[i_trax]

Hi Guys,
I have built a macro rig , Konica Hexanon 50 1.7 with variable number of Pentax extension tubes.
Just noticed that magnification is much lover on K-1 that on K-3 , that make sense.
Now, DFA Macro 2.8 100 WR, seems to behave the same , am I imagining things or not?

[JensE]

K-3 has a higher detector density than K-1, therefore you can achieve higher resolution for the same nominal magnification ratio as indicated by the lens.
The K-1 provides you a greater field of view.

[robthebloke]

K-3 has a higher detector density than K-1, therefore you can achieve higher resolution for the same nominal magnification ratio as indicated by the lens.
The K-1 provides you a greater field of view.

... and better AF on macro lenses.

[Not a Number]

The magnification should be the same. In macro photography magnification is the ratio of the projected image size on the film or sensor plane in relation to the size of the object. Thus in a magnification of 1× or 1:1 a 10mm object would project a 10mm image on the sensor. 2× magnification would project a 20mm image.

Since the K-1 has a 36 × 24mm vs 24 × 16 APS-C sensor (sizes rounded up) the image from the K-1 seems smaller because of the larger frame or field of view when in fact the magnification is the same. Shoot with your K-1 in crop mode and the magnification should look the same.

---

Last edited by Not a Number; 01-04-2017 at 06:00 AM.

[Doundounba]

Shoot with your K-1 in crop mode and the magnification should look the same.

But you'll only have a 16MP image, instead of the K-3's 24MP. I think a fair comparison is to state that at 1:1 macro magnification, a 24MP crop of a K-1 image will be 29.3mm wide, vrs 23.5mm for a 24MP image on the K-3. So to get an equivalent image on the K-1 (same number of pixels on the same width of frame), you'd actually need 1.25:1 magnification on your setup, which would give you a 24MP crop that is 23.5mm. Of course, then you'd still have that extra 12MP around the subject.

So, the upshot is that you need a bit more magnification to get equivalent detail on the K-1, but when you get there you still have a slightly wider field of view.

[WPRESTO]

The technicalities have been well explained in preceding replies, but the real nut is: 1) Which camera body gets the result you want? and 2) Is there a difference in convenience of use? I really wanted a K1 for macro because in the field because many macros are best taken from a low vantage = on a level with the subject, and I can no longer easily get up from my knees (it will soon require a 911 call), I had been using a Reconverter A on my K3 (and previously on my K5, K20, K10, *ist, LX, ZX5n, PZ20, well, you get the picture, and so did I), but the tilt screen with focus peaking of the K1 is VASTLY easier to use. I can place the camera directly on the ground and frame-focus by just bending over; impossible with the Refconverter.

[photoptimist]

The magnification should be the same. In macro photography magnification is the ratio of the projected image size on the film or sensor plane in relation to the size of the object. Thus in a magnification of 1× or 1:1 a 10mm object would project a 10mm image on the sensor. 2× magnification would project a 20mm image.

Since the K-1 has a 36 × 24mm vs 24 × 16 APS-C sensor (sizes rounded up) the image from the K-1 seems smaller because of the larger frame or field of view when in fact the magnification is the same. Shoot with your K-1 in crop mode and the magnification should look the same.

^^^^^THIS^^^^^

The same "extra reach" offered by the crop sensor of APS-C for telephoto images seems to provide extra magnification in macro shots. The optical magnification created by the lens is not any different but the smaller sensor of the crop camera means the subject fills more of the frame and looks bigger.

[UncleVanya]

The DFA 100 should show a similar bump in "apparent magnification" on the k-3 over the k-1 due to pixel density. I can't explain why you see this on the 50mm Konica and not on the DFA 100. Shoot a few shots of a ruler or a line of coins and compare them carefully. You subject matter may be misleading your eyes.

[Not a Number]

Pixel count and density is a bit of a red herring. In terms of macro photography at 1× magnification a 10mm object will project a 10mm image regardless of what you put in the image plane, be it a 24 megapixel or 3 megapixel sensor, 135mm or APS color or BW film, 8 × 10 glass or tin plate. Pixel count/density or film grain size will effect how much you can enlarge or zoom into the image.

I would suggest you spend more time enjoying your overall image rather than pixel peeping.

[UncleVanya]

Pixel count and density is a bit of a red herring. In terms of macro photography at 1× magnification a 10mm object will project a 10mm image regardless of what you put in the image plane, be it a 24 megapixel or 3 megapixel sensor, 135mm or APS color or BW film, 8 × 10 glass or tin plate. Pixel count/density or film grain size will effect how much you can enlarge or zoom into the image.

I would suggest you spend more time enjoying your overall image rather than pixel peeping.

I don't think anyone here misunderstands this. The fact is that viewed on screen the 24mp K-3 image will appear to have greater magnification than the 36mp K-1 because the 10mm object occupies a larger chunk of the sensor. Cropping the K-1 to the same size as the K-3 will lose detail and start to fall apart sooner than the K-3 image but for many images that would just be pixel peeping nonsense and good printed copy could be made at reasonable size with the same apparent image size. However for some objects the extra cropping you could do may matter.

What's more interesting is that the OP suggests that they see this effect with the 50mm but not the DFA 100 - which makes no sense at a technical level but may make sense at a perceptual level since the magnification of the 50mm on a bellows may be pretty high and it may be easier to see relative cues to note the difference vs. the 1:1 DFA which may be framed in such a way as to not show the apparent difference as much. In any case the actual magnification is strictly based on projected image on the sensor vs. life size and has nothing to do with the sensor size. That said, using a Q for macro and a K-1 for macro you won't be using the same ratio's if you want similar end result pictures.

[Not a Number]

Perhaps the OP can post some example images?

[stevebrot]

Just noticed that magnification is much lover on K-1 that on K-3 , that make sense.

Magnification (reproduction ratio) should be the same. Crop, on the other hand will be different per the usual 1.5x rule. As noted above, pixel pitch is a red herring.


Steve

[i_trax]

all clear now

[JensE]

K10D + K-5IIs + K-3II and K-1

With K-1 at the top!

Thanks for illustrating the field of view difference of different sensor sizes. You could likely do some people a favor if you'd also show crops (not resized) from the images of e.g. the central 800x800 pixels in each. Thought of doing this, but it was pointless between my K-5 and K-1.

[i_trax]

yes it should be K-1 K-3II K-5IIs and K10D
full sizes on:
PENTAX D FA Macro 100mm 2.8 WR | Flickr

---------- Post added 01-06-17 at 11:59 ----------

now taking some photos with Konica