ROM lenses on DMR

[rsolomon]

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Leica FAQ - Why do R lenses come in 2/3-CAM or ROM mounts?

 

it goes into some detail around Cam's and Rom. do you think it's possible that the contacts need cleaning and are not making a good connection.

 

i once had a problem with where i could get not the meter to recognize certain apterure ettings. Tt turned out that the Rom conacts needed replacement.

 

BTW: done wile i waited in NJ.

[bono0272]

 

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.

 

 

Well, so far I just know the ROM contacts have advantages to the R8/R9 when using TTL flash with 'film'. If we are not using flash then the ROM contacts have no function to the picture quality when taking with 'film'.

 

Is there any literature confirming the lens with ROM contacts shows advantages (in terms of vignetting, picture quality etc.) over the non-ROM lenses when using with the DMR?

[robsteve]

 

 

Is there any literature confirming the lens with ROM contacts shows advantages (in terms of vignetting, picture quality etc.) over the non-ROM lenses when using with the DMR?

 

There is nothing to confirm this in writing and everybody that mentions it always points to the same thread mentioned earlier where the guy mentions Hasselblad had mapped lenses.

 

Sean Reid did a coded lens test on the M8 and there was a difference with coding turned on or off. I suppose you could shoot an evenly lit white wall with your DMR and a rom lens and then tape over the contacts to see if any vignetting changes.

[robsteve]

I decided to test it for myself. I now stand corrected, the ROM does influence image quality on the DMR. I taped over the ROM contacts on my 19mm and mounted it to the DMR. I then pushed aside some dusty slides on my light table and shot the light table with the camera on manual and f2.8. I then took the tape off the rom contacts, gave them a quick clean with a cloth in case there was any tape residue and shot the light table again, same aperture, same shutter speed. Between mounting and und remounting the lens, I shut off the camera to ensure it read the ROM of the lens on boot up.

 

Can you guess which picture had the ROM contacts. The dust and crap in the picture is on the light table, not the lens. I also shot it too close for any of this stuff on the light table to be in focus.

 

Both of the DNG files were converted in lightroom and the WB dropper was used to neutralize the color. The vignetting difference was also noticable on the DMR review screen, so the in camera software must be dealing with the image corrections. I was not on a tripod, so the areas of the light table are different and the table also does not have perfectly even illumination, so just look for the corner vignetting, not differences elsewhere in the frame.

 

 

[bono0272]

The current firmware shows the focal length.

 

 

I just contacted the Leica local sole agent and asked about the EXIF on the DMR with the ROM lens.

 

The reply from the sole agent was:

 

"as informed by the Solms factory, there are ROM lenses at some focal length may not have the focal length information shown in the EXIF. These include the R 180mm F2.8 APO. Without such focal length information the picture quality will not be affected and there is no need to send the lens or the DMR back to the factory for reparing"

 

Can the above statement be verified by Leica itself?

[rsolomon]

i remember that when the DMR came out, or a month or so before leica offered a live chat with customers on the DMR. I recall a number of questions asked about ROM & DMR. The answer were provided directly from leica. maybe someone has a copy of the transcripts - they were posted on the website at one point

[john_f]

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FYI

 

Here is an excerpt from the LFI article mentioned by Andrew Nemeth in his Leica FAQ website about lensmounts and the ROM chip:

 

“The following lens data are stored digitally in the lens’s ROM chip:

1) The largest and smallest apertures, needed for digital display in the camera’s viewfinder.

2) The focal length, for automatic adaptation of the reflector (i.e. zooming) when using a SCA3000 system flash unit (N.B.: fixed focal length lenses transmit their data directly to the camera – “Vario” lenses are equipped with an additional electronic sensor which supplies information about the lens’s current focal length to the camera).

3) The aperture dynamics. After releasing the shutter, small, light metal blades can be accelerated more rapidly than the diaphragm of a lens with a large diameter. The R8 and R9 take advantage of this state of affairs and opens the shutter with a briefer delay for those lenses with a compact diaphragm.

4) The aperture characteristics. The working aperture of a lens is first determined by setting the aperture preselection ring (the “diaphragm ring”). The actual effective aperture is nevertheless likewise influenced by the unavoidable vignetting which occurs in lenses of high initial aperture. To make quite sure that exposure consistency is maintained under all circumstances, the above transmission factor must also be taken into account. The “effective aperture characteristics” are therefore also stored in the lens ROM chip.

 

At the end of the manufacturing process, every Leica-R lens is individually measured and programmed (into the lens’s ROM chip) in order to make sure that the high potential accuracy of the camera’s exposure metering system is indeed maintained under all circumstances.”

 

Source: LFI Magazine, issue 7/98 (Oct/Nov 1998), pp. 30-31

 

Hope all this helps.

 

Cheers,

 

John F.

[john_f]

i remember that when the DMR came out, or a month or so before leica offered a live chat with customers on the DMR. I recall a number of questions asked about ROM & DMR. The answer were provided directly from leica. maybe someone has a copy of the transcripts - they were posted on the website at one point

 

Rich,

 

I kept a copy of all the "chats". Here are a few excerpts related to the DMR and ROM R-lenses:

 

From the June 2003 World-Wide-Chat on the DMR:

 

[25/Jun/2003:18:45:04] <Leica host 3> nvcmike: Will there be any problems using non Rom lenses?

Leica: No, you can use all R-lenses.

 

[25/Jun/2003:18:53:48] <Leica host 3> fdk: I understand that all R lenses are compatible. However, will ROM lenses have peculiar advantages when used with the digital back?

Leica: The camera body used is still the R8/R9, meaning that all lenses will work on these bodies also when using the DMR. Consequently you can use R-lenses without ROM equipment.

 

[25/Jun/2003:19:05:16] <Leica host 4> grumpitoad: If the digital back works with just the R8 and R9, are there any restrictions regarding the R system lenses that can be used with it ? ie. Can only ROM lenses be used, or will earlier 3-cam lenses work too

Leica: All the LEICA-R-lenses will deliver images of the accustomed character with analogue photography when used with the digital back.

 

From the Nov 23, 2004 World-Wide-Chat on the DMR:

 

[17:25:04] <Leica Moderator 1> richsolomon: Will the ROM contacts on the lens play any role whatesoever in working with the DMR ?

L1: Lenses do not need to be equipped with ROM-contacts but ROM contacts transfer certain lens data concerning vignetting, used aperture and type of lens to the Digital Back. So under certain conditions, ROM contacts are beneficial when working digital.

 

Also these item on TTL/HSS flash metering with the R9+DMR:

 

[17:20:31] <Leica Moderator 3> nicolas: Hi from France, wich issue are you managing regarding the Flash photography TTL sychro etc..

L1 Bonjour Nicolas. As a matter of principle, TTL flash control based on a reflective surface in the film plane is not possible with digital SLRs. Due to the sensor surface's much less diffuse reflectivity as compared to a film's, metering the flash's light reflected from the sensor would result in a faulty exposure.

 

[17:37:08] <Leica Moderator 4> gakhular: No TTL flash exposure control is a problem. What will be the suggested way to get similar functionality?

L4: Use A if it has to be fast, use F or HSS if you have to mesure TTL.

 

[17:45:20] <Leica Moderator 4> CD: Going back to TTL and the DMR - I understand that it's not possible at this time with the current R8/9 configuration. Do you foresee a solution in the future that will allow for TTL flash metering?

L4: Yes as mentioned the HSS function. But you have to release a preflash for that. There is no other solution.

 

[17:48:31] <Leica Moderator 1> John F: Flash photography with SLR cameras has become very sophisticated today. I think many Leica R users would like to have matrix metering with TTL Flash, and automatic HSS flash, with or without the DMR, in the future. Can you say if this is a priority with Leica at the moment? Thanks.

L1: We are aware of the wish, to have full automatic flash exposure. With the current R8 and R9 models, this is not possible. In further developments, this will certainly be implemented. We are convinced, that the F mode as well as the HSS are a good intermediate solution.

 

I should add that the R9 includes an additional meter cell located in its prism. This extra meter cell (not present in the R8) is used for the HSS metering. Also note that with both the R8 and R9, regular flash metering is done using the center-weighted metering pattern, not the Leica's "matrix" or multi-pattern. Maybe the R10 will incorporate fully automatic HSS flash matrix metering. But for the moment, Leica needs to concentrate on their "SNAFU" with the M8. I wish them all the best of luck.

 

Best regards,

 

John F.

[pascal_meheut]

I did the same test with the 15mm/2.8 ASPH. The cyan correction is obvious and even too strong. DMR on tripod, 100 ISO, f/5.6.

 

Here are the pictures without and with the ROM.

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[robsteve]

Pascal:

 

On the two images, try white balanceng using the center of the image and then compare. It looks like there might have been a diffrendt light source temperature on the left than the right. It is really hard to find something evenly illuminated to these types of tests, especially with a wide angle.

 

I would rather it was a bit warm than too cool. This correction may also depend upon the color temperature of the light. My light table had a temperature in the 5000K range.

 

If you have the coded M lenses and an IR filter, can you test to see if this correction is already in the existing firmware? Sean Reid did a cyan corner test with a coded 28mm and IR filter, but did the shoot with the coding turned off, so we cannot tell if the correction is already in the firmware.

[pascal_meheut]

The 2 images where shot at exact same place with the exact same light. And the WB had been set manually on the body before so it is the same on both pictures.

 

I do not have any M coded lens yet. In fact, I was not planning to have any of them coded. I'll set what Leica says next week and then decide to send some lenses back with the M8 or not.