stock lens at telephoto v 35mm adapter

G

Glen Johnson

Member
Hello there

I have just received my SGpro 35mm adapter and will now start the hunt for lenses. My question is this:

Should I buy long telephoto lenses for my SGpro or use the Stock lenses zoomed in?

I plan to buy

20mm, 50mm, 85mm

Im thinking if I need to zoom any closer then the stock lens will cover me...

You seem to get enough DOP when the stock lens is zoomed so as not to get that video look? Good idea or footage won't match...? Or should I buy a zoom lens for the adapter?

Any opinions welcome.

Thanks
 
if you switch to the stock lens for longer shots: 1. it will take time to disconnect the sgpro 2. it WILL look different.

i say get a couple of longer primes instead of zooms
 
The stock HVX lens is a 4.2mm to 55mm zoom, so it won't replace a telephoto on your SG Pro. Zoomed in all the way, the HVX will have a comparable looking DOF as a 50mm on the SG Pro. If you were to use the stock HVX lens in place of the adapter, it would be for wide shots.

For your adapter:

20mm is a pretty wide lens. I have a 28mm that I hardly ever use. When I do need a wide lens, I normally use a 35mm. The 35 is just enough for a nice wide shot without too much distortion (unless that is what you are looking for).

You will need a 50mm of course, and you will love having the 85mm for close-ups and other various shots.

Wide lenses: keep in mind that vignetting (in this case, natural light falloff) is inherent with some wide lenses (depending on the brand and series of lens). Generally, the wider they are the worse the vignetting can be. So, if you do go with a wider lens, you might want to do a little googling to see what people are saying about it at the various photo forums.

As far as matching the look between stock HVX and the adapter. It has been done by folks around here fine. I'm pretty sure that Jack Daniel Stanley has done it in his DVXuser shorts. Anyway, with some adjustments, I'm sure you could get them to match. I'm with wgzn though in that it would be a hassle to be taking the adapter on and off. In my mind, once the adapter is on the camera, it becomes part of it.

Hope that helps
 
I would buy a telephoto. I don't mix the HVX lens and adapter. The only time I mix footage is when I use the HVX lens for it's great macro possibilities.
 
Be sure that your lenses are equal or faster than f/1.4, otherwise the 35mm adapter will have less or no advantage over the stock lens.
 
someday said:
Be sure that your lenses are equal or faster than f/1.4, otherwise the 35mm adapter will have less or no advantage over the stock lens.
Click to expand...

I would totally argue that point. I do agree that faster lenses are the way to go because it will minimize one of the negative attributes of an adapter...but first of all, slow lenses do not remove the advantage of the 35mm. The advantage is achieving less depth of field, using lenses which can exceed the minimum or maximum zoom of the standard lens, and other attributes. The fact it MAY require you to light at a higher minimum f-stop is just a blow to the guerrilla, low budget or un-prepared shooter.

Fast lenses will allow you more flexibility, and options, but slow lenses will not remove the advantage of a 35mm adapter. It will just require more light.
 
Glen Johnson said:
Thanks for your replies,

Would a zoom lens on the adapter be the/a answer?
Click to expand...

Zoom lenses tend to be slower, so it depends how you are using your camera.


If you are shooting mainly outdoors with lots of light, indoors with lots of light, and have the means to light, then a zoom can do nicely.

If you are pressed for lighting gear, if you are shooting more guerrilla style, than *primes are faster.

*Note I am referring to fast primes. (f/1.4, f/2)
 
someday said:
Be sure that your lenses are equal or faster than f/1.4, otherwise the 35mm adapter will have less or no advantage over the stock lens.
Click to expand...

Prodigy= said:
I would totally argue that point. I do agree that faster lenses are the way to go because it will minimize one of the negative attributes of an adapter...but first of all, slow lenses do not remove the advantage of the 35mm. The advantage is achieving less depth of field, using lenses which can exceed the minimum or maximum zoom of the standard lens, and other attributes. The fact it MAY require you to light at a higher minimum f-stop is just a blow to the guerrilla, low budget or un-prepared shooter.

Fast lenses will allow you more flexibility, and options, but slow lenses will not remove the advantage of a 35mm adapter. It will just require more light.
Click to expand...

I'm with Prodigy. Having a lens that is not f/1.4 does not negate having an adapter by any means. Adapters do cause light loss, but I have honestly never run into a situation where I needed just a few more stops to get a shot. Documentary, run-and-gun, and unlit situations are a different story of course... but the HVX (without an adapter) is more suited for that type of shooting anyway.

The key with 35mm adapters isn't so much that they create a short DOF. The key is that they increase the target size so that practically any 35mm lens can be used. Shooting the HVX full wide creates a very deep DOF because the focal length is at 4.2mm. Yes, you can back the HVX up and zoom in all the way for a more shallow DOF, but it just isn't practical to shoot that way all of the time. Adapters give DV filmmakers similar advantages that somebody shooting on a 35mm camera or full size CCD camera have (in terms of using interchangeable lenses). They allow us to choose a deep or shallow DOF and a field of view that the stock HVX lens can't offer (anything above 55mm).

Glen Johnson said:
Thanks for your replies,

Would a zoom lens on the adapter be the/a answer?
Click to expand...

A good zoom lens will cost some $ and will be very bulky to have hanging off the front of the camera+adapter. I'm sure people do it though. My advise would be to put together a nice kit with some Nikon or Canon fixed lenses. The total cost of our Canon FD lens kit was somewhere around $450:

28mm 2.8
35mm 2.0
50mm 1.4
100mm 2.0

All of which have proven to be great lenses. I haven't used the 28 much, but so far so good.

Your best bet is to do some googling and find out what lenses the 35mm still photographers are raving about in the photo forums. Many of the older film SLR Canon and Nikon lenses are excellent lenses and will produce great images with you SG Pro. For example, you might find that a specific f/2.0 50mm is known to produce better images than the f/1.4, etc. That is one of the great things about being able to use some of the older still lenses; they have been used by countless photographers over the years and there is a good info out there as to which ones have proved to produce quality images.

I heart 35mm adapters.

P.S. I heart the RED camera even more, so please send donations via paypal.
 
someday said:
Slower lenses will require tons of lights. If he can afford them...
Click to expand...

I would also say that to get a nice and managable DoF you need lots of light in some situations (maybe not if your going for a grungy low key look, but if you like poping vivid colors...)
I don´t wanne be the focus puller on a wide open shoot, that´s for sure :thumbdown
But outside on a sunny day it can sometimes be hard to not close down too far, unless you like the look of a spinning GG :evil:
 
Spartacus said:
I would also say that to get a nice and managable DoF you need lots of light in some situations (maybe not if your going for a grungy low key look, but if you like poping vivid colors...)
I don´t wanne be the focus puller on a wide open shoot, that´s for sure :thumbdown
But outside on a sunny day it can sometimes be hard to not close down too far, unless you like the look of a spinning GG :evil:
Click to expand...

I know what you mean! I shot at the beach with my 35mm adapter and wow!

To prevent stopping down too far on the lens I utilized the HVX's ND filters, closed the HVX iris just a little more, and sometimes if that was not enough I just changed my shutter speed as last resort.
 
=Prodigy= said:
I know what you mean! I shot at the beach with my 35mm adapter and wow!

To prevent stopping down too far on the lens I utilized the HVX's ND filters, closed the HVX iris just a little more, and sometimes if that was not enough I just changed my shutter speed as last resort.
Click to expand...

Doing the same ATM, looking to buy NDs for the Mattebox...:thumbsup:
 
=Prodigy= said:
To prevent stopping down too far on the lens I utilized the HVX's ND filters, closed the HVX iris just a little more, and sometimes if that was not enough I just changed my shutter speed as last resort.
Click to expand...

Spartacus said:
Doing the same ATM, looking to buy NDs for the Mattebox...:thumbsup:
Click to expand...

Using ND's in front of the 35mm lens is the way to go. Using the in-camera ND filters can reek havoc on the image.
someday said:
Slower lenses will require tons of lights. If he can afford them...
Click to expand...

I wouldn't get too hung up on fast lenses. A f/1.4 50mm lens set to f/5.6 will produce the same DOF as a f/2.0 50mm lens set to f/5.6. So the same amount of light would be required in both cases. If you plan to shoot at f/1.4, then yes, the f/1.4 would require less light. But as Spartacus noted, the DOF from a full open f/1.4 lens is not easy to manage. The key is that the sweet spot of a f/1.4 lens might be around f/4 while the sweet spot of a f/2.0 lens might be around f/5.6. This is not always true though as lenses vary depending on the year they were made, the brand, the series, etc. There are fast lenses that just plain suck. My point is to do some research and choose quality over speed. That being said... I would stick to f/2.8 and faster.
 
snodart can you elaborate on the ND difference? I am not an expert on optics, but I would have ventured to guess that an ND in camera would be about the same as an ND in front of the lens...

Plz explain.

Thanks in advance
 
Snodart,
A debate is raging on DVInfo.net regarding this question of internal ND's with the HVX and a 35mm adapter. Have you actually seen this "reek havoc on the image." I haven't and neither has Barry Green and we've both looked for it.
I don't get it, I don't understand the reasons why people seem to stand by this idea like its gospel. What's wrong with the internal ND's?
So far no one on these forums has actually described seeing a problem. Please enlighten me - I am totally willing to change my opinion. What problems have you actually seen?

Please add your input to:

"Neutral Density filters for use with the HVX"

at DVInfo.net

- Lenny Levy
 
I just read the thread over at DVinfo. Great thread. Honestly, I can't speak for the HVX's internal ND filters. My experience in this matter has been with the DVX, so in my post I should have said, "Using the in-camera ND filters on the DVX can reek havoc on the image". Sorry for that.

Now, I have no idea if the DVX and the HVX are similar as far as the internal ND's go. From my experiences in building adapters though, I can say with certainty that using the DVX's internal ND filters with an adapter can cause problems in the image.

While designing my adapter, I was pulling my hair out trying to figure out why my GG always had bright areas where there seemed to be little change in hue or value. Of course this always happened when I was testing the adapter outside in bright sunlight, and while using the ND's on my DVX. I must have spent months trying to refine the GG and adapter. Then one day, I slapped some ND's on the front of the 35mm lens and turned the ND's of the camera off... and bam! My jaw hit the floor when I saw how blue the sky looked and how clean the image was.

Here is on old grab from some test footage that shows what the DVX's ND filters can do (the text in the image is from my testing and can be ignored).

Why_no_cam_ND.jpg


In FCP pro the only area in the image above that registers as blown out is a small patch in the white cloud right next to the roof of the house. If you look at the cloud in the upper left and at the yellows of the wall on the right you can see the effects of using the DVX's ND filters.

There are so many factors involved that it is hard to determine which way is better in theory: ND in front, or in camera. I think the key thing to keep in mind is that a great deal depends on the focusing element being used in the adapter (we will call it the GG). It is true that the GG cannot expose, but remember that the GG is translucent and designed to "hold" the image on the glass. The ability of the GG to "hold" the image can be effected by the amount of light rays and by the grain of the screen (I'm using grain as a general term here).

When the number of light rays is large, the chances are greater that some of the rays will pass through the GG. The rays that are not "held" by the GG are an aerial image (floating image) from the lens. The rays of course won't create a full aerial image from the lens, but the key is that they will produce something that looks different than the light rays forming an image on the GG. Since these rays are an aerial image they can only be see at the proper viewing angle... and they certainly aren't always passing straight through since they are still having to make their way through the various tiny chips in the glass (or the texture of the plastic). If these rays don’t hit the lens of the camera at the correct angle the details just aren't there (or are at least inaccurate when compared to the image on the GG). Think of looking into the back of a 35mm lens at a slight angle. Brighter GG's are typically a hair more translucent. From what I have seen in my GG tests, the images from brighter screens were the ones most effected by using the internal ND's. This would make sense because the chances of light rays passing through the GG (as apposed to being held by it) are greater with brighter screens and when more light is passing through the lens.

This may be part of the reason that Dennis Wood recommends using external ND's with the Brevis (bright screens). I'm not sure.

A good way to test this idea on the HVX + adapter is to record a 1080 image outside in the brightest of light. Open up the aperture on the 35mm lens all the way so that the majority of the shot is overexposed. Then flip on the HVX's ND filters until the image is properly exposed, and record. Turn the ND's of the HVX off and stack ND's in front of the 35mm lens until the image is properly exposed, and record. Then examine each in an NLE where you can check the edge detail of brighter areas and such. I do think that there would be little if any difference in cases where the original image is not so overexposed.

My point in all of this is that it all depends on the qualities of the GG. I would agree that with an aerial image (floating image) from a 35mm lens, you could pump as much light as you want into the lens and the aerial image would remain the same in terms of detail. With 35mm adapters though the image is being "held" by the translucent qualities of the GG.

Using your analogy of a rear projection screen; it all depends on the qualities of the screen and the screens ability to hold the image. If the screen is too translucent or too opaque, it would seem that adding more light in the projector would in fact effect the image detail... and of course, there is no perfect GG.

That is my take on it for now anyway.
 
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The GG is a linear light trandsmitter. Treat it like any scene the camera would be shooting. Ive shot EVERY possible condition with my SGpro. Sunlight at 12noon, to black night.....

You can stop the 35lens down to F22 if you wish. No grain. There just needs to still be enough light reachingthe CCD's. Also, the internal ND's are perfectly fine. if they "wreaked" havoc you wouldnt be able to use them at all in normal shooting situations. Just try to keep both lenses in the middle of their Fstop ranges, using internal ND's if neccesary. F4-F11 on the 35mm lens and F4-F8 on the HVX. You will get great results every time. and dont forget to TRIPLE CHECK back focus on the GG.

As for Dennis' advice, i think thats specific to his adpater. he uses exotic materials in his GG's that apparently flare if too much light hits them. Other adapters are not affected by this. Infact try to use as few external filtes as possible, save a 4X4Polarizer or a ND grad filter.


Also Justin, Wayne kinney has an example of your eternal 1080 sunny day test. I shot it last month. though maybe i'll make another one tommorow for you guys. what you will find is that the resolution and highlight handling of a 35 adpter system is dependant on thelens itself. the better glass you use the better it looks.
 
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