vignetting". Up is what I'm looking for.

Nope. The rings are simply there to allow you to thread to different camera fronts. I forget the numbers but the HVX/Red Rock combo involves a change in ring size compared to the EX-1/Red Rock combo, for example.

 

[klbasey]

Wow thanks for all the info. I knew absolutely zilch about lenses just a few days ago and now I feel I have a much better grasp on the topic. I can't find much about teleconverters when I query the forums here. These would be ideal if I wanted to increase my zooming capabilities for camcorder without adverse effects, correct? Do teleconverters have an effect on the f-stop?

 

[David.rhsc]

Post edited to remove a bad answer.

 

[wheatgrinder]

Im the canon hfs100 with 35mm adapter dude.

If you already have the hfs100, then spending the cash on a 35mm adapter is worth it. But if your in the market for a camera and haven't spent it yet. , then the T2i will just save you so much pain.

That said, I love my setup and get good looks from it all the time.

If you search some of my older posts you'll find lots of good data on 35mm adapters, its a good time to be in the market, lots of used available and getting cheaper everyday.


One thing to remember is that to use a 35mm adapter you HAVE to zoom the camera in on the imaging element, this will INCREASE your in camera fstop.

 

[wheatgrinder]

in related news.. David.rhsc, I have a FD 50mm f1.8 Ill trade for just about anything... PM if interested..

 

[David.rhsc]

in related news.. David.rhsc, I have a FD 50mm f1.8 Ill trade for just about anything... PM if interested..

Bummer. I have that lens, if you had the 1.4 SSC (I think they were SSC's) I'd pay you cash money.


@klb:

I'm not certain that what you want to do will work without an image plane between the mounted lens and the camera lens.

If you just used a tele-extender and put a 35mm lens in front of that, you wouldn't have any image plane at the proper back-focus distance for the 35mm lens you are using.

That said, you might get some very interesting images as a result. Always worth the experiment.

If you just want to put something in front of your camera lens to widen or add more telephoto, then you are talking diopters like this:

http://cgi.ebay.com/58mm-Pro-HD-Lens-Kit-CANON-VIXIA-HFS11-HFS10-HFS100-/190422622844

Anything you introduce in front of the lens will affect your T-stop, which is actual light transmission. F-stop is just a ratio of lens aperture to focal length. Okay, so that last bit was uber-nerdy.

Since you already have the HFS100, a used Letus (Extreme or Ultimate) or a used P+S Technik (not sure if this one comes in your ring size), with used lenses from ebay is probably the way to go.

 

[klbasey]

The 35mm adapter and 35mm lenses aside for the moment... I'm having trouble grasping the differences I'd have if I used a teleconverter/tele-extender or a diopter on the camera by themselves. If I used a 1.4x teleconverter I could increase the maximum maximum zoom capabilities of the lenses inside my camera by 40% yes(?), but with the disadvantage of losing a stop or so of light. David.rhsc says that diopters also adds telephoto capabilities and widens as well. If I fill the entire frame of my camera with the deodorant stick label sitting about 2ft away from me on my desk with my camera fully zoomed optically I cannot focus the image manually to make out any of the lettering on it, it's all a blur. If I lean just a few inches back it becomes perfectly clear. So I'm wagering a guess that a diopter would be ideal if I was trying to video something very close and very small like you'd see in a discovery channel type show about ants. Correct me if I'm wrong, but is that do to a possible focal length shortening effect caused by the diopter making the minimum focal length of my lens effectively shorter giving me the ability to stand closer to something and still bring it into focus (which would account for the widening effect noted by david.rhsc since you start getting to wide angles the lower you go in mm)? I may be getting carried away, but there wouldn't be much utility for a diopter if I wanted to get an extreme long shot of a subject from a quarter mile away because the diopter would screw with what my camera's perceiving as the max programmed focal length so when my focus is on infinity my subject would still be in a blur(right?). And that's where a teleconverter would come in handy, for those long shots? So in summary a diopter would lower your max focal length (does a +2 diopter lower the focal length by a factor of 2?)and the teleconverter would multiply you focal length (a 1.4xTCON*435mm lens=609mm new focal length or a 40% increase). Again, I might be getting carried away so please by all means school me if my thinking's wrong. So the take away would be if you wanna shoot shorter distances and tiny subjects go with the diopter and if you want to capture subjects further away go for a teleconverter? Please don't give up on this thread I think I might actually be getting some these concepts.

 

[David.rhsc]

Holy wall of text Batman! Going to give this a try. If I am reading you correctly, it seems that you have the concept down. Here come some specifics:

The 35mm adapter and 35mm lenses aside for the moment... I'm having trouble grasping the differences I'd have if I used a teleconverter/tele-extender or a diopter on the camera by themselves.

Okay, definitely two different animals. 35mm adapter + lenses is a different world from attaching screw-on glass to change the characteristics of the lens.

If I used a 1.4x teleconverter I could increase the maximum maximum zoom capabilities of the lenses inside my camera by 40% yes(?), but with the disadvantage of losing a stop or so of light. David.rhsc says that diopters also adds telephoto capabilities and widens as well.

Basically yes. I am not certain that 1.4 == +40%, but that sounds like a good starting point. It's possible that the math is not linear (lots of lens math is logarithmic, so 1 point of input does not always equal 1 point of output).

There are accessories for adding telephoto, going wider, going macro, etc.

If I fill the entire frame of my camera with the deodorant stick label sitting about 2ft away from me on my desk with my camera fully zoomed optically I cannot focus the image manually to make out any of the lettering on it, it's all a blur. If I lean just a few inches back it becomes perfectly clear. So I'm wagering a guess that a diopter would be ideal if I was trying to video something very close and very small like you'd see in a discovery channel type show about ants. Correct me if I'm wrong, but is that do to a possible focal length shortening effect caused by the diopter making the minimum focal length of my lens effectively shorter giving me the ability to stand closer to something and still bring it into focus (which would account for the widening effect noted by david.rhsc since you start getting to wide angles the lower you go in mm)?

What happened here is that you were closer to the object than the "critical focus" on the lens. This is a fancy way of saying the nearest an object can be and still be rendered in sharp focus. Macro/wide attachments will shorten this distance, and allow you to get closer to the subject. Would this setup let you shoot ants like on the Discovery channel? I don't know. That's some serious macro work.

I may be getting carried away, but there wouldn't be much utility for a diopter if I wanted to get an extreme long shot of a subject from a quarter mile away because the diopter would screw with what my camera's perceiving as the max programmed focal length so when my focus is on infinity my subject would still be in a blur(right?). And that's where a teleconverter would come in handy, for those long shots? So in summary a diopter would lower your max focal length (does a +2 diopter lower the focal length by a factor of 2?)and the teleconverter would multiply you focal length (a 1.4xTCON*435mm lens=609mm new focal length or a 40% increase). Again, I might be getting carried away so please by all means school me if my thinking's wrong. So the take away would be if you wanna shoot shorter distances and tiny subjects go with the diopter and if you want to capture subjects further away go for a teleconverter? Please don't give up on this thread I think I might actually be getting some these concepts.

Basically you would want to use one or the other. Tele if you need more "zoom" and wide if you need to get closer, go wider, etc. There may also be purpose built ones for macro. Essentially you'd be looking at a kit of several devices, the choice of which to use depends on the shot. Seems that your math is solid, although I could be wrong about that.

Screw-on bits like this will impact your effective stop and budget ones will introduce various aberrations into the image. Not always a bad thing, sometimes technical imperfections are very cool looking.

I would start by seeing what is available for your particular camera and go from there.