martin_fahey

I have come back to using my R800 printer with CS3, and realise that, in spite

of my best efforts at calibration, my prints are darker than on the screen

(where I think I have a reasonably-well calibrated monitor). Searches show that

Epson USA provided "new" profiles for this printer and epson papers some years

ago. However, I have not been able to find any more updated "canned" profiles.

I believe that the dark image issue has been around for some years with the

R800 and epson profiles. Has nothing been done since then to provide better

canned profiles for this printer and epson papers? (Yes, I know the ultimate

solution is to do a custom profile for my actual printer, but short of that, is

there anything better than these Epson USA profiles?).

 

Thanks

Very good explanation Skip.

 

One way I have of thinking of this is as follows:

 

If you are using 35 mm, have a 35 mm slide frame handy. To see the field of view of a 200 mm lens, hold the 35 mm slide frame 200 mm from your eye. What you see throught the slide frame is what you will get with a 200 mm lens in 35 mm. If I wanted to see what this lens would give on an APS sized sensor, I would need to cut out an APS sized rectangle on a piece of cardboard, and use as above. I will see a smaller field of view at 200 mm than through a 35 mm slide frame. Viola! Very useful (if awkward) to see the extreme field of view of wide angle lenses - i.e. trying to hold the 35 mm (or APS) viewer at 12 mm from your eye is not so easy.

Roger

 

If it's going to operate like the *ist cameras, then, no, you don't have to use stop-down metering with A lenses. And even with M lenses, a single button push does the stop down and metering, with the exposure fixed until the next putton push. The beauty of the A lenses with these cameras is that the focus indicator still works, even with manual focus lenses (useful if your eyesight is not as good as it used to be, like mine). So the A50/1.4 is still an awesome lense with these cameras. (I am assuming that the K10D will retain these features - can't wait to get my hands on one).

(Posted this last month, but got no response, so here goes again)

 

Just bought the AF 360 FGZ flash to go with my *ist-DS. When operating in P-

TTL mode, the result is about 2 stops of underexposure! To get a histogram

over most of the range, I have to set the flash for 1 stop of overexposure

(+1), and do likewise in the camera flash compensation (+1) - then it works

perfectly. This works OK for both direct and bounce flash (including when

using the nice little card pullout reflector). Knowing this, it is not a

problem to do the adjustment as a matter of course, but I wonder if anyone

else has experienced this (and if so, have they found a fix)? Or am I missing

something?

 

Conversely, the AF280T, operating in TTL mode with this camera seems to

produce up to 2 stops overexposure - so I generally have to set the flash

compensation on the camera for 2 stops down to get an even histogram and

proper exposure.

 

Thanks for great forum!

Just bought the AF 360 FGZ flash to go with my *ist-DS. My first impressions,

when operating in P-TTL mode, is that it results in about 2 stops of

underexposure! To get a histogram over most of the range, I have to set the

flash for 1 stop of overexposure (+1), and do likewise in the camera flash

compensation (+1) - then it works perfectly. Knowing this, it is not a

problem to do the adjustment as a matter of course, but I wonder if anyone

else has experienced this (and if so, have they found a fix)? Or am I missing

something?

 

Conversely, the AF280T, operating in TTL mode with this camera seems to

produce up to 2 stops overexposure - so I generally have to set the flash

compensation on the camera for 2 stops down to get an even histogram and

proper exposure.

 

By the way, with regard to the wireless confusion in earlier threads, the

wireless mode operates only in Slave2 mode, and operates only in A or M mode

(not P-TTL). Pity, but not so bad nonetheless.

 

Thanks for great forum!

Thanks everyone. The LED versus LCD argument does not in itself make sense, as the LEDs only operate when the shutter release is part depressed. So, just leaving the prism switched on, but not in use, would not consume power if it was only the LEDs that consumed power. So I think it has to be the meter itself that consumes the power.

 

I think that the last time I left it switched on for a few days it died even though I had used only 1 roll of film - but in that case I did so with it on my office desk without the lens cap on. I know some older cameras effectively switched off the meter if the lens cap was on (Canonet for example, I think). So, I suppose this means that the meter itself, and not the LEDs, is the culprit. I'll have to use some 'aide memoire' to remind me to switch it off after use.

Hmm.. I was afraid of that! I don't suppose there are any suitable 6v rechargable batteries available?

 

Does anyone know if the AE-III has the same behaviour w.r.t. batteries?

 

THanks

I've searched this forum and found some previous references to this

problem, but no definitive answer. Problem is - my newly-acquired

ETRS, with AE-II prism finder, eats batteries! A new Varta 6V

lithium lasted only a week, with only 1 roll shot, and a previous

Duracell lithium lasted only about the same time. However, I forgot

to turn off the meter (leaving it on 'A') when I put the camera back

in the bag (bad habits from having cameras that switch off

automatically). Does the meter use power when it is not activated,

or it there another problem?

I'm a bit confused with the comparison between "equivalent" focal lengths for 35 mm and 645 format.

 

I thought you could either compare the horizontal field of view, or the diagonal.

 

Thus, for the horizontal comparison, the 645 negative is 56 mm wide, and the 35 mm one is 36 mm wide, giving

 

50 mm in 645 being equivalent to 50x36/56 = 32 mm

 

40 mm in 645 being equivalent to 40x36/56 = 25.7 mm

 

Using the diagonals (69.4 mm and 43.3 mm respectively) the comparison becomes:

50 mm equivalent to 31.2 mm

 

40 mm equivalent to 25.0 mm

 

(I think some of the conversions in earlier posts are on the assumption that the 645 negative is 6 cm x 4.5 cm)

Thanks everyone for your replies. I tend to import .jpgs directly into Photoshop. I suppose that if it has been recorded in AdobeRGB, and I use the "convert to working space (AdobeRGB) when opening the file, it does not matter? Have been using photoshop 7.0, but have just acquired CS, so will see if that makes any difference.

I have only recently started using AdobeRGB colour space setting on

the *istDS (coinciding with purchase of Epson R800), and,

concidentally, upgraded to firmware V2.0 at the same time.

 

Something odd happens when I use AdobeRGB space:

- when I subsequently open the (JPEG) image in photoshop, it tells

me that the image has no embedded colour space (when I use sRGB,

that colour space is indeed embedded, and recognised by photoshop)

- the image numbering prefix changes from "IMGP....." to "_IGP....",

with the actual numbering being sequential.

 

That seems odd to me, and I wonder if the fault - if it is a fault -

lies with V2.0 of the firmware (or was it there always, just I never

used AdobeRGB space before).

 

Anyone else experienced this?

 

Thanks

It has been mentioned often that the true power of P-TTL with the

*istDS is only available with the AF-360FGZ pentax flash (or the

just-released AF-540FGZ). But has anyone got any actual experience

of this? Is it worth the investment in the AF-360FGZ? Does it give

reliable exposure in P-TTL mode?

 

I currently use the AF-280T, and generally have to fiddle with

exposure setting (set flash to -2 underexposure) to get anything

sensible out of TTL. Of course, I can also use the flash's auto

function.

Kate

 

I'm surprised you think the 285 is "too powerful" for hot-shoe mounting. I use a 283 occasionally, with no problems. What you have to do is simply check the voltage in the firing circuit - get an electrical or electronics person to do this (a very simple task). On some older flashes it can be very high, but if its only 6 volts or so, it should not be a problem. Maybe get confirmation of this from someone else before you act on it (but as I said, my 283 shows only 6 volts from memory, and I have used it without any problem on my istDS.

David

 

Any Pentax K-mount lens will work with DS. I use Pentax A and M lenses, which are of course manual focus lenses. The A lenses set on A use the automatic (exposure) features, but not the M lenses (which do not have an A setting), but a stop-down feature still gives full metering and setting. I presume the F lens will give you auto focus, but I have no direct experience of this. If the Kinor lenses have a pentax mount, they should work also. THere is no "clipping" - though the angle of view is changed - thus, your 50 mm lens on the DS will have an angle of view equivalent to about a 75 mm lens on 35mm

John Connolly

 

I think there must be something wrong somewhere, as there should be no problem with the AF280T in TTL in Autopict, P, Tv, Av or M modes. There is nothing to set - the camera should detect the flash. You might try the following. If you have an A-lens, put it on, set on A. Find a location where, without the flash, the P mode gives you an aperture of (say) f2.8. I'm doing this as I type - I've got a 28mm 1:2.8 A lens on the camera, and in this room the P mode gives me 1/15 sec and f/2.8. Now turn on the flash, in TTL setting. The camera should switch to 1/180 sec and f/5.6. And the same in Autopict, Tv, Av. If it does not, it may mean that it can't see the AF280T (?).

 

You might find though that you get better exposure with flash compensation set to -1 or even -2 - perhaps due to the "sensor reflectivity" issue discussed elsewhere (the sensor is apparently less reflective than film, so the TTL mode tends to give slight overexposure). Without doing this, the histogram shows some clipping at the top end (and it does indeed look overexposed), but not a "white out" like you describe.

 

Hmmm, not sure if this will prove anything - even with flash in Automatic mode, the camera should see the flash, and set 1/180s and f/5.6.

 

Hope this helps.

I second the suggestion of the AF280T. Bought a (replacement) one in e-Bay a few weeks ago ($78), and it works very well in TTL. Correct exposure both "direct" (not very flattering portraits of course) and in bounce. Of course it does not to P-TTL.

As said above, each aperture stop doubles or halves the light. The aperture number refers to the opening DIAMETER, and the light admitted depends on the aperture AREA - so the relationship that controls the exposure is the Inverse of the SQUARE of the aperture number:

 

f/1, f/1.4, f/2, f/2.8, f/4, f/5.6

 

1^2 = 1

 

1.4^2=1.96 ~ 2

 

2^2 = 4

 

2.8^2 = 7,84 ~ 8

 

4^2 = 16

etc

 

so f/4 lets in 1/8 th the amount of light, for a given time exposure, as f1.4, as it has 1/8th of the area of a f/1.4 aperture

 

So, on this basis, going from f/1.4 to f/1.7 is about a half stop: (1.7^2)/(1.4^2) = 1.47 ~ 1.51.

"I have recently asked the dealer at a camera store and he assures me that this *ist DS will take pretty much any flash and any pentax mount AF lens, is this true?"

 

Yes and no. Any flash (with simple single contact) will fire, but of course you will have to use it either in manual mode or in auto mode if the flash has an auto mode (I've used a Metz 34CS-2 in this way - and also a Vivitar 283, with great results). In auto mode on the flash, you would have to use manual setting of the aperture to correspond to the appropriate aperture for the auto flash. (But appartently there may be a problem with very old flashes with high trigger voltages - check with voltmeter).

 

If you want to have TTL flash metering, then a dedicated Pentax flash is required such as the Pentax AF280T (and many 3rd party flashes). If you want to use the full flash capability, then a high-end Pentax flash is required - such as the Pentax AF360FGZ, which takes advantage of the P-TTL mode).

 

Similarly with lenses. I use all my old A and M lenses. The former, set at A, exploit all the features of the camera, including correct operation in Autopict, P, etc modes, but not autofocus. With the latter, correct exposure requires pushing the AF-L button just prior to firing, to lock in the exposure (this stops down the lens and takes the exposure reading).

I've tried a Metz 34 CS-2, and a Vivitar 283, both on automatic mode, with this camera, without any problems. The AF360FGZ is ideal for it, with P-TTL, but I have not looked for one yet, as I have an AF280T, which I bought to go with a Pentax Super Program. This gives TTL (not P-TTL), and works beautifully, with the *ist DS in auto or P modes.

In all of the discussion on the new generation wide angle zooms for

APS-sized digital cameras (Sigma 12-24, etc), all of them seem to be

for Canon or Nikon mount (e.g.

http://www.photo.net/equipment/wideangle-dslr.html).

 

Are any of these lenses available with a Pentax mount, to operate

with *ist DS (or in the case of the Sigma 12-24, with 35 mm pentax

cameras)?

I tried an experiment a few night ago with my just-acquired Pentax *ist DS and a (classic) Konica Hexar (fixed lens), using autofocus in an almost dark room. The Pentax worked down to a level where I could still clearly see the target, but the Hexar worked (very quickly) down to light levels that were effectively completely dark. What a great camera the Hexar is!

The Pentax AF280T Flash that I used to use with a Pentax Super

Program died before I could use it with my (new) *ist DS. (The

technicial said that it looks like a failed capacitor, and Pentax

does not supply these any more - so assume it is dead).

 

I have the opportunity to acquire an almost new Cobra 700AF flash

(with Pentax z-10 compatibility), which I understand will work with

the *ist DS in TTL (and not in P-TTL), and should also work with the

Pentax Super Program in TTL mode.

 

Can anyone confirm this, or otherwise? Any help gratefully received.

 

Another question: On flashes designed for 35 mm, with zoom heads,

should the zoom be set to the actual focal lenght of the lens, or

the lens corrected for the crop factor?

- ie with the 'kit' lens set at 18 mm (same field of coverage as

about 28 mm in 35 mm), I assume I would set the zoom to 28mm.

- similarly, if I fit a 50/1.4 SMC-A lens, I should set the zoom to

75 mm or nearest equivalent.

 

Is this correct?

Thanks Richard. I had a play with it over the weekend, and as far as I can make out, the focus is not affected by the orientation of the polariser - that is, if it indicates 'in focus' (and it appears to be in focus) with one orientation of the polariser, this does not change as the polariser is rotated. This all done outside, on bright sunny winters day.

 

So it LOOKs like the autofocus system works with a normal linear polariser.

I have always read that autofocus SLRs do not like polarising

filters unless they are 'circular'. Having recently acquired an

*istDS, I was surprised to find that it seems to focus correctly

with a normal linear polariser fitted. (That is, the focus

indicator beeps when it is in focus with a manual focus lens.

Therefore I assume that it would focus correctly with an autofocus

lens with the linear polariser fitted. I can't check this out yet,

as I do not have a polariser that fits the kit autofocus lens that

came with the camera - SMC DA 18-55 AL). Can anyone shed light on

this? Is there any difference between the autofocus system in this

camera that would allow it to operate with a linear polariser,

compared to other autofocus cameras?

I've obtained a Tamron SP 7 element Pentax-A mount X2 teleconverter, and, yes, it does what I have asked above - ie the camera electronics in the P30t recognises when the teleconverter is attached, in working out the exposure. Effectively, it recognises the factor of 4 (2 stops) reduction with the teleconverter, when set on aperture priority automatic. I assume therefore it also recognises it when in Program mode.