lens cap da foe?
- Thread starter Dizkoteck
- Start date
do you mean attaching a 35mm lens onto the adapter?
I don't know what you mean by lens cap (maybe i'm missing something), but you attach the 35mm lens to the adapter via a lens mount... they have different makes for each different brand. Canon has a Canon mount.
Sorry if this has nothing to do with your question
I don't know what you mean by lens cap (maybe i'm missing something), but you attach the 35mm lens to the adapter via a lens mount... they have different makes for each different brand. Canon has a Canon mount.
Sorry if this has nothing to do with your question
Ted Ramasola
Veteran
Dizkoteck
Well-known member
Sorry about that folks, What I meant was if a rear lens cap have any grooves of some sort to mount the lens without it falling off.
But after some research, I may have found out that the real lens cap my friend gave me was just some cheap plastic he got from the cleaner. I'll purchase one today.
But an update to my PEPSI 35.
All that vignetting I mentioned before on my adapter was not cause by anything else except for a loose black tape inside. This has been taken care of and I can proudly say there is absolutely NO vignetting. I am proud ma brovas. Proud
But after some research, I may have found out that the real lens cap my friend gave me was just some cheap plastic he got from the cleaner. I'll purchase one today.
But an update to my PEPSI 35.
All that vignetting I mentioned before on my adapter was not cause by anything else except for a loose black tape inside. This has been taken care of and I can proudly say there is absolutely NO vignetting. I am proud ma brovas. Proud
Dizkoteck
Well-known member
But Teddy Bear, I forgot to ask.
Have you seen any difference using a 35 to a medium lens. I got a 67 in my hands right now but dont know if I should make the effort to build one for it if the 35 works well enough.
I wanna ask a ground glass question but there seem to be 2 going on right now
Have you seen any difference using a 35 to a medium lens. I got a 67 in my hands right now but dont know if I should make the effort to build one for it if the 35 works well enough.
I wanna ask a ground glass question but there seem to be 2 going on right now
setarcos
Well-known member
Just in case this might help you guys:
A medium format lens has indeed a greater coverage (projects a larger image) on a... GG, but:
they all start at about 2.8 and down. Max iris on SLR lenses starts at 1.2 and 1.4.
Between a MFL and an SLR, I would go with the SLR. They have a larger selection of focals (whereas in MFL you are stuck with W (50mm), "normal" (80 or 85mm) and telephoto (120mm). Price of these lenses might be an issue here.
For the purpose, a MFL is a great start (if you have one and you don't have to pay for it)
but will limit your work. An 85mm MFL will give you about the same DOF @2.8 as an SLR 50@1.8. (projected on a smaller screen)
The only "real" advantage is you could "get away" with possibly less vigneting and a smaller achromatic CU lens (and less distortion) but still requires the tube between camcorder and "contraption".
Don’t forget the WEIGHT, the MOUNT and the “stiffness” of the focus ring for those lenses. BTW, I love the mount on these ones, but I am not sure if anyone sells them.
A medium format lens has indeed a greater coverage (projects a larger image) on a... GG, but:
they all start at about 2.8 and down. Max iris on SLR lenses starts at 1.2 and 1.4.
Between a MFL and an SLR, I would go with the SLR. They have a larger selection of focals (whereas in MFL you are stuck with W (50mm), "normal" (80 or 85mm) and telephoto (120mm). Price of these lenses might be an issue here.
For the purpose, a MFL is a great start (if you have one and you don't have to pay for it)
but will limit your work. An 85mm MFL will give you about the same DOF @2.8 as an SLR 50@1.8. (projected on a smaller screen)
The only "real" advantage is you could "get away" with possibly less vigneting and a smaller achromatic CU lens (and less distortion) but still requires the tube between camcorder and "contraption".
Don’t forget the WEIGHT, the MOUNT and the “stiffness” of the focus ring for those lenses. BTW, I love the mount on these ones, but I am not sure if anyone sells them.
Ted Ramasola
Veteran
Dan,
The lenses I use on my adapter comes from my old rb645, I have a wide lens 45mm its aperture is only 2.8 thats true. But the 80mm has its widest at 1.9. This gives a good shallow dof. See my samples at this link
Dizkoteck
I have a mamiya RB67 and RB645. I can't use the 67 coz its so heavy. and big you will need a bigger housing and spinning element to project the image on. I use the rb645 lens since its small enough to mount. The reason why I prefer this over 35mm is that it projects a bigger image for your videocam to capture thus better quality. Remembr that we still hav to crop the projected image since this is circular in shape. Please check out the link above to view my my DIY adapter housing.
The lenses I use on my adapter comes from my old rb645, I have a wide lens 45mm its aperture is only 2.8 thats true. But the 80mm has its widest at 1.9. This gives a good shallow dof. See my samples at this link
Dizkoteck
I have a mamiya RB67 and RB645. I can't use the 67 coz its so heavy. and big you will need a bigger housing and spinning element to project the image on. I use the rb645 lens since its small enough to mount. The reason why I prefer this over 35mm is that it projects a bigger image for your videocam to capture thus better quality. Remembr that we still hav to crop the projected image since this is circular in shape. Please check out the link above to view my my DIY adapter housing.
setarcos
Well-known member
I saw that and is a very good idea and "contraption". The fact that YOU have that lens at 1.9 is a MAJOR BONUS. Big help there. Same thing having a 45mm. That is a major plus as well.
Size and weight.... you know better. I don't see where and how you could use a lens gear and a FF (since there are no rods) but I also know (in my case) how stiff (compared to SLR) the MFL is when it comes to focus changes (rolls) and keep the image steady.
I am not "showing off" (well.... maybe I am a bit) but I have to back up the theory with practical examples (right?) Here are some frames from footage (focus rolls) About 1 second between inf and close:
http://dandiaconu.com/gallery/albums/album46/F1.jpg
http://dandiaconu.com/gallery/albums/album46/F2.jpg , and more of the same on that album.
Anyway, I am sure the image gives you a lot of joy, so... BRAVO! I like it! You did VERY GOOD!!!!! Keep on shooting.
Size and weight.... you know better. I don't see where and how you could use a lens gear and a FF (since there are no rods) but I also know (in my case) how stiff (compared to SLR) the MFL is when it comes to focus changes (rolls) and keep the image steady.
I am not "showing off" (well.... maybe I am a bit) but I have to back up the theory with practical examples (right?) Here are some frames from footage (focus rolls) About 1 second between inf and close:
http://dandiaconu.com/gallery/albums/album46/F1.jpg
http://dandiaconu.com/gallery/albums/album46/F2.jpg , and more of the same on that album.
Anyway, I am sure the image gives you a lot of joy, so... BRAVO! I like it! You did VERY GOOD!!!!! Keep on shooting.
Ted Ramasola
Veteran
Dan,
Thank you for the compliments. I'm also impressed with your adapter, the results are impressive, mine is actually a DIY that I dont plan to massproduce, actually. I don't have much to work with, (please take note of my location), i have to make do with very limited materials. Web sites like yours Dan has inspired producers like me around the world to achieve a certain creative look and technical possibility by creating our own devices with the materials available.
Thank you for sharing also your work through your posts and website.
Thank you for the compliments. I'm also impressed with your adapter, the results are impressive, mine is actually a DIY that I dont plan to massproduce, actually. I don't have much to work with, (please take note of my location), i have to make do with very limited materials. Web sites like yours Dan has inspired producers like me around the world to achieve a certain creative look and technical possibility by creating our own devices with the materials available.
Thank you for sharing also your work through your posts and website.
setarcos
Well-known member
Teddybear,
Considering the location and limited means you achieved your DOF machine, your accomplishment shines 10000 times brighter than mine. I am serious. What bonds us together is the PASSION and for that I salute you brother. I am happy if I was able to add some inspiration to your work. Keep the faith.
Considering the location and limited means you achieved your DOF machine, your accomplishment shines 10000 times brighter than mine. I am serious. What bonds us together is the PASSION and for that I salute you brother. I am happy if I was able to add some inspiration to your work. Keep the faith.
Ted Ramasola
Veteran
My method was kinda crude. But I traced a round pattern first. Then I took my soldering rod and 'melted' a hole through. I smoothened the edges with a file and sandpaper. I'll post more close up images of that part on my site later today.
I had this idea of using a doorknob cutter but some hard plastics crack easily when you drill through them so I decided on the 'melting' method.
I had this idea of using a doorknob cutter but some hard plastics crack easily when you drill through them so I decided on the 'melting' method.
setarcos
Well-known member
Here is what you have to do:
Take the widest lens you have (28? 35? or 50) and set it on inf. (aperture wide open)
Move the mount (or GG) in-out to find the sharpest. (Stars are best). Epoxy and walk away. Make sure you get the GG squared to the lens, or you will not get inf sharp from side to side and corner to corner. Good luck.
Take the widest lens you have (28? 35? or 50) and set it on inf. (aperture wide open)
Move the mount (or GG) in-out to find the sharpest. (Stars are best). Epoxy and walk away. Make sure you get the GG squared to the lens, or you will not get inf sharp from side to side and corner to corner. Good luck.
I have two ways of focusing your adapter.
Use this site "Register Distances" with flange-to-focal plane distances to easily calibrate your adapter
or
follow my quick easy steps!
1)Put the film lens with a 'normal' focal length on your adapter (50mm for 35mm slr, and 80mm for medium format). The wider the lens is, the deeper your depth of field and the harder it is to focus so normal-to-short telephoto lenses are best.
2)Focus your film lens to a distance marked on the lens itself. It should be in either feet or meters.
3)On a flat, level plane, mark out the distance to which you focused the film lens to. Place a focus chart or resolution test chart at exactly one end of the distance and your adapter's ground glass or image plane exactly at the other.
4)Move the rest of the adapter away from or toward the ground glass while still keeping the ground glass at the marked distance. When the image is in focus on the ground glass, your adapter is set.
20 minute epoxy is great in this situation since it gives you just the right amount of time to do things.
Use this site "Register Distances" with flange-to-focal plane distances to easily calibrate your adapter
or
follow my quick easy steps!
1)Put the film lens with a 'normal' focal length on your adapter (50mm for 35mm slr, and 80mm for medium format). The wider the lens is, the deeper your depth of field and the harder it is to focus so normal-to-short telephoto lenses are best.
2)Focus your film lens to a distance marked on the lens itself. It should be in either feet or meters.
3)On a flat, level plane, mark out the distance to which you focused the film lens to. Place a focus chart or resolution test chart at exactly one end of the distance and your adapter's ground glass or image plane exactly at the other.
4)Move the rest of the adapter away from or toward the ground glass while still keeping the ground glass at the marked distance. When the image is in focus on the ground glass, your adapter is set.
20 minute epoxy is great in this situation since it gives you just the right amount of time to do things.
setarcos
Well-known member
Sorry to contradict you, but:rpster88 said:
The wider the lens, the deeper the DOF indeed and therefore the SHALLOWER or critical the focal flange. Try a 15 or an 8mm (fish eye) lens. An 8mm does not have a focus ring at all. It has fixed focus. All sharp from near to infinity. http://www.mir.com.my/rb/photography/companies/nikon/nikkoresources/fisheyes/DanLindsayC.jpg If THAT lens is NOT at the PRECISE focal plane, NOTHING is sharp; therefore, a shorter focal is the one to take for granted in adjusting infinity. (Same goes for adjusting the flange or back focus on a HD lens!; http://dandiaconu.com/gallery/album36/copyIMGA1281
if you zoom-in and it seems to be sharp and then zoom-out and the overall image is soft, your focus HIDES the FLANGE being OFF (on the tele photo position) and the flange IS OFF and you have to adjust it again to find its best position/setting (at wide). Once that's done, you can zoom-in and know for fact that whatever distance you have on the focus ring is true) Best answer is to TRY them both and see for yourself which one is more critical. My 2c on the issue!
Zack Birlew
Veteran
Dizkoteck, are you referring to the rear lens cap that the lens comes with? Like the DVD-Labs DOF Machine design uses?
If so, then I have good "cheap" news. Well, when I was making the hole for the lens part in my DOF machine, I made it too big, though the lens could reach the lens cap and lock in, it would fall out because the hole was a smidge too large. So I went to Target and bought a roll of double sided velcro with sticky tape on the outside (thick double sided tape should work too) and wrapped that around the lens cap. You have to push the cap through the tape a bit or wrap it about mid way so it can reach the lens, but it fits very tightly. I would imagine that this could work for a tubular 35mm adapter as well if you sandwiched the cap between two wraps of double sided velcro or tape.
If so, then I have good "cheap" news. Well, when I was making the hole for the lens part in my DOF machine, I made it too big, though the lens could reach the lens cap and lock in, it would fall out because the hole was a smidge too large. So I went to Target and bought a roll of double sided velcro with sticky tape on the outside (thick double sided tape should work too) and wrapped that around the lens cap. You have to push the cap through the tape a bit or wrap it about mid way so it can reach the lens, but it fits very tightly. I would imagine that this could work for a tubular 35mm adapter as well if you sandwiched the cap between two wraps of double sided velcro or tape.