bono0272 Posted November 10, 2006 Share #1 Posted November 10, 2006 Advertisement (gone after registration) To DMR users: Will the ROM lenses perform different on the DMR, if compare with those 3-cam lenses? It is supposed the R8/R9 knows exactly which lens is being used if it is a ROM. So do the ROM contacts on the R lenses perform the same function as those coding on the new M lenses for the M8? From the factory information the new coding on the M lenses allow the M8 knows exactly the lens characteristics and will utilized the best performance of such lens. Will this happen between the ROM and the DMR? Link to post Share on other sites More sharing options...
Advertisement Posted November 10, 2006 Posted November 10, 2006 Hi bono0272, Take a look here ROM lenses on DMR . I'm sure you'll find what you were looking for!
andybarton Posted November 10, 2006 Share #2 Posted November 10, 2006 ROM contacts transfer lens length info to the EXIF data on the DMR and they allow easier use of TTL flash (with the right flashgun). They do not perform the same function as the 6-bit zebras on M lenses. No in-camera adjustment is made to deal with lens characteristics on a DMR and the results would be identical for ROM'd and non-ROM'd lenses. Link to post Share on other sites More sharing options...
masjah Posted November 10, 2006 Share #3 Posted November 10, 2006 Richard and Andy There has been very considerable previous speculation on this issue - and the odd elliptical remark in some Leica publicity - can't remember where right now - though maybe I put on it a construction that I was looking for. It is possible that the DMR takes the lens identity from the ROM and makes appropriate compensation for vignetting - perhaps Leica should confirm this one way or the other. Link to post Share on other sites More sharing options...
bono0272 Posted November 10, 2006 Author Share #4 Posted November 10, 2006 John, Thanks for your explanation but is such feature of minimizing vignetting can be achieved thru the updated firmware, say the coming 1.3 (if there will be firmware 1.3, of course)? Link to post Share on other sites More sharing options...
masjah Posted November 10, 2006 Share #5 Posted November 10, 2006 Richard My understanding of the "grapevine gossip" was that it speculated that the DMR had this sort of correction built into its firmware right from the start. If this is not true, then your question "can it be added in later revisions" is one I don't know the answer too. I would think though probablly yes in principle, though constraints like memory limitations, processing power and programming complexity (in other words, the usual suspects) might be significant. Link to post Share on other sites More sharing options...
robert_parker Posted November 10, 2006 Share #6 Posted November 10, 2006 One thing that may be worth adding is that certain of the newer lenses use different computations and coatings, some of which suit the DMR's digital 'style' - for example the modern APO lenses appear to suit the digital medium with their added sharpness and colour. Equally many prefer the attractive colours and bokeh available from older lenses. You might find certain of the older lenses (an example being my old 250mm f4) don't seem to come accross as well in the digital medium as they do on film - that's probably simply because the optimisations were made years ago with film in mind and not possibly with half an eye on the digital world to come. Link to post Share on other sites More sharing options...
mwilliamsphotography Posted November 10, 2006 Share #7 Posted November 10, 2006 Advertisement (gone after registration) ROM contacts transfer lens length info to the EXIF data on the DMR and they allow easier use of TTL flash (with the right flashgun). Please explain further. As far as I know there are no TTL flash options when using the DMR. Yes, if using the R8 or R9 as a film camera. Link to post Share on other sites More sharing options...
Guest guy_mancuso Posted November 10, 2006 Share #8 Posted November 10, 2006 There is no TTL with the DMR attached , the flash will zoom for you with the Rom data transmitted to the flash , so a 28 lens than it will zoom to that but you use A mode for flash. Link to post Share on other sites More sharing options...
ho_co Posted November 10, 2006 Share #9 Posted November 10, 2006 ROM contacts transfer lens length info to the EXIF data on the DMR and they allow easier use of TTL flash (with the right flashgun). Please explain further. As far as I know there are no TTL flash options when using the DMR. Yes, if using the R8 or R9 as a film camera. Andy's explanation is correct. Notice that the phrase "on the DMR" is before the "and." Read it: 'ROM contacts transfer lens length into the EXIF data on the DMR. And they allow easier use of TTL flash....' No contradiction. Doesn't imply that TTL is possible with DMR, but places the DMR as a separate item. But I think there is more as well. Somewhere in Leica literature I read the same information that John did: The ROM data are measured for each lens individually. The actual vignetting for the individual lens (not lens type) is stored inside the lens. That is, if we're right. But to Richard's original question: Leica says having ROMs added to existing lenses is of greatest advantage with high-speed lenses and with wide angles. I guess you're wondering whether to have the work done. Just shoot the lenses. If you see vignetting or other artifacts you aren't used to seeing on film, have them modified. --HC Link to post Share on other sites More sharing options...
rsolomon Posted November 10, 2006 Share #10 Posted November 10, 2006 i have debated this issue , eventually i figured the ROM advantage would be significant verse todays ROM value (minor signifacance to me ). then i began to think about my investment. and determined that leica is about the lens, not the camera. Therefor i concluded that i would maintain and upgrade my investment and had all my lenses ROM'd. i figure the price will only go up and i will be ready, ofcourse i have been hoping they the real need would be here by now -- maybe in the R10 or the next firmware release Link to post Share on other sites More sharing options...
jrgeoffrion Posted November 11, 2006 Share #11 Posted November 11, 2006 ROM contacts transfer lens length info to the EXIF data on the DMR ... Actually, ONLY for fixed focal length. Unfortunately, the focal length is NOT included in the EXIF data of any ROM zoom lens. Link to post Share on other sites More sharing options...
bono0272 Posted November 12, 2006 Author Share #12 Posted November 12, 2006 I have another problem: the only one ROM lens I got is the 180mm F2.8 APO (latest version). However, I have found no focal length information recorded in the EXIF when I use this lens with the DMR. I have no other ROM lenses to test with my DMR so I am not sure whether it is my DMR's problem, or bad contacts between the lens and the R8 body. The sole agent of Leica in my city can send the non-ROM lenses back to Solms for modification to ROM version. Do you think it is worth to do so and have any benefits when using with the DMR? Link to post Share on other sites More sharing options...
jrgeoffrion Posted November 12, 2006 Share #13 Posted November 12, 2006 I have another problem: the only one ROM lens I got is the 180mm F2.8 APO (latest version). However, I have found no focal length information recorded in the EXIF when I use this lens with the DMR. I have no other ROM lenses to test with my DMR so I am not sure whether it is my DMR's problem, or bad contacts between the lens and the R8 body. The sole agent of Leica in my city can send the non-ROM lenses back to Solms for modification to ROM version. Do you think it is worth to do so and have any benefits when using with the DMR? IMHO, the coding on the 180 APO will change absolutely nothing. Take my advice with a grain of salt, I just have a few lenses and take no more than a few pictures every year. Link to post Share on other sites More sharing options...
ho_co Posted November 12, 2006 Share #14 Posted November 12, 2006 However, I have found no focal length information recorded in the EXIF when I use this lens with the DMR. Don't worry, Richard. Although I don't have a DMR, I understand the current firmware doesn't show the EXIF info. Just take pictures and enjoy. Next firmware should correct the problem. As for sending other lenses off to install the ROMs, see my post above.--First, use the lenses. If you don't like the results, then send them for modification. Leica was very specific: Wide angles and high-speed lenses are the ones that will benefit most. --HC Link to post Share on other sites More sharing options...
jrgeoffrion Posted November 12, 2006 Share #15 Posted November 12, 2006 I understand the current firmware doesn't show the EXIF info. Just take pictures and enjoy. Next firmware should correct the problem. The current firmware shows the focal length. Link to post Share on other sites More sharing options...
john_f Posted November 12, 2006 Share #16 Posted November 12, 2006 Richard My understanding of the "grapevine gossip" was that it speculated that the DMR had this sort of correction built into its firmware right from the start. If this is not true, then your question "can it be added in later revisions" is one I don't know the answer too. I would think though probablly yes in principle, though constraints like memory limitations, processing power and programming complexity (in other words, the usual suspects) might be significant. John, Richard, Here is the source of the speculation: Leica Users Group - Interesting digital DMR info not seen elsewhere Its author claims that Hasselblad did some sort of "optical mapping" of Leica R lenses. The result of this mapping process was stored in the DMR's firmware and is used to apply "corrections" (for chromatic aberation, vignetting, etc..) to images taken with (ROM equipped?) Leica-R lenses - or so claims the post. This feature is apparently similar to Hasselblad's Digital APO Correction. Here is an excerpt from the Sept 2005 Leica User Group post: "To date, only Hasselblad has successfully managed the microlens sensor in a professional level product, the digital back they make for the Leica R8. While the specification for the chip stated that this behavior would occur with wide-angle lenses, only, Hasselblad discovered that it occurred with all lenses. To correct these aberrations, Hasselblad mapped out the characteristics of each lens in the Leica R8 system at every aperture and light level and included this information in the firmware of the back. The camera would send the lens and exposure data to the back, which would in turn correct the image In other words, the corrections had to be integrated at the system level. Hasselblad has already added the capability for this type of lens to camera to back communication in its latest digital platform, the H2." During a Leica Day last Oct 28, I showed a copy of the article to a Leica rep. While he seemed a bit puzzled at first, he did not deny its content. His answer was that Imacon, not Hasselblad, might have been involved in this since its was Imacon (not Hasselblad) that made the DMR back. I am still trying to get confirmation of all this from Hasselblad/Imacon. John F. Link to post Share on other sites More sharing options...
bono0272 Posted November 12, 2006 Author Share #17 Posted November 12, 2006 Thanks John. A very detail explanation. So what's happening to the ROM data transmission to the DMR? It seems that there are two different opinions here: some members say that there are focal length information in the DMR EXIF, but some say there is nothing. (I am the group with no focal length information with my ROM lens on DMR) I am talking about prime ROM lenses, not zoom lenses. Link to post Share on other sites More sharing options...
rsolomon Posted November 12, 2006 Share #18 Posted November 12, 2006 i can tell you for sure... 1. that all my lenses with ROM show focal length 2. my lenses with 3 cam (i have one) do not show focal length, actually is shows as 0.00mm. And i do know that each ROM contact is specifically coded for a particular lens it would be interesting to see if you are showing the 0.00mm or is it blank. BTW this is info is being read from elements 4. Link to post Share on other sites More sharing options...
bono0272 Posted November 12, 2006 Author Share #19 Posted November 12, 2006 It shows 0.00 mm in the EXIF when I use my 180mm APO ROM with the DMR. Same as the other 3-cam lenses I have. Since I have only one ROM lens so I do not know whether it is the lens problem, the DMR problem or my R8's problem. So it's the 4th element from the left or from the right? Link to post Share on other sites More sharing options...
robsteve Posted November 12, 2006 Share #20 Posted November 12, 2006 ROM contacts transfer lens length info to the EXIF data on the DMR and they allow easier use of TTL flash (with the right flashgun). Please explain further. As far as I know there are no TTL flash options when using the DMR. Yes, if using the R8 or R9 as a film camera. Marc: The DMR will do the HSS mode with the Metz flashes, this is where you do a preflash and the camera uses the TTL sensor to read the light to set the flash. It works the same way as the Canon and Nikons, except you have to do the Pre-flash rather than the camera doing it a few milliseconds before the real flash. It is sort of like the FE button on the Canons. To do the HSS on the DMR, you need a R9, 3502 mod 4 or later and the Metz MZ54. Select TTL on the flash, then spin the little wheel until HSS appears under the TTL in the LCD of the flash. To select HSS, I think you also need the flash on the Camera and the Camera on. To fire the Pre-flash, use the depth of field slider and pull it all the way down to the bottom of its travel and the flash fires. I tried it a few weeks ago when somebody else asked a similar question and it worked. Link to post Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.