HM200 and Letus Elite 35mm adapter: possible? at DVinfo.net

Piotr Wozniacki · June 10th, 2015, 03:42 AM

As some of you guys may know, I'm after a series of unsuccessful neck spine surgeries (my spinal cord is still pressed on - cervical stenosis), so I'm unable to handle the rig I have gathered over the last several years. I'm trying to sell it in order to recover at least partially the money I had invested, but in the case of the Letus 35mm adapter I used to use with my EX1 (in order to create DOF compatible with my other S35 camera, the Fs100), selling it is almost impossible now when everyone can have shallow DOF using DSLR or a large sensor video camera :( Therefore I've been thinking if - assuming I will buy myself an AX100 or JVC 200 camera (4k for being future proof), both 62mm filter thread - it would be possible to use my Canon FD vintage glass with the Letus 35mm adapter fixed to it? I know it may sound like a silly idea, but considering the JVC's 4k is 150 Mbps it looks a nice cam, albeit with a small sensor - would be nice to transform it to 35mm camera with a Letus (same with the AX-100, only the advantages of using the Letus would be smaller as it already has this large 1" sensor)...

What do you guys think - is it possible at all? At least the cash invested in the Letus would not be totally wasted! Opinions welcome:)

Piotr

PS. Sorry Chris - only now did I see your answer to this very question in another thread; thanks.

Piotr Wozniacki · June 11th, 2015, 01:59 AM

OK - I understand well why nobody's even interested in this subject; the 35mm adapter's era is gone and forgotten. But since I already have one (and it's almost impossible to sell for a price that would satisfy me a bit), along with nice vintage glass - I'm seriously thinking about testing it with the Sony AX100, X70 or JVC HM200 (all of these 4k cameras have 62mm thread lenses).

I talked to LetusDirect and they say it's totally possible - the only thing I need is a 62mm thread ring, which - in its Letus Elite version - cost $100 plus shipping. Of course Letus would never say that, but perhaps some of you guys knows whether a general purpose step-up ring from 62mm to 77mm (the size of achromat in the Letus) would suffice to connect the Letus with any of those 3 cameras?

Such a general purpose ring I could buy locally for an equivalent of some $5-10, so the risk in case the results are not satisfactory would be none. Whereas $100 plus shipment from the US to Poland is going to be a serious investment for such an uncertain experiment... What do you think?

Bob Hart · June 11th, 2015, 08:25 AM

An intermediate step-up ring may throw the internal relay focus out of the range available with the camera's own focus but it is something that I would be inclined to try.

The best apparent resolution I was able to get out of any adaptor was with the Letus Extreme and Brevis adaptors, Super35mm-capable fast stills lenses in the T1.3 class, very careful and constant monitoring of the relay focus. I was able to resolve to the practical sharpness available on the SI2K, also the PMW-EX1. This was in the imaging of a resolution chart. The real world in bright outdoors light was less forgiving. I think IR at the wider apertures demanded by the groundglass adaptors may have been softening the image.

An added x-y adjustment enabled me to precisely centre the image for maximum area without picking up an edge in the prism path. This is vital for scaling the grounglass texture softness smallest relative to frame area to save as much sharpness as one can.

I should add that with the SI2K being a single chip CMOS camera, the final result for resolution is not the entire 2K as there are some loss in the debayering.You will not get 4K out of your adaptor but the images as a specialty look may still be pleasing as the "grain" of the groundglass will be more sharply defined. This may seem wrong. The motion of the groundglass is intended to disappear the texture but nevertheless, in certain bright conditions a scintillation effect occurs and it is not unpleasant.

The lenses you use have to be absolutely sharp. The groundglass texture amplifies soft lens images. Here is an old topic on the subject. I did noty progress my endeavours because theDSLR cameras and subsequent RED and other 4K 35mm sized sensor cameras pretty much made it pointless.

http://www.dvinfo.net/forum/silicon-...-use-si2k.html

June 10th, 2015, 03:42 AM	#1
Piotr Wozniacki Inner Circle Join Date: Aug 2006 Location: Poland Posts: 4,086	HM200 and Letus Elite 35mm adapter: possible? As some of you guys may know, I'm after a series of unsuccessful neck spine surgeries (my spinal cord is still pressed on - cervical stenosis), so I'm unable to handle the rig I have gathered over the last several years. I'm trying to sell it in order to recover at least partially the money I had invested, but in the case of the Letus 35mm adapter I used to use with my EX1 (in order to create DOF compatible with my other S35 camera, the Fs100), selling it is almost impossible now when everyone can have shallow DOF using DSLR or a large sensor video camera :( Therefore I've been thinking if - assuming I will buy myself an AX100 or JVC 200 camera (4k for being future proof), both 62mm filter thread - it would be possible to use my Canon FD vintage glass with the Letus 35mm adapter fixed to it? I know it may sound like a silly idea, but considering the JVC's 4k is 150 Mbps it looks a nice cam, albeit with a small sensor - would be nice to transform it to 35mm camera with a Letus (same with the AX-100, only the advantages of using the Letus would be smaller as it already has this large 1" sensor)... What do you guys think - is it possible at all? At least the cash invested in the Letus would not be totally wasted! Opinions welcome:) Piotr PS. Sorry Chris - only now did I see your answer to this very question in another thread; thanks. __________________ Sony PXW-FS7 \| DaVinci Resolve Studio; Magix Vegas Pro; i7-5960X CPU; 64 GB RAM; 2x GTX 1080 8GB GPU; Decklink 4K Extreme 12G; 4x 3TB WD Black in RAID 0; 1TB M.2 NVMe cache drive

June 11th, 2015, 01:59 AM	#2
Piotr Wozniacki Inner Circle Join Date: Aug 2006 Location: Poland Posts: 4,086	Re: HM200 and Letus Elite 35mm adapter: possible? OK - I understand well why nobody's even interested in this subject; the 35mm adapter's era is gone and forgotten. But since I already have one (and it's almost impossible to sell for a price that would satisfy me a bit), along with nice vintage glass - I'm seriously thinking about testing it with the Sony AX100, X70 or JVC HM200 (all of these 4k cameras have 62mm thread lenses). I talked to LetusDirect and they say it's totally possible - the only thing I need is a 62mm thread ring, which - in its Letus Elite version - cost $100 plus shipping. Of course Letus would never say that, but perhaps some of you guys knows whether a general purpose step-up ring from 62mm to 77mm (the size of achromat in the Letus) would suffice to connect the Letus with any of those 3 cameras? Such a general purpose ring I could buy locally for an equivalent of some $5-10, so the risk in case the results are not satisfactory would be none. Whereas $100 plus shipment from the US to Poland is going to be a serious investment for such an uncertain experiment... What do you think? __________________ Sony PXW-FS7 \| DaVinci Resolve Studio; Magix Vegas Pro; i7-5960X CPU; 64 GB RAM; 2x GTX 1080 8GB GPU; Decklink 4K Extreme 12G; 4x 3TB WD Black in RAID 0; 1TB M.2 NVMe cache drive

June 11th, 2015, 08:25 AM	#3
Bob Hart Inner Circle Join Date: Dec 2003 Location: PERTH. W.A. AUSTRALIA. Posts: 4,477	Re: HM200 and Letus Elite 35mm adapter: possible? An intermediate step-up ring may throw the internal relay focus out of the range available with the camera's own focus but it is something that I would be inclined to try. The best apparent resolution I was able to get out of any adaptor was with the Letus Extreme and Brevis adaptors, Super35mm-capable fast stills lenses in the T1.3 class, very careful and constant monitoring of the relay focus. I was able to resolve to the practical sharpness available on the SI2K, also the PMW-EX1. This was in the imaging of a resolution chart. The real world in bright outdoors light was less forgiving. I think IR at the wider apertures demanded by the groundglass adaptors may have been softening the image. An added x-y adjustment enabled me to precisely centre the image for maximum area without picking up an edge in the prism path. This is vital for scaling the grounglass texture softness smallest relative to frame area to save as much sharpness as one can. I should add that with the SI2K being a single chip CMOS camera, the final result for resolution is not the entire 2K as there are some loss in the debayering.You will not get 4K out of your adaptor but the images as a specialty look may still be pleasing as the "grain" of the groundglass will be more sharply defined. This may seem wrong. The motion of the groundglass is intended to disappear the texture but nevertheless, in certain bright conditions a scintillation effect occurs and it is not unpleasant. The lenses you use have to be absolutely sharp. The groundglass texture amplifies soft lens images. Here is an old topic on the subject. I did noty progress my endeavours because theDSLR cameras and subsequent RED and other 4K 35mm sized sensor cameras pretty much made it pointless. http://www.dvinfo.net/forum/silicon-...-use-si2k.html